cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.3454043.v1
title: Reappraisal of Early Cretaceous highly enriched mantle beneath the Dabie Orogen: evidence from mineralogy and geochemistry of the Xiaohekou complex

description: An Early Cretaceous highly enriched mantle beneath the Dabie Orogen, previously proposed on the basis of exceedingly enriched isotopic signatures documented in intermediate–mafic–ultramafic complexes, has been re-evaluated by new field, mineralogical and geochemical data from the best exposed Xiaohekou complex. The Xiaohekou complex consists of three pyroxenite cores intruded by olivine gabbronorite dykes and successively surrounded outward by gabbroic rocks, leucogabbros and monzonites. Textural and compositional data for pyroxenes and plagioclase as well as whole-rock geochemistry suggest two-stage crystallizations. The Sr–Nd isotopic values correlate with the SiO<sub>2</sub> and MgO contents, and one gabbronorite sample from the margin of the complex has sodic plagioclase and highly enriched Sr–Nd isotopic ratios, also pointing to fractional crystallizations and crustal contamination. One gabbro sample from the centre of the complex and three from olivine gabbronorite dykes have the lowest Sr but highest Nd isotopic values close to those of typical Enriched Mantle I (EMI). These data together with isotopic and MELTS modelling suggest that an EMI-like mantle source plus crustal assimilation and crystallization can explain all field, mineralogical and geochemical characteristics of the Xiaohekou complex, without the need to invoke a mantle source more enriched than EMI beneath the Dabie Orogen.
DOI: 10.6084/m9.figshare.3454040
title: Depositional characteristics of the northern South China Sea in response to the evolution of the Pearl River

description: Geochemical data from South China Sea sedimentary rocks show the effects of both source composition and depositional environments. This enables us to link tectonic trends with erosion in the Pearl River region since <em>c.</em> 32 Ma. In particular, a shift in the geochemistry appears to signal a response to a well-recorded regional tectonic event at <em>c.</em> 23–25 Ma, probably corresponding to a jump in the seafloor spreading axis from the west to the SW within the South China Sea. This may correlate with the uplift of the West Yunnan Plateau and possibly also the eastern Tibetan Plateau. Clay mineralogy, sand–mud ratio, and major and rare earth element concentrations, also varied in response to the environment in the drainage areas of the palaeo-Pearl River. By comparing data from the modern sources and the sedimentary record from the northern South China Sea, especially the erosion–transportation–deposition patterns, three groups of index minerals (Ati, GZi, ZTR), as well as rare earth elements can be recognized. These are used to characterize the Pearl River from the east to the west, representing three different parent rock sources. The evolution of the palaeo-Pearl River can be tracked by variations of heavy minerals and key elements that are indicative of provenance.
DOI: 10.6084/m9.figshare.3454040.v1
title: Depositional characteristics of the northern South China Sea in response to the evolution of the Pearl River

description: Geochemical data from South China Sea sedimentary rocks show the effects of both source composition and depositional environments. This enables us to link tectonic trends with erosion in the Pearl River region since <em>c.</em> 32 Ma. In particular, a shift in the geochemistry appears to signal a response to a well-recorded regional tectonic event at <em>c.</em> 23–25 Ma, probably corresponding to a jump in the seafloor spreading axis from the west to the SW within the South China Sea. This may correlate with the uplift of the West Yunnan Plateau and possibly also the eastern Tibetan Plateau. Clay mineralogy, sand–mud ratio, and major and rare earth element concentrations, also varied in response to the environment in the drainage areas of the palaeo-Pearl River. By comparing data from the modern sources and the sedimentary record from the northern South China Sea, especially the erosion–transportation–deposition patterns, three groups of index minerals (Ati, GZi, ZTR), as well as rare earth elements can be recognized. These are used to characterize the Pearl River from the east to the west, representing three different parent rock sources. The evolution of the palaeo-Pearl River can be tracked by variations of heavy minerals and key elements that are indicative of provenance.
DOI: 10.6084/m9.figshare.3454037
title: New species of Neogene radiolarians from the Southern Ocean – part IV

description: In this last paper in our planned series, we describe 25 new radiolarian species from the Antarctic Neogene: 6 spumellarians (<em>Lithatractus</em>? <em>floridus, Spongopylidium</em>? <em>aerostatum, Haeckeliella hederacia, Larcopyle faustae, Excentrodiscus planangulus</em> and <em>E. lappaceus</em>) and 19 nassellarians (<em>Anthocyrtidium</em> sp., <em>Artostrobus</em>? <em>oganeae, Botryostrobus exstructus, Ceratospyris clarki, Cornutella burgundiensis, Cystophormis petrushevskayae, Dendrospyris quadripes, Enneaphormis tippula, Euscenarium funakawai, Lophophaena kamikurii, L. rhopalica, Lychnocanium andreae, Periarachnium pauliani, Peridium tortonianicum, Phormacantha garbela, Phormospyris punnulis, Rhodospyris</em>? <em>morleyi, Rhodospyris pulchra</em> and <em>Tholospyris tautessares</em>). We also report the finding of fragments of an unknown Middle Miocene phaeodarian (<em>Conchellium</em>? sp.).
DOI: 10.6084/m9.figshare.3454037.v1
title: New species of Neogene radiolarians from the Southern Ocean – part IV

description: In this last paper in our planned series, we describe 25 new radiolarian species from the Antarctic Neogene: 6 spumellarians (<em>Lithatractus</em>? <em>floridus, Spongopylidium</em>? <em>aerostatum, Haeckeliella hederacia, Larcopyle faustae, Excentrodiscus planangulus</em> and <em>E. lappaceus</em>) and 19 nassellarians (<em>Anthocyrtidium</em> sp., <em>Artostrobus</em>? <em>oganeae, Botryostrobus exstructus, Ceratospyris clarki, Cornutella burgundiensis, Cystophormis petrushevskayae, Dendrospyris quadripes, Enneaphormis tippula, Euscenarium funakawai, Lophophaena kamikurii, L. rhopalica, Lychnocanium andreae, Periarachnium pauliani, Peridium tortonianicum, Phormacantha garbela, Phormospyris punnulis, Rhodospyris</em>? <em>morleyi, Rhodospyris pulchra</em> and <em>Tholospyris tautessares</em>). We also report the finding of fragments of an unknown Middle Miocene phaeodarian (<em>Conchellium</em>? sp.).
DOI: 10.6084/m9.figshare.3454034
title: A continental-scale geochemical atlas for resource exploration and environmental management: the National Geochemical Survey of Australia

description: The National Geochemical Survey of Australia (NGSA) was carried out to bridge a vast knowledge gap about the concentration and distribution of chemical elements at the Earth’s surface in Australia and consequent poor understanding of processes controlling their distribution here. The aim of the project was to contribute to improving exploration for energy and mineral resources through the pre-competitive delivery of a new spatial layer of compositional data and information. Surface (0–10 cm depth) and shallow (<em>c</em>. 60–80 cm) samples of catchment outlet sediments were collected from 1315 sites located near the outlet of 1186 catchments (<em>c</em>. 10% of which were sampled in duplicate) from across Australia. The total area covered by the survey was 6.174 million km<sup>2</sup>, or <em>c</em>. 81% of Australia, at an average sampling density of 1 site per <em>c</em>. 5200 km<sup>2</sup>. A number of field parameters (e.g. soil colour, pH), bulk parameters (e.g. electrical conductivity, particle size distribution) and geochemical parameters (i.e. multi-element composition of dry sieved &lt;2 mm and &lt;75 μm grain-size fractions) were determined. The grain-size fractions were analysed to determine (1) total, (2) aqua regia soluble, and (3) Mobile Metal Ion (MMI®) extractable element contents. These data were collated into a spreadsheet and graphically represented as a series of 529 geochemical maps (http://www.ga.gov.au/ngsa). These constitute the first continental-scale series of geochemical maps for Australia based on internally consistent, state-of-the-art data pertaining to the same sampling medium collected, prepared and analysed in a uniform and thoroughly documented manner and over a short time period. They are being used to better understand the accumulation, mobility and significance of chemical elements in the near-surface environment. Applications to date and ongoing and future directions are discussed.
DOI: 10.6084/m9.figshare.3454031
title: Progressive orocline formation in the Eastern Pontides–Lesser Caucasus

description: The Eastern Pontides–Lesser Caucasus fold–thrust belt displays a peculiar northwards arc-shaped geometry that was defined as an orocline in earlier studies. The Lesser Caucasus was affected by two main tectonic events that could have caused orocline formation: (1) Paleocene–Eocene collision of the South Armenian Block with Eurasia; and (2) Oligocene–Miocene Arabia–Eurasia collision. We tested the hypothesis that the Lesser Caucasus is an orocline and aimed to time the formation of this orocline. To determine the vertical axis rotations, 37 sites were sampled for palaeomagnetism in rocks of Upper Cretaceous–Miocene age in Georgia and Armenia. In addition, we compiled a review of <em>c.</em> 100 available datasets. A strike test was applied to the remaining datasets, which were divided into four chronological sub-sets, leading us to conclude that the Eastern Pontides–Lesser Caucasus fold–thrust belt forms a progressive orocline. We concluded that: (1) some pre-existing curvature must have been present before the Late Cretaceous; (2) the orocline acquired part of its curvature after the Paleocene and before the Middle Eocene as a result of South Armenian Block–Eurasia collision; and (3) about 50% of the curvature formed after the Eocene and probably before the Late Miocene, probably as a result of Arabia–Eurasia collision.
DOI: 10.6084/m9.figshare.3454034.v1
title: A continental-scale geochemical atlas for resource exploration and environmental management: the National Geochemical Survey of Australia

description: The National Geochemical Survey of Australia (NGSA) was carried out to bridge a vast knowledge gap about the concentration and distribution of chemical elements at the Earth’s surface in Australia and consequent poor understanding of processes controlling their distribution here. The aim of the project was to contribute to improving exploration for energy and mineral resources through the pre-competitive delivery of a new spatial layer of compositional data and information. Surface (0–10 cm depth) and shallow (<em>c</em>. 60–80 cm) samples of catchment outlet sediments were collected from 1315 sites located near the outlet of 1186 catchments (<em>c</em>. 10% of which were sampled in duplicate) from across Australia. The total area covered by the survey was 6.174 million km<sup>2</sup>, or <em>c</em>. 81% of Australia, at an average sampling density of 1 site per <em>c</em>. 5200 km<sup>2</sup>. A number of field parameters (e.g. soil colour, pH), bulk parameters (e.g. electrical conductivity, particle size distribution) and geochemical parameters (i.e. multi-element composition of dry sieved &lt;2 mm and &lt;75 μm grain-size fractions) were determined. The grain-size fractions were analysed to determine (1) total, (2) aqua regia soluble, and (3) Mobile Metal Ion (MMI®) extractable element contents. These data were collated into a spreadsheet and graphically represented as a series of 529 geochemical maps (http://www.ga.gov.au/ngsa). These constitute the first continental-scale series of geochemical maps for Australia based on internally consistent, state-of-the-art data pertaining to the same sampling medium collected, prepared and analysed in a uniform and thoroughly documented manner and over a short time period. They are being used to better understand the accumulation, mobility and significance of chemical elements in the near-surface environment. Applications to date and ongoing and future directions are discussed.
DOI: 10.6084/m9.figshare.3454031.v1
title: Progressive orocline formation in the Eastern Pontides–Lesser Caucasus

description: The Eastern Pontides–Lesser Caucasus fold–thrust belt displays a peculiar northwards arc-shaped geometry that was defined as an orocline in earlier studies. The Lesser Caucasus was affected by two main tectonic events that could have caused orocline formation: (1) Paleocene–Eocene collision of the South Armenian Block with Eurasia; and (2) Oligocene–Miocene Arabia–Eurasia collision. We tested the hypothesis that the Lesser Caucasus is an orocline and aimed to time the formation of this orocline. To determine the vertical axis rotations, 37 sites were sampled for palaeomagnetism in rocks of Upper Cretaceous–Miocene age in Georgia and Armenia. In addition, we compiled a review of <em>c.</em> 100 available datasets. A strike test was applied to the remaining datasets, which were divided into four chronological sub-sets, leading us to conclude that the Eastern Pontides–Lesser Caucasus fold–thrust belt forms a progressive orocline. We concluded that: (1) some pre-existing curvature must have been present before the Late Cretaceous; (2) the orocline acquired part of its curvature after the Paleocene and before the Middle Eocene as a result of South Armenian Block–Eurasia collision; and (3) about 50% of the curvature formed after the Eocene and probably before the Late Miocene, probably as a result of Arabia–Eurasia collision.
DOI: 10.6084/m9.figshare.3454025
title: Mesozoic to recent geological history of southern Crimea and the Eastern Black Sea region

description: We provide a synthesis of stratigraphic data to unravel the history of the geological evolution of South Crimea in the Mesozoic and Cenozoic. The South Crimea Orogen consists of three major mega-sequences: (1) the Triassic–Early Jurassic; (2) the Aalenian–Bathonian; and (3) the Callovian–Eocene. The Late Triassic–Early Jurassic deposits formed in the environment of a forearc basin and a remnant basin. The Aalenian–Bathonian deposits formed above subduction extension and a volcanic belt. Three main Callovian–Eocene tectonic units can be identified in South Crimea: (1) the South Crimean Shelf Basin; (2) the Sudak Deepwater Trough; and (3) the Alchak–Kaya Shelf Basin at the northern margin of the Shatsky Ridge. The Oligocene–Quaternary deposits are considered to be syn-orogenic. A description of the anticipated stratigraphic units on the Shatsky Ridge is suggested for the Middle Jurassic, Callovian–Late Jurassic, Neocomian, Aptian–Albian, Late Cretaceous–Paleocene, Eocene and Maykopian. We propose a model for the geological history of the Eastern Black Sea Basin. Graben formed during the Late Barremian–Albian at the location of the future Eastern Black Sea Basin and a phase of volcanism occurred in the Albian. The main phase of rifting and spreading of oceanic crust took place during Cenomanian–Santonian time.
DOI: 10.6084/m9.figshare.3454025.v1
title: Mesozoic to recent geological history of southern Crimea and the Eastern Black Sea region

description: We provide a synthesis of stratigraphic data to unravel the history of the geological evolution of South Crimea in the Mesozoic and Cenozoic. The South Crimea Orogen consists of three major mega-sequences: (1) the Triassic–Early Jurassic; (2) the Aalenian–Bathonian; and (3) the Callovian–Eocene. The Late Triassic–Early Jurassic deposits formed in the environment of a forearc basin and a remnant basin. The Aalenian–Bathonian deposits formed above subduction extension and a volcanic belt. Three main Callovian–Eocene tectonic units can be identified in South Crimea: (1) the South Crimean Shelf Basin; (2) the Sudak Deepwater Trough; and (3) the Alchak–Kaya Shelf Basin at the northern margin of the Shatsky Ridge. The Oligocene–Quaternary deposits are considered to be syn-orogenic. A description of the anticipated stratigraphic units on the Shatsky Ridge is suggested for the Middle Jurassic, Callovian–Late Jurassic, Neocomian, Aptian–Albian, Late Cretaceous–Paleocene, Eocene and Maykopian. We propose a model for the geological history of the Eastern Black Sea Basin. Graben formed during the Late Barremian–Albian at the location of the future Eastern Black Sea Basin and a phase of volcanism occurred in the Albian. The main phase of rifting and spreading of oceanic crust took place during Cenomanian–Santonian time.
DOI: 10.6084/m9.figshare.3454013
title: Constraining magmatic fluxes through thermal modelling of contact metamorphism

description: The thermal evolution of a contact aureole is strongly dependent on the emplacement mode of the intrusion that is causing the thermal anomaly. Inferences on the emplacement mode can be made if solid temperature estimates are available. The contact aureole of the Western Adamello Tonalite provides a unique combination of magma ascent close to the host rock and suitable rock chemistry. We use three mineral reactions at different distances in the aureole in combination with phase petrology to estimate temperatures. These temperatures are not reproducible by thermal models considering the emplacement of the intrusion as a single batch. The external zone of the intrusion represents a feeder conduit in which magma was transported. We investigated the thermal effect of the conduit on the host rocks using thermal models. Different thermal profiles for the aureole are obtained by varying flow/no-flow times, conduit thickness and magma temperature. We show that only a few combinations match the temperature constraints in the aureole, and that the amount of magma transported through the conduit can be calculated. A comparison with time-averaged fluxes of recent volcanoes and the presence of reworked volcanic sediments in the surroundings of the Adamello batholith indicate that the calculated rates and volumes are plausible.
DOI: 10.6084/m9.figshare.3454013.v1
title: Constraining magmatic fluxes through thermal modelling of contact metamorphism

description: The thermal evolution of a contact aureole is strongly dependent on the emplacement mode of the intrusion that is causing the thermal anomaly. Inferences on the emplacement mode can be made if solid temperature estimates are available. The contact aureole of the Western Adamello Tonalite provides a unique combination of magma ascent close to the host rock and suitable rock chemistry. We use three mineral reactions at different distances in the aureole in combination with phase petrology to estimate temperatures. These temperatures are not reproducible by thermal models considering the emplacement of the intrusion as a single batch. The external zone of the intrusion represents a feeder conduit in which magma was transported. We investigated the thermal effect of the conduit on the host rocks using thermal models. Different thermal profiles for the aureole are obtained by varying flow/no-flow times, conduit thickness and magma temperature. We show that only a few combinations match the temperature constraints in the aureole, and that the amount of magma transported through the conduit can be calculated. A comparison with time-averaged fluxes of recent volcanoes and the presence of reworked volcanic sediments in the surroundings of the Adamello batholith indicate that the calculated rates and volumes are plausible.
DOI: 10.6084/m9.figshare.3454010
title: Lithospheric structure in Central Eurasia derived from elevation, geoid anomaly and thermal analysis

description: We present new crustal and lithospheric thickness maps for Central Eurasia from the combination of elevation and geoid anomaly data and thermal analysis. The results are strongly constrained by numerous previous data based on seismological and seismic experiments, tomographic imaging and integrated geophysical studies. Our results indicate that high topography regions are associated with crustal thickening that is at a maximum below the Zagros, Himalaya, Tien Shan and the Tibetan Plateau. The stiffer continental blocks that remain undeformed within the continental collision areas are characterized by a slightly thickened crust and flat topography. Lithospheric thickness and crustal thickness show different patterns that highlight an important strain partitioning within the lithosphere. The Arabia–Eurasia collision zone is characterized by a thick lithosphere underneath the Zagros belt, whereas a thin to non-existent lithospheric mantle is observed beneath the Iranian and Anatolian plateaus. Conversely, the India–Eurasia collision zone is characterized by a very thick lithosphere below its southern part as a consequence of the underplating of the cold and stiff Indian lithosphere. Our new model presents great improvements compared to previous global models available for the region, and allows us to discuss major aspects related to the lithospheric structure and acting geodynamic processes in Central Eurasia.
DOI: 10.6084/m9.figshare.3454010.v1
title: Lithospheric structure in Central Eurasia derived from elevation, geoid anomaly and thermal analysis

description: We present new crustal and lithospheric thickness maps for Central Eurasia from the combination of elevation and geoid anomaly data and thermal analysis. The results are strongly constrained by numerous previous data based on seismological and seismic experiments, tomographic imaging and integrated geophysical studies. Our results indicate that high topography regions are associated with crustal thickening that is at a maximum below the Zagros, Himalaya, Tien Shan and the Tibetan Plateau. The stiffer continental blocks that remain undeformed within the continental collision areas are characterized by a slightly thickened crust and flat topography. Lithospheric thickness and crustal thickness show different patterns that highlight an important strain partitioning within the lithosphere. The Arabia–Eurasia collision zone is characterized by a thick lithosphere underneath the Zagros belt, whereas a thin to non-existent lithospheric mantle is observed beneath the Iranian and Anatolian plateaus. Conversely, the India–Eurasia collision zone is characterized by a very thick lithosphere below its southern part as a consequence of the underplating of the cold and stiff Indian lithosphere. Our new model presents great improvements compared to previous global models available for the region, and allows us to discuss major aspects related to the lithospheric structure and acting geodynamic processes in Central Eurasia.
DOI: 10.6084/m9.figshare.3454007
title: Talas–Fergana Fault Cenozoic timing of deformation and its relation to Pamir indentation

description: Regional strike-slip faults are widely distributed in continental interiors and play a major role in the distribution of far-field deformation due to continental collisions. Constraining the deformation history of the Talas–Fergana Fault (TFF), one of the largest of such faults in the Himalayan deformed interior, is vital to comprehend the hinterland kinematics of the India–Asia collision. New apatite fission track results from the NW Tien Shan define a rapid exhumation event at <em>c.</em> 25 Ma. This event is correlated with a synchronous pulse in the South Tien Shan, implying that both ranges experienced a simultaneous onset of rapid exhumation. We suggest that strike-slip motion along the TFF commenced at <em>c.</em> 25 Ma, facilitating counter-clockwise rotation of the Fergana Basin and enabling exhumation of the linked horsetail splays. Pamir indentation, located south of the Western Tien Shan, is postulated to be underway by <em>c.</em> 20 Ma. Recently published results suggest synchronous strike-slip deformation in the western Tarim Basin and eastern flank of the Pamir. Based on our results and published data, we are able to connect Tarim and Pamir deformation to the onset of TFF slip. We suggest that this pre-existing regional structure was responsible for transferring Pamir-induced shortening to the NW Tien Shan.