cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.3453578
title: A sedimentary archive of tectonic switching from Emeishan Plume to Indosinian orogenic sources in SW China

description: Upper Permian to Middle Triassic sedimentary rocks in the Youjiang Basin, SW China, record a change from a within-plate mafic-dominated source to the NW, to a mixed source involving magmatic arc and recycled orogenic detritus that lay to the west and east. Upper Permian and some Lower Triassic sedimentary rocks are characterized by relatively high contents of TiO<sub>2</sub> and Nb, and low ratios of Al<sub>2</sub>O<sub>3</sub>/TiO<sub>2</sub> and Th/Nb. Detrital zircons yield U–Pb ages of <em>c</em>. 260 Ma and have geochemical affinities to those crystallized from the within-plate type magmas. These features, combined with extensive basaltic lithic fragments and plagioclase grains in the sandstones, imply a sedimentary source dominated by the Emeishan Large Igneous Province exposed to the NW of the basin. The Early and Middle Triassic marked a significant change in sediment provenance, with rocks displaying geochemical affinity to upper continental crust. U–Pb ages and trace elements of detrital zircons from this material show input from multiple sedimentary sources including the subduction–collision rocks related to the Indosinian Orogeny to the west of the basin and the recycled Precambrian–early Palaeozoic sedimentary and granitic rocks in the South China hinterland to the east of the basin. The Early Triassic change in the nature of the source supplying detritus to the Youjiang Basin, together with regional sedimentary and tectonothermal events, suggests a tectonic transition from the Emeishan Plume to the Indosinian Orogeny in SW China. Regional stratigraphic correlation and provenance data suggest that the Emeishan basalts provided a large sediment influx for the riverine–littoral–marine systems in the Late Permian. This basaltic particulate and dissolved input may have contributed significant unradiogenic Sr to the Late Permian seawater.
DOI: 10.6084/m9.figshare.3453578.v1
title: A sedimentary archive of tectonic switching from Emeishan Plume to Indosinian orogenic sources in SW China

description: Upper Permian to Middle Triassic sedimentary rocks in the Youjiang Basin, SW China, record a change from a within-plate mafic-dominated source to the NW, to a mixed source involving magmatic arc and recycled orogenic detritus that lay to the west and east. Upper Permian and some Lower Triassic sedimentary rocks are characterized by relatively high contents of TiO<sub>2</sub> and Nb, and low ratios of Al<sub>2</sub>O<sub>3</sub>/TiO<sub>2</sub> and Th/Nb. Detrital zircons yield U–Pb ages of <em>c</em>. 260 Ma and have geochemical affinities to those crystallized from the within-plate type magmas. These features, combined with extensive basaltic lithic fragments and plagioclase grains in the sandstones, imply a sedimentary source dominated by the Emeishan Large Igneous Province exposed to the NW of the basin. The Early and Middle Triassic marked a significant change in sediment provenance, with rocks displaying geochemical affinity to upper continental crust. U–Pb ages and trace elements of detrital zircons from this material show input from multiple sedimentary sources including the subduction–collision rocks related to the Indosinian Orogeny to the west of the basin and the recycled Precambrian–early Palaeozoic sedimentary and granitic rocks in the South China hinterland to the east of the basin. The Early Triassic change in the nature of the source supplying detritus to the Youjiang Basin, together with regional sedimentary and tectonothermal events, suggests a tectonic transition from the Emeishan Plume to the Indosinian Orogeny in SW China. Regional stratigraphic correlation and provenance data suggest that the Emeishan basalts provided a large sediment influx for the riverine–littoral–marine systems in the Late Permian. This basaltic particulate and dissolved input may have contributed significant unradiogenic Sr to the Late Permian seawater.
DOI: 10.6084/m9.figshare.3453575
title: Sinai hinge belt: a major crustal boundary in NE Africa

description: The Sinai hinge belt is a major crustal boundary in northern Sinai separating different tectonic terranes. This boundary started as a number of ENE–WSW-oriented faults of Precambrian or Palaeozoic age and played a major role in the Mesozoic and Cenozoic tectonic evolution of NE Africa. The Sinai hinge belt was reactivated by normal faulting during Early Mesozoic opening of Neotethys and was later reactivated by dextral transpression during Late Cretaceous–Early Tertiary closure of Neotethys and dextral transtension in the Miocene. This study highlights the structural characteristics of the hinge belt and the nature of deformation of its fault segments. It also highlights the role of this basement structure as a crustal boundary between terranes of different tectonic settings as well as its relationship to the structural development of the nearby areas in NE Africa.
DOI: 10.6084/m9.figshare.3453575.v1
title: Sinai hinge belt: a major crustal boundary in NE Africa

description: The Sinai hinge belt is a major crustal boundary in northern Sinai separating different tectonic terranes. This boundary started as a number of ENE–WSW-oriented faults of Precambrian or Palaeozoic age and played a major role in the Mesozoic and Cenozoic tectonic evolution of NE Africa. The Sinai hinge belt was reactivated by normal faulting during Early Mesozoic opening of Neotethys and was later reactivated by dextral transpression during Late Cretaceous–Early Tertiary closure of Neotethys and dextral transtension in the Miocene. This study highlights the structural characteristics of the hinge belt and the nature of deformation of its fault segments. It also highlights the role of this basement structure as a crustal boundary between terranes of different tectonic settings as well as its relationship to the structural development of the nearby areas in NE Africa.
DOI: 10.6084/m9.figshare.3453572
title: An astronomical time scale for the Maastrichtian based on the Zumaia and Sopelana sections (Basque country, northern Spain)

description: The rhythmically bedded limestone–marl alternations in the coastal cliffs of Sopelana and Zumaia in the Basque country, northern Spain, permit testing and refining of existing Maastrichtian chronologies (latest Cretaceous). The recently established astronomical time scale for the late Maastrichtian at Zumaia is extended into C31n with the integrated stratigraphy of the Sopelana section. The cyclic alternations of hemipelagic limestones and marls at Sopelana show a strong influence of eccentricity-modulated precession. Together, the Zumaia and Sopelana sections span almost the entire Maastrichtian, and encompass thirteen 405 kyr cycles spanning a total duration of 5.3 myr. From the Cretaceous–Paleogene (K–Pg) boundary downwards, 405 kyr minima in the lithological, magnetic susceptibility and reflectance data records are tuned to successive 405 kyr minima in the new La2011 eccentricity solution. Assuming a K–Pg boundary age of 65.97 Ma, we present orbitally tuned ages of biostratigraphic and magnetostratigraphic events. Whereas the bases of Chrons C29r and C30n were reliably established at Zumaia and are in good agreement with previous studies, new data from Sopelana provide a refinement of the basal age of Chron C31r. Additional planktonic foraminifera and calcareous nannoplankton data from Zumaia, and new calcareous nannoplankton data from Sopelana, allow for worldwide correlation of the cyclostratigraphy of the Basque country.
DOI: 10.6084/m9.figshare.3453572.v1
title: An astronomical time scale for the Maastrichtian based on the Zumaia and Sopelana sections (Basque country, northern Spain)

description: The rhythmically bedded limestone–marl alternations in the coastal cliffs of Sopelana and Zumaia in the Basque country, northern Spain, permit testing and refining of existing Maastrichtian chronologies (latest Cretaceous). The recently established astronomical time scale for the late Maastrichtian at Zumaia is extended into C31n with the integrated stratigraphy of the Sopelana section. The cyclic alternations of hemipelagic limestones and marls at Sopelana show a strong influence of eccentricity-modulated precession. Together, the Zumaia and Sopelana sections span almost the entire Maastrichtian, and encompass thirteen 405 kyr cycles spanning a total duration of 5.3 myr. From the Cretaceous–Paleogene (K–Pg) boundary downwards, 405 kyr minima in the lithological, magnetic susceptibility and reflectance data records are tuned to successive 405 kyr minima in the new La2011 eccentricity solution. Assuming a K–Pg boundary age of 65.97 Ma, we present orbitally tuned ages of biostratigraphic and magnetostratigraphic events. Whereas the bases of Chrons C29r and C30n were reliably established at Zumaia and are in good agreement with previous studies, new data from Sopelana provide a refinement of the basal age of Chron C31r. Additional planktonic foraminifera and calcareous nannoplankton data from Zumaia, and new calcareous nannoplankton data from Sopelana, allow for worldwide correlation of the cyclostratigraphy of the Basque country.
DOI: 10.6084/m9.figshare.3453569
title: Deposit temperature of pyroclastic density currents emplaced during the El Chichón 1982 and Colima 1913 eruptions

description: New data on the pyroclastic density current (PDC) deposit temperature (<em>T</em><sub>dep</sub>) are provided for two prominent eruptions of Mexican volcanoes of the twentieth century: the 1982 eruption of El Chichón and the 1913 eruption of Colima. In spite of similar lithofacies, magma composition and pre-eruptive conditions, the <em>T</em><sub>dep</sub> of the PDCs from the 1982 (El Chichón) and 1913 (Colima) eruptions differ significantly, with intervals of <em>T</em><sub>dep</sub> of 360–420 °C and 250–330 °C, respectively. These new data emphasize that a full understanding of the physical mechanisms responsible for equilibrium temperature attainment within a pyroclastic deposit has not yet been realized. The <em>T</em><sub>dep</sub> measured for El Chichón PDC deposits confirm the preliminary data published elsewhere, while Colima magnetic temperatures provide different values to those published previously.
DOI: 10.6084/m9.figshare.3453566
title: Argon extraction from geological samples by CO<sub>2</sub> scanning laser step-heating

description: Lasers are fundamental tools for sampling in geochemical studies and have found wide application in mass spectrometric sample introduction systems. Here we describe an isotope extraction method for <sup>40</sup>Ar/<sup>39</sup>Ar geochronology using a new scanning CO<sub>2</sub> laser system. This method can partially un-mix radiogenic (<sup>40</sup>Ar*) from trapped argon components and provides an alternative to furnace step-heating methods. A key advantage of the laser scanning method developed at the Scottish Universities Environmental Research Centre (SUERC) is the ability to step-heat samples as large as 100 mg to fusion using low raster speeds, although care must be taken to avoid self-shielding of grains and proper laser targeting. The scanning laser extraction system has the potential for lower overall blanks and the ability to run blanks and calibrations between steps of a heating sequence. This provides better control on system performance and characterization during sample measurement and can result in improved data quality.
DOI: 10.6084/m9.figshare.3453569.v1
title: Deposit temperature of pyroclastic density currents emplaced during the El Chichón 1982 and Colima 1913 eruptions

description: New data on the pyroclastic density current (PDC) deposit temperature (<em>T</em><sub>dep</sub>) are provided for two prominent eruptions of Mexican volcanoes of the twentieth century: the 1982 eruption of El Chichón and the 1913 eruption of Colima. In spite of similar lithofacies, magma composition and pre-eruptive conditions, the <em>T</em><sub>dep</sub> of the PDCs from the 1982 (El Chichón) and 1913 (Colima) eruptions differ significantly, with intervals of <em>T</em><sub>dep</sub> of 360–420 °C and 250–330 °C, respectively. These new data emphasize that a full understanding of the physical mechanisms responsible for equilibrium temperature attainment within a pyroclastic deposit has not yet been realized. The <em>T</em><sub>dep</sub> measured for El Chichón PDC deposits confirm the preliminary data published elsewhere, while Colima magnetic temperatures provide different values to those published previously.
DOI: 10.6084/m9.figshare.3453566.v1
title: Argon extraction from geological samples by CO<sub>2</sub> scanning laser step-heating

description: Lasers are fundamental tools for sampling in geochemical studies and have found wide application in mass spectrometric sample introduction systems. Here we describe an isotope extraction method for <sup>40</sup>Ar/<sup>39</sup>Ar geochronology using a new scanning CO<sub>2</sub> laser system. This method can partially un-mix radiogenic (<sup>40</sup>Ar*) from trapped argon components and provides an alternative to furnace step-heating methods. A key advantage of the laser scanning method developed at the Scottish Universities Environmental Research Centre (SUERC) is the ability to step-heat samples as large as 100 mg to fusion using low raster speeds, although care must be taken to avoid self-shielding of grains and proper laser targeting. The scanning laser extraction system has the potential for lower overall blanks and the ability to run blanks and calibrations between steps of a heating sequence. This provides better control on system performance and characterization during sample measurement and can result in improved data quality.
DOI: 10.6084/m9.figshare.3453563
title: Impacts of arc collision on small orogens: new insights from the Coastal Range detrital record, Taiwan

description: Taiwan is considered the archetypical orogen in the development of critical wedge models of mountain building; however, the issue of how arc collision progressed along the margin remains poorly understood. To resolve this, the detrital archive of orogenesis preserved in Coastal Range rocks of eastern Taiwan was used to reconstruct the erosional response of arc collision. The spatial and temporal distribution of exhumation recorded in this detrital record is consistent with southwards progression of arc–continent collision in a punctuated rather than sequential manner with deposition confined to segmented foredeep basins. Apparent increases in sedimentation rates in Taiwan during the Pleistocene may not reflect increased erosion, but instead may be due to the collisional margin architecture.
DOI: 10.6084/m9.figshare.3453557
title: Palaeomagnetic evidence for the age of the Cumbrian and Manx hematite ore deposits: implications for the origin of hematite mineralization at the margins of the East Irish Sea Basin, UK

description: Examples of epigenetic hematite mineralization located at the margins of the East Irish Sea Basin have been sampled for palaeomagnetic investigation to establish the timing of ore formation. Samples collected from 10 sites in Cumbria are dominated by hematite of near-pure composition and characterized by dual polarity and, in part, dual component magnetizations that yield palaeopoles (nine sites) between 50°N, 130°E and 50°N, 150°E. In contrast, samples recovered from seven sites on the Isle of Man have more varied mineralogical compositions that include ferromagnets with lower unblocking temperatures. Manx hematite mineralization also exhibits dual polarity, but magnetizations yield steeper inclinations with palaeopoles lying between 55°N, 130°E and 70°N, 150°E. Steeper directions probably reflect minor tilting of the Manx block following hematite emplacement. Correlation of poles with the European apparent polar wander path indicates that these ore deposits formed during the Middle Triassic. Results show that hematite mineralization sited at the margins of the East Irish Sea Basin is essentially contemporaneous and establishes, for the first time, an underlying temporal relationship between these geographically dispersed ore bodies. Dating places the mineralization within a broader extensional geotectonic regime associated with the early rifting of Pangaea in the North Atlantic. The context implies a causal link between crustal extension, development of ore-forming fluids within the evolving East Irish Sea Basin, and subsequent migration of fluids to basin margins where iron was precipitated as hematite.
DOI: 10.6084/m9.figshare.3453557.v1
title: Palaeomagnetic evidence for the age of the Cumbrian and Manx hematite ore deposits: implications for the origin of hematite mineralization at the margins of the East Irish Sea Basin, UK

description: Examples of epigenetic hematite mineralization located at the margins of the East Irish Sea Basin have been sampled for palaeomagnetic investigation to establish the timing of ore formation. Samples collected from 10 sites in Cumbria are dominated by hematite of near-pure composition and characterized by dual polarity and, in part, dual component magnetizations that yield palaeopoles (nine sites) between 50°N, 130°E and 50°N, 150°E. In contrast, samples recovered from seven sites on the Isle of Man have more varied mineralogical compositions that include ferromagnets with lower unblocking temperatures. Manx hematite mineralization also exhibits dual polarity, but magnetizations yield steeper inclinations with palaeopoles lying between 55°N, 130°E and 70°N, 150°E. Steeper directions probably reflect minor tilting of the Manx block following hematite emplacement. Correlation of poles with the European apparent polar wander path indicates that these ore deposits formed during the Middle Triassic. Results show that hematite mineralization sited at the margins of the East Irish Sea Basin is essentially contemporaneous and establishes, for the first time, an underlying temporal relationship between these geographically dispersed ore bodies. Dating places the mineralization within a broader extensional geotectonic regime associated with the early rifting of Pangaea in the North Atlantic. The context implies a causal link between crustal extension, development of ore-forming fluids within the evolving East Irish Sea Basin, and subsequent migration of fluids to basin margins where iron was precipitated as hematite.
DOI: 10.6084/m9.figshare.3453551
title: Tectonomagmatic evolution of the Early Ordovician suprasubduction-zone ophiolites of the Trondheim Region, Mid-Norwegian Caledonides

description: The Trondheim Region ophiolites in the Mid-Norwegian Caledonides represent variably tectonized ophiolite fragments. We present high-precision thermal-ionization mass spectrometry and secondary-ion mass spectrometry (SIMS) U–Pb zircon dates, whole-rock geochemical and Sm–Nd data and Lu–Hf zircon analyses that permit the timing and nature of various stages in the evolution of the ophiolite to be elucidated. Plagiogranite intrusions dated at 487 and 480 Ma have relatively juvenile Nd and Hf isotopic compositions (ε<sub>Nd(<em>t</em>)</sub>=6.3, ε<sub>Hf(<em>t</em>)</sub>=8.2–12.4). Geochemical data indicate a subduction-zone influence, suggesting formation in an oceanic back-arc setting. At 481 Ma, a granitoid body with a relatively strong unradiogenic Nd and Hf isotopic composition (ε<sub>Nd(<em>t</em>)</sub>=−2.6 to −4.0, ε<sub>Hf(<em>t</em>)</sub>=3.8–6.4) and subduction-zone geochemical signature intruded the ophiolite. We interpret this stage to reflect the formation or migration of an oceanic arc above a subduction zone influenced by continentally derived sediments. At <em>c.</em> 475–465 Ma, a greenstone-dominated conglomerate and volcaniclastic sequence was deposited on the eroded ophiolite, indicating obduction between about 480 and 475 Ma. At <em>c.</em> 468–467 Ma, the deformed ophiolite and its sedimentary cover was intruded by trondhjemite dykes and shoshonitic volcanic rocks with intermediate Nd and Hf isotopic compositions (ε<sub>Nd(<em>t</em>)</sub>=3.0–3.9, ε<sub>Hf(<em>t</em>)</sub>=4.4–10.2). We interpret this magmatism to reflect subduction-polarity reversal and establishment of a magmatic arc at the continental margin shortly after obduction.
DOI: 10.6084/m9.figshare.3453548
title: Tectonic-diffusion estimates of global mineral resources: extending the method: granitic tin deposits

description: In this study, we have used tectonic-diffusion model calculations to estimate resources of bedrock-hosted granitic tin deposits of Phanerozoic age. These deposits range from proximal skarns, greisens and pegmatites in or near plutonic granites, to distal veins and disseminations, many of which are associated with subvolcanic rhyolites. Tin is also found in residual and placer deposits, some of which are associated with bedrock deposits. Most of the bedrock deposits formed at temperatures of 200–500 °C from fluids with a wide range of salinities and CO<sub>2</sub> contents. Limited information suggests that they formed over a relatively continuous range of depths from a few hundred metres to as much as 6 km, with an average of about 2 km. Information was obtained on 547 deposits, including 435 with measured or estimated ages and 301 with estimated tin contents, almost all of which are bedrock rather than residual-placer deposits. The bedrock deposits have an average size of 58 000 t, and the largest five deposits, including one in Bolivia and four in China, account for 46% of the total tin resources in all deposits. Tectonic-diffusion model calculations indicate that approximately 14 520 granitic tin deposits remain in the crust and that they contain 8.4×10<sup>8</sup> t of tin. If about 50% of the deposits above depths of 1 km can be discovered and mined, current tin production of about 260 000 t annually can continue for about another 200 years.
DOI: 10.6084/m9.figshare.3453548.v1
title: Tectonic-diffusion estimates of global mineral resources: extending the method: granitic tin deposits

description: In this study, we have used tectonic-diffusion model calculations to estimate resources of bedrock-hosted granitic tin deposits of Phanerozoic age. These deposits range from proximal skarns, greisens and pegmatites in or near plutonic granites, to distal veins and disseminations, many of which are associated with subvolcanic rhyolites. Tin is also found in residual and placer deposits, some of which are associated with bedrock deposits. Most of the bedrock deposits formed at temperatures of 200–500 °C from fluids with a wide range of salinities and CO<sub>2</sub> contents. Limited information suggests that they formed over a relatively continuous range of depths from a few hundred metres to as much as 6 km, with an average of about 2 km. Information was obtained on 547 deposits, including 435 with measured or estimated ages and 301 with estimated tin contents, almost all of which are bedrock rather than residual-placer deposits. The bedrock deposits have an average size of 58 000 t, and the largest five deposits, including one in Bolivia and four in China, account for 46% of the total tin resources in all deposits. Tectonic-diffusion model calculations indicate that approximately 14 520 granitic tin deposits remain in the crust and that they contain 8.4×10<sup>8</sup> t of tin. If about 50% of the deposits above depths of 1 km can be discovered and mined, current tin production of about 260 000 t annually can continue for about another 200 years.