# Geochemical Architecture of the Lower- to Middle-crustal Section of a Paleo-island Arc (Kohistan Complex, JijalKamila Area, Northern Pakistan): Implications for the Evolution of an Oceanic Subduction Zone

Bruno Dhuime, Delphine Bosch, Carlos J. Garrido, Jean-Louis Bodinier, Olivier Bruguier, Sahid S Hussain, Hamid Dawood

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Bruno Dhuime, Delphine Bosch, Carlos J. Garrido, Jean-Louis Bodinier, Olivier Bruguier, et al.. Geochemical Architecture of the Lower- to Middle-crustal Section of a Paleo-island Arc (Kohistan Complex, JijalKamila Area, Northern Pakistan): Implications for the Evolution of an Oceanic Subduction Zone. Journal of Petrology, 2009, 50 (3), pp.531-569. 10.1093/petrology/egp010. hal-00420068

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Distributed under a Creative Commons CC BY 4.0 - Attribution - International License
Geochemical Architecture of the Lower- to
Middle-crustal Section of a Paleo-island Arc
(Kohistan Complex, Jijal–Kamila Area,
Northern Pakistan): Implications for the
Evolution of an Oceanic Subduction Zone

BRUNO DHUIME<fnref n="1" />*, DELPHINE BOSCH<fnref n="1" />, CARLOS J. GARRIDO<fnref n="2" />, JEAN-LOUIS BODINIER<fnref n="1" />, OLIVIER BRUGUIER<fnref n="1" />, SAHID S. HUSSAIN<fnref n="3" /> AND HAMID DAWOOD<fnref n="3" />

RECEIVED MARCH 17, 2008; ACCEPTED FEBRUARY 13, 2009

ADVANCE ACCESS PUBLICATION MARCH 19, 2009

The processes active in the deep crust above an oceanic subduction zone during its evolution have been constrained through a detailed geochemical study (major and trace elements and Sr, Nd and Pb isotopes) of representative samples through an ~30 km thick exhumed crustal section of the Cretaceous Kohistan oceanic island arc (Northern Pakistan). The use of both trace elements and radiogenic isotopes reveals two distinct geochemical suites (suites A and B) within the Jijal-Patan-Kiru-Kamila (JPKK) complex. Suite A is characterized by a progressive enrichment in ²⁰⁷Pb and a decrease in ¹⁴³Nd/¹⁴⁴Nd with increasing La/N/Sm/N. Suite B has higher ²⁰⁷Pb/²⁰⁴Pb and lower ¹⁴³Nd/¹⁴⁴Nd ratios with approximately constant La/N/Sm/N. By combining trace elements with different partitioning behaviour it is demonstrated that there is an increasing contribution of the subduction component in the magmas with time. It is also possible to distinguish a slab component imprint carried by aqueous fluids from one corresponding to sediment melts. Intrusive granites are abundant in the upper levels of the JPKK section. All were generated at the arc root level (Jijal crustal section) during dehydration-melting of hornblende-rich plutonic rocks. A three-stage geodynamic model is proposed for the evolution of the arc over a period of ~30 Myr. The first stage (~117–105 Ma) starts with the

onset of subduction, which was followed by the building of the volcanic arc. The second stage (~105–99 Ma to ~96–91 Ma) corresponds to a major igneous event, which was characterized by abundant magma underplating and granulite-facies metamorphism at the arc base. Recycling of the residual–cumulative lower crust into the convective asthenospheric mantle was efficient during this stage, and was probably related to thermo-mechanical erosion of the base of the crust. The last stage (~95–85 Ma) corresponds to a period of low magmatic activity, which marked the end of the intra-oceanic subduction. This is related to the formation of a ‘cold blanket’ above the slab surface as a result of thermo-mechanical erosion of the cold walls of the subduction zone (i.e. the upper part of the slab and the base of the overriding plate), and corner flow dragging the cold material into the zone of melt generation. Ultimately, a voluminous magmatic pulse occurred around 85 Ma (forming the Chilas complex), before arc–continent collision.

KEY WORDS: arc magmas; geochemistry; island arc; Kohistan; Sr, Nd, Pb isotopes

<footnote n="1">¹LABORATOIRE GÉOSCIENCES MONTPELLIER, EQUIPE MANTEAU-NOYAU, UMR 5243, CNRS & UNIVERSITÉ DE MONTPELLIER 2, CC 60, 34095 MONTPELLIER CEDEX 05, FRANCE</footnote>

<footnote n="2">²INSTITUTO ANDALUZ DE CIENCIAS DE LA TIERRA (IACT), CSIC & UGR, FACULTAD DE CIENCIAS, FUENTENUEVA
S/N, 18002 GRANADA, SPAIN</footnote>

<footnote n="3">³PAKISTAN MUSEUM OF NATURAL HISTORY, GARDEN AVENUE, SHAKARPARIAN, 44000 ISLAMABAD, PAKISTAN</footnote>

<footnote>*Corresponding author. Present address: Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK. Telephone: +44 (0) 117 95 45 247. Fax: +44 (0) 117 92 53 385. E-mail: B.Dhuime@bristol.ac.uk</footnote>
## INTRODUCTION

Subduction is a major geodynamic process in the evolution of the Earth. Active margins represent key sites for recycling of sediments from the Earth's surface to the mantle, contributing to upper mantle heterogeneity. Moreover, subduction zones have been considered as the main site for the formation of juvenile crust in the Phanerozoic (e.g. McLennan & Taylor, 1985; Rudnick, 1995; Condie & Chomiak, 1996). Thus the characterization of arc magmas, their evolution in space and time, and the relationship between arc magmatism and continental crust formation have been major research topics in petrology and geochemistry during the last three decades.

Most island arc lavas are thought to originate from magmas formed during partial melting of the sub-arc peridotitic mantle wedge in response to flux melting triggered by aqueous fluids and/or silicate melts from the subducting plate (Nicholls & Ringwood, 1973; Ringwood, 1974; Gill, 1981; Arculus & Powell, 1986; Tatsumi et al., 1986; Ellam & Hawkesworth, 1988; Tatsumi, 1989; McCulloch & Gamble, 1991; Davies & Stevenson, 1992; Hawkesworth et al., 1993; Pearce & Parkinson, 1993; Plank & Langmuir, 1993; Woodhead et al., 1993; Arculus, 1994; Stolper & Newman, 1994). Fluids and/or melts derived from both the sediment and variably altered oceanic crust portions of the slab modify the composition of the sub-arc mantle wedge (Tera et al., 1986; Ellam & Hawkesworth, 1988; von Huene & Scholl, 1993; Miller et al., 1994; Kamenetsky et al., 1997). The mantle wedge is generally thought to have an initial composition similar to the depleted MORB mantle source (DMM) of mid-ocean ridge basalts (MORB) (Perfit et al., 1980; Hawkesworth, 1982; White & Patchett, 1984; Tatsumi et al., 1986; Davidson, 1987; Ewart & Hawkesworth, 1987; Ryerson & Watson, 1987), although a more enriched source similar to that of ocean island basalts (OIB) has been proposed in some cases (e.g. Morris & Hart, 1983; Woodhead, 1989; Crawford et al., 1995; Peate et al., 1997).

Island arc basalts are distinguished from other basalts (e.g. MORB and OIB) by their enrichment in large ion lithophile elements (LILE) and, to a lesser extent, in light rare earth elements (LREE) relative to high field strength elements (HFSE) (e.g. Gill, 1981; Pearce, 1982; Hawkesworth et al., 1991, 1993). To explain the distinctive geochemical characteristics of island arc basalts, many studies have argued for a multi-component model involving contributions from the mantle wedge and from one or more 'subduction components' conveyed by aqueous fluids and/or silicate melts (e.g. Kay, 1980; Ellam & Hawkesworth, 1988; Miller et al., 1994; Gamble et al., 1996; Turner et al., 1996; Elliott et al., 1997; Hawkesworth et al., 1997a, 1997b; Turner et al., 1997; Münker, 2000; Garrido et al., 2005). However, many uncertainties remain, notably concerning the extent of slab-mantle interaction, and the

decoupling between fluids and melts derived from the slab (e.g. Hawkesworth et al., 1991, 1993; McCulloch & Gamble, 1991; Saunders et al., 1991; Davies & Stevenson, 1992; Plank & Langmuir, 1993; Woodhead et al., 1993).

The processes active in subduction zones and their temporal evolution can be followed indirectly via the study of erupted lavas or of well-preserved, exhumed, paleo-arc sections such as the Jurassic Talkeetna arc in Alaska (e.g. Barker & Grantz, 1982; DeBari & Coleman, 1989) and the Cretaceous Kohistan arc in North Pakistan (e.g. Bard, 1983; Treloar et al., 1996). This study provides the first detailed geochemical study of the Kohistan arc that combines major element, transition metal, REE and incompatible element analysis of whole-rocks with high-precision Sr, Nd and Pb isotopic data for whole-rocks and mineral separates. It is based on representative samples collected across an ~30 km lower- to middle-crustal section of the Kohistan Arc Complex (KAC, Northern Pakistan, Fig. 1). We specifically focus on the geochemical variations across a section of the arc and on the determination of genetic relationships between the various rock types exposed. The aims are to define the source(s) of the arc magmatism and the processes of magmatic evolution and arc building through time.

Our results suggest an evolutionary continuum between contributions from three main components in the source (i.e. 'DMM-like' asthenospheric mantle, subducted sediments and altered oceanic crust). The precise characterization of trace element distribution in the arc crust reveals that the subduction component was conveyed by slab fluids during the first phase of arc magmatism with subsequent evolution of the subduction zone characterized by the superimposition and the amplification of a 'slab melt' component in the source of the younger magmas. Based on our geochemical data and radiometric ages from previous studies, we propose a three-stage geodynamic model of arc evolution, starting with subduction initiation and leading up to arc-continent collision.

## TECTONIC AND GEOLOGICAL SETTING

The Kohistan Arc Complex is located in northern Pakistan, between the Karakoram (Asian) plate to the north and the Indian plate to the south (Fig. 1). It is separated from these blocks by two major faults; the Main Karakoram Thrust (or Northern Suture) and the Main Mantle Thrust (or Indus Suture), respectively. The KAC constitutes the exhumed section of a Cretaceous intra-oceanic island arc formed during the northward subduction of the Neo-Tethys ocean beneath the Karakoram
<figure><img src="image_2.png" /><figcaption>**Fig. 1.** Simplified geological map of the Kohistan Island Arc Complex (KAC, Northern Pakistan), modified after Burg *et al.* (1998). (1) Jijal ultramafic-mafic complex; (2) Kamila amphibolite belt or 'metaplutonic complex'; (3) intrusive Chilas ultramafic-mafic complex (~85 Ma); (4) Kohistan Batholith; (5) Jurassic to Cretaceous metasedimentary and metavolcanic units of the Jaglot and Utror-Chalt groups; (6) Albian-Aptian volcano-sedimentary Yasin group. The sampled zone between Jijal-Patan and Dasu is shown in more detail in Fig. 3.</figcaption></figure>

plate (Tahirkheli, 1979; Bard *et al.*, 1980; Coward *et al.*, 1982, 1986; Bard, 1983). The KAC is subdivided into six distinct units (Jijal complex; 'Kamila amphibolite belt' or 'metaplutonic complex'; Chilas complex; Kohistan Batholith; Jaglot and Utror-Chalt groups; Yasin group) from south to north along a transect spanning ~200 km (Fig. 1). This study focuses on the Jijal complex and the overlying metaplutonic complex (Fig. 2), that represent the lower and mid- to upper sections, respectively, of an ~30 km thick crust accreted during the island arc building stage between ~117 Ma and 85 Ma (Le Fort *et al.*, 1983; Schärer *et al.*, 1984; Petterson & Windley, 1985; Pudsey, 1986; Treloar *et al.*, 1989; Debon & Khan, 1996; Mikoshiba *et al.*, 1999; Yamamoto & Nakamura, 2000; Fraser *et al.*, 2001; Schaltegger *et al.*, 2002; Yamamoto *et al.*, 2005; Garrido *et al.*, 2006; Dhuime *et al.*, 2007).

The Jijal complex consists of a lower ultramafic and an upper mafic section (Jan, 1979; Bard *et al.*, 1980; Jan & Howie, 1981; Miller & Christensen, 1994; Burg *et al.*, 1998; Garrido *et al.*, 2006, 2007). The ultramafic section formed at 117 ± 7 Ma (Dhuime *et al.*, 2007) during melt-rock reaction between lithospheric mantle and REE-depleted 'boninite-like' melts (Dhuime *et al.*, 2007; Garrido *et al.*, 2007). The transition between the spinel-bearing peridotites of the ultramafic section (dunites, wehrlites and pyroxenites)

and the gabbroic rocks of the mafic section (mainly garnet-bearing gabbros, also referred to as 'garnet granulites' in the literature) represents the mantle–crust transition of the KAC (Bard, 1983; Miller *et al.*, 1991; Burg *et al.*, 1998; Dhuime *et al.*, 2007; Garrido *et al.*, 2007). The crustal section of the Jijal complex was metamorphosed to form high-pressure granulites ($T = 700–950°C, P>1 GPa$) at ~91–96 Ma (Yamamoto, 1993; Yamamoto & Nakamura, 1996, 2000; Yoshino *et al.*, 1998; Ringuette *et al.*, 1999; Anczkiewicz & Vance, 2000; Anczkiewicz *et al.*, 2002).

The metaplutonic complex (Zeilinger, 2002) crops out along the Karakoram highway (Fig. 2). It represents a thick pile of metabasic rocks that was metamorphosed and variably deformed under amphibolite-facies conditions (i.e. 550–650°C and 0.9–1.0 GPa; Tahirkheli *et al.*, 1979; Bard, 1983; Jan, 1988; Treloar *et al.*, 1989, 1990; Khan *et al.*, 1993; Zeilinger, 2002), prior to 83 ± 1 Ma [Ar–Ar cooling age on hornblende after Treloar *et al.* (1990)]. Most of these rocks were originally laccoliths and they are interlayered with rocks interpreted as either former volcanic or volcano-sedimentary formations or remnants of oceanic crust (Bard *et al.*, 1980; Coward *et al.*, 1986; Jan, 1988; Khan *et al.*, 1993; Treloar *et al.*, 1996; Bignold *et al.*, 2006).
<figure><img src="image_3.png" /><figcaption>**Fig. 2.** Simplified geological map of the Jijal–Patan–Kiru–Kamila (JPKK) transect of the Kohistan arc along the Indus valley, modified after Zeilinger (2002) and Garrido *et al.* (2006). Published radiometric ages are reported after: (¹) Yamamoto & Nakamura (1996); (²) Anczkiewicz & Vance (1997); (³) Yamamoto & Nakamura (2000); (⁴) Anczkiewicz *et al.* (2002); (⁵) Schaltegger *et al.* (2002); (⁶) Yamamoto *et al.* (2005); (⁷) Dhuime *et al.* (2007). Grt, garnet; Hbl, hornblende; Cpx, clinopyroxene.</figcaption></figure>

## FIELD RELATIONS AND SAMPLE SELECTION

### The Jijal complex (mafic crustal section)

The mafic section of the Jijal complex constitutes the lowermost exposed crustal levels of the KAC (Figs 2 and 3a). This ~3 km thick granulite section is dominated by garnet-bearing metagabbroic rocks (garnet granulite). Scarce hornblende-bearing gabbronorites present in the top of the section are inferred to represent the magmatic protolith for the garnet granulites (Bard, 1983; Yamamoto, 1993; Yoshino *et al.*, 1998; Yamamoto & Nakamura, 2000; Garrido *et al.*, 2006). Hornblendite lenses (10–100 m thick) are enclosed in the garnet granulites. These rocks are more abundant at the base of the section and show, at outcrop scale, modal variations between (± clinopyroxene)–garnet-hornblendite and hornblende-garnetite. Detailed petrological–geochemical (Garrido *et al.*, 2006) and Sr–Nd–Pb isotopic studies (Dhuime *et al.*, 2007, Fig. 3a) have

already been undertaken on the mafic section of the Jijal complex.

### The Patan–Kiru–Kamila metaplutonic complex

The metaplutonic complex can be subdivided into three sequences; these are, from bottom to top, the Patan, Kiru and Kamila sequences (Fig. 2). Samples were collected along a SW–NE transect that is roughly orthogonal to the arc stratification.

#### *The Patan sequence*

The Patan sequence forms an ~7 km thick pile of interlayered metagabbros and metadiorites, and is heterogeneously deformed along anastomosing shear zone networks (Figs 2 and 3a). The ‘Sarangar gabbro’ at the base of the Patan sequence constitutes up to 50% of the entire sequence. It is a thick, massive gabbroic body of
<figure><img src="image_4.png" /></figure>

<figure><img src="image_5.png" /><figcaption>**Fig. 3.** Geological cross-section and associated geological map showing sample type and location through the JPKK crustal section of the Kohistan arc, modified after Zeilinger (2002). Geometric symbols reflect SiO₂ content [ultramafic: SiO₂ ≤ 45%; gabbro: 45% < SiO₂ ≤ 55%; diorite: 55% < SiO₂ ≤ 63%; 'intrusive granites' (tonalites and granodiorites): SiO₂ > 63%]. The location of the volcanic-plutonic rocks as a function of their trace element characteristics, from Type-1 to Type-5 (see Fig. 4), is also indicated. (a) Section from the lower garnet granulite zone of the Jijal complex to the Patan sequence of the metaplutonic complex [including samples of Dhuime *et al.* (2007)]; (b) section through the Kiru sequence of the metaplutonic complex; (c) section through the Kamila sequence of the metaplutonic complex (i.e. the uppermost section of the metaplutonic complex, close to the contact with the intrusive Chilas complex). The black ellipse indicates the projected position of the UM01-133 to -135 samples (out of map) along the CC cross-section.</figcaption></figure>
<figure><img src="image_6.png" /><figcaption>**Fig. 3.** Continued</figcaption></figure>

coarse-grained meta-gabbro or gabbrodiorite with locally preserved igneous layering (Zeilinger, 2002). The Sarangar gabbro is intrusive into the underlying Jijal garnet-bearing metagabbros (Zeilinger, 2002). The top of the Patan sequence consists of metagabbro, diorite and hornblendite sills of various thicknesses, which are occasionally intruded by pegmatite and hornblendite dykes. The contact between these units and the underlying Sarangar gabbro forms an ~100 m thick magmatic breccia that includes gabbroic to tonalitic facies rocks.

Twenty-two representative samples from the Patan sequence were selected (Fig. 3a and Table 1): 10 Sarangar gabbros (KH97-115, KH97-116, KG-07, KG-09, KG-11, KH97-117, KG-08, KG-10, KH97-118 and KH97-119); four magmatic breccias (KG-13a, KG-13b, KG-14 and KG-15); and eight metaplutonic samples from the upper Patan sequence (KG-17, KG-18, KG-19, KG-20, KG-21, KG-23, KG-26 and KG-27).

*The Kiru sequence*

The contact between the Patan and Kiru sequences is irregular, and it is characterized by interfingered slices from both formations (Zeilinger, 2002). The Kiru sequence forms an ~7 km thick pile of strongly deformed, imbricated sills with compositions that range from gabbroic to dioritic (Figs 2 and 3b). Its lower part contains fine-grained and layered rocks from gabbroic to dioritic facies [the ‘Kiru amphibolites’ of Zeilinger (2002)], which are intruded by coarse- to medium-grained hornblende-rich metadiorites. A thick pile of interlayered gabbros (with rare enclosed metacarbonates lenses) and diorites showing various degrees of amphibolitization and deformation occurs further up section. The top of the Kiru sequence [the ‘Mandraza amphibolites’ of Zeilinger (2002)] is composed of coarse- to medium-grained metagabbros or metadiorites and is interlayered with fine-grained hornblende-rich rocks. Intrusive pegmatites and granites
<table><caption>Table 1: Major and trace elements for the JPKK crustal section</caption><thead><tr><th></th><th colspan="6">Type-1 plutonics-volcanics</th></tr></thead><tbody><tr><td>Lat. (N):</td><td>35°10′51.25″</td><td>35°11′30.01″</td><td>35°11′35.81″</td><td>35°11′40.99″</td><td>35°12′06.01″</td><td>35°12′21.49″</td></tr><tr><td>Long. (E):</td><td>73°06′33.26″</td><td>73°07′09.62″</td><td>73°07′16.72″</td><td>73°07′20.86″</td><td>73°07′35.80″</td><td>73°07′52.57″</td></tr><tr><td>Sample:</td><td>UM01-122</td><td>KG-37</td><td>KG-38</td><td>KG-39</td><td>KG-40</td><td>KG-41</td></tr><tr><td>Unit:</td><td>Kiru</td><td>Kiru</td><td>Kiru</td><td>Kiru</td><td>Kiru</td><td>Kiru</td></tr><tr><td>Rock type:</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td></tr><tr><td>Geochemical suite:</td><td>A</td><td>A</td><td>A</td><td>A</td><td>A</td><td>A</td></tr><tr><td>wt %</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>49.81</td><td>46.23</td><td>48.12</td><td>47.11</td><td>46.96</td><td>48.35</td></tr><tr><td>TiO<sub>2</sub></td><td>0.70</td><td>0.18</td><td>0.22</td><td>0.30</td><td>1.40</td><td>0.56</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>15.82</td><td>19.37</td><td>18.32</td><td>17.02</td><td>15.79</td><td>16.72</td></tr><tr><td>FeO<sub>T</sub></td><td>7.79</td><td>5.67</td><td>3.72</td><td>6.95</td><td>11.65</td><td>6.94</td></tr><tr><td>MnO</td><td>0.16</td><td>0.11</td><td>0.08</td><td>0.12</td><td>0.20</td><td>0.13</td></tr><tr><td>MgO</td><td>8.52</td><td>9.35</td><td>8.59</td><td>9.82</td><td>7.26</td><td>8.50</td></tr><tr><td>CaO</td><td>12.42</td><td>13.86</td><td>16.93</td><td>13.50</td><td>12.14</td><td>14.34</td></tr><tr><td>Na<sub>2</sub>O</td><td>1.83</td><td>1.47</td><td>0.88</td><td>1.54</td><td>2.25</td><td>1.57</td></tr><tr><td>K<sub>2</sub>O</td><td>0.11</td><td>0.08</td><td>0.02</td><td>0.03</td><td>0.03</td><td>0.06</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.09</td><td>0.01</td><td>0.01</td><td>0.01</td><td>0.02</td><td>0.01</td></tr><tr><td>LOI</td><td>1.53</td><td>2.17</td><td>1.84</td><td>2.55</td><td>0.96</td><td>1.71</td></tr><tr><td>Total</td><td>98.78</td><td>98.50</td><td>98.73</td><td>98.95</td><td>98.66</td><td>98.89</td></tr><tr><td>Mg-no.</td><td>66</td><td>75</td><td>80</td><td>72</td><td>53</td><td>69</td></tr><tr><td>ppm</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Sc</td><td>37</td><td>26</td><td>43</td><td>34</td><td>42</td><td>46</td></tr><tr><td>Ti</td><td>3212</td><td>1341</td><td>1629</td><td>1730</td><td>8677</td><td>4030</td></tr><tr><td>V</td><td>164</td><td>128</td><td>157</td><td>136</td><td>415</td><td>242</td></tr><tr><td>Ni</td><td>121</td><td>179</td><td>175</td><td>179</td><td>64</td><td>133</td></tr><tr><td>Cr</td><td>263</td><td>323</td><td>426</td><td>363</td><td>175</td><td>238</td></tr><tr><td>Rb</td><td>1.70</td><td>1.75</td><td>0.45</td><td>0.58</td><td>0.77</td><td>1.11</td></tr><tr><td>Sr</td><td>187</td><td>119</td><td>120</td><td>103</td><td>171</td><td>140</td></tr><tr><td>Y</td><td>19.7</td><td>5.03</td><td>5.97</td><td>5.82</td><td>13.3</td><td>10.5</td></tr><tr><td>Zr-XRF</td><td>22.0</td><td>9.6</td><td>9.4</td><td>9.2</td><td>14.0</td><td>12.4</td></tr><tr><td>Nb</td><td>1.52</td><td>0.11</td><td>0.03</td><td>0.16</td><td>0.24</td><td>0.06</td></tr><tr><td>Cs</td><td>0.03</td><td>0.07</td><td>0.02</td><td>0.03</td><td>0.02</td><td>0.05</td></tr><tr><td>Ba</td><td>16.5</td><td>13.0</td><td>4.80</td><td>9.33</td><td>9.71</td><td>11.6</td></tr><tr><td>La</td><td>2.40</td><td>0.43</td><td>0.28</td><td>0.28</td><td>0.48</td><td>0.39</td></tr><tr><td>Ce</td><td>7.01</td><td>1.06</td><td>0.86</td><td>0.88</td><td>1.61</td><td>1.21</td></tr><tr><td>Pr</td><td>1.20</td><td>0.17</td><td>0.17</td><td>0.19</td><td>0.33</td><td>0.25</td></tr><tr><td>Nd</td><td>6.94</td><td>1.02</td><td>1.12</td><td>1.23</td><td>2.33</td><td>1.70</td></tr><tr><td>Sm</td><td>2.39</td><td>0.41</td><td>0.48</td><td>0.58</td><td>1.07</td><td>0.77</td></tr><tr><td>Eu</td><td>0.90</td><td>0.31</td><td>0.34</td><td>0.41</td><td>0.86</td><td>0.50</td></tr><tr><td>Gd</td><td>3.37</td><td>0.70</td><td>0.85</td><td>1.01</td><td>1.88</td><td>1.38</td></tr><tr><td>Tb</td><td>0.59</td><td>0.13</td><td>0.15</td><td>0.19</td><td>0.34</td><td>0.26</td></tr><tr><td>Dy</td><td>4.22</td><td>0.93</td><td>1.10</td><td>1.37</td><td>2.46</td><td>1.89</td></tr><tr><td>Ho</td><td>0.88</td><td>0.19</td><td>0.23</td><td>0.29</td><td>0.50</td><td>0.39</td></tr><tr><td>Er</td><td>2.53</td><td>0.53</td><td>0.62</td><td>0.83</td><td>1.38</td><td>1.03</td></tr><tr><td>Tm</td><td>0.37</td><td>0.07</td><td>0.09</td><td>0.11</td><td>0.19</td><td>0.15</td></tr><tr><td>Yb</td><td>2.39</td><td>0.46</td><td>0.53</td><td>0.72</td><td>1.18</td><td>0.90</td></tr><tr><td>Lu</td><td>0.37</td><td>0.07</td><td>0.08</td><td>0.11</td><td>0.19</td><td>0.14</td></tr><tr><td>Ta</td><td>0.11</td><td>0.01</td><td>0.00</td><td>0.01</td><td>0.02</td><td>0.00</td></tr><tr><td>Pb</td><td>0.46</td><td>0.29</td><td>0.21</td><td>1.27</td><td>0.25</td><td>0.48</td></tr><tr><td>Th</td><td>0.04</td><td>0.02</td><td>0.01</td><td>0.01</td><td>0.01</td><td>0.01</td></tr><tr><td>U</td><td>0.02</td><td>0.02</td><td>0.01</td><td>0.002</td><td>0.01</td><td>0.02</td></tr><tr><td>ΣREE (ppm)</td><td>35.6</td><td>6.49</td><td>6.89</td><td>8.20</td><td>14.8</td><td>11.0</td></tr><tr><td>Eu*</td><td>0.97</td><td>1.73</td><td>1.62</td><td>1.60</td><td>1.84</td><td>1.47</td></tr><tr><td>La<sub>N</sub></td><td>10.1</td><td>1.82</td><td>1.18</td><td>1.19</td><td>2.04</td><td>1.63</td></tr><tr><td>Yb<sub>N</sub></td><td>14.0</td><td>2.69</td><td>3.12</td><td>4.22</td><td>6.94</td><td>5.28</td></tr><tr><td>Ce<sub>N</sub>/Yb<sub>N</sub></td><td>0.82</td><td>0.64</td><td>0.45</td><td>0.34</td><td>0.38</td><td>0.37</td></tr><tr><td>La<sub>N</sub>/Sm<sub>N</sub></td><td>0.65</td><td>0.68</td><td>0.38</td><td>0.31</td><td>0.29</td><td>0.32</td></tr></tbody></table>

(continued)
<table><caption>Table 1: Continued</caption><thead><tr><th></th><th colspan="6">Type-2 plutonics-volcanics</th></tr></thead><tbody><tr><td>Lat. (N):</td><td>35°07'42.78"</td><td>35°07'42.78"</td><td>35°07'43.18"</td><td>35°07'43.86"</td><td>35°16'55.16"</td><td>35°17'09.72"</td></tr><tr><td>Long. (E):</td><td>73°02'48.88"</td><td>73°02'48.88"</td><td>73°02'49.24"</td><td>73°02'49.31"</td><td>73°13'27.91"</td><td>73°13'24.02"</td></tr><tr><td>Sample:</td><td>KG-13a</td><td>KG-13b</td><td>KG-14</td><td>KG-15</td><td>KG-59</td><td>UM01-126</td></tr><tr><td>Unit:</td><td>Patan</td><td>Patan</td><td>Patan</td><td>Patan</td><td>Kamila</td><td>Kamila</td></tr><tr><td>Rock type:</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>UB</td></tr><tr><td>Geochemical suite:</td><td>A</td><td>A</td><td>A</td><td>A</td><td>A</td><td>A</td></tr><tr><td>wt %</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>48.60</td><td>46.76</td><td>45.33</td><td>44.05</td><td>44.73</td><td>42.40</td></tr><tr><td>TiO<sub>2</sub></td><td>1.13</td><td>1.03</td><td>1.63</td><td>1.31</td><td>1.29</td><td>1.99</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>22.16</td><td>18.45</td><td>18.83</td><td>10.56</td><td>19.85</td><td>14.35</td></tr><tr><td>FeO<sub>T</sub></td><td>6.37</td><td>9.29</td><td>11.04</td><td>14.65</td><td>10.00</td><td>11.54</td></tr><tr><td>MnO</td><td>0.08</td><td>0.13</td><td>0.15</td><td>0.24</td><td>0.14</td><td>0.14</td></tr><tr><td>MgO</td><td>3.06</td><td>6.41</td><td>5.22</td><td>12.30</td><td>5.91</td><td>12.87</td></tr><tr><td>CaO</td><td>10.25</td><td>10.34</td><td>10.48</td><td>10.24</td><td>10.83</td><td>10.69</td></tr><tr><td>Na<sub>2</sub>O</td><td>4.02</td><td>2.96</td><td>2.88</td><td>1.23</td><td>2.78</td><td>2.32</td></tr><tr><td>K<sub>2</sub>O</td><td>0.15</td><td>0.15</td><td>0.18</td><td>0.15</td><td>0.20</td><td>0.24</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.26</td><td>0.15</td><td>0.41</td><td>0.09</td><td>0.10</td><td>0.05</td></tr><tr><td>LOI</td><td>1.50</td><td>1.46</td><td>0.89</td><td>1.42</td><td>2.63</td><td>1.78</td></tr><tr><td>Total</td><td>97.58</td><td>97.13</td><td>97.04</td><td>96.24</td><td>98.46</td><td>98.37</td></tr><tr><td>Mg-no.</td><td>46</td><td>55</td><td>46</td><td>60</td><td>51</td><td>66</td></tr><tr><td>ppm</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Sc</td><td>23</td><td>41</td><td>41</td><td>73</td><td>21</td><td>51</td></tr><tr><td>Ti</td><td>6199</td><td>5862</td><td>8907</td><td>7145</td><td>7787</td><td>10761</td></tr><tr><td>V</td><td>232</td><td>313</td><td>304</td><td>418</td><td>287</td><td>395</td></tr><tr><td>Ni</td><td>10</td><td>32</td><td>18</td><td>76</td><td>53</td><td>173</td></tr><tr><td>Cr</td><td>34</td><td>85</td><td>35</td><td>150</td><td>82</td><td>209</td></tr><tr><td>Rb</td><td>0.87</td><td>0.60</td><td>0.71</td><td>0.63</td><td>1.15</td><td>0.93</td></tr><tr><td>Sr</td><td>560</td><td>427</td><td>375</td><td>34</td><td>533</td><td>171</td></tr><tr><td>Y</td><td>14.5</td><td>19.7</td><td>23.5</td><td>33.7</td><td>19.3</td><td>22.3</td></tr><tr><td>Zr-XRF</td><td>25.5</td><td>28.8</td><td>31.5</td><td>45.4</td><td>46.6</td><td>47.0</td></tr><tr><td>Nb</td><td>0.86</td><td>0.84</td><td>1.65</td><td>1.27</td><td>1.41</td><td>1.73</td></tr><tr><td>Cs</td><td>0.07</td><td>0.05</td><td>0.07</td><td>0.03</td><td>0.04</td><td>0.02</td></tr><tr><td>Ba</td><td>89.4</td><td>50.3</td><td>60.0</td><td>21.5</td><td>32.8</td><td>25.4</td></tr><tr><td>La</td><td>3.21</td><td>2.40</td><td>5.20</td><td>1.37</td><td>3.34</td><td>2.55</td></tr><tr><td>Ce</td><td>8.75</td><td>7.23</td><td>15.7</td><td>6.51</td><td>10.3</td><td>8.92</td></tr><tr><td>Pr</td><td>1.34</td><td>1.20</td><td>2.52</td><td>1.37</td><td>1.80</td><td>1.70</td></tr><tr><td>Nd</td><td>7.55</td><td>6.96</td><td>14.1</td><td>9.00</td><td>10.7</td><td>10.4</td></tr><tr><td>Sm</td><td>2.22</td><td>2.35</td><td>4.23</td><td>3.45</td><td>3.28</td><td>3.46</td></tr><tr><td>Eu</td><td>0.94</td><td>0.95</td><td>1.32</td><td>0.98</td><td>1.28</td><td>1.28</td></tr><tr><td>Gd</td><td>3.01</td><td>3.25</td><td>5.41</td><td>4.99</td><td>4.10</td><td>4.69</td></tr><tr><td>Tb</td><td>0.48</td><td>0.53</td><td>0.86</td><td>0.85</td><td>0.64</td><td>0.77</td></tr><tr><td>Dy</td><td>3.14</td><td>3.62</td><td>5.78</td><td>5.93</td><td>4.08</td><td>5.21</td></tr><tr><td>Ho</td><td>0.62</td><td>0.73</td><td>1.18</td><td>1.24</td><td>0.81</td><td>1.03</td></tr><tr><td>Er</td><td>1.62</td><td>2.00</td><td>3.30</td><td>3.46</td><td>2.11</td><td>2.82</td></tr><tr><td>Tm</td><td>0.22</td><td>0.27</td><td>0.46</td><td>0.50</td><td>0.29</td><td>0.37</td></tr><tr><td>Yb</td><td>1.27</td><td>1.58</td><td>2.86</td><td>3.02</td><td>1.79</td><td>2.32</td></tr><tr><td>Lu</td><td>0.19</td><td>0.24</td><td>0.45</td><td>0.47</td><td>0.28</td><td>0.35</td></tr><tr><td>Ta</td><td>0.03</td><td>0.03</td><td>0.08</td><td>0.06</td><td>0.07</td><td>0.09</td></tr><tr><td>Pb</td><td>1.88</td><td>1.23</td><td>1.14</td><td>5.29</td><td>0.78</td><td>1.17</td></tr><tr><td>Th</td><td>0.12</td><td>0.06</td><td>0.22</td><td>0.01</td><td>0.04</td><td>0.04</td></tr><tr><td>U</td><td>0.05</td><td>0.04</td><td>0.08</td><td>0.03</td><td>0.03</td><td>0.03</td></tr><tr><td>ΣREE (ppm)</td><td>34.5</td><td>33.3</td><td>63.3</td><td>43.1</td><td>44.8</td><td>45.8</td></tr><tr><td>Eu*</td><td>1.11</td><td>1.05</td><td>0.84</td><td>0.72</td><td>1.07</td><td>0.97</td></tr><tr><td>La<sub>N</sub></td><td>13.5</td><td>10.1</td><td>21.9</td><td>5.8</td><td>14.1</td><td>10.8</td></tr><tr><td>Yb<sub>N</sub></td><td>7.44</td><td>9.3</td><td>16.8</td><td>17.8</td><td>10.5</td><td>13.6</td></tr><tr><td>Ce<sub>N</sub>/Yb<sub>N</sub></td><td>1.92</td><td>1.27</td><td>1.52</td><td>0.60</td><td>1.61</td><td>1.07</td></tr><tr><td>La<sub>N</sub>/Sm<sub>N</sub></td><td>0.93</td><td>0.66</td><td>0.79</td><td>0.26</td><td>0.66</td><td>0.48</td></tr></tbody></table>

(continued)
<table><caption>Table 1: Continued</caption><thead><tr><th></th><th colspan="2">Type-2 plutonics-volcanics</th><th colspan="4">Type-3 plutonics-volcanics</th></tr></thead><tbody><tr><td>Lat. (N):</td><td>35°17′15.84"</td><td>35°17′21.80"</td><td>35°06′56.12"</td><td>35°07′04.46"</td><td>35°07′07.28"</td><td>35°07′15.64"</td></tr><tr><td>Long. (E):</td><td>73°13′25.28"</td><td>73°13′25.70"</td><td>73°00′26.02"</td><td>73°00′46.26"</td><td>73°00′52.38"</td><td>73°01′16.20"</td></tr><tr><td>Sample:</td><td>UM01-127</td><td>UM01-128</td><td>KH97-115</td><td>KH97-116<sup>1</sup></td><td>KG-07<sup>1</sup></td><td>KH97-117<sup>1</sup></td></tr><tr><td>Unit:</td><td>Kamila</td><td>Kamila</td><td>Patan</td><td>Patan</td><td>Patan</td><td>Patan</td></tr><tr><td>Rock type:</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td></tr><tr><td>Geochemical suite:</td><td>A</td><td>A</td><td>B, group B1</td><td>B, group B1</td><td>B, group B1</td><td>B, group B1</td></tr><tr><td>wt %</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>44.73</td><td>51.78</td><td>48.18</td><td>51.62</td><td>52.14</td><td>53.66</td></tr><tr><td>TiO<sub>2</sub></td><td>1.12</td><td>1.05</td><td>0.71</td><td>0.88</td><td>0.82</td><td>0.79</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>21.66</td><td>19.65</td><td>18.22</td><td>16.60</td><td>17.49</td><td>17.08</td></tr><tr><td>FeO<sub>T</sub></td><td>9.61</td><td>8.08</td><td>10.26</td><td>9.34</td><td>9.05</td><td>8.96</td></tr><tr><td>MnO</td><td>0.19</td><td>0.18</td><td>0.18</td><td>0.18</td><td>0.17</td><td>0.19</td></tr><tr><td>MgO</td><td>3.30</td><td>4.13</td><td>6.18</td><td>5.15</td><td>5.52</td><td>4.92</td></tr><tr><td>CaO</td><td>11.06</td><td>8.42</td><td>10.95</td><td>9.46</td><td>9.78</td><td>9.32</td></tr><tr><td>Na<sub>2</sub>O</td><td>3.55</td><td>4.15</td><td>2.14</td><td>3.76</td><td>2.09</td><td>2.43</td></tr><tr><td>K<sub>2</sub>O</td><td>0.09</td><td>0.24</td><td>0.29</td><td>0.69</td><td>0.49</td><td>0.38</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.58</td><td>0.17</td><td>0.03</td><td>0.18</td><td>0.11</td><td>0.14</td></tr><tr><td>LOI</td><td>2.42</td><td>0.66</td><td>1.12</td><td>1.08</td><td>0.90</td><td>0.63</td></tr><tr><td>Total</td><td>98.31</td><td>98.51</td><td>98.26</td><td>98.94</td><td>98.56</td><td>98.49</td></tr><tr><td>Mg-no.</td><td>38</td><td>48</td><td>52</td><td>49</td><td>52</td><td>49</td></tr><tr><td>ppm</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Sc</td><td>13</td><td>16</td><td>38</td><td>37</td><td>32</td><td>34</td></tr><tr><td>Ti</td><td>6535</td><td>5793</td><td>—</td><td>—</td><td>4993</td><td>—</td></tr><tr><td>V</td><td>119</td><td>139</td><td>245</td><td>262</td><td>249</td><td>253</td></tr><tr><td>Ni</td><td>3</td><td>8</td><td>20</td><td>23</td><td>30</td><td>19</td></tr><tr><td>Cr</td><td>3</td><td>3</td><td>80</td><td>79</td><td>176</td><td>73</td></tr><tr><td>Rb</td><td>0.39</td><td>1.14</td><td>1.51</td><td>3.71</td><td>2.77</td><td>1.61</td></tr><tr><td>Sr</td><td>573</td><td>551</td><td>253</td><td>235</td><td>293</td><td>242</td></tr><tr><td>Y</td><td>25.7</td><td>21.5</td><td>12.3</td><td>20.8</td><td>15.0</td><td>20.7</td></tr><tr><td>Zr-XRF</td><td>120</td><td>32.0</td><td>25.0</td><td>48.2</td><td>44.1</td><td>38.9</td></tr><tr><td>Nb</td><td>2.71</td><td>4.13</td><td>0.87</td><td>2.04</td><td>1.24</td><td>2.16</td></tr><tr><td>Cs</td><td>0.26</td><td>0.05</td><td>0.02</td><td>0.24</td><td>0.16</td><td>0.06</td></tr><tr><td>Ba</td><td>34.1</td><td>50.3</td><td>108</td><td>233</td><td>138</td><td>156</td></tr><tr><td>La</td><td>4.63</td><td>7.13</td><td>3.68</td><td>7.65</td><td>5.59</td><td>8.32</td></tr><tr><td>Ce</td><td>15.2</td><td>19.2</td><td>7.64</td><td>16.5</td><td>13.1</td><td>17.9</td></tr><tr><td>Pr</td><td>2.69</td><td>3.04</td><td>1.12</td><td>2.39</td><td>1.73</td><td>2.55</td></tr><tr><td>Nd</td><td>15.7</td><td>16.4</td><td>5.21</td><td>10.9</td><td>8.34</td><td>11.4</td></tr><tr><td>Sm</td><td>4.67</td><td>4.87</td><td>1.54</td><td>2.99</td><td>2.25</td><td>2.99</td></tr><tr><td>Eu</td><td>1.71</td><td>1.50</td><td>0.77</td><td>1.08</td><td>0.81</td><td>1.06</td></tr><tr><td>Gd</td><td>5.71</td><td>5.55</td><td>2.09</td><td>3.76</td><td>2.86</td><td>3.69</td></tr><tr><td>Tb</td><td>0.90</td><td>0.82</td><td>0.36</td><td>0.62</td><td>0.48</td><td>0.61</td></tr><tr><td>Dy</td><td>5.95</td><td>5.25</td><td>2.55</td><td>4.32</td><td>3.33</td><td>4.26</td></tr><tr><td>Ho</td><td>1.19</td><td>0.99</td><td>0.55</td><td>0.92</td><td>0.69</td><td>0.91</td></tr><tr><td>Er</td><td>3.42</td><td>2.76</td><td>1.62</td><td>2.62</td><td>2.04</td><td>2.58</td></tr><tr><td>Tm</td><td>0.49</td><td>0.38</td><td>0.25</td><td>0.39</td><td>0.30</td><td>0.39</td></tr><tr><td>Yb</td><td>3.21</td><td>2.54</td><td>1.62</td><td>2.53</td><td>1.99</td><td>2.59</td></tr><tr><td>Lu</td><td>0.50</td><td>0.39</td><td>0.28</td><td>0.42</td><td>0.33</td><td>0.43</td></tr><tr><td>Ta</td><td>0.13</td><td>0.23</td><td>0.05</td><td>0.11</td><td>0.09</td><td>0.12</td></tr><tr><td>Pb</td><td>10.2</td><td>1.98</td><td>1.47</td><td>6.57</td><td>3.06</td><td>3.27</td></tr><tr><td>Th</td><td>0.07</td><td>0.07</td><td>0.12</td><td>0.26</td><td>0.21</td><td>0.13</td></tr><tr><td>U</td><td>0.04</td><td>0.03</td><td>0.04</td><td>0.08</td><td>0.06</td><td>0.05</td></tr><tr><td>ΣREE (ppm)</td><td>66.0</td><td>70.9</td><td>29.3</td><td>57.0</td><td>43.8</td><td>59.7</td></tr><tr><td>Eu*</td><td>1.01</td><td>0.88</td><td>1.31</td><td>0.99</td><td>0.98</td><td>0.98</td></tr><tr><td>La<sub>N</sub></td><td>19.5</td><td>30.1</td><td>15.5</td><td>32.3</td><td>23.6</td><td>35.1</td></tr><tr><td>Yb<sub>N</sub></td><td>18.9</td><td>14.9</td><td>9.55</td><td>14.9</td><td>11.7</td><td>15.3</td></tr><tr><td>Ce<sub>N</sub>/Yb<sub>N</sub></td><td>1.32</td><td>2.10</td><td>1.31</td><td>1.81</td><td>1.82</td><td>1.92</td></tr><tr><td>La<sub>N</sub>/Sm<sub>N</sub></td><td>0.64</td><td>0.95</td><td>1.54</td><td>1.65</td><td>1.61</td><td>1.80</td></tr></tbody></table>

(continued)
<table><caption>Table 1: Continued</caption><thead><tr><th></th><th colspan="6">Type-3 plutonics-volcanics</th></tr></thead><tbody><tr><td>Lat. (N):</td><td>35°07'14.23"</td><td>35°07'12.54"</td><td>35°06'59.54"</td><td>35°06'58.90"</td><td>35°07'10.55"</td><td>35°07'07.96"</td></tr><tr><td>Long. (E):</td><td>73°01'22.73"</td><td>73°01'35.58"</td><td>73°01'38.78"</td><td>73°01'45.16"</td><td>73°01'54.89"</td><td>73°02'22.84"</td></tr><tr><td>Sample:</td><td>KG-08</td><td>KG-10</td><td>KG-09<sup>1</sup></td><td>KG-11<sup>1</sup></td><td>KH97-118<sup>1</sup></td><td>KH97-119<sup>1</sup></td></tr><tr><td>Unit:</td><td>Patan</td><td>Patan</td><td>Patan</td><td>Patan</td><td>Patan</td><td>Patan</td></tr><tr><td>Rock type:</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Diorite</td><td>Gabbro</td><td>Gabbro</td></tr><tr><td>Geochemical suite:</td><td>B, group B1</td><td>B, group B1</td><td>B, group B1</td><td>B, group B1</td><td>B, group B1</td><td>B, group B1</td></tr><tr><td>wt %</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>49.80</td><td>52.49</td><td>53.91</td><td>53.49</td><td>53.15</td><td>51.99</td></tr><tr><td>TiO<sub>2</sub></td><td>0.81</td><td>0.80</td><td>0.95</td><td>0.84</td><td>1.05</td><td>0.69</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>17.65</td><td>17.57</td><td>19.28</td><td>16.62</td><td>16.70</td><td>18.19</td></tr><tr><td>FeO<sub>T</sub></td><td>10.30</td><td>8.68</td><td>9.48</td><td>9.12</td><td>8.95</td><td>9.15</td></tr><tr><td>MnO</td><td>0.19</td><td>0.16</td><td>0.16</td><td>0.17</td><td>0.16</td><td>0.18</td></tr><tr><td>MgO</td><td>5.90</td><td>5.03</td><td>4.68</td><td>4.93</td><td>4.81</td><td>5.57</td></tr><tr><td>CaO</td><td>10.47</td><td>9.62</td><td>10.17</td><td>9.10</td><td>9.45</td><td>10.45</td></tr><tr><td>Na<sub>2</sub>O</td><td>1.73</td><td>2.27</td><td>2.26</td><td>2.32</td><td>2.41</td><td>1.96</td></tr><tr><td>K<sub>2</sub>O</td><td>0.44</td><td>0.41</td><td>0.24</td><td>0.34</td><td>0.45</td><td>0.31</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.06</td><td>0.21</td><td>0.13</td><td>0.09</td><td>0.17</td><td>0.08</td></tr><tr><td>LOI</td><td>0.61</td><td>0.87</td><td>0.63</td><td>1.08</td><td>1.12</td><td>0.04</td></tr><tr><td>Total</td><td>97.96</td><td>98.11</td><td>101.89</td><td>98.10</td><td>98.42</td><td>98.62</td></tr><tr><td>Mg-no.</td><td>50</td><td>51</td><td>47</td><td>49</td><td>49</td><td>52</td></tr><tr><td>ppm</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Sc</td><td>35</td><td>34</td><td>27</td><td>33</td><td>33</td><td>25</td></tr><tr><td>Ti</td><td>4856</td><td>3674</td><td>4486</td><td>4081</td><td>—</td><td>—</td></tr><tr><td>V</td><td>270</td><td>235</td><td>266</td><td>301</td><td>221</td><td>250</td></tr><tr><td>Ni</td><td>24</td><td>22</td><td>18</td><td>20</td><td>16</td><td>19</td></tr><tr><td>Cr</td><td>88</td><td>105</td><td>121</td><td>94</td><td>61</td><td>94</td></tr><tr><td>Rb</td><td>3.20</td><td>3.36</td><td>0.97</td><td>1.02</td><td>2.51</td><td>2.85</td></tr><tr><td>Sr</td><td>291</td><td>272</td><td>266</td><td>256</td><td>238</td><td>232</td></tr><tr><td>Y</td><td>15.6</td><td>16.2</td><td>15.5</td><td>14.4</td><td>18.6</td><td>15.7</td></tr><tr><td>Zr-XRF</td><td>49.0</td><td>42.7</td><td>43.3</td><td>35.8</td><td>43.0</td><td>31.8</td></tr><tr><td>Nb</td><td>0.97</td><td>0.76</td><td>1.11</td><td>0.60</td><td>1.78</td><td>1.22</td></tr><tr><td>Cs</td><td>0.12</td><td>0.08</td><td>0.06</td><td>0.09</td><td>0.11</td><td>0.09</td></tr><tr><td>Ba</td><td>185</td><td>115</td><td>80.5</td><td>71.7</td><td>139</td><td>120</td></tr><tr><td>La</td><td>5.24</td><td>6.41</td><td>5.49</td><td>4.18</td><td>6.65</td><td>4.43</td></tr><tr><td>Ce</td><td>11.9</td><td>15.3</td><td>12.6</td><td>9.77</td><td>15.5</td><td>10.2</td></tr><tr><td>Pr</td><td>1.58</td><td>2.06</td><td>1.70</td><td>1.36</td><td>2.10</td><td>1.34</td></tr><tr><td>Nd</td><td>7.71</td><td>10.1</td><td>8.40</td><td>6.75</td><td>10.3</td><td>6.70</td></tr><tr><td>Sm</td><td>2.18</td><td>2.73</td><td>2.38</td><td>1.99</td><td>2.80</td><td>1.84</td></tr><tr><td>Eu</td><td>0.86</td><td>1.06</td><td>0.93</td><td>0.79</td><td>1.09</td><td>0.73</td></tr><tr><td>Gd</td><td>2.81</td><td>3.38</td><td>3.06</td><td>2.60</td><td>3.66</td><td>2.34</td></tr><tr><td>Tb</td><td>0.48</td><td>0.55</td><td>0.50</td><td>0.45</td><td>0.61</td><td>0.39</td></tr><tr><td>Dy</td><td>3.35</td><td>3.80</td><td>3.49</td><td>3.14</td><td>4.16</td><td>2.79</td></tr><tr><td>Ho</td><td>0.71</td><td>0.78</td><td>0.73</td><td>0.66</td><td>0.87</td><td>0.58</td></tr><tr><td>Er</td><td>2.13</td><td>2.27</td><td>2.14</td><td>1.91</td><td>2.51</td><td>1.71</td></tr><tr><td>Tm</td><td>0.31</td><td>0.32</td><td>0.31</td><td>0.28</td><td>0.37</td><td>0.26</td></tr><tr><td>Yb</td><td>2.14</td><td>2.16</td><td>1.99</td><td>1.85</td><td>2.41</td><td>1.65</td></tr><tr><td>Lu</td><td>0.34</td><td>0.35</td><td>0.33</td><td>0.30</td><td>0.39</td><td>0.27</td></tr><tr><td>Ta</td><td>0.07</td><td>0.06</td><td>0.08</td><td>0.04</td><td>0.12</td><td>0.07</td></tr><tr><td>Pb</td><td>2.51</td><td>2.75</td><td>2.30</td><td>1.70</td><td>2.88</td><td>1.95</td></tr><tr><td>Th</td><td>0.12</td><td>0.67</td><td>0.29</td><td>0.17</td><td>0.42</td><td>0.29</td></tr><tr><td>U</td><td>0.05</td><td>0.19</td><td>0.09</td><td>0.09</td><td>0.13</td><td>0.08</td></tr><tr><td>ΣREE (ppm)</td><td>41.7</td><td>51.3</td><td>44.1</td><td>36.0</td><td>53.4</td><td>35.3</td></tr><tr><td>Eu*</td><td>1.07</td><td>1.07</td><td>1.05</td><td>1.07</td><td>1.04</td><td>1.08</td></tr><tr><td>La<sub>N</sub></td><td>22.1</td><td>27.1</td><td>23.2</td><td>17.6</td><td>28.1</td><td>18.7</td></tr><tr><td>Yb<sub>N</sub></td><td>12.6</td><td>12.7</td><td>11.7</td><td>10.9</td><td>14.2</td><td>9.70</td></tr><tr><td>Ce<sub>N</sub>/Yb<sub>N</sub></td><td>1.54</td><td>1.97</td><td>1.77</td><td>1.47</td><td>1.78</td><td>1.72</td></tr><tr><td>La<sub>N</sub>/Sm<sub>N</sub></td><td>1.55</td><td>1.51</td><td>1.49</td><td>1.36</td><td>1.53</td><td>1.55</td></tr></tbody></table>

(continued)
<table><caption>Table 1: Continued</caption><thead><tr><th></th><th colspan="6">Type-3 plutonics-volcanics</th></tr><tr><th></th><th>35'08'06.94"</th><th>35'08'06.90"</th><th>35'08'14.02"</th><th>35'08'14.02"</th><th>35'08'16.01"</th><th>35'08'18.82"</th></tr></thead><tbody><tr><td>Lat. (N):</td><td>73'03'30.92"</td><td>73'03'30.53"</td><td>73'03'25.70"</td><td>73'03'25.70"</td><td>73'03'24.08"</td><td>73'03'22.28"</td></tr><tr><td>Long. (E):</td><td>73'03'30.92"</td><td>73'03'30.53"</td><td>73'03'25.70"</td><td>73'03'25.70"</td><td>73'03'24.08"</td><td>73'03'22.28"</td></tr><tr><td>Sample:</td><td>KG-17</td><td>KG-18</td><td>KG-19a</td><td>KG-19b</td><td>KG-20</td><td>KG-21</td></tr><tr><td>Unit:</td><td>Patan</td><td>Patan</td><td>Patan</td><td>Patan</td><td>Patan</td><td>Patan</td></tr><tr><td>Rock type:</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td></tr><tr><td>Geochemical suite:</td><td>B, group B2</td><td>B, group B2</td><td>B, group B2</td><td>B, group B2</td><td>B, group B2</td><td>B, group B2</td></tr><tr><td>wt %</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>53.08</td><td>50.78</td><td>48.36</td><td>45.76</td><td>57.74</td><td>52.54</td></tr><tr><td>TiO<sub>2</sub></td><td>0.92</td><td>1.04</td><td>1.09</td><td>1.00</td><td>0.70</td><td>0.75</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>17.44</td><td>18.12</td><td>18.51</td><td>19.33</td><td>16.64</td><td>16.97</td></tr><tr><td>FeO<sub>T</sub></td><td>9.21</td><td>10.31</td><td>11.01</td><td>11.42</td><td>6.78</td><td>8.86</td></tr><tr><td>MnO</td><td>0.19</td><td>0.21</td><td>0.24</td><td>0.23</td><td>0.15</td><td>0.15</td></tr><tr><td>MgO</td><td>4.37</td><td>4.93</td><td>5.34</td><td>5.64</td><td>4.46</td><td>3.29</td></tr><tr><td>CaO</td><td>9.15</td><td>9.80</td><td>10.10</td><td>10.97</td><td>9.06</td><td>12.94</td></tr><tr><td>Na<sub>2</sub>O</td><td>2.54</td><td>2.59</td><td>2.60</td><td>2.50</td><td>2.60</td><td>0.40</td></tr><tr><td>K<sub>2</sub>O</td><td>0.28</td><td>0.29</td><td>0.20</td><td>0.33</td><td>0.19</td><td></td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.17</td><td>0.19</td><td>0.20</td><td>0.21</td><td>0.15</td><td>0.16</td></tr><tr><td>LOI</td><td>0.69</td><td>0.15</td><td>0.18</td><td>0.59</td><td>0.27</td><td>2.79</td></tr><tr><td>Total</td><td>98.04</td><td>98.41</td><td>97.83</td><td>97.98</td><td>98.74</td><td>98.85</td></tr><tr><td>Mg-no.</td><td>46</td><td>46</td><td>46</td><td>47</td><td>54</td><td>40</td></tr><tr><td>ppm</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Sc</td><td>33</td><td>36</td><td>37</td><td>31</td><td>27</td><td>26</td></tr><tr><td>Ti</td><td>5921</td><td>6039</td><td>6183</td><td>6051</td><td>4062</td><td>4510</td></tr><tr><td>V</td><td>305</td><td>276</td><td>359</td><td>357</td><td>222</td><td>227</td></tr><tr><td>Ni</td><td>11</td><td>9</td><td>12</td><td>13</td><td>35</td><td>17</td></tr><tr><td>Cr</td><td>28</td><td>40</td><td>30</td><td>14</td><td>43</td><td>196</td></tr><tr><td>Rb</td><td>0.68</td><td>0.65</td><td>0.23</td><td>0.58</td><td>0.24</td><td>0.02</td></tr><tr><td>Sr</td><td>306</td><td>291</td><td>329</td><td>327</td><td>243</td><td>667</td></tr><tr><td>Y</td><td>26.8</td><td>24.8</td><td>21.7</td><td>22.5</td><td>24.3</td><td>12.3</td></tr><tr><td>Zr-XRF</td><td>75.9</td><td>68.2</td><td>54.6</td><td>44.4</td><td>87.2</td><td>39.1</td></tr><tr><td>Nb</td><td>1.97</td><td>2.28</td><td>1.76</td><td>1.54</td><td>1.57</td><td>1.41</td></tr><tr><td>Cs</td><td>0.01</td><td>0.01</td><td>0.004</td><td>0.01</td><td>0.01</td><td>0.01</td></tr><tr><td>Ba</td><td>88.5</td><td>86.9</td><td>63.0</td><td>81.2</td><td>56.3</td><td>9.81</td></tr><tr><td>La</td><td>9.26</td><td>9.38</td><td>7.34</td><td>8.22</td><td>6.00</td><td>6.16</td></tr><tr><td>Ce</td><td>23.6</td><td>24.1</td><td>18.3</td><td>21.1</td><td>15.8</td><td>14.2</td></tr><tr><td>Pr</td><td>3.09</td><td>3.37</td><td>2.41</td><td>2.80</td><td>2.18</td><td>1.85</td></tr><tr><td>Nd</td><td>14.7</td><td>16.3</td><td>11.5</td><td>13.2</td><td>10.7</td><td>8.66</td></tr><tr><td>Sm</td><td>3.72</td><td>4.15</td><td>2.98</td><td>3.30</td><td>2.92</td><td>2.13</td></tr><tr><td>Eu</td><td>1.23</td><td>1.35</td><td>1.18</td><td>1.38</td><td>1.02</td><td>0.89</td></tr><tr><td>Gd</td><td>4.33</td><td>4.95</td><td>3.54</td><td>3.77</td><td>3.55</td><td>2.53</td></tr><tr><td>Tb</td><td>0.70</td><td>0.81</td><td>0.57</td><td>0.61</td><td>0.60</td><td>0.41</td></tr><tr><td>Dy</td><td>4.76</td><td>5.56</td><td>3.84</td><td>4.07</td><td>4.09</td><td>2.80</td></tr><tr><td>Ho</td><td>0.99</td><td>1.15</td><td>0.80</td><td>0.85</td><td>0.84</td><td>0.57</td></tr><tr><td>Er</td><td>2.85</td><td>3.31</td><td>2.30</td><td>2.43</td><td>2.47</td><td>1.66</td></tr><tr><td>Tm</td><td>0.42</td><td>0.48</td><td>0.34</td><td>0.36</td><td>0.37</td><td>0.24</td></tr><tr><td>Yb</td><td>2.70</td><td>3.23</td><td>2.17</td><td>2.29</td><td>2.33</td><td>1.60</td></tr><tr><td>Lu</td><td>0.43</td><td>0.52</td><td>0.36</td><td>0.38</td><td>0.37</td><td>0.25</td></tr><tr><td>Ta</td><td>0.12</td><td>0.12</td><td>0.09</td><td>0.07</td><td>0.09</td><td>0.08</td></tr><tr><td>Pb</td><td>2.03</td><td>2.03</td><td>1.60</td><td>1.91</td><td>0.96</td><td>3.11</td></tr><tr><td>Th</td><td>0.09</td><td>0.06</td><td>0.12</td><td>0.25</td><td>0.06</td><td>0.07</td></tr><tr><td>U</td><td>0.03</td><td>0.03</td><td>0.04</td><td>0.08</td><td>0.03</td><td>0.03</td></tr><tr><td>ΣREE (ppm)</td><td>72.8</td><td>78.7</td><td>57.6</td><td>64.7</td><td>53.2</td><td>43.9</td></tr><tr><td>Eu*</td><td>0.94</td><td>0.91</td><td>1.11</td><td>1.20</td><td>0.96</td><td>1.17</td></tr><tr><td>La<sub>N</sub></td><td>39.1</td><td>39.6</td><td>31.0</td><td>34.7</td><td>25.3</td><td>26.0</td></tr><tr><td>Yb<sub>N</sub></td><td>15.9</td><td>19.0</td><td>12.8</td><td>13.5</td><td>13.7</td><td>9.41</td></tr><tr><td>Ce<sub>N</sub>/Yb<sub>N</sub></td><td>2.43</td><td>2.08</td><td>2.34</td><td>2.56</td><td>1.88</td><td>2.47</td></tr><tr><td>La<sub>N</sub>/Sm<sub>N</sub></td><td>1.61</td><td>1.46</td><td>1.59</td><td>1.61</td><td>1.33</td><td>1.87</td></tr></tbody></table>

(continued)
<table><caption>Table 1: Continued</caption><thead><tr><th></th><th colspan="6">Type-3 plutonics-volcanics</th></tr></thead><tbody><tr><td>Lat. (N):</td><td>35°08'41.03"</td><td>35°08'41.21"</td><td>35°08'54.64"</td><td>35°09'52.20"</td><td>35°10'39.47"</td><td>35°11'03.41"</td></tr><tr><td>Long. (E):</td><td>73°03'30.85"</td><td>73°04'36.44"</td><td>73°05'08.52"</td><td>73°06'07.81"</td><td>73°06'29.05"</td><td>73°06'34.70"</td></tr><tr><td>Sample:</td><td>KG-23</td><td>KG-26</td><td>KG-27</td><td>KG-30</td><td>KG-31</td><td>KG-35</td></tr><tr><td>Unit:</td><td>Patan</td><td>Patan</td><td>Patan</td><td>Kiru</td><td>Kiru</td><td>Kiru</td></tr><tr><td>Rock type:</td><td>Gabbro</td><td>UB</td><td>Diorite</td><td>Diorite</td><td>Diorite</td><td>Gabbro</td></tr><tr><td>Geochemical suite:</td><td>B, group B2</td><td>B, group B2</td><td>B, group B2</td><td>A</td><td>A</td><td>A</td></tr><tr><td>wt %</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>53.41</td><td>41.83</td><td>54.56</td><td>58.48</td><td>56.98</td><td>52.40</td></tr><tr><td>TiO<sub>2</sub></td><td>1.11</td><td>1.07</td><td>0.96</td><td>0.59</td><td>0.57</td><td>0.40</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>18.35</td><td>20.58</td><td>16.74</td><td>18.19</td><td>18.94</td><td>17.97</td></tr><tr><td>FeO<sub>T</sub></td><td>8.96</td><td>12.95</td><td>8.82</td><td>5.17</td><td>5.92</td><td>7.02</td></tr><tr><td>MnO</td><td>0.27</td><td>0.18</td><td>0.20</td><td>0.11</td><td>0.15</td><td>0.15</td></tr><tr><td>MgO</td><td>3.75</td><td>6.03</td><td>4.51</td><td>2.58</td><td>2.70</td><td>6.92</td></tr><tr><td>CaO</td><td>8.20</td><td>12.26</td><td>8.57</td><td>7.17</td><td>7.40</td><td>10.19</td></tr><tr><td>Na<sub>2</sub>O</td><td>2.90</td><td>1.08</td><td>2.37</td><td>4.15</td><td>3.84</td><td>2.87</td></tr><tr><td>K<sub>2</sub>O</td><td>0.16</td><td>0.13</td><td>0.20</td><td>0.50</td><td>0.43</td><td>0.43</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.31</td><td>0.27</td><td>0.23</td><td>0.22</td><td>0.22</td><td>0.10</td></tr><tr><td>LOI</td><td>0.83</td><td>1.31</td><td>1.02</td><td>1.44</td><td>1.87</td><td>0.96</td></tr><tr><td>Total</td><td>98.25</td><td>97.69</td><td>98.18</td><td>98.60</td><td>99.02</td><td>99.41</td></tr><tr><td>Mg-no.</td><td>43</td><td>45</td><td>48</td><td>47</td><td>45</td><td>64</td></tr><tr><td>ppm</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Sc</td><td>31</td><td>33</td><td>28</td><td>11</td><td>10</td><td>22</td></tr><tr><td>Ti</td><td>6714</td><td>6829</td><td>5970</td><td>3360</td><td>3175</td><td>2745</td></tr><tr><td>V</td><td>208</td><td>445</td><td>212</td><td>137</td><td>104</td><td>135</td></tr><tr><td>Ni</td><td>7</td><td>7</td><td>21</td><td>14</td><td>17</td><td>79</td></tr><tr><td>Cr</td><td>18</td><td>13</td><td>45</td><td>121</td><td>247</td><td>64</td></tr><tr><td>Rb</td><td>0.91</td><td>0.94</td><td>1.40</td><td>4.04</td><td>3.58</td><td>8.81</td></tr><tr><td>Sr</td><td>300</td><td>350</td><td>285</td><td>641</td><td>426</td><td>209</td></tr><tr><td>Y</td><td>36.3</td><td>17.6</td><td>20.5</td><td>12.0</td><td>15.6</td><td>16.8</td></tr><tr><td>Zr-XRF</td><td>73.2</td><td>21.8</td><td>37.3</td><td>127</td><td>94.3</td><td>115</td></tr><tr><td>Nb</td><td>2.01</td><td>0.87</td><td>1.70</td><td>2.39</td><td>2.81</td><td>2.90</td></tr><tr><td>Cs</td><td>0.05</td><td>0.11</td><td>0.01</td><td>0.15</td><td>0.14</td><td>0.15</td></tr><tr><td>Ba</td><td>45.4</td><td>30.1</td><td>67.0</td><td>172</td><td>130</td><td>73.4</td></tr><tr><td>La</td><td>7.48</td><td>4.92</td><td>6.31</td><td>7.27</td><td>8.52</td><td>7.88</td></tr><tr><td>Ce</td><td>18.7</td><td>13.0</td><td>15.1</td><td>18.4</td><td>21.2</td><td>18.6</td></tr><tr><td>Pr</td><td>2.59</td><td>1.83</td><td>2.06</td><td>2.56</td><td>2.91</td><td>2.33</td></tr><tr><td>Nd</td><td>13.0</td><td>9.12</td><td>10.5</td><td>11.7</td><td>13.4</td><td>10.1</td></tr><tr><td>Sm</td><td>3.41</td><td>2.27</td><td>2.73</td><td>2.62</td><td>2.95</td><td>2.22</td></tr><tr><td>Eu</td><td>1.41</td><td>0.85</td><td>1.17</td><td>0.90</td><td>1.02</td><td>0.78</td></tr><tr><td>Gd</td><td>4.39</td><td>2.67</td><td>3.29</td><td>2.69</td><td>3.20</td><td>2.51</td></tr><tr><td>Tb</td><td>0.73</td><td>0.42</td><td>0.51</td><td>0.40</td><td>0.49</td><td>0.41</td></tr><tr><td>Dy</td><td>5.45</td><td>2.87</td><td>3.45</td><td>2.52</td><td>3.29</td><td>2.83</td></tr><tr><td>Ho</td><td>1.22</td><td>0.59</td><td>0.71</td><td>0.50</td><td>0.67</td><td>0.59</td></tr><tr><td>Er</td><td>3.77</td><td>1.68</td><td>1.97</td><td>1.45</td><td>1.95</td><td>1.72</td></tr><tr><td>Tm</td><td>0.58</td><td>0.25</td><td>0.27</td><td>0.21</td><td>0.29</td><td>0.26</td></tr><tr><td>Yb</td><td>3.83</td><td>1.54</td><td>1.71</td><td>1.38</td><td>1.95</td><td>1.81</td></tr><tr><td>Lu</td><td>0.65</td><td>0.25</td><td>0.28</td><td>0.22</td><td>0.33</td><td>0.30</td></tr><tr><td>Ta</td><td>0.08</td><td>0.04</td><td>0.08</td><td>0.13</td><td>0.13</td><td>0.18</td></tr><tr><td>Pb</td><td>1.13</td><td>0.78</td><td>1.39</td><td>3.61</td><td>2.99</td><td>1.40</td></tr><tr><td>Th</td><td>0.07</td><td>0.16</td><td>0.26</td><td>0.13</td><td>0.14</td><td>0.70</td></tr><tr><td>U</td><td>0.04</td><td>0.07</td><td>0.11</td><td>0.09</td><td>0.04</td><td>0.22</td></tr><tr><td>ΣREE (ppm)</td><td>67.1</td><td>42.2</td><td>50.1</td><td>52.9</td><td>62.2</td><td>52.3</td></tr><tr><td>Eu*</td><td>1.12</td><td>1.05</td><td>1.19</td><td>1.02</td><td>1.01</td><td>1.01</td></tr><tr><td>La<sub>N</sub></td><td>31.6</td><td>20.7</td><td>26.6</td><td>30.7</td><td>36.0</td><td>33.3</td></tr><tr><td>Yb<sub>N</sub></td><td>22.5</td><td>9.07</td><td>10.0</td><td>8.13</td><td>11.5</td><td>10.6</td></tr><tr><td>Ce<sub>N</sub>/Yb<sub>N</sub></td><td>1.35</td><td>2.33</td><td>2.47</td><td>3.70</td><td>3.02</td><td>2.85</td></tr><tr><td>La<sub>N</sub>/Sm<sub>N</sub></td><td>1.42</td><td>1.40</td><td>1.49</td><td>1.80</td><td>1.86</td><td>2.29</td></tr></tbody></table>

(continued)
<table><caption>Table 1: Continued</caption><thead><tr><th></th><th colspan="3">Type-3 plutonics-volcanics</th><th colspan="3">Type-4 plutonics-volcanics</th></tr></thead><tbody><tr><td>Lat. (N):</td><td>35°18′55.70"</td><td>35°21′00.30"</td><td>35°22′24.40"</td><td>35°11′49.88"</td><td>35°13′37.49"</td><td>35°14′38.22"</td></tr><tr><td>Long. (E):</td><td>73°11′31.10"</td><td>73°12′13.50"</td><td>73°12′15.80"</td><td>73°11′42.90"</td><td>73°08′47.18"</td><td>73°10′45.41"</td></tr><tr><td>Sample:</td><td>UM01-133</td><td>UM01-134</td><td>UM01-135</td><td>KG-47</td><td>KG-45</td><td>KG-51</td></tr><tr><td>Unit:</td><td>Kamila</td><td>Kamila</td><td>Kamila</td><td>Kiru</td><td>Kiru</td><td>Kamila</td></tr><tr><td>Rock type:</td><td>Gabbro</td><td>Diorite</td><td>Gabbro</td><td>Diorite</td><td>Diorite</td><td>Gabbro</td></tr><tr><td>Geochemical suite:</td><td>B, group B3</td><td>B, group B3</td><td>B, group B3</td><td>A</td><td>A</td><td>A</td></tr><tr><td>wt %</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>52.08</td><td>54.66</td><td>51.16</td><td>56.99</td><td>54.66</td><td>51.55</td></tr><tr><td>TiO<sub>2</sub></td><td>0.72</td><td>0.90</td><td>0.82</td><td>0.65</td><td>0.44</td><td>0.59</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>19.01</td><td>16.34</td><td>16.16</td><td>15.18</td><td>20.72</td><td>18.81</td></tr><tr><td>FeO<sub>T</sub></td><td>7.34</td><td>7.70</td><td>8.40</td><td>7.04</td><td>5.44</td><td>6.92</td></tr><tr><td>MnO</td><td>0.15</td><td>0.16</td><td>0.18</td><td>0.12</td><td>0.13</td><td>0.15</td></tr><tr><td>MgO</td><td>5.72</td><td>5.33</td><td>6.99</td><td>5.13</td><td>2.79</td><td>5.35</td></tr><tr><td>CaO</td><td>10.06</td><td>8.10</td><td>9.18</td><td>7.85</td><td>8.37</td><td>9.63</td></tr><tr><td>Na<sub>2</sub>O</td><td>3.07</td><td>3.21</td><td>2.86</td><td>2.79</td><td>3.36</td><td>2.54</td></tr><tr><td>K<sub>2</sub>O</td><td>0.42</td><td>0.52</td><td>0.36</td><td>0.31</td><td>0.40</td><td>0.77</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.10</td><td>0.18</td><td>0.11</td><td>0.12</td><td>0.15</td><td>0.11</td></tr><tr><td>LOI</td><td>0.00</td><td>1.53</td><td>2.04</td><td>2.70</td><td>2.41</td><td>2.12</td></tr><tr><td>Total</td><td>98.67</td><td>98.63</td><td>98.26</td><td>98.88</td><td>98.87</td><td>98.54</td></tr><tr><td>Mg-no.</td><td>58</td><td>55</td><td>60</td><td>56</td><td>48</td><td>58</td></tr><tr><td>ppm</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Sc</td><td>21</td><td>25</td><td>27</td><td>29</td><td>6</td><td>22</td></tr><tr><td>Ti</td><td>3936</td><td>5843</td><td>4820</td><td>4460</td><td>2011</td><td>4137</td></tr><tr><td>V</td><td>132</td><td>220</td><td>206</td><td>220</td><td>74</td><td>160</td></tr><tr><td>Ni</td><td>48</td><td>75</td><td>108</td><td>61</td><td>11</td><td>29</td></tr><tr><td>Cr</td><td>72</td><td>257</td><td>164</td><td>101</td><td>87</td><td>10</td></tr><tr><td>Rb</td><td>3.25</td><td>1.41</td><td>1.26</td><td>9.01</td><td>10.1</td><td>21.3</td></tr><tr><td>Sr</td><td>604</td><td>288</td><td>349</td><td>129</td><td>393</td><td>217</td></tr><tr><td>Y</td><td>11.2</td><td>16.6</td><td>14.6</td><td>16.2</td><td>7.05</td><td>13.8</td></tr><tr><td>Zr-XRF</td><td>31</td><td>90</td><td>70</td><td>73.5</td><td>26.1</td><td>40.5</td></tr><tr><td>Nb</td><td>1.41</td><td>2.78</td><td>2.14</td><td>1.19</td><td>2.09</td><td>2.23</td></tr><tr><td>Cs</td><td>0.13</td><td>0.15</td><td>1.24</td><td>0.19</td><td>0.24</td><td>0.36</td></tr><tr><td>Ba</td><td>118</td><td>145</td><td>101</td><td>84.1</td><td>164</td><td>191</td></tr><tr><td>La</td><td>6.46</td><td>9.26</td><td>6.08</td><td>5.18</td><td>7.51</td><td>6.68</td></tr><tr><td>Ce</td><td>14.3</td><td>20.4</td><td>14.1</td><td>12.6</td><td>16.3</td><td>14.9</td></tr><tr><td>Pr</td><td>1.90</td><td>2.56</td><td>1.96</td><td>1.66</td><td>2.00</td><td>1.80</td></tr><tr><td>Nd</td><td>8.8</td><td>11.6</td><td>9.4</td><td>7.95</td><td>9.10</td><td>7.89</td></tr><tr><td>Sm</td><td>2.14</td><td>2.77</td><td>2.47</td><td>2.06</td><td>2.10</td><td>1.88</td></tr><tr><td>Eu</td><td>0.84</td><td>0.95</td><td>0.89</td><td>0.79</td><td>0.77</td><td>0.81</td></tr><tr><td>Gd</td><td>2.46</td><td>3.27</td><td>2.96</td><td>2.59</td><td>2.11</td><td>2.34</td></tr><tr><td>Tb</td><td>0.38</td><td>0.52</td><td>0.48</td><td>0.43</td><td>0.29</td><td>0.38</td></tr><tr><td>Dy</td><td>2.51</td><td>3.44</td><td>3.24</td><td>3.03</td><td>1.70</td><td>2.54</td></tr><tr><td>Ho</td><td>0.50</td><td>0.69</td><td>0.66</td><td>0.63</td><td>0.32</td><td>0.51</td></tr><tr><td>Er</td><td>1.46</td><td>1.89</td><td>1.87</td><td>1.73</td><td>0.84</td><td>1.37</td></tr><tr><td>Tm</td><td>0.20</td><td>0.28</td><td>0.27</td><td>0.26</td><td>0.12</td><td>0.20</td></tr><tr><td>Yb</td><td>1.34</td><td>1.78</td><td>1.80</td><td>1.66</td><td>0.78</td><td>1.34</td></tr><tr><td>Lu</td><td>0.22</td><td>0.28</td><td>0.28</td><td>0.27</td><td>0.12</td><td>0.22</td></tr><tr><td>Ta</td><td>0.10</td><td>0.20</td><td>0.14</td><td>0.08</td><td>0.14</td><td>0.17</td></tr><tr><td>Pb</td><td>3.54</td><td>4.52</td><td>4.38</td><td>1.41</td><td>4.26</td><td>1.85</td></tr><tr><td>Th</td><td>0.25</td><td>0.06</td><td>0.06</td><td>0.80</td><td>0.73</td><td>2.08</td></tr><tr><td>U</td><td>0.06</td><td>0.02</td><td>0.02</td><td>0.17</td><td>0.24</td><td>0.54</td></tr><tr><td>ΣREE (ppm)</td><td>43.5</td><td>59.8</td><td>46.5</td><td>40.8</td><td>44.1</td><td>42.8</td></tr><tr><td>Eu*</td><td>1.11</td><td>0.97</td><td>1.01</td><td>1.05</td><td>1.11</td><td>1.17</td></tr><tr><td>La<sub>N</sub></td><td>27.2</td><td>39.1</td><td>25.7</td><td>21.8</td><td>31.7</td><td>28.2</td></tr><tr><td>Yb<sub>N</sub></td><td>7.9</td><td>10.5</td><td>10.6</td><td>9.76</td><td>4.58</td><td>7.86</td></tr><tr><td>Ce<sub>N</sub>/Yb<sub>N</sub></td><td>2.97</td><td>3.18</td><td>2.17</td><td>2.11</td><td>5.82</td><td>3.09</td></tr><tr><td>La<sub>N</sub>/Sm<sub>N</sub></td><td>1.95</td><td>2.16</td><td>1.59</td><td>1.63</td><td>2.31</td><td>2.29</td></tr></tbody></table>

(continued)
<table><caption>Table 1: Continued</caption><thead><tr><th></th><th colspan="2">Type-4 plutonics-volcanics</th><th colspan="3">Type-5 plutonics-volcanics</th></tr></thead><tbody><tr><td>Lat. (N):</td><td>35°14'40.24"</td><td>35°14'43.48"</td><td>35°14'19.57"</td><td>35°14'30.08"</td><td>35°14'47.94"</td></tr><tr><td>Long. (E):</td><td>73°10'54.16"</td><td>73°11'07.30"</td><td>73°12'00.54"</td><td>73°12'11.09"</td><td>73°11'50.60"</td></tr><tr><td>Sample:</td><td>KG-53</td><td>KG-54</td><td>KG-52</td><td>KG-55</td><td>KG-56</td></tr><tr><td>Unit:</td><td>Kamila</td><td>Kamila</td><td>Kamila</td><td>Kamila</td><td>Kamila</td></tr><tr><td>Rock type:</td><td>Diorite</td><td>Diorite</td><td>Gabbro</td><td>Gabbro</td><td>Gabbro</td></tr><tr><td>Geochemical suite:</td><td>A</td><td>A</td><td>A</td><td>A</td><td>A</td></tr><tr><td>wt %</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>61.43</td><td>57.65</td><td>49.35</td><td>47.11</td><td>49.45</td></tr><tr><td>TiO<sub>2</sub></td><td>0.51</td><td>0.81</td><td>0.79</td><td>0.94</td><td>0.89</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>14.20</td><td>16.58</td><td>20.75</td><td>19.02</td><td>16.73</td></tr><tr><td>FeO<sub>T</sub></td><td>5.90</td><td>7.30</td><td>7.74</td><td>9.86</td><td>10.58</td></tr><tr><td>MnO</td><td>0.14</td><td>0.15</td><td>0.15</td><td>0.19</td><td>0.22</td></tr><tr><td>MgO</td><td>5.54</td><td>3.29</td><td>3.18</td><td>4.29</td><td>5.45</td></tr><tr><td>CaO</td><td>6.93</td><td>7.21</td><td>8.67</td><td>9.52</td><td>10.64</td></tr><tr><td>Na<sub>2</sub>O</td><td>2.60</td><td>2.73</td><td>3.08</td><td>2.38</td><td>1.47</td></tr><tr><td>K<sub>2</sub>O</td><td>1.01</td><td>0.83</td><td>1.91</td><td>1.88</td><td>1.05</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.13</td><td>0.18</td><td>0.47</td><td>0.74</td><td>0.18</td></tr><tr><td>LOI</td><td>1.46</td><td>1.55</td><td>2.64</td><td>2.53</td><td>2.42</td></tr><tr><td>Total</td><td>99.85</td><td>98.28</td><td>98.73</td><td>98.46</td><td>99.08</td></tr><tr><td>Mg-no.</td><td>63</td><td>44</td><td>42</td><td>44</td><td>48</td></tr><tr><td>ppm</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Sc</td><td>23</td><td>25</td><td>17</td><td>19</td><td>34</td></tr><tr><td>Ti</td><td>3547</td><td>5275</td><td>5595</td><td>5610</td><td>5462</td></tr><tr><td>V</td><td>158</td><td>216</td><td>215</td><td>264</td><td>401</td></tr><tr><td>Ni</td><td>100</td><td>13</td><td>6</td><td>7</td><td>23</td></tr><tr><td>Cr</td><td>444</td><td>44</td><td>9</td><td>16</td><td>30</td></tr><tr><td>Rb</td><td>28.7</td><td>25.4</td><td>54.1</td><td>50.4</td><td>34.5</td></tr><tr><td>Sr</td><td>170</td><td>255</td><td>865</td><td>690</td><td>761</td></tr><tr><td>Y</td><td>15.4</td><td>27.2</td><td>23.3</td><td>27.4</td><td>29.6</td></tr><tr><td>Zr-XRF</td><td>88.0</td><td>88.9</td><td>107</td><td>73.7</td><td>108</td></tr><tr><td>Nb</td><td>3.12</td><td>3.15</td><td>4.89</td><td>5.42</td><td>7.42</td></tr><tr><td>Cs</td><td>0.28</td><td>0.49</td><td>0.96</td><td>0.93</td><td>0.46</td></tr><tr><td>Ba</td><td>242</td><td>150</td><td>1445</td><td>1014</td><td>600</td></tr><tr><td>La</td><td>10.8</td><td>11.7</td><td>63.5</td><td>46.2</td><td>71.1</td></tr><tr><td>Ce</td><td>23.1</td><td>26.9</td><td>107</td><td>89.4</td><td>125</td></tr><tr><td>Pr</td><td>2.65</td><td>3.37</td><td>10.7</td><td>9.85</td><td>12.6</td></tr><tr><td>Nd</td><td>11.1</td><td>15.3</td><td>39.9</td><td>39.8</td><td>46.1</td></tr><tr><td>Sm</td><td>2.36</td><td>3.69</td><td>6.33</td><td>7.02</td><td>7.25</td></tr><tr><td>Eu</td><td>0.80</td><td>1.23</td><td>2.21</td><td>2.17</td><td>2.25</td></tr><tr><td>Gd</td><td>2.63</td><td>4.37</td><td>5.66</td><td>6.56</td><td>6.43</td></tr><tr><td>Tb</td><td>0.42</td><td>0.72</td><td>0.76</td><td>0.92</td><td>0.93</td></tr><tr><td>Dy</td><td>2.79</td><td>4.86</td><td>4.60</td><td>5.54</td><td>5.77</td></tr><tr><td>Ho</td><td>0.57</td><td>1.01</td><td>0.89</td><td>1.08</td><td>1.15</td></tr><tr><td>Er</td><td>1.55</td><td>2.89</td><td>2.34</td><td>2.91</td><td>3.25</td></tr><tr><td>Tm</td><td>0.24</td><td>0.43</td><td>0.33</td><td>0.41</td><td>0.49</td></tr><tr><td>Yb</td><td>1.52</td><td>2.77</td><td>2.02</td><td>2.47</td><td>3.15</td></tr><tr><td>Lu</td><td>0.25</td><td>0.46</td><td>0.32</td><td>0.39</td><td>0.51</td></tr><tr><td>Ta</td><td>0.27</td><td>0.22</td><td>0.20</td><td>0.19</td><td>0.38</td></tr><tr><td>Pb</td><td>1.08</td><td>2.07</td><td>4.76</td><td>3.42</td><td>4.76</td></tr><tr><td>Th</td><td>3.00</td><td>2.50</td><td>9.87</td><td>7.29</td><td>13.0</td></tr><tr><td>U</td><td>0.58</td><td>0.68</td><td>1.13</td><td>1.55</td><td>1.65</td></tr><tr><td>ΣREE (ppm)</td><td>60.8</td><td>79.6</td><td>246</td><td>215</td><td>286</td></tr><tr><td>Eu*</td><td>0.97</td><td>0.94</td><td>1.10</td><td>0.96</td><td>0.99</td></tr><tr><td>La<sub>N</sub></td><td>45.7</td><td>49.2</td><td>268</td><td>195</td><td>300</td></tr><tr><td>Yb<sub>N</sub></td><td>8.95</td><td>16.3</td><td>11.9</td><td>14.5</td><td>18.5</td></tr><tr><td>Ce<sub>N</sub>/Yb<sub>N</sub></td><td>4.21</td><td>2.69</td><td>14.7</td><td>10.1</td><td>11.1</td></tr><tr><td>La<sub>N</sub>/Sm<sub>N</sub></td><td>2.97</td><td>2.04</td><td>6.48</td><td>4.24</td><td>6.33</td></tr></tbody></table>

(continued)
<table><caption>Table 1: Continued</caption><thead><tr><th></th><th colspan="5">Intrusive granites</th></tr><tr><th>Lat. (N):</th><td>35°10′55.34″</td><td>35°13′27.92″</td><td>35°14′15.47″</td><td>35°14′30.62″</td><td>35°14′42.22″</td></tr><tr><th>Long. (E):</th><td>73°06′30.92″</td><td>73°09′20.85″</td><td>73°10′36.08″</td><td>73°10′42.49″</td><td>73°12′12.31″</td></tr><tr><th>Sample:</th><td>KG-32</td><td>UM01-124<sup>1</sup></td><td>KG-48</td><td>KG-50<sup>1</sup></td><td>UM01-125<sup>1</sup></td></tr><tr><th>Unit:</th><td>Kiru</td><td>Kiru</td><td>Kamila</td><td>Kamila</td><td>Kamila</td></tr><tr><th>Rock type:</th><td>Tonalite</td><td>Tonalite</td><td>Tonalite</td><td>Tonalite</td><td>Tonalite</td></tr><tr><th>wt %</th><td></td><td></td><td></td><td></td><td></td></tr><tr><th>SiO<sub>2</sub></th><td>63.27</td><td>64.72</td><td>74.03</td><td>67.88</td><td>71.20</td></tr><tr><th>TiO<sub>2</sub></th><td>0.43</td><td>0.38</td><td>0.11</td><td>0.21</td><td>0.22</td></tr><tr><th>Al<sub>2</sub>O<sub>3</sub></th><td>20.02</td><td>17.40</td><td>14.88</td><td>16.56</td><td>15.37</td></tr><tr><th>FeO<sub>T</sub></th><td>2.36</td><td>3.46</td><td>1.29</td><td>2.35</td><td>2.35</td></tr><tr><th>MnO</th><td>0.04</td><td>0.10</td><td>0.03</td><td>0.06</td><td>0.07</td></tr><tr><th>MgO</th><td>1.04</td><td>1.32</td><td>0.54</td><td>0.86</td><td>0.73</td></tr><tr><th>CaO</th><td>7.08</td><td>5.84</td><td>2.81</td><td>4.52</td><td>3.38</td></tr><tr><th>Na<sub>2</sub>O</th><td>4.31</td><td>3.48</td><td>4.35</td><td>3.88</td><td>3.77</td></tr><tr><th>K<sub>2</sub>O</th><td>0.15</td><td>0.90</td><td>0.75</td><td>1.15</td><td>1.28</td></tr><tr><th>P<sub>2</sub>O<sub>5</sub></th><td>0.14</td><td>0.13</td><td>0.03</td><td>0.09</td><td>0.05</td></tr><tr><th>LOI</th><td>0.34</td><td>1.60</td><td>0.89</td><td>1.54</td><td>1.18</td></tr><tr><th>Total</th><td>99.18</td><td>99.33</td><td>99.71</td><td>99.10</td><td>99.60</td></tr><tr><th>Mg-no.</th><td>44</td><td>40</td><td>43</td><td>39</td><td>36</td></tr><tr><th>ppm</th><td></td><td></td><td></td><td></td><td></td></tr><tr><th>Sc</th><td>3</td><td>7</td><td>1</td><td>2</td><td>1</td></tr><tr><th>Ti</th><td>3070</td><td>—</td><td>562</td><td>1415</td><td>872</td></tr><tr><th>V</th><td>49</td><td>41</td><td>12</td><td>30</td><td>11</td></tr><tr><th>Ni</th><td>7</td><td>2</td><td>3</td><td>3</td><td>1</td></tr><tr><th>Cr</th><td>15</td><td>27</td><td>47</td><td>39</td><td>1</td></tr><tr><th>Rb</th><td>5.06</td><td>33.5</td><td>22.3</td><td>44.0</td><td>48.7</td></tr><tr><th>Sr</th><td>399</td><td>386</td><td>289</td><td>332</td><td>364</td></tr><tr><th>Y</th><td>4.48</td><td>5.75</td><td>1.02</td><td>2.59</td><td>2.84</td></tr><tr><th>Zr-XRF</th><td>122</td><td>78.0</td><td>89.7</td><td>73.7</td><td>70.0</td></tr><tr><th>Nb</th><td>2.22</td><td>2.50</td><td>1.03</td><td>1.82</td><td>5.55</td></tr><tr><th>Cs</th><td>0.22</td><td>0.43</td><td>0.31</td><td>0.51</td><td>0.48</td></tr><tr><th>Ba</th><td>120</td><td>431</td><td>343</td><td>516</td><td>889</td></tr><tr><th>La</th><td>4.44</td><td>10.5</td><td>2.81</td><td>11.0</td><td>50.9</td></tr><tr><th>Ce</th><td>10.7</td><td>21.0</td><td>5.15</td><td>20.3</td><td>93.7</td></tr><tr><th>Pr</th><td>1.36</td><td>2.35</td><td>0.55</td><td>2.02</td><td>8.29</td></tr><tr><th>Nd</th><td>6.09</td><td>9.64</td><td>2.17</td><td>7.44</td><td>28.8</td></tr><tr><th>Sm</th><td>1.27</td><td>1.94</td><td>0.38</td><td>1.11</td><td>3.43</td></tr><tr><th>Eu</th><td>0.50</td><td>0.77</td><td>0.26</td><td>0.58</td><td>0.82</td></tr><tr><th>Gd</th><td>1.13</td><td>1.80</td><td>0.32</td><td>0.90</td><td>2.02</td></tr><tr><th>Tb</th><td>0.14</td><td>0.23</td><td>0.04</td><td>0.10</td><td>0.19</td></tr><tr><th>Dy</th><td>0.77</td><td>1.36</td><td>0.23</td><td>0.54</td><td>0.78</td></tr><tr><th>Ho</th><td>0.14</td><td>0.25</td><td>0.04</td><td>0.10</td><td>0.11</td></tr><tr><th>Er</th><td>0.36</td><td>0.69</td><td>0.12</td><td>0.26</td><td>0.25</td></tr><tr><th>Tm</th><td>0.05</td><td>0.10</td><td>0.02</td><td>0.04</td><td>0.03</td></tr><tr><th>Yb</th><td>0.33</td><td>0.68</td><td>0.13</td><td>0.24</td><td>0.22</td></tr><tr><th>Lu</th><td>0.05</td><td>0.11</td><td>0.02</td><td>0.04</td><td>0.04</td></tr><tr><th>Ta</th><td>0.18</td><td>0.17</td><td>0.06</td><td>0.09</td><td>0.21</td></tr><tr><th>Pb</th><td>1.56</td><td>3.25</td><td>2.81</td><td>2.60</td><td>5.08</td></tr><tr><th>Th</th><td>0.57</td><td>2.21</td><td>0.42</td><td>2.08</td><td>13.96</td></tr><tr><th>U</th><td>0.14</td><td>0.45</td><td>0.04</td><td>0.32</td><td>0.77</td></tr><tr><th>ΣREE (ppm)</th><td>27.3</td><td>51.5</td><td>12.2</td><td>44.6</td><td>190</td></tr><tr><th>Eu*</th><td>1.24</td><td>1.24</td><td>2.22</td><td>1.73</td><td>0.87</td></tr><tr><th>La<sub>N</sub></th><td>18.7</td><td>44.4</td><td>11.9</td><td>46.3</td><td>214.6</td></tr><tr><th>Yb<sub>N</sub></th><td>1.95</td><td>4.02</td><td>0.75</td><td>1.41</td><td>1.26</td></tr><tr><th>Ce<sub>N</sub>/Yb<sub>N</sub></th><td>8.95</td><td>8.56</td><td>11.2</td><td>23.6</td><td>121</td></tr><tr><th>La<sub>N</sub>/Sm<sub>N</sub></th><td>2.26</td><td>3.50</td><td>4.83</td><td>6.39</td><td>9.58</td></tr></thead></table>

(continued)
<table><caption>Table 1: Continued</caption><thead><tr><th></th><th colspan="3">Intrusive granites</th></tr></thead><tbody><tr><td>Lat. (N):</td><td>35°13'02.32"</td><td>35°13'07.28"</td><td>35°13'05.52"</td></tr><tr><td>Long. (E):</td><td>73°08'55.68"</td><td>73°09'01.48"</td><td>73°09'02.75"</td></tr><tr><td>Sample:</td><td>KG-42<sup>1</sup></td><td>KG-43</td><td>UM01-123<sup>1</sup></td></tr><tr><td>Unit:</td><td>Kiru</td><td>Kiru</td><td>Kiru</td></tr><tr><td>Rock type:</td><td>Granodiorite</td><td>Granodiorite</td><td>Granodiorite</td></tr><tr><td>wt %</td><td></td><td></td><td></td></tr><tr><td>SiO<sub>2</sub></td><td>74.35</td><td>74.80</td><td>74.09</td></tr><tr><td>TiO<sub>2</sub></td><td>0.05</td><td>0.05</td><td>0.03</td></tr><tr><td>Al<sub>2</sub>O<sub>3</sub></td><td>14.95</td><td>14.66</td><td>14.87</td></tr><tr><td>FeO<sub>T</sub></td><td>1.09</td><td>0.90</td><td>0.82</td></tr><tr><td>MnO</td><td>0.18</td><td>0.22</td><td>0.15</td></tr><tr><td>MgO</td><td>0.27</td><td>0.25</td><td>0.26</td></tr><tr><td>CaO</td><td>2.20</td><td>2.13</td><td>1.80</td></tr><tr><td>Na<sub>2</sub>O</td><td>3.56</td><td>3.13</td><td>2.90</td></tr><tr><td>K<sub>2</sub>O</td><td>1.57</td><td>1.86</td><td>2.28</td></tr><tr><td>P<sub>2</sub>O<sub>5</sub></td><td>0.07</td><td>0.05</td><td>0.04</td></tr><tr><td>LOI</td><td>0.97</td><td>0.99</td><td>1.22</td></tr><tr><td>Total</td><td>99.26</td><td>99.04</td><td>98.46</td></tr><tr><td>Mg-no.</td><td>31</td><td>33</td><td>36</td></tr><tr><td>ppm</td><td></td><td></td><td></td></tr><tr><td>Sc</td><td>1</td><td>2</td><td>3</td></tr><tr><td>Ti</td><td>257</td><td>222</td><td>—</td></tr><tr><td>V</td><td>5</td><td>9</td><td>21</td></tr><tr><td>Ni</td><td>9</td><td>6</td><td>2</td></tr><tr><td>Cr</td><td>209</td><td>105</td><td>24</td></tr><tr><td>Rb</td><td>50.4</td><td>53.2</td><td>63.6</td></tr><tr><td>Sr</td><td>206</td><td>148</td><td>154</td></tr><tr><td>Y</td><td>9.79</td><td>13.3</td><td>8.02</td></tr><tr><td>Zr-XRF</td><td>42.0</td><td>47.5</td><td>38.0</td></tr><tr><td>Nb</td><td>5.89</td><td>6.88</td><td>7.12</td></tr><tr><td>Cs</td><td>1.12</td><td>0.98</td><td>1.13</td></tr><tr><td>Ba</td><td>853</td><td>773</td><td>841</td></tr><tr><td>La</td><td>8.35</td><td>6.95</td><td>6.38</td></tr><tr><td>Ce</td><td>17.3</td><td>14.6</td><td>13.3</td></tr><tr><td>Pr</td><td>1.94</td><td>1.67</td><td>1.53</td></tr><tr><td>Nd</td><td>7.61</td><td>6.56</td><td>6.17</td></tr><tr><td>Sm</td><td>1.62</td><td>1.69</td><td>1.46</td></tr><tr><td>Eu</td><td>0.35</td><td>0.28</td><td>0.29</td></tr><tr><td>Gd</td><td>1.70</td><td>1.98</td><td>1.67</td></tr><tr><td>Tb</td><td>0.26</td><td>0.35</td><td>0.25</td></tr><tr><td>Dy</td><td>1.79</td><td>2.41</td><td>1.54</td></tr><tr><td>Ho</td><td>0.35</td><td>0.45</td><td>0.27</td></tr><tr><td>Er</td><td>1.01</td><td>1.28</td><td>0.74</td></tr><tr><td>Tm</td><td>0.16</td><td>0.20</td><td>0.11</td></tr><tr><td>Yb</td><td>1.11</td><td>1.37</td><td>0.83</td></tr><tr><td>Lu</td><td>0.19</td><td>0.22</td><td>0.14</td></tr><tr><td>Ta</td><td>0.65</td><td>0.75</td><td>0.75</td></tr><tr><td>Pb</td><td>15.65</td><td>8.22</td><td>11.90</td></tr><tr><td>Th</td><td>2.05</td><td>1.60</td><td>1.61</td></tr><tr><td>U</td><td>0.56</td><td>0.54</td><td>0.36</td></tr><tr><td>ΣREE (ppm)</td><td>43.7</td><td>40.0</td><td>34.7</td></tr><tr><td>Eu*</td><td>0.65</td><td>0.46</td><td>0.57</td></tr><tr><td>La<sub>N</sub></td><td>35.2</td><td>29.3</td><td>26.9</td></tr><tr><td>Yb<sub>N</sub></td><td>6.54</td><td>8.03</td><td>4.88</td></tr><tr><td>Ce<sub>N</sub>/Yb<sub>N</sub></td><td>4.31</td><td>2.97</td><td>4.45</td></tr><tr><td>La<sub>N</sub>/Sm<sub>N</sub></td><td>3.32</td><td>2.66</td><td>2.82</td></tr></tbody></table>

<footnote>*Sample names from Garrido *et al.* (2006). Rock types are established as a function of the SiO₂ content of the rocks. UM: ultramafic (SiO₂ ≤ 45%); gabbros: gabbros *sensu stricto* and gabbrodiorites [45 < SiO₂ (wt %) ≤ 55]; diorites [55 < SiO₂ (wt %) ≤ 63]; intrusive granites (tonalites and granodiorites, SiO₂ > 63%). Because zircons, expressed as an accessory mineral phase in granitoids, were not completely dissolved during the ICP-MS acid digestion procedure, Zr values were taken from the XRF analyses. 'Suite A' and 'suite B' are defined based on combined trace element and isotopic analysis. —, not analyzed; LOI, loss on ignition; N, chondrite-normalized, after Sun & McDonough (1989). Mg-number = 100 × MgO/(MgO + FeO<sub>Total</sub>), on a molar basis.</footnote>
are common in the Kiru sequence and are most abundant
in the upper section.

Eleven plutonic and volcanic rocks samples were selected (Fig. 3b and Table 1): three ‘Kiru amphibolite’ samples (KG-30, KG-35, UM01-l22); one metadiorite taken from a large sill intrusive into the Kiru amphibolites (KG-3l); five gabbros from the thick pile of interlayered gabbro–diorite found above the Kiru amphibolites (KG-37, KG-38, KG-39, KG-40, KG-4l); and two diorites from the ‘Mandraza amphibolites’ (KG-45, KG-47). In addition, five intrusive granitic rocks were sampled: one tonalite intrusive into the Kiru amphibolites (KG-32); one tonalite (UM01-l24) and three granodiorites (KG-42, KG-43, UM01-l23) intrusive into the Mandraza amphibolites (Fig. 3b and Table 1).

*The Kamila sequence*

The Kamila sequence (>10 km thick) represents the upper-
most crustal level investigated in this study (Figs 2 and 3c).
It comprises various types of fine-grained and layered
amphibolite (i.e. ortho-amphibolites, metapelites, metavol-
canic rocks and carbonates), which are heavily intruded by
amphibolitized rocks of gabbroic to granitic composition.
These amphibolites may be remnants of an upper crustal
sequence (Zeilinger, 2002). One thick (~500 m) metagab-
broic body is intrusive into the amphibolites, which are in
turn intruded by numerous pegmatites or dykes and by
large granite bodies. The largest granite (up to 1 km thick)
is located at the bottom of the Kamila sequence and is also
intrusive into the underlying Mandraza amphibolites of
the Kiru sequence. The upper amphibolites are overlain
by massive coarse-grained metadiorites that are associated
with metacarbonates and quartzites.

Thirteen plutonic or volcanic rocks samples were selected (Fig. 3c and Table 1): six amphibolite samples taken from the sequence base (KG-5l, KG-53, KG-54, KG-55, KG-52, KG-56); two amphibolites from the top of the section (KG-59, UM01-l26); two metagabbros from the thick gabbroic body intrusive into the amphibolites (UM01-l27, UM01-l28); and three metagabbros or diorites from the uppermost part of the Kamila sequence, near the contact with the intrusive Chilas complex (UM01-l33, UM01-l34, UM01-l35). In addition, three intrusive tonalites (KG-48, KG-50 and UM01-l25) were sampled from the bottom of the Kamila sequence (Fig. 3c and Table 1).

ANALYTICAL METHODS

Rock samples were crushed and then pulverized in an
agate mill for whole-rock analyses. Plagioclases and clino-
pyroxenes were extracted from 100–150 µm mineral frac-
tions using a Frantz magnetic separator, and were then
carefully hand-picked to avoid composite grains and
inclusions.

Whole-rock major elements were analyzed by X-ray flu-
orescence (XRF) on a Philips PW1404/10 instrument at the

CIC (University of Granada, Spain). The system was cali-
brated using 24 international standards to ensure accuracy
and the calibration was periodically monitored using four
internal standards. The reproducibility of the major ele-
ment data is 0.3% absolute. Trace elements and REE
abundances in whole-rocks and minerals were analyzed
by inductively coupled plasma mass spectrometry (ICP-
MS) using a VG Plasmaquad II system at the University
of Montpellier II. The results from the international rock
standards BEN (n = 13) and UBN (n = 13) yielded limits of
detection below 1.5 ppb and a relative standard deviation
(RSD) of 4–7%, except for Rb, Sr, Nb, Zr, and Ta (RSD
~7–15%).

Before undertaking the acid digestion for the Sr, Nd and
Pb isotopic analyses, clinopyroxenes were leached for
30 min in 6N HCl at 80°C and plagioclases were leached
for 15 min in 2.5N HCl at 60°C. All whole-rocks were lea-
ched for 30 min with 6N HCl at 80°C. After the leaching
steps, the residues were rinsed three times in purified milli-
Q H₂O. The Sr, Nd and Pb separation procedures were
slightly modified from those of Manhès et al. (1980) and
Pin et al. (1994). The total blank contents for Pb, Sr and
Nd were less than 65, 60 and 30 pg, respectively, for a
100 mg sample. Pb and Nd isotopic compositions were
measured by multicollector (MC)-ICP-MS using the VG
Plasma 54 and the Nu 500 systems at the Ecole Normale
Supérieure in Lyon (France). The Pb isotopic compositions
were measured with an external precision of ~100–
150 ppm for 206, 207, 208Pb)/²⁰⁴Pb, using the Tl normalization
method described by White et al. (2000). The NIST 981
standard was measured every two samples, and the Nd iso-
topic measurements were bracketed between the ‘Lyon in-
house’ Nd standard every two samples. This Nd standard is
a 500 ppb dilution of the JMC commercial solution, batch
801149A (Luais et al., 1997) with an average of
¹⁴³Nd/¹⁴⁴Nd = 0.512134 ± 24 (2σ) (n = 102). The Sr isotopic
compositions were measured on a Finnigan Triton TI mass
spectrometer at the Laboratoire de Géochimie GIS of
Nîmes (France). The results from the NBS 987 Sr standard
yielded a mean value of ⁸⁷Sr/⁸⁶Sr = 0.710256 ± 10 (2σ)
(n = 22). The initial isotopic compositions of the entire
dataset were corrected for *in situ* decay, assuming an age
of ~100 Ma according to the U–Pb zircon ages obtained
by Schaltegger *et al.* (2002) relating to the main period of
magmatism in the KAC.

RESULTS

Major and trace elements

The major and trace element compositions of 55 samples
from the JPKK crustal section are reported in Table 1.
Two groups of rocks can be distinguished as a function of
their tectonic emplacement: (1) plutonic-volcanic rocks
of ultramafic to dioritic composition; (2) later rocks
intrusive into group (1) of quartz-diorite to granitic composition, referred to as 'intrusive granites'.

## Plutonic-volcanic rocks

We have subdivided the plutonic-volcanic rocks into five 'types' on the basis of their trace element compositions. These are referred to as 'Type-1' to 'Type-5' rocks in Table 1 and Figs 3 and 4.

Chondrite-normalized REE patterns and primitive mantle-normalized trace element patterns are reported in Fig. 4. The transition from Type-1 to Type-5 patterns is mainly characterized by the enrichment of highly incompatible elements (HIE) [i.e. LILE (Cs, Rb, Ba, Pb, Sr), LREE, Th and U] in relation to HFSE (Nb, Ta, Zr).

Type-1 rocks are gabbroic [$48 < \text{SiO}_2 \, (\text{wt} \%) < 51$] on an anhydrous basis; see Table A in the Supplementary Data, available for downloading at http://www.petrology.oxford-journals.org/ with a large range in Mg-number values ($53 < \text{Mg-number} < 80$) and low REE contents [$6.5 < \text{REE} \, (\text{ppm}) < 36$]. Five samples appear to be cumulates, characterized by strong REE depletion [$6.5 < \text{REE} \, (\text{ppm}) < 15$], highly fractionated REE patterns with a strong LREE/MREE (middle REE) depletion ($0.34 < \text{Ce}_N/\text{Yb}_N < 0.64$; $1.2 < \text{La}_N < 2.0$; $2.7 < \text{Yb}_N < 6.9$ and $0.29 < \text{La}_N/\text{Sm}_N < 0.68$), and a marked positive Eu anomaly [$1.5 < \text{Eu}^* < 1.8$; $\text{Eu}^* = 2 \times \text{Eu}_N/(\text{Sm}_N + \text{Gd}_N)$] that is correlated with positive Sr and Pb anomalies in primitive mantle normalized trace element patterns (Fig. 4). One sample (UM01-122) is distinguished by a weakly fractionated REE pattern (Ce$_N$/Yb$_N = 0.82$), a slight depletion in LREE (La$_N$/Sm$_N = 0.65$) and no Eu anomaly ($\text{Eu}^* = 0.97$). A liquid-cumulate relationship between this sample and the clino-pyroxene from the cumulate sample (KG-37) is suggested by their complementary REE patterns (Fig. 5).

In Harker variation diagrams (Fig. 6), the Type-1 rocks deviate from the global trend defined by modern island arc lavas. For a given SiO$_2$ content, Type-1 samples have lower TiO$_2$, Zr, FeO$_T$ and Na$_2$O + K$_2$O, and higher CaO and MgO contents. All of the samples except one (KG-40) plot in the calc-alkaline field of the Mg-number vs SiO$_2$ diagram.

Type-2 rocks have ultramafic to gabbroic compositions [$44 < \text{SiO}_2 \, (\text{wt} \%) < 53$] with primitive to highly differentiated Mg-number values ($38 < \text{Mg-number} < 66$). Compared with Type-1, the Type-2 samples are significantly enriched in REE ($33 < \text{REE} \, (\text{ppm}) < 71$), show slightly fractionated, 'N-MORB-like' REE patterns ($0.6 < \text{Ce}_N/\text{Yb}_N < 2.1$; $6 < \text{La}_N < 30$; $7 < \text{Yb}_N < 19$) with variable LREE/MREE depletion ($0.26 < \text{La}_N/\text{Sm}_N < 0.95$). They have slightly negative to positive Eu anomalies ($0.7 < \text{Eu}^* < 1.1$).

In Harker variation diagrams, the Type-2 samples are scattered and deviate from the modern island arc lavas trend (Fig. 6). In the Na$_2$O + K$_2$O vs SiO$_2$ diagram, they

display a slight enrichment in total alkalis compared with the main trend of the data. All Type-2 samples plot in the holeiitic domain in the Mg-number vs SiO$_2$ diagram.

Type-3 rocks have ultramafic to dioritic compositions [$43 < \text{SiO}_2 \, (\text{wt} \%) < 60$] with variable Mg-number from primitive to highly differentiated values ($40 < \text{Mg-number} < 64$). Compared with the Type-2 samples, Type-3

<figure><img src="image_7.png" /><figcaption>**Fig. 4.** (a) Chondrite-normalized REE patterns and (b) primitive mantle-normalized extended trace element diagrams of JPKK crustal section rocks (including plutonic-volcanic rocks and intrusive granites). Normalization values after Sun & McDonough (1989). Five main types of patterns (Type-1 to Type-5) are distinguished for the plutonic-volcanic rocks throughout the ~30 km arc crust section (see text for explanation). Only one representative pattern for each type of granite is plotted in (b). The trace element patterns of the Type-3 rocks are similar to those of gabbros and diorites from the Chilas complex (Jagoutz *et al.*, 2006; Takahashi *et al.*, 2006).</figcaption></figure>
<figure><img src="image_8.png" /><figcaption>**Fig. 4.** Continued</figcaption></figure>

rocks have similar ΣREE values [30 < REE (ppm) < 79] but display stronger LREE/HREE and LREE/MREE enrichments (1.3 < Ce/N/Yb/N < 3.7; 1.3 < La/N/Sm/N < 2.3). The Eu anomalies are slightly negative to slightly positive (0.9 < Eu* < 1.3), and there are Sr and Pb positive spikes in the mantle-normalized trace element patterns (Fig. 4).

Trace element patterns of the gabbros and diorites from the Chilas complex (Jagoutz *et al.*, 2006; Takahashi *et al.*, 2006) are reported in the inset of Fig. 4b for comparison. These patterns are similar to the Type-3 patterns and show marked HFSE anomalies that are typical features of arc magmas.
<figure><img src="image_9.png" /><figcaption>**Fig. 5.** Chondrite-normalized REE pattern of the calculated liquid in equilibrium with the KG-37 cumulate sample compared with that of UM01-122. The composition of the liquid has been calculated from dissolution ICP-MS data, for an ~10 mg clinopyroxene fraction from KG-37, and using clinopyroxene-melt distribution coefficients of Hart & Dunn (1993). Normalization values after Sun & McDonough (1989).</figcaption></figure>

In the Harker variation diagrams (Fig. 6), the Type-3 samples roughly follow the trend of modern island arc lavas. In the Mg-number vs SiO₂ diagram, two groups of samples can be distinguished: (1) a group located in the tholeiitic domain, formed by the Jijal and Patan samples (except for KG-20); (2) a calc-alkaline group, formed by one Patan sample (KG-20) and by rocks from the Kiru and Kamila sequences (see Table 1).

Type-4 rocks show more differentiated compositions [54 < SiO₂ (wt %) < 62]; four of the five samples are dioritic in composition (Table 1). This is consistent with the Mg-number values of these rocks (44 < Mg-number < 63). When compared with Type-2 and -3, Type-4 samples display similar ΣREE values [41 < ΣREE (ppm) < 81] but are characterized by a stronger LREE/HREE and LREE/MREE enrichment (2·1 < CeN/YbN < 5·8; 16 < LaN/SmN < 3·0), and by an overall enrichment in the most incompatible elements (Cs-U segment in Fig. 4b). These rocks show no marked Eu anomalies (0·9 < Eu* < 1·2), but weak positive to prominent Pb and Sr spikes. Samples from this group plot roughly in the Type-3-modern island arc lavas field in the Harker diagrams (Fig. 6) and clearly show a calc-alkaline character in the Mg-number vs SiO₂ diagram.

Type-5 rocks are restricted to the Kamila sequence and are located in the field close to the Type-4 samples (Fig. 3c). Type-5 samples have a gabbroic composition [49 < SiO₂ (wt %) < 51] and differentiated Mg-number values (42 < Mg-number < 48). These samples are notably distinguished from the Type-4 rocks by an extreme enrichment in REE [215 < ΣREE (ppm) < 286], a strong enrichment of LREE relative to HREE and MREE (10 < CeN/YbN < 15; 4·2 < LaN/SmN < 6·5), an overall enrichment in the most incompatible elements (Cs-U segment in Fig. 4b) and no marked Eu, Sr or Pb anomalies. Type-5

samples roughly plot in an intermediate position between the Type-2 and Type-3 groups in Fig. 6.

### Intrusive granites

Three granites have been analyzed and are reported in Table 1; a further five samples were analysed by Garrido *et al.* (2006). According to those workers, two types of granitoid can be distinguished in the Kiru-Kamila section, tonalites and granodiorites. Overall, tonalites are characterized by a strong fractionation of LREE/HREE (6·5 < CeN/YbN < 12) and a positive Eu anomaly (1·2 < Eu* < 2·2; Fig. 4). The granodiorites are distinguished by a weaker LREE/HREE fractionation (3·0 < CeN/YbN < 4·5) and a marked negative Eu anomaly (0·5 < Eu* < 0·7; Fig. 4).

All the granites plot along the modern island arc lavas trend for TiO₂, CaO, FeO, MgO and Na₂O + K₂O, and in the calc-alkaline area in the Mg-number vs SiO₂ diagram (Fig. 6).

### Sr, Nd and Pb isotope compositions

Sr, Nd and Pb isotopic data are reported in Table 2 along with data from Dhuime *et al.* (2007) for 17 samples from the crustal section of the Jijal complex (i.e. ‘Jijal gabbroic rocks’, including hornblende gabbronorites and garnet granulites; and ‘Jijal hornblendites’, including rocks from the hornblendite-garnetite transition; see Fig. 3a). In addition to the leached-whole rock analyses, the isotopic compositions of clinopyroxenes and plagioclases have also been determined for some samples (Table 2).

### Plutonic-volcanic rocks

In a Nd-Sr isotope diagram (Fig. 7), the leached-whole rocks and clinopyroxenes from Type-1 to Type-5 rocks define a very large domain (0·51261 < $^{143}$Nd/$^{144}$Nd(i) < 0·51265).
<figure><img src="image_10.png" /><figcaption>**Fig. 6.** Harker variation diagrams for JPKK crustal section rocks. The Jijal 'hornblendites' (i.e. hornblendite-garnetite) and Jijal 'gabbroic rocks' (i.e. hornblende gabbronorites and garnet granulites) compositions are from Garrido *et al.* (2006) and Dhuime *et al.* (2007). The grey array of data points corresponds to the modern island arc lavas field (n = 7807, after http://georoc.mpch-mainz.gwdg.de/georoc/Entry.html). Squares including diamonds indicate average continental crust compositions after Taylor & McLennan (1985) (white diamond) and Rudnick & Fountain (1995) (black diamond). Calc-alkaline-tholeiitic transition is after Miyashiro (1974).</figcaption></figure>
<table><caption>Table 2: Isotope compositions for the JPKK crustal rocks</caption><thead><tr><th>Sample</th><th>Unit</th><th>Mineral</th><th><sup>87</sup>Rb/<br/><sup>86</sup>Sr</th><th><sup>87</sup>Sr/<br/><sup>86</sup>Sr</th><th><sup>87</sup>Sr/<br/><sup>86</sup>Sr<sub>(ii)</sub></th><th>εSr<sub>(ii)</sub></th><th><sup>147</sup>Sm/<br/><sup>144</sup>Nd</th><th><sup>143</sup>Nd/<br/><sup>144</sup>Nd</th><th><sup>143</sup>Nd/<br/><sup>144</sup>Nd<sub>(ii)</sub></th><th>εNd<sub>(ii)</sub></th><th><sup>206</sup>Pb/<br/><sup>204</sup>Pb</th><th><sup>207</sup>Pb/<br/><sup>204</sup>Pb</th><th><sup>208</sup>Pb/<br/><sup>204</sup>Pb</th><th><sup>206</sup>Pb/<br/><sup>204</sup>Pb<sub>(ii)</sub></th><th><sup>207</sup>Pb/<br/><sup>204</sup>Pb<sub>(ii)</sub></th><th><sup>208</sup>Pb/<br/><sup>204</sup>Pb<sub>(ii)</sub></th></tr></thead><tbody><tr><td colspan="18" style="text-align: left; font-weight: bold;">Geochemical suite 'A'</td></tr><tr><td colspan="18" style="text-align: left; font-weight: bold;">Type-1 trace element patterns</td></tr><tr><td>UM01-122</td><td>Kiru</td><td>WR</td><td>0.026</td><td>0.703211 ± 7</td><td>0.70317</td><td>-17.2</td><td>0.208</td><td>0.512984 ± 4</td><td>0.51285</td><td>6.6</td><td>18.0698 ± 8</td><td>15.5185 ± 8</td><td>38.1074 ± 18</td><td>18.028</td><td>15.516</td><td>38.081</td></tr><tr><td rowspan="3">KG-37</td><td rowspan="3">Kiru</td><td>WR</td><td>0.043</td><td>0.703173 ± 5</td><td>0.70311</td><td>-18.0</td><td>0.243</td><td>0.513164 ± 24</td><td>0.51301</td><td>9.6</td><td>18.1982 ± 27</td><td>15.5456 ± 24</td><td>38.2779 ± 67</td><td>18.140</td><td>15.543</td><td>38.258</td></tr><tr><td>Cpx</td><td>0.459</td><td>0.703694 ± 3</td><td>0.70304</td><td>-19.1</td><td>0.297</td><td>0.513094 ± 30</td><td>0.51290</td><td>7.6</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>PI</td><td>0.011</td><td>0.703132 ± 5</td><td>0.70312</td><td>-18.0</td><td>0.236</td><td>0.512997 ± 42</td><td>0.51284</td><td>6.5</td><td>18.1324 ± 22</td><td>15.5127 ± 19</td><td>38.1950 ± 49</td><td>18.131</td><td>15.513</td><td>38.194</td></tr><tr><td rowspan="2">KG-40</td><td rowspan="2">Kiru</td><td>WR</td><td>0.013</td><td>0.703140 ± 6</td><td>0.70312</td><td>-17.9</td><td>0.276</td><td>0.513092 ± 14</td><td>0.51291</td><td>7.8</td><td>18.1195 ± 17</td><td>15.5235 ± 16</td><td>38.1849 ± 35</td><td>18.097</td><td>15.522</td><td>38.175</td></tr><tr><td>PI</td><td>0.001</td><td>0.703117 ± 2</td><td>0.70312</td><td>-18.0</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>18.0866 ± 42</td><td>15.4923 ± 36</td><td>38.1221 ± 93</td><td>18.087</td><td>15.492</td><td>38.122</td></tr><tr><td colspan="18" style="text-align: left; font-weight: bold;">Type-2 trace element patterns</td></tr><tr><td>KG-59</td><td>Kamila</td><td>WR</td><td>0.006</td><td>0.703676 ± 3</td><td>0.70367</td><td>-10.2</td><td>0.185</td><td>0.512940 ± 5</td><td>0.51282</td><td>6.0</td><td>18.3130 ± 8</td><td>15.5511 ± 7</td><td>38.3763 ± 18</td><td>18.273</td><td>15.549</td><td>38.358</td></tr><tr><td rowspan="2">UM01-128</td><td rowspan="2">Kamila</td><td>WR</td><td>0.006</td><td>0.703627 ± 13</td><td>0.70362</td><td>-10.9</td><td>0.179</td><td>0.512973 ± 19</td><td>0.51286</td><td>6.7</td><td>18.2367 ± 6</td><td>15.5306 ± 6</td><td>38.2788 ± 16</td><td>18.224</td><td>15.530</td><td>38.268</td></tr><tr><td>PI</td><td>0.001</td><td>0.703610 ± 3</td><td>0.70361</td><td>-11.0</td><td>0.102</td><td>0.512929 ± 13</td><td>0.51286</td><td>6.8</td><td>18.1923 ± 5</td><td>15.5325 ± 5</td><td>38.2280 ± 16</td><td>18.192</td><td>15.532</td><td>38.228</td></tr><tr><td rowspan="2">KG-13a</td><td rowspan="2">Patan</td><td>WR</td><td>0.005</td><td>0.703730 ± 1</td><td>0.70372</td><td>-9.4</td><td>0.178</td><td>0.512890 ± 11</td><td>0.51277</td><td>5.1</td><td>18.3656 ± 4</td><td>15.5538 ± 4</td><td>38.4861 ± 14</td><td>18.342</td><td>15.553</td><td>38.466</td></tr><tr><td>PI</td><td>0.003</td><td>0.703729 ± 6</td><td>0.70373</td><td>-9.4</td><td>0.322</td><td>0.513103 ± 12</td><td>0.51289</td><td>7.4</td><td>18.3553 ± 8</td><td>15.5479 ± 8</td><td>38.4641 ± 25</td><td>18.355</td><td>15.548</td><td>38.464</td></tr><tr><td rowspan="2">KG-14</td><td rowspan="2">Patan</td><td>WR</td><td>0.005</td><td>0.703733 ± 5</td><td>0.70373</td><td>-9.3</td><td>0.182</td><td>0.512887 ± 7</td><td>0.51277</td><td>5.0</td><td>18.3286 ± 7</td><td>15.5456 ± 6</td><td>38.4423 ± 17</td><td>18.258</td><td>15.542</td><td>38.380</td></tr><tr><td>PI</td><td>0.001</td><td>0.703727 ± 9</td><td>0.70373</td><td>-9.4</td><td>0.093</td><td>0.512917 ± 62</td><td>0.51286</td><td>6.7</td><td>18.2994 ± 10</td><td>15.5382 ± 9</td><td>38.3974 ± 22</td><td>18.299</td><td>15.538</td><td>38.397</td></tr><tr><td colspan="18" style="text-align: left; font-weight: bold;">Type-3 trace element patterns</td></tr><tr><td>KG-30</td><td>Kiru</td><td>WR</td><td>0.018</td><td>0.703607 ± 6</td><td>0.70358</td><td>-11.4</td><td>0.134</td><td>0.512903 ± 8</td><td>0.51281</td><td>5.9</td><td>18.2996 ± 8</td><td>15.5510 ± 7</td><td>38.3361 ± 24</td><td>18.275</td><td>15.550</td><td>38.325</td></tr><tr><td rowspan="2">KG-31</td><td rowspan="2">Kiru</td><td>WR</td><td>0.024</td><td>0.703617 ± 3</td><td>0.70358</td><td>-11.4</td><td>0.133</td><td>0.512913 ± 5</td><td>0.51283</td><td>6.1</td><td>18.2746 ± 5</td><td>15.5350 ± 5</td><td>38.3433 ± 14</td><td>18.261</td><td>15.534</td><td>38.328</td></tr><tr><td>PI</td><td>0.030</td><td>0.703606 ± 2</td><td>0.70356</td><td>-11.6</td><td>0.102</td><td>0.513023 ± 11</td><td>0.51296</td><td>8.7</td><td>18.2526 ± 10</td><td>15.5265 ± 8</td><td>38.3083 ± 24</td><td>18.252</td><td>15.526</td><td>38.308</td></tr><tr><td colspan="18" style="text-align: left; font-weight: bold;">Type-4 trace element patterns</td></tr><tr><td>KG-45</td><td>Kamila</td><td>WR</td><td>0.075</td><td>0.703727 ± 6</td><td>0.70362</td><td>-10.8</td><td>0.139</td><td>0.512871 ± 7</td><td>0.51278</td><td>5.2</td><td>18.3911 ± 6</td><td>15.5470 ± 3</td><td>38.5107 ± 11</td><td>18.336</td><td>15.544</td><td>38.455</td></tr><tr><td>KG-47</td><td>Kamila</td><td>WR</td><td>0.202</td><td>0.703830 ± 8</td><td>0.70354</td><td>-12.0</td><td>0.156</td><td>0.512853 ± 4</td><td>0.51275</td><td>4.7</td><td>18.3593 ± 5</td><td>15.5527 ± 5</td><td>38.5179 ± 13</td><td>18.240</td><td>15.547</td><td>38.334</td></tr><tr><td rowspan="2">KG-51</td><td rowspan="2">Kamila</td><td>WR</td><td>0.283</td><td>0.703968 ± 3</td><td>0.70357</td><td>-11.6</td><td>0.144</td><td>0.512923 ± 9</td><td>0.51283</td><td>6.2</td><td>18.6839 ± 9</td><td>15.5717 ± 8</td><td>38.8825 ± 21</td><td>18.398</td><td>15.558</td><td>38.517</td></tr><tr><td>PI</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>18.5005 ± 44</td><td>15.5513 ± 36</td><td>38.5045 ± 92</td><td>18.389</td><td>15.546</td><td>38.485</td></tr><tr><td colspan="18" style="text-align: left; font-weight: bold;">Type-5 trace element patterns</td></tr><tr><td>KG-52</td><td>Kamila</td><td>WR</td><td>0.181</td><td>0.704070 ± 7</td><td>0.70381</td><td>-8.1</td><td>0.096</td><td>0.512793 ± 3</td><td>0.51273</td><td>4.3</td><td>18.8707 ± 8</td><td>15.5740 ± 8</td><td>39.4558 ± 23</td><td>18.634</td><td>15.563</td><td>38.773</td></tr><tr><td>KG-55</td><td>Kamila</td><td>WR</td><td>0.211</td><td>0.704125 ± 8</td><td>0.70382</td><td>-7.9</td><td>0.107</td><td>0.512809 ± 5</td><td>0.51274</td><td>4.4</td><td>19.0924 ± 4</td><td>15.5917 ± 4</td><td>39.5890 ± 13</td><td>18.638</td><td>15.570</td><td>38.884</td></tr><tr><td>KG-56</td><td>Kamila</td><td>WR</td><td>0.131</td><td>0.703954 ± 3</td><td>0.70377</td><td>-8.8</td><td>0.095</td><td>0.512805 ± 6</td><td>0.51274</td><td>4.5</td><td>18.9767 ± 5</td><td>15.5939 ± 4</td><td>39.6994 ± 13</td><td>18.630</td><td>15.577</td><td>38.795</td></tr><tr><td colspan="18" style="text-align: left; font-weight: bold;">Jijal hornblendite-garnetite lenses (Dhuime et al., 2007)</td></tr><tr><td>KH04-06*</td><td>Jijal</td><td>WR</td><td>0.014</td><td>0.703664 ± 2</td><td>0.70364</td><td>-10.5</td><td>0.260</td><td>0.512987 ± 6</td><td>0.51282</td><td>6.0</td><td>18.4444 ± 7</td><td>15.5861 ± 6</td><td>38.5832 ± 17</td><td>18.442</td><td>15.586</td><td>38.581</td></tr><tr><td>KH04-07*</td><td>Jijal</td><td>WR</td><td>0.011</td><td>0.703753 ± 2</td><td>0.70374</td><td>-9.2</td><td>0.394</td><td>0.513078 ± 8</td><td>0.51282</td><td>6.0</td><td>18.4664 ± 35</td><td>15.5842 ± 31</td><td>38.5695 ± 78</td><td>18.452</td><td>15.584</td><td>38.564</td></tr><tr><td>KH04-19*</td><td>Jijal</td><td>WR</td><td>0.005</td><td>0.703759 ± 2</td><td>0.70375</td><td>-9.0</td><td>0.466</td><td>0.513067 ± 8</td><td>0.51276</td><td>4.9</td><td>18.4321 ± 17</td><td>15.5744 ± 16</td><td>38.5550 ± 40</td><td>18.399</td><td>15.573</td><td>38.547</td></tr><tr><td>KH04-21*</td><td>Jijal</td><td>WR</td><td>0.009</td><td>0.703713 ± 2</td><td>0.70370</td><td>-9.7</td><td>0.242</td><td>0.512968 ± 6</td><td>0.51281</td><td>5.8</td><td>18.3772 ± 7</td><td>15.5638 ± 6</td><td>38.4886 ± 23</td><td>18.370</td><td>15.563</td><td>38.483</td></tr><tr><td rowspan="2">KH97-104*</td><td rowspan="2">Jijal</td><td>WR</td><td>0.023</td><td>0.703603 ± 3</td><td>0.70357</td><td>-11.6</td><td>0.246</td><td>0.512969 ± 16</td><td>0.51281</td><td>5.8</td><td>18.3327 ± 6</td><td>15.5430 ± 6</td><td>38.4251 ± 16</td><td>18.319</td><td>15.542</td><td>38.417</td></tr><tr><td>Hbl</td><td>0.025</td><td>0.703590 ± 3</td><td>0.70355</td><td>-11.8</td><td>0.247</td><td>0.512974 ± 9</td><td>0.51281</td><td>5.9</td><td>18.3467 ± 7</td><td>15.5410 ± 6</td><td>38.4446 ± 16</td><td>18.341</td><td>15.541</td><td>38.441</td></tr><tr><td rowspan="2">KH97-107*</td><td rowspan="2">Jijal</td><td>WR</td><td>0.009</td><td>0.703772 ± 2</td><td>0.70376</td><td>-8.9</td><td>0.230</td><td>0.512924 ± 18</td><td>0.51277</td><td>5.1</td><td>18.4126 ± 7</td><td>15.5776 ± 7</td><td>38.5405 ± 20</td><td>18.404</td><td>15.577</td><td>38.535</td></tr><tr><td>Hbl</td><td>0.012</td><td>0.703776 ± 2</td><td>0.70376</td><td>-8.9</td><td>0.234</td><td>0.512941 ± 15</td><td>0.51279</td><td>5.4</td><td>18.4774 ± 6</td><td>15.5811 ± 7</td><td>38.6292 ± 16</td><td>18.474</td><td>15.581</td><td>38.626</td></tr></tbody></table>

(continued)
<table><caption>Table 2: Continued</caption><thead><tr><th>Sample</th><th>Unit</th><th>Group</th><th>Mineral</th><th><sup>87</sup>Rb/<br><sup>86</sup>Sr</th><th><sup>87</sup>Sr/<br><sup>86</sup>Sr</th><th><sup>87</sup>Sr/<br><sup>86</sup>Sr<sub>(ii)</sub></th><th>εSr<sub>(ii)</sub></th><th><sup>147</sup>Sm/<br><sup>144</sup>Nd</th><th><sup>143</sup>Nd/<br><sup>144</sup>Nd<sub>(ii)</sub></th><th>εNd<sub>(ii)</sub></th><th><sup>206</sup>Pb/<br><sup>204</sup>Pb</th><th><sup>207</sup>Pb/<br><sup>204</sup>Pb</th><th><sup>208</sup>Pb/<br><sup>204</sup>Pb</th><th><sup>206</sup>Pb/<br><sup>204</sup>Pb<sub>(ii)</sub></th><th><sup>207</sup>Pb/<br><sup>204</sup>Pb<sub>(ii)</sub></th><th><sup>208</sup>Pb/<br><sup>204</sup>Pb<sub>(ii)</sub></th></tr></thead><tbody><tr><td colspan="18" style="text-align: left; font-weight: bold;">Geochemical suite 'B'</td></tr><tr><td colspan="18" style="text-align: left;">(Type-3 trace element patterns only)</td></tr><tr><td colspan="18" style="text-align: left;">Jijal gabbroic rocks (Dhuime et al., 2007)</td></tr><tr><td rowspan="2">KH97-102*</td><td rowspan="2">Jijal</td><td rowspan="2">B1</td><td>WR</td><td>0.002</td><td>0.704016 ± 3</td><td>0.70401</td><td>-5.3</td><td>0.195</td><td>0.512932 ± 15</td><td>0.51280</td><td>5.7</td><td>18.5735 ± 24</td><td>15.5870 ± 19</td><td>38.7628 ± 53</td><td>18.565</td><td>15.587</td><td>38.760</td></tr><tr><td>PI</td><td>0.010</td><td>0.704035 ± 2</td><td>0.70402</td><td>-5.2</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>KH04-23*</td><td>Jijal</td><td>B1</td><td>WR</td><td>0.001</td><td>0.703995 ± 4</td><td>0.70399</td><td>-5.5</td><td>0.187</td><td>0.512932 ± 3</td><td>0.51281</td><td>5.8</td><td>18.5398 ± 5</td><td>15.5839 ± 5</td><td>38.7144 ± 15</td><td>18.533</td><td>15.584</td><td>38.714</td></tr><tr><td>KH04-17*</td><td>Jijal</td><td>B1</td><td>WR</td><td>0.012</td><td>0.703991 ± 3</td><td>0.70397</td><td>-5.8</td><td>0.177</td><td>0.512962 ± 11</td><td>0.51285</td><td>6.5</td><td>18.5349 ± 5</td><td>15.5812 ± 6</td><td>38.7067 ± 14</td><td>18.516</td><td>15.580</td><td>38.691</td></tr><tr><td>KH97-110*</td><td>Jijal</td><td>B1</td><td>WR</td><td>0.002</td><td>0.703942 ± 2</td><td>0.70394</td><td>-6.3</td><td>0.216</td><td>0.512933 ± 29</td><td>0.51279</td><td>5.5</td><td>18.5144 ± 8</td><td>15.5761 ± 7</td><td>38.6761 ± 18</td><td>18.507</td><td>15.576</td><td>38.672</td></tr><tr><td rowspan="3">KH97-111*</td><td rowspan="3">Jijal</td><td rowspan="3">B1</td><td>WR</td><td>0.001</td><td>0.703925 ± 10</td><td>0.70392</td><td>-6.5</td><td>0.218</td><td>0.512929 ± 14</td><td>0.51279</td><td>5.4</td><td>18.5190 ± 11</td><td>15.5843 ± 10</td><td>38.6967 ± 27</td><td>18.515</td><td>15.584</td><td>38.695</td></tr><tr><td>Cpx</td><td>0.004</td><td>0.703937 ± 3</td><td>0.70393</td><td>-6.4</td><td>0.143</td><td>0.512895 ± 5</td><td>0.51280</td><td>5.7</td><td>18.4957 ± 32</td><td>15.5746 ± 16</td><td>38.6604 ± 53</td><td>18.487</td><td>15.574</td><td>38.656</td></tr><tr><td>PI</td><td>0.000</td><td>0.703938 ± 3</td><td>0.70394</td><td>-6.3</td><td>0.058</td><td>0.512872 ± 9</td><td>0.51283</td><td>6.3</td><td>18.5207 ± 9</td><td>15.5802 ± 8</td><td>38.6899 ± 25</td><td>18.521</td><td>15.580</td><td>38.690</td></tr><tr><td rowspan="3">KG-03-A*</td><td rowspan="3">Jijal</td><td rowspan="3">B1</td><td>WR</td><td>0.007</td><td>0.703953 ± 10</td><td>0.70394</td><td>-6.3</td><td>0.185</td><td>0.512962 ± 21</td><td>0.51284</td><td>6.4</td><td>18.5323 ± 9</td><td>15.5829 ± 9</td><td>38.7036 ± 25</td><td>18.518</td><td>15.582</td><td>38.692</td></tr><tr><td>WR</td><td>0.007</td><td>0.703938 ± 4</td><td>0.70393</td><td>-6.5</td><td>0.177</td><td>0.512897 ± 13</td><td>0.51278</td><td>5.3</td><td>18.5299 ± 6</td><td>15.5830 ± 8</td><td>38.7108 ± 22</td><td>18.513</td><td>15.582</td><td>38.697</td></tr><tr><td>Cpx</td><td>0.021</td><td>0.703958 ± 6</td><td>0.70393</td><td>-6.5</td><td>0.125</td><td>0.512949 ± 14</td><td>0.51287</td><td>6.9</td><td>18.5273 ± 16</td><td>15.5781 ± 12</td><td>38.7493 ± 33</td><td>18.518</td><td>15.578</td><td>38.675</td></tr><tr><td rowspan="2">KH97-114*</td><td rowspan="2">Jijal</td><td rowspan="2">B1</td><td>WR</td><td>0.003</td><td>0.703937 ± 5</td><td>0.70393</td><td>-6.4</td><td>0.046</td><td>0.512863 ± 10</td><td>0.51283</td><td>6.3</td><td>18.5330 ± 7</td><td>15.5819 ± 9</td><td>38.7085 ± 24</td><td>18.533</td><td>15.582</td><td>38.708</td></tr><tr><td>PI</td><td>0.012</td><td>0.703926 ± 2</td><td>0.70391</td><td>-6.7</td><td>0.188</td><td>0.512948 ± 8</td><td>0.51282</td><td>6.1</td><td>18.5446 ± 6</td><td>15.5832 ± 6</td><td>38.7090 ± 15</td><td>18.515</td><td>15.582</td><td>38.682</td></tr><tr><td rowspan="3">BKI-158-B*</td><td rowspan="3">Jijal</td><td rowspan="3">B1</td><td>WR</td><td>0.071</td><td>0.703944 ± 7</td><td>0.70384</td><td>-7.7</td><td>0.135</td><td>0.512914 ± 4</td><td>0.51283</td><td>6.1</td><td>18.5505 ± 13</td><td>15.5752 ± 10</td><td>38.8200 ± 30</td><td>18.520</td><td>15.574</td><td>38.697</td></tr><tr><td>Cpx</td><td>0.005</td><td>0.703909 ± 15</td><td>0.70390</td><td>-6.8</td><td>0.051</td><td>0.512795 ± 15</td><td>0.51276</td><td>4.9</td><td>18.5259 ± 9</td><td>15.5791 ± 7</td><td>38.6921 ± 24</td><td>18.526</td><td>15.579</td><td>38.692</td></tr><tr><td>PI</td><td>0.010</td><td>0.703958 ± 18</td><td>0.70394</td><td>-6.3</td><td>0.176</td><td>0.512942 ± 14</td><td>0.51283</td><td>6.2</td><td>18.5236 ± 3</td><td>15.5861 ± 5</td><td>38.6805 ± 16</td><td>18.516</td><td>15.586</td><td>38.674</td></tr><tr><td rowspan="3">KG-03-B*</td><td rowspan="3">Jijal</td><td rowspan="3">B1</td><td>WR</td><td>0.016</td><td>0.703969 ± 5</td><td>0.70395</td><td>-6.2</td><td>0.178</td><td>0.512925 ± 8</td><td>0.51281</td><td>5.8</td><td>18.5281 ± 4</td><td>15.5763 ± 5</td><td>38.6853 ± 14</td><td>18.501</td><td>15.575</td><td>38.661</td></tr><tr><td>Cpx</td><td>0.002</td><td>0.704256 ± 3</td><td>0.70425</td><td>-1.9</td><td>0.144</td><td>0.512935 ± 4</td><td>0.51284</td><td>6.4</td><td>18.5800 ± 5</td><td>15.5828 ± 4</td><td>38.7711 ± 12</td><td>18.564</td><td>15.582</td><td>38.764</td></tr><tr><td>PI</td><td>0.001</td><td>0.703937 ± 4</td><td>0.70394</td><td>-6.4</td><td>0.068</td><td>0.512795 ± 22</td><td>0.51275</td><td>4.7</td><td>18.5312 ± 10</td><td>15.5806 ± 8</td><td>38.7077 ± 29</td><td>18.531</td><td>15.581</td><td>38.708</td></tr><tr><td rowspan="3">KH97-113*</td><td rowspan="3">Jijal</td><td rowspan="3">B1</td><td>WR</td><td>0.048</td><td>0.703971 ± 3</td><td>0.70390</td><td>-6.8</td><td>0.217</td><td>0.512925 ± 5</td><td>0.51278</td><td>5.3</td><td>18.6269 ± 8</td><td>15.5873 ± 6</td><td>38.8318 ± 17</td><td>18.553</td><td>15.584</td><td>38.727</td></tr><tr><td>Cpx</td><td>0.001</td><td>0.703908 ± 5</td><td>0.70391</td><td>-6.8</td><td>0.071</td><td>0.512840 ± 9</td><td>0.51279</td><td>5.5</td><td>18.5300 ± 10</td><td>15.5776 ± 7</td><td>38.6933 ± 24</td><td>18.529</td><td>15.578</td><td>38.693</td></tr><tr><td>PI</td><td>0.013</td><td>0.703933 ± 5</td><td>0.70391</td><td>-6.7</td><td>0.096</td><td>0.512851 ± 10</td><td>0.51279</td><td>5.4</td><td>18.5059 ± 7</td><td>15.5845 ± 7</td><td>38.6646 ± 23</td><td>18.505</td><td>15.584</td><td>38.664</td></tr><tr><td rowspan="2">BKI-158-A*</td><td rowspan="2">Jijal</td><td rowspan="2">B1</td><td>WR</td><td>0.027</td><td>0.703939 ± 9</td><td>0.70390</td><td>-6.9</td><td>0.163</td><td>0.512868 ± 7</td><td>0.51276</td><td>4.9</td><td>18.5233 ± 4</td><td>15.5887 ± 4</td><td>38.6998 ± 11</td><td>18.503</td><td>15.588</td><td>38.678</td></tr><tr><td>PI</td><td>0.004</td><td>0.703929 ± 2</td><td>0.70392</td><td>-6.5</td><td>0.095</td><td>0.512814 ± 11</td><td>0.51275</td><td>4.7</td><td>18.4990 ± 6</td><td>15.5848 ± 6</td><td>38.6612 ± 18</td><td>18.499</td><td>15.585</td><td>38.661</td></tr><tr><td colspan="18" style="text-align: left;">Patan-Kiru-Kamila section</td></tr><tr><td>KH97-116</td><td>Patan</td><td>B1</td><td>PI</td><td>0.013</td><td>0.703933 ± 5</td><td>0.70391</td><td>-6.7</td><td>0.096</td><td>0.512851 ± 10</td><td>0.51279</td><td>5.4</td><td>18.5059 ± 7</td><td>15.5845 ± 7</td><td>38.6646 ± 23</td><td>18.505</td><td>15.584</td><td>38.664</td></tr><tr><td>KG-07</td><td>Patan</td><td>B1</td><td>WR</td><td>0.027</td><td>0.703939 ± 9</td><td>0.70390</td><td>-6.9</td><td>0.163</td><td>0.512868 ± 7</td><td>0.51276</td><td>4.9</td><td>18.5233 ± 4</td><td>15.5887 ± 4</td><td>38.6998 ± 11</td><td>18.503</td><td>15.588</td><td>38.678</td></tr><tr><td>KH97-117</td><td>Patan</td><td>B1</td><td>PI</td><td>0.004</td><td>0.703929 ± 2</td><td>0.70392</td><td>-6.5</td><td>0.095</td><td>0.512814 ± 11</td><td>0.51275</td><td>4.7</td><td>18.4990 ± 6</td><td>15.5848 ± 6</td><td>38.6612 ± 18</td><td>18.499</td><td>15.585</td><td>38.661</td></tr></tbody></table>

(continued)
<table><caption>Table 2: Continued</caption><thead><tr><th>Sample</th><th>Unit</th><th>Group</th><th>Mineral</th><th><sup>87</sup>Rb/<br/><sup>86</sup>Sr</th><th><sup>87</sup>Sr/<br/><sup>86</sup>Sr</th><th><sup>87</sup>Sr/<br/><sup>86</sup>Sr<sub>(ii)</sub></th><th>εSr<sub>(ii)</sub></th><th><sup>147</sup>Sm/<br/><sup>144</sup>Nd</th><th><sup>143</sup>Nd/<br/><sup>144</sup>Nd</th><th><sup>143</sup>Nd/<br/><sup>144</sup>Nd<sub>(ii)</sub></th><th>εNd<sub>(ii)</sub></th><th><sup>206</sup>Pb/<br/><sup>204</sup>Pb</th><th><sup>207</sup>Pb/<br/><sup>204</sup>Pb</th><th><sup>208</sup>Pb/<br/><sup>204</sup>Pb</th><th><sup>206</sup>Pb/<br/><sup>204</sup>Pb<sub>(ii)</sub></th><th><sup>207</sup>Pb/<br/><sup>204</sup>Pb<sub>(ii)</sub></th><th><sup>208</sup>Pb/<br/><sup>204</sup>Pb<sub>(ii)</sub></th></tr></thead><tbody><tr><td rowspan="2">KG-11</td><td rowspan="2">Patan</td><td rowspan="2">B1</td><td>WR</td><td>0.011</td><td>0.703933 ± 3</td><td>0.70392</td><td>-6.6</td><td>0.177</td><td>0.512876 ± 5</td><td>0.51276</td><td>4.9</td><td>18.5484 ± 5</td><td>15.5878 ± 5</td><td>38.7064 ± 13</td><td>18.495</td><td>15.585</td><td>38.674</td></tr><tr><td>PI</td><td>0.006</td><td>0.703918 ± 8</td><td>0.70391</td><td>-6.7</td><td>—</td><td>—</td><td>—</td><td>—</td><td>18.5120 ± 10</td><td>15.5851 ± 9</td><td>38.6685 ± 24</td><td>18.512</td><td>15.585</td><td>38.668</td></tr><tr><td>KH97-118</td><td>Patan</td><td>B1</td><td>WR</td><td>0.031</td><td>0.703963 ± 9</td><td>0.70392</td><td>-6.6</td><td>0.165</td><td>0.512862 ± 11</td><td>0.51275</td><td>4.7</td><td>18.5423 ± 6</td><td>15.5808 ± 6</td><td>38.6916 ± 18</td><td>18.497</td><td>15.579</td><td>38.645</td></tr><tr><td rowspan="2">KG-119</td><td rowspan="2">Patan</td><td rowspan="2">B1</td><td>Cpx</td><td>0.036</td><td>0.703978 ± 5</td><td>0.70393</td><td>-6.5</td><td>0.166</td><td>0.512853 ± 22</td><td>0.51274</td><td>4.5</td><td>18.5673 ± 28</td><td>15.5709 ± 22</td><td>38.7619 ± 67</td><td>18.528</td><td>15.569</td><td>38.714</td></tr><tr><td>PI</td><td>0.017</td><td>0.703899 ± 2</td><td>0.70387</td><td>-7.2</td><td>0.071</td><td>0.512814 ± 9</td><td>0.51277</td><td>5.0</td><td>18.5212 ± 7</td><td>15.5842 ± 8</td><td>38.6834 ± 25</td><td>18.520</td><td>15.584</td><td>38.681</td></tr><tr><td>KG-17</td><td>Patan</td><td>B1</td><td>PI</td><td>0.006</td><td>0.703961 ± 7</td><td>0.70395</td><td>-6.1</td><td>—</td><td>—</td><td>—</td><td>—</td><td>18.5411 ± 7</td><td>15.6016 ± 7</td><td>38.6562 ± 18</td><td>18.527</td><td>15.601</td><td>38.642</td></tr><tr><td rowspan="2">KG-18</td><td rowspan="2">Patan</td><td rowspan="2">B2</td><td>WR</td><td>0.006</td><td>0.703976 ± 3</td><td>0.70397</td><td>-5.9</td><td>0.154</td><td>0.512831 ± 8</td><td>0.51273</td><td>4.3</td><td>18.5529 ± 7</td><td>15.6098 ± 6</td><td>38.6813 ± 16</td><td>18.541</td><td>15.609</td><td>38.671</td></tr><tr><td>PI</td><td>0.000</td><td>0.703976 ± 4</td><td>0.70398</td><td>-5.8</td><td>0.055</td><td>0.512923 ± 20</td><td>0.51289</td><td>7.3</td><td>18.5481 ± 6</td><td>15.6066 ± 5</td><td>38.6643 ± 15</td><td>18.548</td><td>15.607</td><td>38.664</td></tr><tr><td rowspan="2">KG-26</td><td rowspan="2">Patan</td><td rowspan="2">B2</td><td>WR</td><td>0.008</td><td>0.703988 ± 3</td><td>0.70398</td><td>-5.8</td><td>0.150</td><td>0.512810 ± 5</td><td>0.51271</td><td>3.9</td><td>18.6037 ± 9</td><td>15.6085 ± 9</td><td>38.7327 ± 22</td><td>18.521</td><td>15.604</td><td>38.665</td></tr><tr><td>PI</td><td>0.072</td><td>0.703920 ± 4</td><td>0.70382</td><td>-8.1</td><td>—</td><td>—</td><td>—</td><td>—</td><td>18.5121 ± 6</td><td>15.5853 ± 5</td><td>38.6632 ± 18</td><td>18.512</td><td>15.585</td><td>38.663</td></tr><tr><td rowspan="3">UM01-133</td><td rowspan="3">Kamila</td><td rowspan="3">B3</td><td>WR</td><td>0.016</td><td>0.703806 ± 2</td><td>0.70378</td><td>-8.5</td><td>0.147</td><td>0.512789 ± 7</td><td>0.51269</td><td>3.5</td><td>18.5042 ± 7</td><td>15.6173 ± 8</td><td>38.6839 ± 24</td><td>18.487</td><td>15.617</td><td>38.661</td></tr><tr><td>Cpx</td><td>0.136</td><td>0.703920 ± 3</td><td>0.70373</td><td>-9.3</td><td>0.174</td><td>0.512761 ± 9</td><td>0.51265</td><td>2.7</td><td>18.5280 ± 7</td><td>15.6195 ± 5</td><td>38.7473 ± 14</td><td>18.490</td><td>15.618</td><td>38.674</td></tr><tr><td>PI</td><td>0.003</td><td>0.703788 ± 2</td><td>0.70378</td><td>-8.5</td><td>0.062</td><td>0.512672 ± 11</td><td>0.51263</td><td>2.3</td><td>18.5054 ± 9</td><td>15.6213 ± 11</td><td>38.6890 ± 28</td><td>18.505</td><td>15.621</td><td>38.689</td></tr><tr><td rowspan="2">UM01-134</td><td rowspan="2">Kamila</td><td rowspan="2">B3</td><td>WR</td><td>0.014</td><td>0.704172 ± 2</td><td>0.70415</td><td>-3.3</td><td>0.144</td><td>0.512701 ± 2</td><td>0.51261</td><td>1.9</td><td>18.5329 ± 4</td><td>15.6336 ± 4</td><td>38.7585 ± 12</td><td>18.528</td><td>15.633</td><td>38.755</td></tr><tr><td>PI</td><td>0.009</td><td>0.704162 ± 3</td><td>0.70415</td><td>-3.3</td><td>0.075</td><td>0.512724 ± 16</td><td>0.51267</td><td>3.2</td><td>18.5348 ± 5</td><td>15.6309 ± 5</td><td>38.7509 ± 16</td><td>18.535</td><td>15.631</td><td>38.751</td></tr><tr><td rowspan="2">UM01-135</td><td rowspan="2">Kamila</td><td rowspan="2">B3</td><td>WR</td><td>0.010</td><td>0.704041 ± 2</td><td>0.70403</td><td>-5.1</td><td>0.158</td><td>0.512783 ± 7</td><td>0.51268</td><td>3.3</td><td>18.5023 ± 5</td><td>15.6220 ± 5</td><td>38.7001 ± 14</td><td>18.498</td><td>15.622</td><td>38.696</td></tr><tr><td>PI</td><td>0.005</td><td>0.704038 ± 2</td><td>0.70403</td><td>-5.0</td><td>0.082</td><td>0.512762 ± 10</td><td>0.51271</td><td>3.8</td><td>18.5095 ± 6</td><td>15.6237 ± 6</td><td>38.7151 ± 21</td><td>18.510</td><td>15.624</td><td>38.715</td></tr><tr><td colspan="17">Intrusive granites</td></tr><tr><td rowspan="2">KG-32</td><td rowspan="2">Kiru</td><td rowspan="2">tonalites</td><td>WR</td><td>0.037</td><td>0.703467 ± 3</td><td>0.70342</td><td>-13.8</td><td>0.126</td><td>0.512973 ± 12</td><td>0.51289</td><td>7.4</td><td>18.3052 ± 7</td><td>15.5431 ± 8</td><td>38.4528 ± 30</td><td>18.220</td><td>15.539</td><td>38.334</td></tr><tr><td>PI</td><td>0.011</td><td>0.703440 ± 5</td><td>0.70342</td><td>-13.6</td><td>0.104</td><td>0.512971 ± 17</td><td>0.51290</td><td>7.6</td><td>18.2548 ± 12</td><td>15.5300 ± 11</td><td>38.3494 ± 28</td><td>18.237</td><td>15.529</td><td>38.305</td></tr><tr><td rowspan="2">UM01-124</td><td rowspan="2">Kiru</td><td rowspan="2">tonalites</td><td>WR</td><td>0.251</td><td>0.704070 ± 7</td><td>0.70371</td><td>-9.5</td><td>0.122</td><td>0.512844 ± 13</td><td>0.51276</td><td>4.9</td><td>18.6553 ± 6</td><td>15.5791 ± 8</td><td>38.9798 ± 23</td><td>18.519</td><td>15.572</td><td>38.758</td></tr><tr><td>PI</td><td>0.201</td><td>0.704013 ± 3</td><td>0.70373</td><td>-9.3</td><td>0.202</td><td>0.513459 ± 13</td><td>0.51333</td><td>15.9</td><td>18.4901 ± 5</td><td>15.5687 ± 6</td><td>38.6670 ± 18</td><td>18.487</td><td>15.569</td><td>38.666</td></tr><tr><td rowspan="2">KG-50</td><td rowspan="2">Kamila</td><td rowspan="2">tonalites</td><td>WR</td><td>0.383</td><td>0.704045 ± 4</td><td>0.70350</td><td>-12.6</td><td>0.090</td><td>0.512851 ± 7</td><td>0.51279</td><td>5.5</td><td>18.4857 ± 8</td><td>15.5666 ± 8</td><td>38.7705 ± 26</td><td>18.366</td><td>15.561</td><td>38.510</td></tr><tr><td>PI</td><td>0.549</td><td>0.704117 ± 6</td><td>0.70334</td><td>-14.9</td><td>—</td><td>—</td><td>—</td><td>—</td><td>18.4207 ± 26</td><td>15.5571 ± 24</td><td>38.5697 ± 62</td><td>18.412</td><td>15.557</td><td>38.566</td></tr><tr><td rowspan="2">UM01-125</td><td rowspan="2">Kamila</td><td rowspan="2">tonalites</td><td>WR</td><td>0.387</td><td>0.704097 ± 7</td><td>0.70355</td><td>-11.9</td><td>0.072</td><td>0.512844 ± 12</td><td>0.51280</td><td>5.6</td><td>18.7555 ± 5</td><td>15.5813 ± 5</td><td>39.9073 ± 18</td><td>18.603</td><td>15.574</td><td>38.998</td></tr><tr><td>PI</td><td>0.359</td><td>0.704025 ± 2</td><td>0.70352</td><td>-12.3</td><td>0.125</td><td>0.512860 ± 24</td><td>0.51278</td><td>5.2</td><td>18.5868 ± 18</td><td>15.5709 ± 14</td><td>38.9269 ± 40</td><td>18.571</td><td>15.570</td><td>38.923</td></tr><tr><td rowspan="2">KG-42</td><td rowspan="2">Kiru</td><td rowspan="2">granodiorites</td><td>WR</td><td>0.707</td><td>0.704806 ± 7</td><td>0.70380</td><td>-8.3</td><td>0.129</td><td>0.512948 ± 21</td><td>0.51286</td><td>6.9</td><td>18.3914 ± 5</td><td>15.5650 ± 6</td><td>38.4811 ± 15</td><td>18.356</td><td>15.563</td><td>38.439</td></tr><tr><td>PI</td><td>1.196</td><td>0.705672 ± 9</td><td>0.70397</td><td>-5.8</td><td>0.143</td><td>0.512976 ± 6</td><td>0.51288</td><td>7.3</td><td>18.3781 ± 5</td><td>15.5545 ± 5</td><td>38.5478 ± 15</td><td>18.349</td><td>15.553</td><td>38.504</td></tr><tr><td rowspan="2">UM01-123</td><td rowspan="2">Kiru</td><td rowspan="2">granodiorites</td><td>WR</td><td>0.266</td><td>0.704238 ± 3</td><td>0.70386</td><td>-7.4</td><td>0.137</td><td>0.512922 ± 6</td><td>0.51283</td><td>6.3</td><td>18.3560 ± 8</td><td>15.5544 ± 7</td><td>38.4954 ± 24</td><td>18.327</td><td>15.553</td><td>38.486</td></tr><tr><td>PI</td><td>0.266</td><td>0.704238 ± 3</td><td>0.70386</td><td>-7.4</td><td>0.137</td><td>0.512922 ± 6</td><td>0.51283</td><td>6.3</td><td>18.3560 ± 8</td><td>15.5544 ± 7</td><td>38.4954 ± 24</td><td>18.327</td><td>15.553</td><td>38.486</td></tr></tbody></table>

<footnote>*Sample names from Dhuime *et al.* (2007). Abbreviations are given in Table 1. WR, whole-rock; Cpx, clinopyroxene; PI, plagioclase; Hbl, hornblende. —, not analyzed. The initial ratios were calculated at t₀ = 100 Ma according to Schaltegger *et al.* (2002). The εSr(i) and εNd(i) values were calculated using (⁸⁷Sr/⁸⁶Sr)CHUR(100 Ma) = 0.704384 and (¹⁴³Nd/¹⁴⁴Nd)CHUR(100Ma) = 0.512511, respectively. Errors for the Sr, Nd and Pb isotopic ratios are given at the 2σ level and refer to the last significant digits.</footnote>
<figure><img src="image_11.png" /><figcaption>**Fig. 7.** Nd–Sr isotope diagram for the JPKK crustal section (initial compositions recalculated at t₀=100 Ma). Only whole-rock and clinopyroxene data (where available) are plotted. The Jijal crustal section fields of ‘hornblendites’ (i.e. hornblendite-garnetite) and ‘gabbroic rocks’ (i.e. hornblende gabbronorites and garnet granulites) are from Dhuime *et al.* (2007). The classification of plutonic–volcanic rocks (Types 1–5) and intrusive granites is determined based on their trace element compositions (see explanation in the text and Fig. 4).</figcaption></figure>

<0.51301; 0.70304 < <sup>87</sup>Sr/<sup>86</sup>Sr<sub>(i)</sub> < 0.70430) that broadly encompasses the Jijal crustal section (0.51276 < <sup>143</sup>Nd/<sup>144</sup>Nd<sub>(i)</sub>) < 0.51287; 0.70355 < <sup>87</sup>Sr/<sup>86</sup>Sr<sub>(i)</sub>) < 0.70401) (Table 2). Type-1 rocks define a distinct field with depleted Nd and Sr isotopic compositions (0.51285 < <sup>143</sup>Nd/<sup>144</sup>Nd<sub>(i)</sub>) < 0.51301; 0.70304 < <sup>87</sup>Sr/<sup>86</sup>Sr<sub>(i)</sub>) < 0.70317). Types-2, -4 and -5 together define a limited field (0.51274 < <sup>143</sup>Nd/<sup>144</sup>Nd<sub>(i)</sub>) < 0.51286; 0.70357 < <sup>87</sup>Sr/<sup>86</sup>Sr<sub>(i)</sub>) < 0.70377) that is isotopically enriched relative to the Type-1 rocks. Type-3 samples plot in a wide Nd–Sr isotopic domain (0.51261 < <sup>143</sup>Nd/<sup>144</sup>Nd<sub>(i)</sub>) < 0.51283; 0.70357 < <sup>87</sup>Sr/<sup>86</sup>Sr<sub>(i)</sub>) < 0.70415) that partly overlaps the field of the Type-2, -4 and -5 rocks. Two groups are distinguished: (1) a small group which is overlapped by the fields of the Type-4 samples and the Jijal hornblendites; (2) samples that have enriched Nd and Sr isotopic compositions (see Fig. 7).

In Pb–Pb isotope diagrams (Fig. 8) the leached-whole rocks and plagioclase separates from Type-1 to Type-5 rocks define a large domain (18.028 < <sup>206</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) < 18.638) that encompasses the Jijal crustal section field (18.319 < <sup>206</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) < 18.565). In the <sup>208</sup>Pb/<sup>204</sup>Pb vs <sup>206</sup>Pb/<sup>204</sup>Pb diagram (Fig. 8a), all of the samples plot along a straight line, above and roughly parallel to the Northern Hemisphere Reference Line (NHRL). An increase of the Pb isotopic ratios is observed from the Type-1 samples (18.028 < <sup>206</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) < 18.140) to the Type-2 (18.192 < <sup>206</sup>Pb/

<sup>204</sup>Pb<sub>(i)</sub>) < 18.355), Type-4 (18.240 < <sup>206</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) < 18.398) and Type-5 samples (18.630 < <sup>206</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) < 18.638). As already noted for the Nd–Sr diagram (Fig. 7), the Type-3 samples define two groups that are particularly well differentiated in the <sup>207</sup>Pb/<sup>204</sup>Pb vs <sup>206</sup>Pb/<sup>204</sup>Pb diagram (Fig. 8b): (1) a small group with depleted compositions (18.252 < <sup>206</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) < 18.275; 15.492 < <sup>207</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) < 15.577), forming a field within the main data array, which trends more or less parallel to the NHRL; (2) an enriched group (18.487 < <sup>206</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) < 18.548; 15.579 < <sup>207</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) < 15.633) that shows significantly radiogenic <sup>207</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) for near-constant <sup>206</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) and plots within a sub-vertical field, scattering away from the main, NHRL-parallel data trend, towards higher <sup>207</sup>Pb/<sup>204</sup>Pb values. A negative correlation is observed between the <sup>207</sup>Pb/<sup>204</sup>Pb and <sup>143</sup>Nd/<sup>144</sup>Nd ratios for these samples (not shown).

## Intrusive granites

The tonalites define the largest range of isotopic variation (0.51276 < <sup>143</sup>Nd/<sup>144</sup>Nd<sub>(i)</sub>) < 0.51289; 0.70342 < <sup>87</sup>Sr/<sup>86</sup>Sr<sub>(i)</sub>) < 0.70371; 18.220 < <sup>206</sup>Pb/<sup>204</sup>Pb<sub>(i)</sub>) < 18.603) with a spread that encompasses the field defined by the granodiorites in the Pb–Pb diagrams (Fig. 8) but is distinguished by lower <sup>87</sup>Sr/<sup>86</sup>Sr ratios in the Nd–Sr diagram (Fig. 7). The field containing all of the intrusive granites is encompassed by the plutonic–volcanic rock field in the Nd–Sr and <sup>207</sup>Pb/<sup>204</sup>Pb vs <sup>206</sup>Pb/<sup>204</sup>Pb diagrams (Figs 7 and 8b), but
<figure><img src="image_12.png" /><figcaption>**Fig. 8.** Variation of $^{208}\text{Pb}/^{204}\text{Pb}$ (a) and $^{207}\text{Pb}/^{204}\text{Pb}$ (b) vs $^{206}\text{Pb}/^{204}\text{Pb}$ for the JPKK crustal section (initial isotopic compositions recalculated at $t_0$ = 100 Ma). Only whole-rock and plagioclase data (where available) are plotted. Fields as in Fig. 7. NHRL, Northern Hemisphere Reference Line (Hart, 1984).</figcaption></figure>

in the $^{208}\text{Pb}/^{204}\text{Pb}$ vs $^{206}\text{Pb}/^{204}\text{Pb}$ plot, the tonalite extends towards slightly higher $^{208}\text{Pb}/^{204}\text{Pb}$ values at the high $^{206}\text{Pb}/^{204}\text{Pb}$ end of the data array (Fig. 8a). This feature is ascribed to the very low U/Th (and high Th content) of some of the tonalite samples (see Table 1).

# DISCUSSION

## Relative contribution of the subduction component in the JPKK section

The chemical and Nd–Sr–Pb isotopic diversity of primitive island arc magmas is usually attributed to the composition of the mantle wedge with a variable overprint of components derived from the subducting slab (i.e. altered

oceanic crust, subducted oceanic and fore-arc sediments). From a geochemical point of view, this subduction component is characterized by a relative enrichment in LILE, U, Pb and, to a lesser extent, LREE and Th relative to HFSE and HREE. The enrichment in these incompatible trace elements is accounted for by their higher solubility in slab-derived fluids or melts that transfer these elements from the slab into the overlying mantle wedge where the subduction-related magmas are generated (e.g. Ellam & Hawkesworth, 1988).

The relative contribution and nature of the subduction component in the several plutonic–volcanic rock types that we have identified in the JPKK section can be gauged by comparing the primitive mantle normalized trace element pattern of each type to that of average
<figure><img src="image_13.png" /><figcaption>**Fig. 9.** Evolution of trace element characteristics in the JPKK crustal section. Concentrations are mean values for each type, and normalized to primitive mantle values after Sun & McDonough (1989). The evolution from Type-1 to Type-5 trace element patterns reflects the progressive contribution of a subduction component to the source of the arc magmas (see text). The inset indicates the behaviour of Th and U for the Type-3 samples, which can be classified into three sub-types: (1) those with no Th-U anomaly (thin Th-U segment), which is typically also observed for Types-1 and -2; (2) those with a marked positive U anomaly and no notable Th enrichment (black dashed line and arrow I). Given the lower distribution coefficient of U in fluids compared with the LILE, the U enrichment is interpreted as an indicator of a strong increase in a 'slab fluid' component in the magma source. (3) Trace element patterns with both U and Th enrichment (grey dotted line and arrow II). Given that Th is known to be immobile in aqueous fluids, the Th enrichment would suggest the contribution of a 'slab melt' component to the mantle source. This is consistent with the strong LREE enrichment observed. The 'mean pattern' for Type-3 samples is represented by the thick black line.</figcaption></figure>

N-MORB (e.g. Hofmann, 1988; Sun & McDonough, 1989) representative of a partial melt of a DMM mantle wedge source (Fig. 9). The significant increase from Type-1 to -5 in the LILE content, concomitant with relatively higher contents of Pb, Sr and LREE, and the development of a HFSE (Nb, Ta) negative anomaly from Type-3 to Type-5, may be accounted for by an increasing contribution of a subduction component in the source (Fig. 9, grey shaded area). On the basis of the different chemical behaviour of the various trace elements plotted, it is possible to distinguish between a contribution from a subduction component dominated by aqueous fluids (i.e. the 'slab fluid' component) and one by sediment melts (i.e. the 'slab melt' component). For example, fluid component involvement can be visualized on normalized trace element diagrams by a slight enrichment of LILE, which are highly mobile in aqueous fluids (Kogiso et al., 1997; Tatsumi & Kogiso, 1997) compared with HFSE and LREE. This can also be monitored using ratios of elements with similar partition coefficients during mantle melting but contrasting behaviours in aqueous fluids [e.g. Ba/La, U/Th and Pb/Ce (Brenan et al., 1995; Elliott et al., 1997; Hawkesworth et al., 1997a, 1997b; Plank et al., 2006]. The variable contribution of a fluid and/or melt component in the different pattern types of the JPKK section can be portrayed in plots

showing the U/Th and Pb/Ce ratios as a function of ratios of REE with different compatibility in melts (e.g. La/Yb) (Fig. 10). In these plots the major participation of a slab fluid component is observed for samples from Type-1 and Type-2, reflected by high U/Th and Pb/Ce ratios associated with low La/Yb ratios. An increasing contribution of a slab melt component from Type-3 to Type-5 is manifest by a pronounced negative Nb-Ta anomaly relative to LILE and LREE, higher contents of LILE and Th, and REE enrichment correlated with an increasing fractionation of LREE relative to HREE (Fig. 9). In the U/Th and Pb/Ce vs La/Yb diagrams (Fig. 10), the involvement of the slab melt component is reflected by a decrease of the U/Th and Pb/Ce ratios associated with an increase of the La/Yb ratio.

Studies on high-pressure and ultrahigh-pressure metamorphic terranes (e.g. Hermann et al., 2006), along with experimental studies (Hermann & Green, 2001; Spandler et al., 2007; Hermann & Spandler, 2008), have shown that aqueous fluids released at the blueschist- to eclogite-facies transition contain only moderate amounts of LILE, Sr and Pb and do not transport significant amounts of LREE, U and Th. Fluid-present melting of sediments on top of the slab is required to transfer significant amounts of trace elements from the slab to the mantle wedge; with
<figure><img src="image_14.png" /><figcaption>**Fig. 10.** (a) U/Th vs La/Yb and (b) Pb/Ce vs La/Yb for samples from the JPKK crustal section.</figcaption></figure>

a top slab temperature in the range of 700–900°C at sub-arc depths (Hermann *et al.*, 2006; Hermann & Spandler, 2008). The hydrous, granitic melts produced during slab melting are not significantly enriched in LREE because of the presence of allanite in the residue above 750°C (Hermann & Green, 2001; Klimm *et al.*, 2008). Consequently, the strong LREE enrichment observed in the Type-3 REE patterns, progressively increasing in the Type-4 and Type-5 patterns, may indicate high melting degrees of slab sediments to consume LREE-rich phases such as allanite.

The JPKK trace element signatures unambiguously indicate an increasing contribution of a subduction component from Type-1 to -5, with a relatively higher contribution of a slab fluid component from Type-1 to -3, and an increasing involvement of a slab melt component from Type-3 to -5. Because the timescale for the transfer of aqueous fluids through the mantle wedge is significantly shorter than that for sediment melts (Hawkesworth *et al.*, 1997a, 1997b; Turner & Hawkesworth, 1997; Turner *et al.*, 1997), it is conceivable that the parental magmas of Types-3 to -5 were generated later than those of Types-1 and -2 during the mature stage of evolution of the Kohistan subduction zone.

## Evidence for two geochemical and temporal magmatic suites in the JPKK section

A plot of La/N/Sm_N vs ²⁰⁷Pb/²⁰⁴Pb(i) and ¹⁴³Nd/¹⁴⁴Nd(i) (expressed as εNd_i) reveals the existence of two distinct

<figure><img src="image_15.png" /><figcaption>**Fig. 11.** (a) ²⁰⁷Pb/²⁰⁴Pb vs La_N/Sm_N and (b) εNd vs La_N/Sm_N diagrams for non-cumulative rocks from the JPKK crustal section (at t₀ = 100 Ma). Two geochemical suites, A' (pale grey arrow) and B' (dark grey arrow) have been distinguished (see text for explanation).</figcaption></figure>

geochemical suites (hereafter referred to as suites A and B; Fig. 11), as follows.

(1) Suite A encompasses samples from Types-1, -2, -4 and -5 and the isotopically depleted Type-3 samples (i.e. high εNd and low ²⁰⁷Pb/²⁰⁴Pb ratios). There is a progressive increase in ²⁰⁷Pb/²⁰⁴Pb (and reduction in εNd) with increasing La_N/Sm_N from Type-1 to -5 rocks.

(2) Suite B encompasses the isotopically enriched samples of Type-3. It differs from suite A by its higher ²⁰⁷Pb/²⁰⁴Pb and lower ¹⁴³Nd/¹⁴⁴Nd at similar La_N/Sm_N. We further differentiate within this suite three groups of samples (Bl, B2 and B3; Fig. 11) characterized by an increasing enrichment of ²⁰⁷Pb relative to ²⁰⁴Pb combined with decreasing ¹⁴³Nd/¹⁴⁴Nd from group B1 to B3.

Suites A and B are emplaced at distinct levels of the JPKK section (Fig. 12). Suite A rocks are mainly located in the middle-upper arc section, whereas suite B rocks are located either in the lower arc crust (groups B1 and B2) or in the uppermost arc crust (group B3).

The existence of two suites with distinct and correlated trace element and isotopic characteristics suggests that these geochemical signatures were imposed on their
<figure><img src="image_16.png" /><figcaption>**Fig. 12.** Simplified maps of the JPKK crustal section indicating the rocks from (a) suite A and (b) suite B (see text for explanation). The position of the metasomatized mantle (Jijal dunite-wehrlite-pyroxenite in contact with the granulitic lower arc crust), together with the granites intrusive into the Kiru-Kamila sequences, is shown for comparison.</figcaption></figure>

parental magmas from their mantle sources and were not the result of late dehydration-melting processes during intra-crustal metamorphism. Samples from the Jijal complex considered to have undergone dehydration-melting that modified their original trace element signature (Garrido *et al.*, 2006; Padrón-Navarta *et al.*, 2008) have been excluded from comparison with these suites. Jijal garnet hornblendites show isotopic characteristics akin to Type-2, -3 and -4 samples of suite A (Table 2). They are interpreted as the deep plutonic equivalent of shallower samples from Type-2 to Type-4 (Dhuime *et al.*, 2006, 2007; Garrido *et al.*, 2006). On the other hand, Jijal gabbroic rocks show isotopic compositions akin to the less-enriched samples of suite B (i.e. group Bl; Table 2), suggesting a common source.

Published ages for samples of suite A are limited (see Fig. 2). Yamamoto *et al.* (2005) reported a secondary ionization mass spectrometry (SIMS) U-Pb zircon age of 107.7 ± 1.8 Ma for a tonalite dike intrusive into rocks with Type-1 and -3 signatures and an age of 110.7 ± 4.9 Ma for an amphibolite xenolith in granites intrusive into Type-4 and -5 rocks. Such results are consistent with an older age for samples from suite A (i.e. >100 Ma), with an upper age bound set by subduction initiation at ~117 Ma (Dhuime *et al.*, 2007), and a lower age bound of ~105 Ma established by the oldest ages of the intrusive rocks.

Suite B samples of group Bl, characterized by the lowest ²⁰⁷Pb/²⁰⁴Pb ratio of this suite, are from the 'Sarangar gabbro' unit, for which Schaltegger *et al.* (2002) have reported a precise magmatic U-Pb zircon age of 98.9 ± 0.4 Ma. This unit intrudes and overlies the upper gabbroic rocks of the Jijal section, which are isotopically akin to group Bl. Precise ages for the Jijal gabbroic rocks are lacking: their intrusive age can be bracketed between 118 ± 12 Ma (the Sm/Nd age of a hornblende gabbronorite; Yamamoto & Nakamura, 2000) and ~96 Ma (the maximum age for the granulite-facies metamorphism; Anczkiewicz & Vance, 1997; Anczkiewicz *et al.*, 2002). These ages indicate a younger age for group Bl samples, between ~105 Ma (minimum age of the Jijal gabbros) and ~99 Ma (Sarangar gabbro). The minimum emplacement age for the most enriched samples of suite B (group B3) is 80.6 ± 4.5 Ma (U-Pb zircon age of an intrusive tonalite; Yamamoto *et al.*, 2005). The Chilas complex, which intrudes and shares many geochemical similarities with group B3 (see Figs 4, 13 and 14), yields ~85 Ma zircon U-Pb ages (Zeitler *et al.*, 1981; Schaltegger *et al.*, 2002), indicating a short time lag between the intrusion of the group B3 and Chilas magmas. Although no age is available for group B2, its ²⁰⁷Pb/²⁰⁴Pb and Nd isotopic compositions plot intermediate between the Bl and B3 groups and might indicate a transitional magmatic stage
<figure><img src="image_17.png" /><figcaption>**Fig. 13.** $\varepsilon_{Nd}$ vs $\varepsilon_{Sr}$ ($t_0=100$ Ma) variation in the JPKK crustal section. Shown for comparison are data for Indian Ocean sediments (Ben Othman *et al.*, 1989; Plank & Langmuir, 1998), the Neotethys altered oceanic crust (Mahoney *et al.*, 1998), Indian MORB (Mahoney *et al.*, 1998, 2002, *n*=120), modern island arc lavas (GEOROC compilation, http://georoc.mpch-mainz.gwdg.de/georoc/Entry.html, *n*=389) and the Chilas complex (Khan *et al.*, 1997, *n*=4). The Chilas complex has enriched isotopic compositions similar to those of the B3 group. The range of Nd-Sr variation for the Chilas complex is slightly broader than that defined by Khan *et al.* (1997): Mikoshiba *et al.* (1999) reported $\varepsilon_{Sr(i)}$ values between -6.9 and +1.5 (*n*=24) and Jagoutz *et al.* (2006) obtained $\varepsilon_{Nd(i)}$ values between +4.2 and +5.1 (*n*=12). The compositions of the DMM (Depleted MORB Mantle), HIMU (high $\mu$ = $^{238}$U/$^{204}$Pb), EM1 (Enriched Mantle 1) and EM2 (Enriched Mantle 2) mantle end-members are from Zindler & Hart (1986), Hart (1988) and Hofmann (2003). NHRL, Northern Hemisphere Reference Line (Hart, 1984). The dashed lines indicate mixing between DMM, subducted sediment and altered oceanic crust end-members and have been calculated using the methods of Faure (1986) and the following parameters: DMM: Sr = 11.3 ppm and Nd = 1.2 ppm (Eisele *et al.*, 2002); Indian Ocean sediments: Sr = 100-200 ppm and Nd = 15-30 ppm (Ben Othman *et al.*, 1989; Plank & Langmuir, 1998); altered oceanic crust: Sr = 100-300 ppm and Nd = 15-30 ppm (Mahoney *et al.*, 2002).</figcaption></figure>

with intrusion ages between those of groups B1 and B3 (i.e. between 105–99 Ma and 85 Ma). Intrusion ages of ~105–99 Ma, ~95 Ma and ~85 Ma are proposed as approximate ages for groups B1, B2 and B3, respectively.

**Origin of intrusive granites in the JKPP section**

Garrido *et al.* (2006) have proposed that the Kiru-Kamila intrusive granites were generated by dehydration-melting of different amphibole-bearing lithologies within the Jijal crustal section. Our isotopic data (Figs 7 and 8; Table 2) show that the isotopic signature of these granites is consistent with a combination of sources located in the arc root

of the crustal section (i.e. Jijal hornblendites and Jijal-Patan gabbroic rocks), with variable contributions from the granites' host-rocks. This latter contribution predominates, for example, in sample UM01-125, which has a Pb isotope composition consistent with contamination by Type-5 host-rocks (Table 2). Our data suggest that the granite magmas underwent variable assimilation and interaction with their host-rocks during their ascent and emplacement from the lower crust.

**Comparison with other intra-oceanic arcs**

In terms of their Sr-Nd-Pb isotope compositions, samples from both suites A and B plot within a triangular domain delimited by the DMM reservoir, Indian Ocean sediments
<figure><img src="image_18.png" /><figcaption>**Fig. 14.** Variation of $^{207}$Pb/$^{204}$Pb vs $^{206}$Pb/$^{204}$Pb and $\varepsilon_{Nd}$ vs $^{206}$Pb/$^{204}$Pb ($t_0$=100 Ma) for the JPKK crustal section. The various fields and end-members are the same as in Fig. 13. The mixing lines between the DMM, sediments and altered oceanic crust end-members are calculated after Faure (1986), using the following parameters: DMM: Nd = 1.12 ppm and Pb = 0.050 ppm (Eisele *et al.*, 2002); Indian Ocean sediments: Nd = 15–30 ppm and Pb = 1.5–30 ppm (Ben Othman *et al.*, 1989; Plank & Langmuir, 1998); altered oceanic crust: Nd = 15–30 ppm and Pb = 1–3 ppm (Mahoney *et al.*, 2002). NHRL, Northern Hemisphere Reference Line (Hart, 1984).</figcaption></figure>

and Neotethyan altered oceanic crust (Figs 13 and 14). Previous studies of intra-oceanic arcs worldwide (e.g. Marianas, Tonga-Kermadec, Izu-Bonin) have often interpreted such geochemical characteristics as a result of

three-component mixing in which the sediment-related subduction input is determined either by the amount of sediment dragged down to the zone of magma formation and/or the thickness of the sedimentary cover on the
subducting oceanic crust (e.g. Gamble *et al.*, 1996; Regelous *et al.*, 1997) or in terms of nature of the sedimentary component; that is, whether it is pelagic or detrital in origin (e.g. Chauvel *et al.*, 2009). The importance of the nature and composition of the mantle wedge before fluid or melt addition from the subducting slab has also been considered (e.g. Ewart *et al.*, 1998; Woodhead *et al.*, 1998; Pearce *et al.*, 2007). Until now, there have been few insights into the mechanisms by which fluids or silicate melts are added to the mantle wedge, particularly with respect to their timing in relation to the dynamic evolution of the subduction zone (Hawkesworth *et al.*, 1997a, 1997b). It is noteworthy that of the many variables that can play an important role in controlling the geochemical signatures of arc lavas, the most important are intrinsic to the particular arc system and involve both physical-dynamic and geochemical parameters.

The fossil Kohistan arc constitutes one of the best examples in which the trends exhibited by various geochemical tracers can be explained by combining both geochemical and physical-dynamic parameters, in particular during drastic changes in the subduction regime. The following section summarizes the evolution we propose for the JPKK section in relation to both geodynamic and geochemical parameters.

## A three-stage geodynamical evolution model for the KAC

Combination of our new trace element and Sr-Nd-Pb isotope data with previous results (Dhuime *et al.*, 2007; Garrido *et al.*, 2007) and available geochronological data (Zeitler *et al.*, 1981; Yamamoto & Nakamura, 1996, 2000; Anczkiewicz & Vance, 1997; Anczkiewicz *et al.*, 2002; Schaltegger *et al.*, 2002; Yamamoto *et al.*, 2005; Dhuime *et al.*, 2007) allows us to propose a three-stage model for the evolution of the Kohistan island arc magmatism.

### Stage 1 (≥117 Ma to ~105 Ma): subduction initiation and growth of the volcanic arc

This stage encompasses the initiation of an intra-oceanic subduction system and the onset of subduction (Fig. 15a, Stages 1-a and 1-b, respectively). Initiation of subduction most probably occurred near a mid-ocean ridge transform fault or fracture zone, separating young, thin lithosphere from old, thick lithosphere (Stern & Bloomer, 1992; Stern, 2004; Fig. 15a, Stage 1-a). Subduction started at around 117 Ma (Dhuime *et al.*, 2007; Fig. 15a, Stage 1-b). Extension in the overlying lithosphere (the 'proto fore-arc') was associated with LREE-depleted and high-(LILE, $^{207}$Pb/$^{204}$Pb, $^{87}$Sr/$^{86}$Sr) 'boninite-like' magmatism that interacted with the pre-existing lithospheric mantle, giving rise to the Jijal dunite-wehrlite-pyroxenite sequence (Dhuime *et al.*, 2007; Garrido *et al.*, 2007).

The mantle component involved in the genesis of the suite A rocks may represent ambient asthenosphere.

### (a) Stage 1: ≥117 Ma to ~105 Ma

**Geochemical suite 'A'**

**Subduction initiation & formation of a volcanic arc**

<figure><img src="image_19.png" /><figcaption>**Fig. 15.** Three-stage schematic evolution of the Kohistan arc from ~117 to 85 Ma. (a) Stage 1; (b) Stage 2; (c) Stage 3. (See text for detailed explanation.)</figcaption></figure>

The gradual enrichment of LILE, REE and the Nd-Sr-Pb isotope composition observed from Type-1 to Type-2 may reflect the increasing but limited contribution of a slab component. Further growth of the arc occurred subsequently by intrusion of Type-3 magmas with an island arc tholeiite geochemical signature, representing ~8-10% of the JPKK section (Fig. 15a, Stage 1-c). The enrichment in fluid-immobile elements characteristic of Type-3 samples (Figs 9 and 10) suggests that at this stage the subduction component was dominated by a slab melt rather than a slab fluid. The progressive building of the volcanic arc is characterized by the increase in the slab melt component in Type-4 and Type-5 rocks, which together represent approximately 10% of the total thickness of the JPKK crustal section. The enrichment in the Nd-Sr-Pb isotopic compositions observed in suite A is consistent with a progressive increase in the subduction contribution as the
<figure><img src="image_20.png" /><figcaption>**Fig. 15.** Continued</figcaption></figure>

<figure><img src="image_21.png" /><figcaption>a: ~10 Ma low-activity magmatism
b: (end of stage 3) emplacement of upper JPKK section magmas, then intrusion of Chilas complex (from ~85 Ma)</figcaption></figure>

volcanic arc evolved. The increasing influence of a slab melt component is probably related to the activation of convection in the mantle wedge, allowing a continuous 'circulation' of hot mantle at the slab surface (e.g. Kincaid & Sacks, 1997; van Keken et al., 2002). The conductive heating of the slab surface by the overlying asthenospheric mantle caused it to partially melt (i.e. the sediments ± the underlying altered oceanic crust), followed by the injection of slab melts into the mantle wedge

*Stage 2 (~105–99 Ma to 96–91 Ma): major thermal event: magmatic underplating, granulite-facies metamorphism and erosion-delamination of the arc base*

The initiation of Stage 2 is associated with the development of suite B. Two major events occurred at around 100 Ma, just after the building of the volcanic part of the arc, and over a period of ~10 Myr.

(l) Magmatic underplating of the arc crust (Fig. 15b, Stage 2-a), caused the emplacement of large volumes of gabbroic rocks with B1 and then B2 geochemical signatures: these represent approximately 20% and 10% of the

total thickness of the JPKK crustal section, respectively. This event resulted in significant crustal thickening ($P_{max}$ = 14–2·1 GPa, Jan & Howie, 1981; Yamamoto, 1993; Ringuette et al., 1999). The evolved character of the underplated magmas (43 < Mg-number < 59, Table 1) implies that there was likely to have been a thick cumulate sequence [up to 30–35 km (Garrido et al., 2007)], which is not preserved in the obducted section of the Kohistan arc (Dhuime et al., 2007; Garrido et al., 2007).

Compared with suite A, suite B rocks (Stage 2-a) have a rather homogeneous composition, despite the large volumes of magma involved. Their enriched Nd and $^{207}$Pb/$^{204}$Pb isotope compositions indicate significant changes in the magmatic source during the transition from suite A to suite B. The isotopic enrichment of suite B rocks can be explained by the 'subduction erosion' of fore-arc metasediments (e.g. von Huene & Scholl, 1991, 1993; Ranero & von Huene, 2000) and the mixing between these sediments and DMM-type asthenospheric mantle. This mixed, enriched material was later dragged down by corner flow towards the magma source region of suite B
(Fig. 15b, Stage 2-b), accounting for the progressive geochemical enrichment observed for this suite.

(2) Granulite-facies metamorphism at the base of the arc sequence (Fig. 15b, stage 2-b) occurred in association with dehydration-melting of hornblende-bearing mafic and ultramafic rocks and the development of granitic melts. The migration of these granitic melts to shallower crustal levels, and their interaction with their host-rocks, constitutes the main mechanism for intra-crustal differentiation in the Kohistan arc (Garrido et al., 2006); as well as in Cenozoic paleo-arc complexes such as the Hidaka Metamorphic Belt in Japan (Kemp et al., 2007).

The distinct Sr-Nd-Pb isotopic signature of the garnet-bearing rocks (i.e. garnet granulites and garnet hornblende) at the roots of the Kohistan arc invalidates claims that these rocks are cogenetic high-pressure, garnet-bearing cumulates (Alonso Perez et al., 2008). The absence in the exhumed section of the Kohistan arc of cogenetic ultramafic cumulates with the evolved gabbroic rocks formed in Stage 2-a points to their removal at Stage 2-b either by gravitational collapse (Kay & Kay, 1985, 1993; Tatsumi, 2000; Jull & Kelemen, 2001) or by thermo-mechanical erosion of the infra-arc lithosphere (Eberle et al., 2002; Morency & Doin, 2004; Arcay et al., 2005, 2006).

The time span (~15-20 Myr) between the volcanic arc stage (~10 Ma) and the granulite-facies metamorphism (~96-91 Ma) is too short for the development of gravitational instabilities leading to delamination (Jull & Kelemen, 2001; Kelemen et al., 2003). In our model, magmatic underplating and granulite-facies metamorphism result from a single event, associated with an increase of mantle convection efficiency. The water-dependent modification of asthenospheric mantle rheology (Mackwell et al., 1985; Karato et al., 1986; Hirth & Kohlstedt, 1996; Mei & Kohlstedt, 2000a, 2000b; Karato, 2003), induced by fluids from a dehydrating subducted slab (Billen & Gurnis, 2001; Billen et al., 2003; Honda & Saito, 2003; van Keken, 2003), have been inferred to trigger an acceleration of convection in the mantle wedge (Arcay et al., 2005). This acceleration of the convection process causes thermo-mechanical erosion and dragging of the 'cold walls' of the mantle wedge (i.e. along the upper part of the slab and the base of the overriding plate). Numerical models suggest that thermo-mechanical erosion provides a good explanation for the removal of the missing cumulates (Arcay et al., 2006) and could happen within 15 Myr.

*Stage 3 (~95-85 Ma): low magmatic activity, emplacement of the upper JPKK magmas, and intrusion of the Chilas complex from 85 Ma (last stage of magmatism in intra-oceanic setting)*

The rocks associated with Stage 3 constitute the most isotopically enriched magmas of suite B (B3). These rocks are found in the uppermost part of the JPKK section (~20%

of the total thickness of the JPKK crustal section) and in the Chilas complex (see Fig. 12). The Chilas ultramafic-mafic complex was emplaced in an intra-arc rift setting at ~85 Ma (Zeitler et al., 1981; Bard, 1983; Coward et al., 1987; Khan et al., 1989; Treloar et al., 1996; Burg et al., 1998; Schaltegger et al., 2002; Jagoutz et al., 2006). It is intrusive into the uppermost JPKK rocks, suggesting an older age for those rocks. However, given the apparent geochemical similarity between the upper JPKK and the Chilas gabbroic-dioritic rocks (see Figs 4, 13 and 14), the ~85 Ma zircon age for the Chilas gabbroic rocks (Zeitler et al., 1981; Schaltegger et al., 2002) is probably the best estimate for the maximum age of the B3 magmas. Such an age implies an ~10 Myr period of 'low magmatic activity' (Fig. 15c, Stage 3-a) between the ~96-91 Ma granulite-facies metamorphism and associated mechanical erosion (Fig. 15b, Stage 2-b), and the formation of the B3 magmas (Fig. 15c, Stage 3-b).

The B3 magmas are associated with the final stage of thermo-mechanical erosion of the arc base. The thinning of the overriding plate at the arc base level could have provoked the rifting of the arc after a significant period (<10 Myr) of stagnation and homogenization of a large volume of magma. Recent numerical models of subduction zones (Kincaid & Sacks, 1997; Arcay et al., 2007) suggest the formation of a thermal shield—or 'cold blanket'—above the slab surface. A similar scenario could account for the period of low magmatic activity observed in the Kohistan arc. In our model, a shield was formed when the eroded 'cold walls' (see Stage 2 above) were progressively dragged into the zone of melt generation through convection in the mantle wedge (see Fig. 15c, Stage 3-a). The cold blanket inhibited the dehydration and partial melting of subducted material, and thus the partial melting of the mantle wedge. This continued until the cold blanket was removed by corner flow and/or was thermally re-equilibrated, before the emplacement of the B3 magmas (Fig. 15c, Stage 3-b).

## CONCLUSIONS

The detailed study of the JPKK crustal section of the Kohistan Arc Complex, from the Moho transition zone to the contact with the Chilas complex has, for the first time, characterized the geochemistry of a continuous ~30 km thick section of lower- to middle-arc crust. The results suggest that the intra-oceanic evolution of the Kohistan arc occurred over a period of ~30 Myr (117 Ma > tinitiation-collision > 85 Ma). Three major stages characterize its evolution: (1) the progressive building of a 'volcanic arc' between ~117 Ma and ~105 Ma; (2) magmatic underplating of large quantities of magma in the arc base (~100 Ma) and the development of a major granulite-facies metamorphic event in the lower arc crust (~96-91 Ma); (3)
a period of ‘low magmatic activity’ between ~95 Ma and ~85 Ma before a final magmatic pulse at ~85 Ma preceding arc-continent collision.

The transition between Stages 1 and 2 was probably induced by the progressive hydration of the mantle wedge, which modified its rheology and induced convection. This resulted in thermo-mechanical erosion of the lower parts of the crustal section and, at least in part, provided the heat required to trigger granulite-facies metamorphism at the arc base. As the main process for recycling lower arc crust into the mantle, thermo-mechanical erosion has the advantage over classical models of delamination by gravitational collapse of being compatible with the relatively short duration of the magmatic activity in the Kohistan arc.

The bulk chemical composition of the arc magmas can be interpreted in terms of mixing, in different proportions, between a depleted ‘DMM-like’ mantle component and a subduction component. The latter has a geochemical composition that reflects the involvement of sediments from the Indian Ocean and altered oceanic crust. Depending on the stage of evolution of the subduction system, the subduction component is transported initially in dehydration fluids and then later in silicate melts. The latter are related to the activation of convection in the mantle wedge and the circulation of hot mantle at the slab surface, leading eventually to partial melting of the uppermost levels of the slab (i.e. sediments ± altered oceanic crust).

## ACKNOWLEDGEMENTS

This work has benefited from financial support from the ‘Institut National des Sciences de l’Univers du Centre National de la Recherche Scientifique’ (‘DyETI Program, Thème IV’) in 2004 and 2006 to D.B. and from a PhD grant of 3 years from the research ministry to B.D. C.J.G. acknowledges funding from the Spanish ‘Ministerio de Ciencia e Innovación’ (research grants CGL2006-04440/BTE, CGL2007-61205 and PCI2006-A9-0580) and the ‘Junta de Andalucía’ (research group RMNI31). We would like to thank Béatrice Galland for technical assistance in the chemistry clean room, Simone Pourtalès for help during ICP-MS analyses, and J. P. Burg and G. Zeilinger for providing some samples. The technical assistance of Philippe Télouk during Nd and Pb data acquisition (Service Commun National, ENS, Lyon) and of Patrick Verdoux during Sr isotope analyses (GIS laboratory, Nîmes) has been greatly appreciated. This paper benefited from helpful reviews from R. Price and an anonymous reviewer. The authors greatly appreciate discussions with D. Arcay, S. Guillot, C. J. Hawkesworth, S. Lallemand and R. Maury. Special thanks go to S. Mullin for improving the quality of English.

## SUPPLEMENTARY DATA

Supplementary data for this paper are available at *Journal of Petrology* online.

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