cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.21839003.v1
title: Turonian-coniacian definition of the Caribbean plate: tectonic and metamorphic record in the Median Belt, Dominican Republic

description: Uplift and unroofing of Jurassic-Cretaceous, mantle and crust, arc- and plume-related rock units in the Median Belt of the Dominican Republic exposed basement rocks with a protracted record of tectono-thermal events delineating the evolution of the northern edge of the Caribbean plate. In this article we focus on crustal rock units in the north-eastern half of the Median Belt. First <sup>40</sup>Ar/<sup>39</sup>Ar dating of metamorphic ferri-winchite (86.4 ± 2.5 Ma; crystallization date) and albite (82.3 ± 5.8 and 79.8 ± 1.6 Ma; cooling dates) in metabasites of boninitic photolith from the Aptian-Albian Maimón Formation in the Ozama shear zone points to a tectono-metamorphic event in the Upper Cretaceous. Beltwide, this event caused syn-metamorphic N- to NNE-directed, simple-shear dominated, mylonitic and phyllonitic deformation of the Maimón Formation at peak metamorphic conditions of 8.2 kbar and 380°C. Such conditions are consistent with subduction of a coherent portion of forearc (represented by the Maimón Formation) to depths of ~25-29 km. The tectono-metamorphic event dated here overlaps with the inception of Turonian-Coniacian SW-dipping subduction and metamorphic sole formation in a back-arc position recorded in the Moa-Baracoa ophiolite complex in neighboring Eastern Cuba. Contemporaneity between the subduction inception of forearc and back-arc portions of the Caribbean arc and the main pulse of plume activity recorded in the Caribbean Large Igneous Province (CLIP) suggests that plume activity promoted general plate instability leading to a regional-scale plate reorganization. This mantle-plume-induced plate margin reorganization was coeval with the inception of the NE-dipping subduction of the Farallón plate beneath Central America leading to the definition of the Caribbean Plate by double-verging subduction zones along its northern and southwestern margins.
DOI: 10.6084/m9.figshare.22707399
title: Middle Triassic to Jurassic convergence at the north-western margin of Gondwana: insights from the Central Cordillera of Colombia

description: The northern Andes are crucial for understanding the processes associated with the break-up of Pangea and its impact on the evolution of the Pacific margin of South America. Despite its importance, the origin and significance of mafic magmatism and its relationship with the Permian arc-related granitoids in the northern Andes remains controversial. To address this, we examined the Tierradentro gneisses and amphibolites, which comprise Permian-Triassic lithologies that may help resolve this controversy. Our study focuses on representative lithologies of the Central Cordillera of Colombia, including mylonitized granitoids, metabasites, metapelites, and serpentinites, to shed light on the history of the western margin of Gondwana during and after its break-up (~230 to 200 Ma). To investigate these lithologies, we conducted field observations, petrographic analyses, U-Pb dating of zircons, and whole-rock geochemical, Nd, Pb, and Hf isotopic analyses. Our results show that mylonitized mafic rocks with Triassic crystallization ages (ca. 236 Ma) intruded Permian granitoids. Furthermore, these mafic and felsic rocks were intruded by Jurassic calc-alkaline batholiths. The geochemical and isotopic signatures of these rocks indicate their subduction-related extension origin and further mylonitic deformation, possibly during the Jurassic strike-slip movement of the Farallón plate relative to western Gondwana. The Otú-Pericos fault bounds these rocks to the west, where Jurassic metabasic and metapelitic sequences with serpentinites interleaved and formed in a collisional setting. Our findings suggest that the Pacific margin of northern South America underwent subduction-related extension during the middle Triassic and evolved towards a more oblique convergence during the Jurassic.
DOI: 10.6084/m9.figshare.23544866.v1
title: Exotic vs local Caribbean origin for the arc-related Mabujina Amphibolite Complex (Cuba): implications for segmentation of the Caribbean arc during the Cretaceous

description: The Mabujina Complex exposed in south-central Cuba consists of an elongated body of metamorphosed volcanic and subvolcanic mafic rocks and tonalitic gneisses. The complex is largely composed of greenschist facies rocks (Porvenir Formation) directly below the Cretaceous volcanic arc section and of a deeper sequence of deformed amphibolite facies rocks (Mabujina Amphibolite Complex). The origin of the protolith of the Mabujina Complex has been the subject of intense debate in the past. While some authors consider the Mabujina Complex to represent the deepest and oldest (Early Cretaceous) exposed section (root) of the Cretaceous Caribbean volcanic arc others suggested an exotic (non-Caribbean related) Early Cretaceous volcanic arc section. The later proposal implies the tectonic emplacement underneath the Caribbean arc of a segment of the Pacific-related Early Cretaceous Mexican Guerrero volcanic arc terrane. A new set of whole-rock geochemical analyses presented in this study shows that the protoliths of the Mabujina Amphibolite Complex constitute an island-arc sequence with a) less abundant island-arc tholeiitic mafic rocks similar to the Early Cretaceous tholeiitic island arc of the Caribbean and b) dominant transitional to calc-alkaline mafic and felsic igneous rocks that resemble the Early to Late Cretaceous magmatism of the Caribbean arc. The high initial Nd ratios of the rocks from the Mabujina Amphibolite Complex are indistinguishable from the tholeiitic to calc-alkaline sequences from the Caribbean arc, reflecting a depleted MORB mantle source with limited subduction-related component input. The present data, together with published geochemical and geochronological data of the protoliths, allow identifying a Caribbean origin for the Mabujina Complex instead of an exotic provenance in the Guerrero Arc of western Mexico. However, even if the interpretation of the geochemical data favours a Caribbean origin, the Mabujina Amphibolite Complex cannot represent the root of the volcanic arc. Here, we propose that the Mabujina Amphibolite Complex is a fragment of the Early to Mid-Cretaceous Caribbean arc that was tectonically emplaced below this same arc as a likely consequence of arc segmentation and strike-slip trans-compression triggered by oblique subduction during the mid-Cretaceous.
DOI: 10.6084/m9.figshare.24006950.v2
title: Pre-Alpine prograde evolution of the Upper Alpujarride (Betic-Rif belt) reveals a Paleotethys-related collision

description: Medium and high grade kyanite-bearing graphitic metapelites of the basement of the Torrox Unit (Upper Alpujarride, Western Mediterranean) show kyanite-andalusite-kyanite replacements and coexisting garnet types with complex compositional zoning and growth-dissolution stages. This allows inferring two clockwise <i>P-T</i> paths associated with contrasted orogenic cycles of latest Carboniferous – earliest Permian and Eocene(?)-Miocene age, respectively. Dated (306 ± 77 Ma) prograde medium grade garnet cores with relatively low to moderate Ca content indicates pre-Alpine barrovian metamorphism in the kyanite stability field (<i>ca</i>. 600°C, 0.7–0.8 GPa). This implies a prograde pressurization of the sequence followed by decompression, as inferred from andalusite replacements after kyanite. Deeper in the sequence, anatectic granitic orthogneisses contain high-grade graphitic kyanite-bearing metapelitic restitic enclaves. Dating of rutile (with inclusions of kyanite) and monazite (shielded in biotite) from the pelitic enclaves provided pre-Alpine ages (<i>ca</i>. 300 Ma) rejuvenated due to Alpine overprint. Such pressurization event is not consistent with a late Variscan stage, commonly identified with a tectonic scenario characterized by orogenic collapse and decompression at ca. 300 Ma. Instead, we propose a post-Variscan collision event related to the closure of the western Paleotethys. On the other hand, Ca-rich cores of garnet porphyroblasts in the medium-grade metapelites formed at 1.1–1.2 GPa, 500°C, implying a metamorphic gradient of ca. 11.5°C/km related to Eocene (?) subduction. Kyanite+phengite replacements after andalusite are related to this stage. Late Mg-rich Ca-poorer overgrowths in garnet porphyroblasts document increasing temperature during the first stage of decompression (down to 0.9 GPa at ca. 650°C) with increasing thermal gradient up to ca. 20°C/km. These two complete metamorphic cycles of pressurization and heating followed by decompression allow reconciling previous contradictory conclusions about the paragenetic and thermal gradient development during the Paleotethyan and Alpine cycles in different units of the Betic-Rif belt.
DOI: 10.6084/m9.figshare.21201682
title: A fragment of inherited Archaean lithospheric mantle rules the metallogeny of central Mexico

description: Mantle xenoliths from Santo Domingo, Ventura-Espíritu Santo and Durango volcanic fields (Mesa Central in Mexico) experienced low degrees of partial melting in the stability fields of garnet (⁓ 2%) and spinel peridotites (⁓ 2–4%), and interacted with hydrous alkaline melts possibly during the Basin and Range extensional tectonism since Late Oligocene. Enclosed and intergranular grains of monosulfide solid solution (mss) in Santo Domingo peridotites are residues after the extraction of 0.1–0.5 fractions of Ni-Cu-rich sulphide melt during mantle melting events. On the other hand, glo˜bular sulphides (pentlandite ± chalcopyrite) hosted in glass veinlets in the Ventura-Espíritu Santo and Durango peridotites crystallized from Ni-Cu-rich droplets of sulphide melt, immiscible in the Quaternary silicate magmas that brought the xenoliths to the surface. Rhenium-depletion model ages of these sulphide populations indicate that part of the subcontinental lithospheric mantle (SCLM) of the Oaxaquia terrane (beneath Santo Domingo and Ventura-Espíritu Santo) originated in the Archaean-Paleoproterozoic as the southernmost extension of the Laurentia craton, and was assembled with the Central terrane (beneath Durango) during the Grenville orogeny (⁓ 1.0 Ga). Early Palaeozoic (⁓ 500 Ma) model ages common to sulphides from the peridotite xenoliths of the three volcanic fields suggest that the Oaxaquia-Central composite block split away from North America during the Rodinia break-up and experienced the Pan-African-Brasiliano orogeny that led to Gondwana assembly. During the Cenozoic, the reactivation of translithospheric faults bounding this composite old SCLM provided preferential pathways for focusing the ascent of ore-productive magmas/fluids associated with the subduction-related metallogeny of the Pacific active margin of Mexico.
DOI: 10.6084/m9.figshare.21286834.v1
title: Opening and closure of Cadomian peri-Gondwanan oceans: age and evolution of the Mérida Ophiolite (SW Iberia)

description: In the SW Iberian Massif, the Ossa-Morena Complex contains a stack of units of different origin and tectonothermal evolution. Individual terranes of the complex record a Cadomian history, traditionally interpreted in relation to the dynamics of a peri-Gondwanan volcanic arc. The interpretation of the Cadomian terranes is a key issue in the reconstruction of the Ediacaran margin of Gondwana in NW Africa. In the Mérida Massif, a mafic – ultramafic unit stacked between two units of continental or arc affinity is interpreted as a Cadomian ophiolite, the Mérida Ophiolite. Within it, mafic lithologies dated at <i>c</i>. 596 Ma (U-Pb in zircon) have calc-alkaline or tholeiitic affinity, indicating generation in a supra-subduction zone setting. The ophiolite shows a main event of Cadomian metamorphism (<i>c</i>. 590 Ma, U-Pb garnet dating) with a prograde P-T path and peak conditions at <i>c</i>. 700°C and 8 kbar. The mafic rocks show Nd isotopic compositions clearly different from those characteristics of the mafic rocks formed in the axial zone of the volcanic arc. Hence, the Mérida Ophiolite probably represents oceanic lithosphere of a back-arc basin, opened between the volcanic arc and the outer margin of Gondwana. Closure of the back-arc occurred during collision of the volcanic arc with the margin of Gondwana (starting at <i>c</i>. 590 Ma), which caused rapid accretion of the back-arc oceanic lithosphere beneath the arc and prograde metamorphism typical of subduction inception. The Mérida Ophiolite was finally obducted above the continental margin of Gondwana, presently preserved in gneissic unit piled beneath the ophiolite. Cadomian evolution of this peri-Gondwanan arc section continued with new tectonothermal events dated in the range 560–540 Ma that alternated with episodes of intense magmatic activity and preceded the collapse of the magmatic arc and its erosive levelling, followed by the generation of a new episode of intense magmatic activity in the arc and the unconformable deposition of the Ediacaran-Cambrian Malcocinado Formation.
DOI: 10.6084/m9.figshare.23544866
title: Exotic vs local Caribbean origin for the arc-related Mabujina Amphibolite Complex (Cuba): implications for segmentation of the Caribbean arc during the Cretaceous

description: The Mabujina Complex exposed in south-central Cuba consists of an elongated body of metamorphosed volcanic and subvolcanic mafic rocks and tonalitic gneisses. The complex is largely composed of greenschist facies rocks (Porvenir Formation) directly below the Cretaceous volcanic arc section and of a deeper sequence of deformed amphibolite facies rocks (Mabujina Amphibolite Complex). The origin of the protolith of the Mabujina Complex has been the subject of intense debate in the past. While some authors consider the Mabujina Complex to represent the deepest and oldest (Early Cretaceous) exposed section (root) of the Cretaceous Caribbean volcanic arc others suggested an exotic (non-Caribbean related) Early Cretaceous volcanic arc section. The later proposal implies the tectonic emplacement underneath the Caribbean arc of a segment of the Pacific-related Early Cretaceous Mexican Guerrero volcanic arc terrane. A new set of whole-rock geochemical analyses presented in this study shows that the protoliths of the Mabujina Amphibolite Complex constitute an island-arc sequence with a) less abundant island-arc tholeiitic mafic rocks similar to the Early Cretaceous tholeiitic island arc of the Caribbean and b) dominant transitional to calc-alkaline mafic and felsic igneous rocks that resemble the Early to Late Cretaceous magmatism of the Caribbean arc. The high initial Nd ratios of the rocks from the Mabujina Amphibolite Complex are indistinguishable from the tholeiitic to calc-alkaline sequences from the Caribbean arc, reflecting a depleted MORB mantle source with limited subduction-related component input. The present data, together with published geochemical and geochronological data of the protoliths, allow identifying a Caribbean origin for the Mabujina Complex instead of an exotic provenance in the Guerrero Arc of western Mexico. However, even if the interpretation of the geochemical data favours a Caribbean origin, the Mabujina Amphibolite Complex cannot represent the root of the volcanic arc. Here, we propose that the Mabujina Amphibolite Complex is a fragment of the Early to Mid-Cretaceous Caribbean arc that was tectonically emplaced below this same arc as a likely consequence of arc segmentation and strike-slip trans-compression triggered by oblique subduction during the mid-Cretaceous.
DOI: 10.6084/m9.figshare.24006950.v1
title: Pre-Alpine prograde evolution of the Upper Alpujarride (Betic-Rif belt) reveals a Paleotethys-related collision

description: Medium and high grade kyanite-bearing graphitic metapelites of the basement of the Torrox Unit (Upper Alpujarride, Western Mediterranean) show kyanite-andalusite-kyanite replacements and coexisting garnet types with complex compositional zoning and growth-dissolution stages. This allows inferring two clockwise <i>P-T</i> paths associated with contrasted orogenic cycles of latest Carboniferous – earliest Permian and Eocene(?)-Miocene age, respectively. Dated (306 ± 77 Ma) prograde medium grade garnet cores with relatively low to moderate Ca content indicates pre-Alpine barrovian metamorphism in the kyanite stability field (<i>ca</i>. 600°C, 0.7–0.8 GPa). This implies a prograde pressurization of the sequence followed by decompression, as inferred from andalusite replacements after kyanite. Deeper in the sequence, anatectic granitic orthogneisses contain high-grade graphitic kyanite-bearing metapelitic restitic enclaves. Dating of rutile (with inclusions of kyanite) and monazite (shielded in biotite) from the pelitic enclaves provided pre-Alpine ages (<i>ca</i>. 300 Ma) rejuvenated due to Alpine overprint. Such pressurization event is not consistent with a late Variscan stage, commonly identified with a tectonic scenario characterized by orogenic collapse and decompression at ca. 300 Ma. Instead, we propose a post-Variscan collision event related to the closure of the western Paleotethys. On the other hand, Ca-rich cores of garnet porphyroblasts in the medium-grade metapelites formed at 1.1–1.2 GPa, 500°C, implying a metamorphic gradient of ca. 11.5°C/km related to Eocene (?) subduction. Kyanite+phengite replacements after andalusite are related to this stage. Late Mg-rich Ca-poorer overgrowths in garnet porphyroblasts document increasing temperature during the first stage of decompression (down to 0.9 GPa at ca. 650°C) with increasing thermal gradient up to ca. 20°C/km. These two complete metamorphic cycles of pressurization and heating followed by decompression allow reconciling previous contradictory conclusions about the paragenetic and thermal gradient development during the Paleotethyan and Alpine cycles in different units of the Betic-Rif belt.
DOI: 10.6084/m9.figshare.19771481
title: Tectonics and geothermal gradients from subduction to collision in the NW Variscan Iberian Massif

description: The earliest tectonometamorphic record of tectonic slices incorporated to the base of an orogen holds the key to understand how an orogen is built. The tectonic pile of the NW Iberian section of the Variscan Orogen includes tectonic slices separated by crustal-scale thrusts. The earliest tectonometamorphic record in the uppermost parautochthon is calculated at 11–14 kbar and 450–500°C (P-T gradient about 13°C/km), suggesting a subduction-related metamorphic recrystallization at lower pressure than the overlying Lower Allochthon. Early conditions calculated in the autochthon (9–10 kbar and 425–450°C; 16°C/km) point to a relatively ‘cold’ collisional setting. Higher thermal gradients obtained from some sections of the autochthon (11–12 kbar and 700–725°C; 21°C/km) and the Lower Parautochthon (7.5 kbar and 550–700°C; 24–31°C/km), correspond to more advanced and ‘hot’ stages of collision. New U–Pb monazite geochronology indicates a 318–311 Ma age for the final formation of HT domes in the region. We propose the rapid decrease in P-T gradient (from &lt;10 to 16°C/km) documents a fail to sustain further burial along a regular subduction zone. We consider the subsequent increase in the geothermal gradient (from 16 to 31°C/km) as the culmination of previous crustal accretion and the onset of crustal underthrusting and later processes in a collisional stage. We propose these switches in the early tectonometamorphic record of individual tectonic slices as potential markers to track the transition from subduction to collision in collisional orogens.
DOI: 10.6084/m9.figshare.22707399.v1
title: Middle Triassic to Jurassic convergence at the north-western margin of Gondwana: insights from the Central Cordillera of Colombia

description: The northern Andes are crucial for understanding the processes associated with the break-up of Pangea and its impact on the evolution of the Pacific margin of South America. Despite its importance, the origin and significance of mafic magmatism and its relationship with the Permian arc-related granitoids in the northern Andes remains controversial. To address this, we examined the Tierradentro gneisses and amphibolites, which comprise Permian-Triassic lithologies that may help resolve this controversy. Our study focuses on representative lithologies of the Central Cordillera of Colombia, including mylonitized granitoids, metabasites, metapelites, and serpentinites, to shed light on the history of the western margin of Gondwana during and after its break-up (~230 to 200 Ma). To investigate these lithologies, we conducted field observations, petrographic analyses, U-Pb dating of zircons, and whole-rock geochemical, Nd, Pb, and Hf isotopic analyses. Our results show that mylonitized mafic rocks with Triassic crystallization ages (ca. 236 Ma) intruded Permian granitoids. Furthermore, these mafic and felsic rocks were intruded by Jurassic calc-alkaline batholiths. The geochemical and isotopic signatures of these rocks indicate their subduction-related extension origin and further mylonitic deformation, possibly during the Jurassic strike-slip movement of the Farallón plate relative to western Gondwana. The Otú-Pericos fault bounds these rocks to the west, where Jurassic metabasic and metapelitic sequences with serpentinites interleaved and formed in a collisional setting. Our findings suggest that the Pacific margin of northern South America underwent subduction-related extension during the middle Triassic and evolved towards a more oblique convergence during the Jurassic.
DOI: 10.6084/m9.figshare.19771481.v1
title: Tectonics and geothermal gradients from subduction to collision in the NW Variscan Iberian Massif

description: The earliest tectonometamorphic record of tectonic slices incorporated to the base of an orogen holds the key to understand how an orogen is built. The tectonic pile of the NW Iberian section of the Variscan Orogen includes tectonic slices separated by crustal-scale thrusts. The earliest tectonometamorphic record in the uppermost parautochthon is calculated at 11–14 kbar and 450–500°C (P-T gradient about 13°C/km), suggesting a subduction-related metamorphic recrystallization at lower pressure than the overlying Lower Allochthon. Early conditions calculated in the autochthon (9–10 kbar and 425–450°C; 16°C/km) point to a relatively ‘cold’ collisional setting. Higher thermal gradients obtained from some sections of the autochthon (11–12 kbar and 700–725°C; 21°C/km) and the Lower Parautochthon (7.5 kbar and 550–700°C; 24–31°C/km), correspond to more advanced and ‘hot’ stages of collision. New U–Pb monazite geochronology indicates a 318–311 Ma age for the final formation of HT domes in the region. We propose the rapid decrease in P-T gradient (from &lt;10 to 16°C/km) documents a fail to sustain further burial along a regular subduction zone. We consider the subsequent increase in the geothermal gradient (from 16 to 31°C/km) as the culmination of previous crustal accretion and the onset of crustal underthrusting and later processes in a collisional stage. We propose these switches in the early tectonometamorphic record of individual tectonic slices as potential markers to track the transition from subduction to collision in collisional orogens.