cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.3453053.v1
title: Late Palaeozoic architecture and evolution of the southwestern Barents Sea: insights from a new generation of aeromagnetic data

description: A new generation of aeromagnetic surveys highlights the Caledonian basement grain and pre-Permian basin architecture of the southwestern Barents Sea. This configuration involved several Caledonian thrust sheets that reactivated and controlled the post-Caledonian rift development of the southwestern Barents Sea during Late Palaeozoic time. Contrary to previous geological models, we consider that the sub-Permian basins and underlying basement grain have a dominantly NNW–SSE orientation in most of the southwestern Barents Sea. Moreover, we do not see magnetic evidence that could support a major NE–SW or NNE–SSW regional axis that has commonly been proposed for the Late Palaeozoic rift system and inherited Caledonian structural grain in the Barents Sea.
DOI: 10.6084/m9.figshare.3453050
title: Tectonic evolution of the Sibumasu–Indochina terrane collision zone in Thailand and Malaysia: constraints from new U–Pb zircon chronology of SE Asian tin granitoids

description: Three principal granite provinces are defined across SE Asia, as follows. (1) The Western Thailand–Myanmar/Burma province consists of hornblende–biotite I-type granodiorite–granites and felsic biotite–K-feldspar (± garnet ± tourmaline) granites associated with abundant tin mineralization in greisen-type veins. New ion microprobe U–Pb dating results from Phuket Island show zircon core ages of 212 ± 2 and 214 ± 2 Ma and a thermal overprint with rims of 81.2 ± 1.2 and 85–75 Ma. (2) The North Thailand–West Malaya Main Range province has mainly S-type biotite granites and abundant tin mineralization resulting from crustal thickening following collision of the Sibumasu plate with Indochina during the Mid-Triassic. Biotite granites around Kuala Lumpur contain extremely U-rich zircons (up to 38000 ppm) that yield ages of 215 ± 7 and 210 ± 7 Ma. (3) The East Malaya province consists of dominantly Permian–Triassic I-type hornblende–biotite granites but with subordinate S-type plutons and A-type syenite–gabbros. Biotite–K-feldspar granites from Tioman Island off the east coast of Malaysia also yield a zircon age of 80 ± 1 Ma, showing Cretaceous magmatism in common with province 1. Geological and U–Pb geochronological data suggest that two east-dipping (in present-day coordinates) subduction zones are required during the Triassic, one along the Bentong–Raub Palaeo-Tethyan suture, and the other west of the Phuket–Burma province 1 belt.
DOI: 10.6084/m9.figshare.3453050.v1
title: Tectonic evolution of the Sibumasu–Indochina terrane collision zone in Thailand and Malaysia: constraints from new U–Pb zircon chronology of SE Asian tin granitoids

description: Three principal granite provinces are defined across SE Asia, as follows. (1) The Western Thailand–Myanmar/Burma province consists of hornblende–biotite I-type granodiorite–granites and felsic biotite–K-feldspar (± garnet ± tourmaline) granites associated with abundant tin mineralization in greisen-type veins. New ion microprobe U–Pb dating results from Phuket Island show zircon core ages of 212 ± 2 and 214 ± 2 Ma and a thermal overprint with rims of 81.2 ± 1.2 and 85–75 Ma. (2) The North Thailand–West Malaya Main Range province has mainly S-type biotite granites and abundant tin mineralization resulting from crustal thickening following collision of the Sibumasu plate with Indochina during the Mid-Triassic. Biotite granites around Kuala Lumpur contain extremely U-rich zircons (up to 38000 ppm) that yield ages of 215 ± 7 and 210 ± 7 Ma. (3) The East Malaya province consists of dominantly Permian–Triassic I-type hornblende–biotite granites but with subordinate S-type plutons and A-type syenite–gabbros. Biotite–K-feldspar granites from Tioman Island off the east coast of Malaysia also yield a zircon age of 80 ± 1 Ma, showing Cretaceous magmatism in common with province 1. Geological and U–Pb geochronological data suggest that two east-dipping (in present-day coordinates) subduction zones are required during the Triassic, one along the Bentong–Raub Palaeo-Tethyan suture, and the other west of the Phuket–Burma province 1 belt.
DOI: 10.6084/m9.figshare.3453047
title: Palaeomagnetism and <sup>40</sup>Ar/<sup>39</sup>Ar dating from Lower Jurassic rocks in Gastre, central Patagonia: further data to explore tectonomagmatic events associated with the break-up of Gondwana

description: New <sup>40</sup>Ar/<sup>39</sup>Ar data indicate ages of <em>c</em>. 185 Ma for the Lonco Trapial volcanic field in Gastre, north–central Patagonia, implying that this andesitic unit is roughly coeval with the Marifil silicic province that crops out in the eastern part of northern Patagonia. These volcanic fields are therefore roughly coeval with the Karoo–Ferrar large igneous province, further contributing to the huge, 185–180 Ma magmatic outpouring in southern Gondwana. The comparison of palaeomagnetic results from the unit with Early Jurassic reference palaeopoles suggests that Gastre records a small, anticlockwise finite rotation with respect to stable South America. This contrasts sharply with the large clockwise rotation recorded by roughly coeval dolerites from the Falkland/Malvinas Islands, and argues against a direct relationship between the rotation of the islands and the tectonic activity in Gastre. The results support previous suggestions that the Gastre Fault System is not the locus of major strike-slip displacement activity in the Jurassic as some workers have suggested. Taken as a whole, palaeomagnetic data from Patagonia suggest a more complex than previously thought pattern of distributed and variable deformation during the early stages of Gondwana breakup. The crustal block boundaries in the region remain cryptic.
DOI: 10.6084/m9.figshare.3453047.v1
title: Palaeomagnetism and <sup>40</sup>Ar/<sup>39</sup>Ar dating from Lower Jurassic rocks in Gastre, central Patagonia: further data to explore tectonomagmatic events associated with the break-up of Gondwana

description: New <sup>40</sup>Ar/<sup>39</sup>Ar data indicate ages of <em>c</em>. 185 Ma for the Lonco Trapial volcanic field in Gastre, north–central Patagonia, implying that this andesitic unit is roughly coeval with the Marifil silicic province that crops out in the eastern part of northern Patagonia. These volcanic fields are therefore roughly coeval with the Karoo–Ferrar large igneous province, further contributing to the huge, 185–180 Ma magmatic outpouring in southern Gondwana. The comparison of palaeomagnetic results from the unit with Early Jurassic reference palaeopoles suggests that Gastre records a small, anticlockwise finite rotation with respect to stable South America. This contrasts sharply with the large clockwise rotation recorded by roughly coeval dolerites from the Falkland/Malvinas Islands, and argues against a direct relationship between the rotation of the islands and the tectonic activity in Gastre. The results support previous suggestions that the Gastre Fault System is not the locus of major strike-slip displacement activity in the Jurassic as some workers have suggested. Taken as a whole, palaeomagnetic data from Patagonia suggest a more complex than previously thought pattern of distributed and variable deformation during the early stages of Gondwana breakup. The crustal block boundaries in the region remain cryptic.
DOI: 10.6084/m9.figshare.3453044
title: Middle Triassic arc magmatism along the northeastern margin of the Tibet: U–Pb and Lu–Hf zircon characterization of the Gangcha complex in the West Qinling terrane, central China

description: The tectonic setting of Mesozoic magmatic complexes in the northeastern margin of the Tibet plateau is disputed, and hence gives rise to uncertainty concerning the tectonic evolution of the northeastern Tibet Plateau and the timing of the closure of the Palaeo-Tethys ocean. The Gangcha complex is typical of these complexes, consisting of andesite, dacite, gabbro, gabbroic diorite, granodiorite, quartz diorite, and diorite with typical chemical traits of continental margin arc rocks. Andesite, gabbroic diorite, and mineralization-associated potassic-altered diorite yield weighted mean <sup>206</sup>Pb/<sup>238</sup>U ages of 242.1 ± 1.2 Ma, 243.8 ± 1.0 Ma and 234.0 ± 0.6 Ma respectively. Zircon ϵ<sub>Hf</sub>(t) for magmatic grains ranges from −3.5 to +5.7, interpreted to demonstrate that the Gangcha complex contains crustally contaminated mantle magmas. Inherited zircons in the complex yield similar U–Pb ages (777–310 Ma) to the A’nyemaqen composite ophiolite assemblage with ϵ<sub>Hf</sub>(t) of −17.4 to +11.6. This suggests that components of this older ophiolite melted and contributed to the Gangcha complex magmas. Hence the Gangcha complex is considered to have formed as a continental margin arc in northeastern Tibet by northward subduction during consumption of the Palaeo-Tethys ocean. Regionally, it corresponds to the arc magmatism along the eastern and western Kunlun sutures to the west and the Mianlue suture to the east.
DOI: 10.6084/m9.figshare.3453038
title: Late Cretaceous–Cenozoic sediment and turbidite reservoir supply to South Atlantic margins

description: Maps have been compiled of indicators of uplift, denudation, sedimentation rates, igneous activity and climate over South Atlantic margins in order to develop the most consistent interpretation of the development of topography, climate and sediment supply through time. Continental margin uplifts and associated topography are concentrated in the Late Cretaceous and Oligocene–Recent periods, with the rates of sediment supply from these dependent on the occurrence of wet or rapidly changing climate. An irregular bimodality is seen on several aspects of African and Brazilian margin geology through time, particularly on periods of sediment progradation, high sedimentation rates and turbidite reservoir development, with peaks of "each centred on the Santonian and Miocene. Some regions show only one of these sedimentation rate peaks and the bimodal pattern, in general, is weaker for the Brazil margin, attributed to continuing uplift of southern Brazilian margins in the early Palaeogene. A crude relationship is observed between sedimentation rate and reserves in turbidite reservoirs. Sedimentary rate mapping can thus be used to identify turbidite fairways of different ages, tied in turn to drainage catchments containing a combination of high topography and wet climate. Additional implications for source rock development and burial history are also explored.
DOI: 10.6084/m9.figshare.3453038.v1
title: Late Cretaceous–Cenozoic sediment and turbidite reservoir supply to South Atlantic margins

description: Maps have been compiled of indicators of uplift, denudation, sedimentation rates, igneous activity and climate over South Atlantic margins in order to develop the most consistent interpretation of the development of topography, climate and sediment supply through time. Continental margin uplifts and associated topography are concentrated in the Late Cretaceous and Oligocene–Recent periods, with the rates of sediment supply from these dependent on the occurrence of wet or rapidly changing climate. An irregular bimodality is seen on several aspects of African and Brazilian margin geology through time, particularly on periods of sediment progradation, high sedimentation rates and turbidite reservoir development, with peaks of "each centred on the Santonian and Miocene. Some regions show only one of these sedimentation rate peaks and the bimodal pattern, in general, is weaker for the Brazil margin, attributed to continuing uplift of southern Brazilian margins in the early Palaeogene. A crude relationship is observed between sedimentation rate and reserves in turbidite reservoirs. Sedimentary rate mapping can thus be used to identify turbidite fairways of different ages, tied in turn to drainage catchments containing a combination of high topography and wet climate. Additional implications for source rock development and burial history are also explored.
DOI: 10.6084/m9.figshare.3453035.v1
title: Geochemical and petrological characterization of gem opals from Wegel Tena, Wollo, Ethiopia: opal formation in an Oligocene soil

description: Gem opals from Wegel Tena, Wollo Province, Ethiopia, occur in Oligocene rhyolitic ignimbrites. They display a unique geochemistry, with some samples yielding the highest Ba concentrations ever recorded. They are generally much richer in chemical impurities than opals from other localities. For example, the sum Al+Fe or the sum Na+Mg+Ca+K+Ba are often higher. These geochemical features make them easy to distinguish from other opals worldwide. We observed strong geochemical variations and some good positive correlations in our samples, such as Al+Fe vs. Na+Mg+Ca+K+Ba, Al vs Ca, or Ba vs Ca. This shows that the crystallography of opal has controlled, at least in part, the incorporation of chemical impurities, although opal is not well-crystallized. In addition, the multimodal distributions of several chemical impurities (e.g. U vs Sr, Al vs Ca, Ba vs Ca, etc.) suggest at least two origins of silica: weathering of feldspars and weathering of volcanic glass. In addition, opals from Wegel Tena contain numerous well-preserved microscopic plant fossils. Moreover, their host rock exhibits features typical of pedogenesis (abundant clays, desiccation cracks, and grain size sorting). We propose that the opals at Wegel Tena formed during the Oligocene period when volcanic emissions stopped for a time long enough to allow weathering of ingimbrites and therefore liberation of silica. This accompanied the formation of soil and development of plant life, and some plants were trapped in opal.
DOI: 10.6084/m9.figshare.3453032
title: Continental break-up along strike-slip fault zones; observations from the Equatorial Atlantic

description: The study focuses on Equatorial Atlantic margins, and draws from seismic, well, gravimetric and magnetic data combined with thermo-mechanical numerical modelling. Our data and numerical modelling indicates that early drift along strike-slip-originated margins is frequently characterized by up to 10°–20° spreading vector adjustments. In combination with the warm, thinned crust of the continental margin, these adjustments control localized transpression. Our observations indicate that early-drift margin slopes are too steep to hold sedimentary cover, which results in their inability to develop a moderately steep slope undergoing cycles of gravitational instability resulting in cyclic gravity gliding. These slopes either never develop such conditions or gain them at later development stages. Our modelling suggests that the continental margin undergoing strike-slip-controlled break-up experiences warming due to thinning along pull-apart basin systems. Pull-apart basins eventually develop sea-floor spreading ridges. Margins bounded by strike-slip faults located among pull-apart basins with these ridges first undergo cooling. However, spreading ridges leaving the break-up trace along its strike eventually pass by these cooling margins, warming them again before the final cooling proceeds. As a result, the structural highs surrounded by several source rock kitchens witness a sequential expulsion onset in different kitchens along the trajectory of spreading ridges.
DOI: 10.6084/m9.figshare.3453032.v1
title: Continental break-up along strike-slip fault zones; observations from the Equatorial Atlantic

description: The study focuses on Equatorial Atlantic margins, and draws from seismic, well, gravimetric and magnetic data combined with thermo-mechanical numerical modelling. Our data and numerical modelling indicates that early drift along strike-slip-originated margins is frequently characterized by up to 10°–20° spreading vector adjustments. In combination with the warm, thinned crust of the continental margin, these adjustments control localized transpression. Our observations indicate that early-drift margin slopes are too steep to hold sedimentary cover, which results in their inability to develop a moderately steep slope undergoing cycles of gravitational instability resulting in cyclic gravity gliding. These slopes either never develop such conditions or gain them at later development stages. Our modelling suggests that the continental margin undergoing strike-slip-controlled break-up experiences warming due to thinning along pull-apart basin systems. Pull-apart basins eventually develop sea-floor spreading ridges. Margins bounded by strike-slip faults located among pull-apart basins with these ridges first undergo cooling. However, spreading ridges leaving the break-up trace along its strike eventually pass by these cooling margins, warming them again before the final cooling proceeds. As a result, the structural highs surrounded by several source rock kitchens witness a sequential expulsion onset in different kitchens along the trajectory of spreading ridges.
DOI: 10.6084/m9.figshare.3453029
title: ImplementationGuide.pdf

description: The implementation guide for the Giving Researchers Credit for Their Data project, currently in phase 3 <br>
DOI: 10.6084/m9.figshare.3453029.v1
title: ImplementationGuide.pdf

description: The implementation guide for the Giving Researchers Credit for Their Data project, currently in phase 3 <br>
DOI: 10.6084/m9.figshare.3453023
title: Oxygen isotope variability in conodonts: implications for reconstructing Palaeozoic palaeoclimates and palaeoceanography

description: Conodonts have the potential to elucidate the intricacies of Palaeozoic climates, especially if δ<sup>18</sup>O values of single apatitic tooth-like ‘elements’ can be used to map evolving sea surface temperatures and differentiate oceanic water masses. Their ecological distribution as pelagic and nektobenthic organisms, high-resolution biostratigraphy, and abundance in Cambrian–Triassic rocks qualifies them as potentially robust climate archives. Previous ion microprobe conodont δ<sup>18</sup>O studies have proceeded directly to palaeotemperature interpretation without appreciation of inter- and intra-element variability or post-mortem artefacts. Here, ion microprobe analyses of Ordovician and Silurian conodonts establishes that: intra-element crown tissue δ<sup>18</sup>O typically varies by ≤1‰ (53% of conodonts analysed), is normally ≤2‰ (92% of analyses), and rarely varies by 2–4‰; δ<sup>18</sup>O can vary across elements, suggesting a microstructural and/or diagenetic control; δ<sup>18</sup>O can vary between species representatives by <em>c</em>. 3‰; δ<sup>18</sup>O of pelagic and nektobenthic taxa can be offset by 2–3‰; elements processed with formic acid have highly variable δ<sup>18</sup>O; and thermal alteration does affect δ<sup>18</sup>O. Conodont ion microprobe δ<sup>18</sup>O values are comparable with those of bulk methods, but utilization of material with no consideration of geological context or processing history may introduce significant artefacts. A protocol for future conodont oxygen isotope ion microprobe studies is proposed.
DOI: 10.6084/m9.figshare.3453020
title: Major early thrusting as a control on the Palaeoproterozoic evolution of the Lewisian Complex: evidence from the Outer Hebrides, NW Scotland

description: New structural, metamorphic and geochronological data suggest that the Lewisian Complex of the Outer Hebrides can be interpreted as a Proterozoic orogen in which a thrust sheet of juvenile arc material was driven over Archaean gneisses at an early stage. Incubation and loading of the underlying Archaean gneisses triggered prograde metamorphism and extensive ductile deformation with a strong gravitational flattening component combined with top-to-the-WNW transport. Large shear zones developed at this time are of local importance, but are not fundamental structural boundaries. The recognition of early orogenic thrusting followed by extensive ductile deformation shows a close resemblance to the sequence of events recognized within the Nagssugtoqidian orogen, with which the Lewisian Complex is correlated. As in the Nagssugtoqidian orogen, younger penetrative ductile deformation often masks the major structural boundaries formed by older thrusts.
DOI: 10.6084/m9.figshare.3453020.v1
title: Major early thrusting as a control on the Palaeoproterozoic evolution of the Lewisian Complex: evidence from the Outer Hebrides, NW Scotland

description: New structural, metamorphic and geochronological data suggest that the Lewisian Complex of the Outer Hebrides can be interpreted as a Proterozoic orogen in which a thrust sheet of juvenile arc material was driven over Archaean gneisses at an early stage. Incubation and loading of the underlying Archaean gneisses triggered prograde metamorphism and extensive ductile deformation with a strong gravitational flattening component combined with top-to-the-WNW transport. Large shear zones developed at this time are of local importance, but are not fundamental structural boundaries. The recognition of early orogenic thrusting followed by extensive ductile deformation shows a close resemblance to the sequence of events recognized within the Nagssugtoqidian orogen, with which the Lewisian Complex is correlated. As in the Nagssugtoqidian orogen, younger penetrative ductile deformation often masks the major structural boundaries formed by older thrusts.
DOI: 10.6084/m9.figshare.3453017
title: An Early Mesozoic transcontinental palaeoriver in South China: evidence from detrital zircon U–Pb geochronology and Hf isotopes

description: Detrital zircon geochronology reveals that Late Triassic–Early Jurassic fluvial sandstones from the major basins of the South China Craton have similar age patterns and define four populations at 2.6–2.4 Ga, 2.0–1.7 Ga, 850–700 Ma and 480–210 Ma. The late Palaeoproterozoic group is predominant in all of the five samples, and yielded remarkable age peaks at <em>c</em>. 1.85 Ga. These zircons have ϵ<sub>Hf</sub>(t) values between −22.5 and +3.6, suggesting derivation from reworked Archaean crust and minor juvenile crustal additions in the late Palaeoproterozoic. These characteristics differ from those of the Yangtze Block but correlate well with those of samples from the eastern Cathaysia Block. Palaeocurrent analysis of the Early Mesozoic sandstones shows predominant west- and NW-directed palaeoflows, supporting derivation of the sediments from the Cathaysia Block. The remarkable similarities in provenance signatures and spatial changes of lithofacies of the Triassic–Jurassic around the South China Craton delineate an east–west-trending sedimentary zone extending from Korea to West China. Accumulation of these sediments was probably related to the development of an active continental margin produced by westward subduction of the Palaeo-Pacific Plate. A <em>c</em>. 2000 km long westerly draining transcontinental palaeoriver probably had existed in the Early Mesozoic and fed the basins in Korea, South China and West China.