cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.3453017.v1
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.
DOI: 10.6084/m9.figshare.3453014
title: Carboniferous appinitic intrusions from the northern North China craton: geochemistry, petrogenesis and tectonic implications

description: Laser ablation inductively coupled plasma mass spectrometry zircon U–Pb dating and geochemical study document Carboniferous (<em>c</em>. 320–317 Ma) appinitic intrusions from the northern North China craton. The rock suite mainly consists of hornblende diorites and monzodiorites, with an SiO<sub>2</sub> range from 46.8 to 55.4%. These rocks exhibit high alkali contents, strong enrichment in large ion lithophile elements and light rare earth elements, and depletion in high field strength elements, with radiogenic <sup>87</sup>Sr/<sup>86</sup>Sr<sub>i</sub> ratios of 0.7058–0.7093, unradiogenic ϵ<sub>Nd</sub>(t) of −9.3 to −13.9 and zircon ϵ<sub>Hf</sub>(t) from −8.5 to −18.4. These geochemical features suggest that their generation may involve a distinctive two-stage process: (1) a precursory metasomatism stage of mantle peridotites by melts from subduction-related sediments; (2) a delayed partial melting stage probably initiated by post-subduction transcurrent movements along pre-existing lithospheric shear zones. These mafic to intermediate intrusions, plus other coeval mafic– ultramafic complexes and high Ba–Sr granites from neighbouring regions, not only witness a heterogeneously enriched subcontinental lithospheric mantle along the northern North China craton, but also attest to a reworking-dominated metacratonic process within a post-subduction transtensional regime.
DOI: 10.6084/m9.figshare.3453014.v1
title: Carboniferous appinitic intrusions from the northern North China craton: geochemistry, petrogenesis and tectonic implications

description: Laser ablation inductively coupled plasma mass spectrometry zircon U–Pb dating and geochemical study document Carboniferous (<em>c</em>. 320–317 Ma) appinitic intrusions from the northern North China craton. The rock suite mainly consists of hornblende diorites and monzodiorites, with an SiO<sub>2</sub> range from 46.8 to 55.4%. These rocks exhibit high alkali contents, strong enrichment in large ion lithophile elements and light rare earth elements, and depletion in high field strength elements, with radiogenic <sup>87</sup>Sr/<sup>86</sup>Sr<sub>i</sub> ratios of 0.7058–0.7093, unradiogenic ϵ<sub>Nd</sub>(t) of −9.3 to −13.9 and zircon ϵ<sub>Hf</sub>(t) from −8.5 to −18.4. These geochemical features suggest that their generation may involve a distinctive two-stage process: (1) a precursory metasomatism stage of mantle peridotites by melts from subduction-related sediments; (2) a delayed partial melting stage probably initiated by post-subduction transcurrent movements along pre-existing lithospheric shear zones. These mafic to intermediate intrusions, plus other coeval mafic– ultramafic complexes and high Ba–Sr granites from neighbouring regions, not only witness a heterogeneously enriched subcontinental lithospheric mantle along the northern North China craton, but also attest to a reworking-dominated metacratonic process within a post-subduction transtensional regime.
DOI: 10.6084/m9.figshare.3453011
title: Occurrence of inherited supra-subduction zone mantle in the oceanic lithosphere as inferred from mantle xenoliths from Dragon Seamount (southern Tore–Madeira Rise)

description: Spinel-bearing peridotite and pyroxenite xenoliths dredged from the Dragon Seamount (southern Tore–Madeira Rise, West Iberia and Morocco margin) give an insight into the composition of the underlying lithosphere. These xenoliths are devoid of evidence of strong host lava–peridotite interaction and re-equilibration or late impregnation in the plagioclase facies. The spinels and pyroxenes from the Dragon peridotites have compositions distinct from those of both lherzolites and harzburgites from the Iberia margin and the Mid-Atlantic Ridge. They display a highly depleted composition, in particular, high Cr-number, up to 0.63 in the spinels, consistent with a melting degree between 12 and 19%. Because of the strong chemical similarities between the Tore–Madeira Rise, Newfoundland peridotites, and peridotites from supra-subduction zones, we propose that the Dragon peridotites formed in a similar context. The pyroxenites display a cumulate texture and are probably a high-temperature–high-pressure cumulate formed by fractional crystallization from a melt. The Tore–Madeira Rise peridotites may represent a former mantle wedge in an oceanic arc, later included into the continental lithosphere and finally tectonically disseminated within the lithosphere during the rifting of the Newfoundland–Iberia continental lithosphere. As a consequence, rifting processes may produce heterogeneities in the oceanic lithosphere and influence isotopic compositions of ocean island basalt-type lavas during plume–lithosphere interactions, as inferred for the southern Tore–Madeira Rise.
DOI: 10.6084/m9.figshare.3453011.v1
title: Occurrence of inherited supra-subduction zone mantle in the oceanic lithosphere as inferred from mantle xenoliths from Dragon Seamount (southern Tore–Madeira Rise)

description: Spinel-bearing peridotite and pyroxenite xenoliths dredged from the Dragon Seamount (southern Tore–Madeira Rise, West Iberia and Morocco margin) give an insight into the composition of the underlying lithosphere. These xenoliths are devoid of evidence of strong host lava–peridotite interaction and re-equilibration or late impregnation in the plagioclase facies. The spinels and pyroxenes from the Dragon peridotites have compositions distinct from those of both lherzolites and harzburgites from the Iberia margin and the Mid-Atlantic Ridge. They display a highly depleted composition, in particular, high Cr-number, up to 0.63 in the spinels, consistent with a melting degree between 12 and 19%. Because of the strong chemical similarities between the Tore–Madeira Rise, Newfoundland peridotites, and peridotites from supra-subduction zones, we propose that the Dragon peridotites formed in a similar context. The pyroxenites display a cumulate texture and are probably a high-temperature–high-pressure cumulate formed by fractional crystallization from a melt. The Tore–Madeira Rise peridotites may represent a former mantle wedge in an oceanic arc, later included into the continental lithosphere and finally tectonically disseminated within the lithosphere during the rifting of the Newfoundland–Iberia continental lithosphere. As a consequence, rifting processes may produce heterogeneities in the oceanic lithosphere and influence isotopic compositions of ocean island basalt-type lavas during plume–lithosphere interactions, as inferred for the southern Tore–Madeira Rise.
DOI: 10.6084/m9.figshare.3453002
title: A field guide to the engineering geology of the French Alps, Grenoble

description: It is now well established in the field of engineering geology that a comprehensive ground model is critical to the success of any engineered project. This ground model must contain elements of the site geology, geomorphology and geotechnics and demonstrate the potential interactions between these elements to be of value to the engineer or geologist working on a given project. The area around Grenoble in the French Alps offers an ideal field location to exemplify and demonstrate these concepts. Here there are a number of large engineering structures that highlight the importance of sound engineering geological investigation and the establishment of detailed ground models to understand problematic ground behaviour and performance. The area demonstrates the key issues of geotechnical hazard, vulnerability and associated risks, as well as the significance of understanding both the solid and superficial ground conditions. This field guide provides details on and discusses a variety of key localities where these issues can be fully demonstrated and explored.
DOI: 10.6084/m9.figshare.3453002.v1
title: A field guide to the engineering geology of the French Alps, Grenoble

description: It is now well established in the field of engineering geology that a comprehensive ground model is critical to the success of any engineered project. This ground model must contain elements of the site geology, geomorphology and geotechnics and demonstrate the potential interactions between these elements to be of value to the engineer or geologist working on a given project. The area around Grenoble in the French Alps offers an ideal field location to exemplify and demonstrate these concepts. Here there are a number of large engineering structures that highlight the importance of sound engineering geological investigation and the establishment of detailed ground models to understand problematic ground behaviour and performance. The area demonstrates the key issues of geotechnical hazard, vulnerability and associated risks, as well as the significance of understanding both the solid and superficial ground conditions. This field guide provides details on and discusses a variety of key localities where these issues can be fully demonstrated and explored.
DOI: 10.6084/m9.figshare.3452999
title: Geology and diamond provenance of the Proterozoic Banganapalle conglomerates, Kurnool Group, India

description: The Banganapalle Quartzite Formation occurs in the Cuddapah Basin in India and is characterized by a basal diamond-bearing conglomerate horizon. The diamonds within this placer are generally thought to have been sourced from the erosion of kimberlites of the Wajrakurur cluster. De Beers' India's exploration efforts have resulted in the discovery of a number of dykes within the basin, with petrographical and geochemical similarities to lamproites. It is proposed that far-field stresses related to the Eastern Ghats Mobile Belt (EGMB) provided extensional sites during the time of lamproite emplacement. The dykes have not been dated. However, zircons recovered from heavy mineral stream samples in the area exhibit a number of age groupings, including one in the range of 1287–1370 Ma. This age is interpreted as the emplacement age of the dykes in this region. Kimberlitic indicator minerals (KIMs), recovered from conglomerate waste dumps, indicate the uniqueness of the garnet population relative to that of the known kimberlite clusters to the west of the basin. We propose that the emplacement of lamproites occurred as dyke–sill complexes at 1.4–1.3 Ga and that the lamproites represent the source of the diamonds in the Banganapalle conglomerates.
DOI: 10.6084/m9.figshare.3452999.v1
title: Geology and diamond provenance of the Proterozoic Banganapalle conglomerates, Kurnool Group, India

description: The Banganapalle Quartzite Formation occurs in the Cuddapah Basin in India and is characterized by a basal diamond-bearing conglomerate horizon. The diamonds within this placer are generally thought to have been sourced from the erosion of kimberlites of the Wajrakurur cluster. De Beers' India's exploration efforts have resulted in the discovery of a number of dykes within the basin, with petrographical and geochemical similarities to lamproites. It is proposed that far-field stresses related to the Eastern Ghats Mobile Belt (EGMB) provided extensional sites during the time of lamproite emplacement. The dykes have not been dated. However, zircons recovered from heavy mineral stream samples in the area exhibit a number of age groupings, including one in the range of 1287–1370 Ma. This age is interpreted as the emplacement age of the dykes in this region. Kimberlitic indicator minerals (KIMs), recovered from conglomerate waste dumps, indicate the uniqueness of the garnet population relative to that of the known kimberlite clusters to the west of the basin. We propose that the emplacement of lamproites occurred as dyke–sill complexes at 1.4–1.3 Ga and that the lamproites represent the source of the diamonds in the Banganapalle conglomerates.
DOI: 10.6084/m9.figshare.3452993
title: New single crystal <sup>40</sup>Ar/<sup>39</sup>Ar ages improve time scale for deposition of the Omo Group, Omo–Turkana Basin, East Africa

description: Six tuffaceous beds within the Omo Group of the Omo–Turkana Basin have been dated using the <sup>40</sup>Ar/<sup>39</sup>Ar single crystal total fusion method on anorthoclase, yielding eruption ages. The Omo Group constitutes up to 800 m of subaerially exposed sediments surrounding Lake Turkana within the East African Rift system in northern Kenya and southern Ethiopia. Rhyolitic explosive eruptions produced tuffs and pumice clasts that are considered to have been deposited shortly after eruption. The new age data on feldspars from the pumice clasts range from 4.02 ± 0.04 Ma for the Naibar Tuff of the Koobi Fora Formation to 1.53 ± 0.02 Ma for Tuff K of the Shungura Formation. The Orange Tuff in the KBS Member of the Koobi Fora Formation was dated at 1.76 ± 0.03 Ma, providing good control in this part of the sequence where formerly there was a &gt;200 ka gap. Data are consistent with earlier measurements and significantly improve age resolution within the Omo Group, which has yielded many vertebrate fossils, including hominin fossils comprising a number of species. We suggest new age estimates for a limited number of hominin specimens.
DOI: 10.6084/m9.figshare.3452987
title: GrapEl – a simple spreadsheet application for managing and disseminating graptolite biozonal range chart data

description: Biostratigraphical data frequently consist of tables indicating the presence, absence or relative abundance of taxa in a sequence of rock units or time units such as biozones or various chronostratigraphic units. Spreadsheet programs provide a simple means for managing this data and can be used for archiving and disseminating it, in addition to manipulating it. A simple spreadsheet (‘GrapEl’) is used to link the biozonal ranges of graptolite taxa to illustrations of representative or type specimens. Use of the filtering function enables the rapid selection of species from particular biozones, or species belonging to particular genera, and is intended to assist workers with a limited working knowledge of the faunas concerned. This approach is briefly compared to other uses of spreadsheets and databases in the management, analysis and distribution of graptolite biostratigraphical data.
DOI: 10.5258/soton/d1517
title: Dataset for Aerodynamic Noise from a High Speed Train Pantograph and Recess

description: This dataset supports the thesis entitled 'Aerodynamic Noise from a High Speed Train Pantograph and Recess'.
DOI: 10.6084/m9.figshare.3452987.v1
title: GrapEl – a simple spreadsheet application for managing and disseminating graptolite biozonal range chart data

description: Biostratigraphical data frequently consist of tables indicating the presence, absence or relative abundance of taxa in a sequence of rock units or time units such as biozones or various chronostratigraphic units. Spreadsheet programs provide a simple means for managing this data and can be used for archiving and disseminating it, in addition to manipulating it. A simple spreadsheet (‘GrapEl’) is used to link the biozonal ranges of graptolite taxa to illustrations of representative or type specimens. Use of the filtering function enables the rapid selection of species from particular biozones, or species belonging to particular genera, and is intended to assist workers with a limited working knowledge of the faunas concerned. This approach is briefly compared to other uses of spreadsheets and databases in the management, analysis and distribution of graptolite biostratigraphical data.
DOI: 10.6084/m9.figshare.3452984
title: Geology of the Snap Lake kimberlite intrusion, Northwest Territories, Canada: field observations and their interpretation

description: The Cambrian (523 Ma) Snap Lake hypabyssal kimberlite intrusion, Northwest Territories, Canada, is a complex segmented diamond-bearing ore-body. Detailed geological investigations suggest that the kimberlite is a multi-phase intrusion with at least four magmatic lithofacies. In particular, olivine-rich (ORK) and olivine-poor (OPK) varieties of hypabyssal kimberlite have been identified. Key observations are that the olivine-rich lithofacies has a strong tendency to be located where the intrusion is thickest and that there is a good correlation between intrusion thickness, olivine crystal size and crystal content. Heterogeneities in the lithofacies are attributed to variations in intrusion thickness and structural complexities. The geometry and distribution of lithofacies points to magmatic co-intrusion, and flow segregation driven by fundamental rheological differences between the two phases. We envisage that the low-viscosity OPK magma acted as a lubricant for the highly viscous ORK magma. The presence of such low-viscosity, crystal-poor magmas may explain how crystal-laden kimberlite magmas (&gt;60 vol.%) are able to reach the surface during kimberlite eruptions. We also document the absence of crystal settling and the development of an unusual subvertical fabric of elongate olivine crystals, which are explained by rapid degassing-induced quench crystallization of the magmas during and after intrusion.
DOI: 10.6084/m9.figshare.3452984.v1
title: Geology of the Snap Lake kimberlite intrusion, Northwest Territories, Canada: field observations and their interpretation

description: The Cambrian (523 Ma) Snap Lake hypabyssal kimberlite intrusion, Northwest Territories, Canada, is a complex segmented diamond-bearing ore-body. Detailed geological investigations suggest that the kimberlite is a multi-phase intrusion with at least four magmatic lithofacies. In particular, olivine-rich (ORK) and olivine-poor (OPK) varieties of hypabyssal kimberlite have been identified. Key observations are that the olivine-rich lithofacies has a strong tendency to be located where the intrusion is thickest and that there is a good correlation between intrusion thickness, olivine crystal size and crystal content. Heterogeneities in the lithofacies are attributed to variations in intrusion thickness and structural complexities. The geometry and distribution of lithofacies points to magmatic co-intrusion, and flow segregation driven by fundamental rheological differences between the two phases. We envisage that the low-viscosity OPK magma acted as a lubricant for the highly viscous ORK magma. The presence of such low-viscosity, crystal-poor magmas may explain how crystal-laden kimberlite magmas (&gt;60 vol.%) are able to reach the surface during kimberlite eruptions. We also document the absence of crystal settling and the development of an unusual subvertical fabric of elongate olivine crystals, which are explained by rapid degassing-induced quench crystallization of the magmas during and after intrusion.
DOI: 10.6084/m9.figshare.3452981
title: Constraints on palaeodrainage evolution induced by uplift and exhumation on the southern flank of the Zagros–Iranian Plateau

description: Foreland sedimentary rocks from the northern Fars region of Iran contain a record of deformation associated with the Cenozoic collision between Arabia and Eurasia that resulted in formation of the Zagros orogen. The timing of the deformation associated with this event is poorly known. To address this we conducted a study of Miocene foreland sedimentary rocks (19.7–14.8 Ma) of the Chahar–Makan syncline using clast composition, clay mineralogy and low-temperature fission-track dating. The results showed that most of the sedimentary rocks were sourced from ophiolitic rocks. Detrital apatite fission-track (AFT) age signatures of Miocene sedimentary rocks record exhumation in the hanging wall of the Main Zagros Thrust and confirm that the change from underthrusting of the stretched Arabian margin to widespread crustal thickening and deformation in the Zagros region is no younger than 19.7 Ma. A transition from Late Oligocene to Mesozoic–Eocene AFT detrital age signatures between 19.7–16.6 Ma and 16.6–13.8 Ma is interpreted to reflect a possible rearrangement of palaeodrainage distribution that resulted from folding and expansion–uplift of the Zagros–Iranian Plateau region.
DOI: 10.6084/m9.figshare.3452981.v1
title: Constraints on palaeodrainage evolution induced by uplift and exhumation on the southern flank of the Zagros–Iranian Plateau

description: Foreland sedimentary rocks from the northern Fars region of Iran contain a record of deformation associated with the Cenozoic collision between Arabia and Eurasia that resulted in formation of the Zagros orogen. The timing of the deformation associated with this event is poorly known. To address this we conducted a study of Miocene foreland sedimentary rocks (19.7–14.8 Ma) of the Chahar–Makan syncline using clast composition, clay mineralogy and low-temperature fission-track dating. The results showed that most of the sedimentary rocks were sourced from ophiolitic rocks. Detrital apatite fission-track (AFT) age signatures of Miocene sedimentary rocks record exhumation in the hanging wall of the Main Zagros Thrust and confirm that the change from underthrusting of the stretched Arabian margin to widespread crustal thickening and deformation in the Zagros region is no younger than 19.7 Ma. A transition from Late Oligocene to Mesozoic–Eocene AFT detrital age signatures between 19.7–16.6 Ma and 16.6–13.8 Ma is interpreted to reflect a possible rearrangement of palaeodrainage distribution that resulted from folding and expansion–uplift of the Zagros–Iranian Plateau region.
DOI: 10.6084/m9.figshare.3452978
title: Zircon U–Pb age for the Orkney lamprophyre dyke swarm, Scotland, and relations to Permo-Carboniferous magmatism in northwestern Europe

description: Magmatic zircon in the syenite (bostonite) part of a composite NE–SW-trending cogenetic bostonite–camptonite dyke in Orkney, Scotland, yields a laser ablation inductively coupled plasma mass spectrometry age of 313 ± 4 Ma and <em>ε</em>Hf<sub>(313 Ma)</sub> values of +6 to +11. This suggests that the NE–SW-, east–west- and NW–SE-trending Scottish lamprophyre dyke swarms were emplaced during one late Carboniferous magmatic event, contrasting with published K–Ar dates ranging between <em>c</em>. 325 and 250 Ma. This magmatism is interpreted as a response to late Variscan regional extension or an early response to the Skagerrak mantle plume. Lamprophyre magmatism was initiated some 10 Ma earlier in Scotland than in the Oslo Rift.