cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.3453848.v1
title: Effect of diagenetic recrystallization on the strength of planktonic foraminifer tests under compression

description: We present the results of experiments to measure the brittle failure of fossil planktonic foraminifer tests under compression. We compare two upper Eocene species of contrasting morphology, <em>Cribrohantkenina inflata</em> (Howe, 1928) and <em>Turborotalia cerroazulensis</em> (Cole, 1928) in both well-preserved material from the Kilwa Group of Tanzania and recrystallized material from ODP Site 865, central Pacific Ocean. Well-preserved tests were several times stronger than recrystallized tests. <em>Turborotalia cerroazulensis</em> was stronger than <em>C. inflata</em> in both the well-preserved and recrystallized material.
DOI: 10.6084/m9.figshare.3453845
title: Constituents of potential concern for human health risk assessment of petroleum fuel releases

description: When petroleum-based vehicle fuels are released to the subsurface environment, only a small number of chemical constituents typically account for a large majority of human health risks associated with potential exposures to affected soil, soil gas or groundwater. In other words, the risk ‘footprint’ of most fuel constituents is most often contained within the footprint of key risk-driving constituents of potential concern (COPCs). Therefore, assessment and management of an appropriate set of COPCs can support robust management of all potential risks and eliminate unnecessary chemical analyses and evaluation of constituents that rarely (or never) give rise to unacceptable human health risks. This paper presents an approach for identifying COPCs for petroleum fuel releases, based on internationally adopted human health risk assessment practices and available information on fuel composition and chemical toxicity. COPCs are identified as all constituents that could potentially give rise to unacceptable human health risks, based on theoretical upper-bound exposure estimates for exposure pathways. COPC lists are presented to guide the investigation and evaluation of risks at sites where releases of petrol, diesel, and kerosene/jet fuel have occurred. Such lists are generically applicable and may underpin site-specific evaluation of environmental conditions and associated risks.
DOI: 10.6084/m9.figshare.3453845.v1
title: Constituents of potential concern for human health risk assessment of petroleum fuel releases

description: When petroleum-based vehicle fuels are released to the subsurface environment, only a small number of chemical constituents typically account for a large majority of human health risks associated with potential exposures to affected soil, soil gas or groundwater. In other words, the risk ‘footprint’ of most fuel constituents is most often contained within the footprint of key risk-driving constituents of potential concern (COPCs). Therefore, assessment and management of an appropriate set of COPCs can support robust management of all potential risks and eliminate unnecessary chemical analyses and evaluation of constituents that rarely (or never) give rise to unacceptable human health risks. This paper presents an approach for identifying COPCs for petroleum fuel releases, based on internationally adopted human health risk assessment practices and available information on fuel composition and chemical toxicity. COPCs are identified as all constituents that could potentially give rise to unacceptable human health risks, based on theoretical upper-bound exposure estimates for exposure pathways. COPC lists are presented to guide the investigation and evaluation of risks at sites where releases of petrol, diesel, and kerosene/jet fuel have occurred. Such lists are generically applicable and may underpin site-specific evaluation of environmental conditions and associated risks.
DOI: 10.6084/m9.figshare.3453842
title: British Pennsylvanian (Carboniferous) coal-bearing sequences: where is the time?

description: The Lower and Middle Coal Measures of Langsettian (Westphalian A) and Duckmantian (Westphalian B) age (together equals Bashkirian in part) in Britain comprise an alternation of clastic sediments and coal deposited on coastal and alluvial plains over a period of 2–3.5 million years, depending on which time scale is accepted. In both the Pennine and South Wales Basins there are no obvious unconformities. Many of the clastic sequences show evidence of rapid sedimentation (burial of trees, bivalve escape burrows) that may suggest that a significant amount of time is taken up during the peat-forming intervals. Thickness data from a range of boreholes that record continuous sections through this time period were collated. Coal and sediment thicknesses, as well as coal to sediment ratios, are compared both within and across the basins. Data on the coals has allowed consideration of the time taken to deposit the peats. This work considers the compaction of the peat to coal, as well as a range of peat accumulation rates. Assuming the largest de-compaction rates and slowest accumulation rates of the coal formation, less than 50% of the allocated time can be accounted for. In addition however, calculations suggest that peat formation accounts for less than 25% of the total time taken for sediment accumulation. It is suspected that there are major time gaps in the sequences, most probably occurring between seat-earths and coal and within the coals, and it is believed that this finding has significance for the debate over short-term climate changes in the Carboniferous and the causes of peat and sediment alternations.
DOI: 10.6084/m9.figshare.3453842.v1
title: British Pennsylvanian (Carboniferous) coal-bearing sequences: where is the time?

description: The Lower and Middle Coal Measures of Langsettian (Westphalian A) and Duckmantian (Westphalian B) age (together equals Bashkirian in part) in Britain comprise an alternation of clastic sediments and coal deposited on coastal and alluvial plains over a period of 2–3.5 million years, depending on which time scale is accepted. In both the Pennine and South Wales Basins there are no obvious unconformities. Many of the clastic sequences show evidence of rapid sedimentation (burial of trees, bivalve escape burrows) that may suggest that a significant amount of time is taken up during the peat-forming intervals. Thickness data from a range of boreholes that record continuous sections through this time period were collated. Coal and sediment thicknesses, as well as coal to sediment ratios, are compared both within and across the basins. Data on the coals has allowed consideration of the time taken to deposit the peats. This work considers the compaction of the peat to coal, as well as a range of peat accumulation rates. Assuming the largest de-compaction rates and slowest accumulation rates of the coal formation, less than 50% of the allocated time can be accounted for. In addition however, calculations suggest that peat formation accounts for less than 25% of the total time taken for sediment accumulation. It is suspected that there are major time gaps in the sequences, most probably occurring between seat-earths and coal and within the coals, and it is believed that this finding has significance for the debate over short-term climate changes in the Carboniferous and the causes of peat and sediment alternations.
DOI: 10.6084/m9.figshare.3453836
title: Archaean granulite-facies paragneisses from central Swaziland: inferences on Palaeoarchaean crustal reworking and a complex metamorphic history

description: We present a petrographic, petrological, geochemical, and geochronological study (U–Pb/Lu–Hf) on granulite-facies paragneisses of the Mahamba Gneiss Complex in central Swaziland, eastern Kaapvaal Craton. Our data suggest that prograde metamorphism occurred at <em>c</em>. 3.07 Ga. Dating of detrital zircons of a metapelite in combination with geochronological and ambiguous structural relationships with granitoid gneisses suggests two possible scenarios: (1) the time of deposition of the sedimentary protoliths is prior to <em>c</em>. 3.58 Ga; (2) <em>c</em>. 3.58 Ga granitoid crust was the basement for the sedimentary protoliths. Furthermore, enrichment in Ni and Cr in the Mahamba metasediments may originate from erosion of a greenstone terrane similar in composition to the dominantly mafic and ultramafic lithologies of the Barberton Greenstone Belt or Dwalile supracrustal belt. Evidence for an older crustal basement is provided by the oldest detrital zircons, which yield ages up to <em>c</em>. 3.7 Ga. Because the metamorphic conditions of metapelitic rocks have no similarity to <em>P–T</em> paths of modern subduction–collision tectonic settings we conclude that the metamorphic history of the Mahamba Gneiss Complex cannot be explained by this model. We propose that deformation and metamorphism occurred through intracratonic contraction and a thermal event possibly related to Mpuluzi batholith emplacement.
DOI: 10.6084/m9.figshare.3453833
title: Polygonal feeder tubes filled with hydroclasts: a new volcanic lithofacies marking shoreline subaerial–submarine transition

description: This paper describes for the first time a new lithofacies that formed in the passage zone during the construction of pahoehoe lava-fed deltas in the north and NE coastal areas of Gran Canaria (Canary Islands, Atlantic Ocean). These lava-fed deltas, which are Pliocene in age, present similar lithofacies associations to those previously described in the literature, except for two distinct features: low abundance of hyaloclastites and a new lithofacies in the passage zone. This new lithofacies, which we propose to name ‘polygonal feeder tubes filled with hydroclasts’, comprises metre-scale lava feeder tubes with decimetre-scale coherent poorly vesicular and aphanitic rinds of polygonal morphology, filled with closely packed hydroclasts generated <em>in situ</em>. It represents the first stage in the interaction between seawater and thick lava flows entering the sea under the influence of a tidal regime, thus marking sea level. This lithofacies should be easily recognizable in ancient successions, and thus represents a useful marker of palaeoshorelines.
DOI: 10.6084/m9.figshare.3453833.v1
title: Polygonal feeder tubes filled with hydroclasts: a new volcanic lithofacies marking shoreline subaerial–submarine transition

description: This paper describes for the first time a new lithofacies that formed in the passage zone during the construction of pahoehoe lava-fed deltas in the north and NE coastal areas of Gran Canaria (Canary Islands, Atlantic Ocean). These lava-fed deltas, which are Pliocene in age, present similar lithofacies associations to those previously described in the literature, except for two distinct features: low abundance of hyaloclastites and a new lithofacies in the passage zone. This new lithofacies, which we propose to name ‘polygonal feeder tubes filled with hydroclasts’, comprises metre-scale lava feeder tubes with decimetre-scale coherent poorly vesicular and aphanitic rinds of polygonal morphology, filled with closely packed hydroclasts generated <em>in situ</em>. It represents the first stage in the interaction between seawater and thick lava flows entering the sea under the influence of a tidal regime, thus marking sea level. This lithofacies should be easily recognizable in ancient successions, and thus represents a useful marker of palaeoshorelines.
DOI: 10.6084/m9.figshare.3453830
title: The New Siberian Islands and evidence for the continuation of the Uralides, Arctic Russia

description: U–Pb detrital zircon results from New Siberian Islands sandstones illuminate the long-lived controversy regarding the continuation of the Uralian orogen into the Arctic region. A dominant age peak of <em>c</em>. 285 Ma from Permian sandstone requires proximal derivation from Taimyr’s Carboniferous–Permian granites, thought to reflect syn- to post-tectonic Uralian magmatism. The provenance of Devonian sandstone has Baltica affinities. The data record a dramatic change in provenance between Devonian and Permian time, from Baltica to a mixed Baltica + Uralian source. Our results confirm that the Uralian foreland basin extended from Taimyr to the New Siberian Islands.
DOI: 10.6084/m9.figshare.3453830.v1
title: The New Siberian Islands and evidence for the continuation of the Uralides, Arctic Russia

description: U–Pb detrital zircon results from New Siberian Islands sandstones illuminate the long-lived controversy regarding the continuation of the Uralian orogen into the Arctic region. A dominant age peak of <em>c</em>. 285 Ma from Permian sandstone requires proximal derivation from Taimyr’s Carboniferous–Permian granites, thought to reflect syn- to post-tectonic Uralian magmatism. The provenance of Devonian sandstone has Baltica affinities. The data record a dramatic change in provenance between Devonian and Permian time, from Baltica to a mixed Baltica + Uralian source. Our results confirm that the Uralian foreland basin extended from Taimyr to the New Siberian Islands.
DOI: 10.6084/m9.figshare.3453827
title: Henry Culpin (1861–1912): a Yorkshire geologist and palaeontologist, and his collection in the Doncaster Museum and Art Gallery, South Yorkshire

description: Henry Culpin was an autodidact geologist and palaeontologist; he was among the first of very few local people to understand and describe the geological outcrops, and fossils within them, around Doncaster, South Yorkshire. During his excursions, Culpin collected many fossil specimens and gifted several to Beechfield House museum, now Doncaster Museum and Art Gallery. A large percentage of these specimens are of local origin, collected from Carboniferous coal mine deposits that are no longer accessible. They represent some of the most scientifically and locally important fossils from Doncaster, collected when some of the earliest mine shafts were being sunk in the district.
DOI: 10.6084/m9.figshare.3453827.v1
title: Henry Culpin (1861–1912): a Yorkshire geologist and palaeontologist, and his collection in the Doncaster Museum and Art Gallery, South Yorkshire

description: Henry Culpin was an autodidact geologist and palaeontologist; he was among the first of very few local people to understand and describe the geological outcrops, and fossils within them, around Doncaster, South Yorkshire. During his excursions, Culpin collected many fossil specimens and gifted several to Beechfield House museum, now Doncaster Museum and Art Gallery. A large percentage of these specimens are of local origin, collected from Carboniferous coal mine deposits that are no longer accessible. They represent some of the most scientifically and locally important fossils from Doncaster, collected when some of the earliest mine shafts were being sunk in the district.
DOI: 10.6084/m9.figshare.3453824
title: Insight into monogenetic eruption processes at Pelagatos volcano, Sierra Chichinautzin, Mexico: a combined melt inclusion and physical volcanology study

description: Eruptions and magma evolution of monogenetic volcanoes are thought to be controlled by rapid ascent of magmas over a short period of time. Volatiles degassing from magmas control the ascent velocity and therefore eruption intensity. Complex feedbacks exist between the rate and extent of volatile exsolution at shallow levels and groundmass crystallization, affecting the magma rheology, extent of fragmentation, resulting eruptive style and related hazards. Melt inclusions record the volatile contents and compositions of melts at various stages during their evolution, providing insights into degassing–crystallization processes at shallow crustal levels. Here we present new volatile and major element data from olivine-hosted melt inclusions from Pelagatos scoria cone, Mexico. These new data, combined with recent geochemical and textural data on Pelagatos eruptive products, allow us to propose a model for shallow magmatic processes at this volcano. Discharge of volatile-poor, low-viscosity magma drives early effusive activity along the fissure. Decreasing magma fluxes lead to the clogging of the fissure and the formation of a shallow magma reservoir where degassing and fractional crystallization take place. Subsequent explosive cone-forming activity is triggered by influx of deeper (<em>c.</em> 5 km), less evolved, more volatile-rich magma into this shallow (<em>c.</em> 1 km) reservoir.
DOI: 10.6084/m9.figshare.3453824.v1
title: Insight into monogenetic eruption processes at Pelagatos volcano, Sierra Chichinautzin, Mexico: a combined melt inclusion and physical volcanology study

description: Eruptions and magma evolution of monogenetic volcanoes are thought to be controlled by rapid ascent of magmas over a short period of time. Volatiles degassing from magmas control the ascent velocity and therefore eruption intensity. Complex feedbacks exist between the rate and extent of volatile exsolution at shallow levels and groundmass crystallization, affecting the magma rheology, extent of fragmentation, resulting eruptive style and related hazards. Melt inclusions record the volatile contents and compositions of melts at various stages during their evolution, providing insights into degassing–crystallization processes at shallow crustal levels. Here we present new volatile and major element data from olivine-hosted melt inclusions from Pelagatos scoria cone, Mexico. These new data, combined with recent geochemical and textural data on Pelagatos eruptive products, allow us to propose a model for shallow magmatic processes at this volcano. Discharge of volatile-poor, low-viscosity magma drives early effusive activity along the fissure. Decreasing magma fluxes lead to the clogging of the fissure and the formation of a shallow magma reservoir where degassing and fractional crystallization take place. Subsequent explosive cone-forming activity is triggered by influx of deeper (<em>c.</em> 5 km), less evolved, more volatile-rich magma into this shallow (<em>c.</em> 1 km) reservoir.
DOI: 10.6084/m9.figshare.3453821
title: Detrital zircon and tectonostratigraphy of the Parautochthon under the Morais Complex (NE Portugal): implications for the Variscan accretionary history of the Iberian Massif

description: Zircon geochronology using laser ablation inductively coupled plasma mass spectrometry, combined with a new detailed geological map and a stratigraphic study of the Parautochthon at the eastern rim of the Morais Allochthonous Complex, has provided new insights into the evolution of the Iberian Variscan belt. The data confirmed that the Parautochthon is composed of two structural units. The higher and more deformed, called the Upper Parautochthon, consists of recumbently folded pre-Variscan low-grade metasediments deposited in the northern Gondwana passive margin during the opening of the Rheic Ocean. It represents the Variscan tectonic duplication of the NW Iberian autochthonous sedimentary sequence triggered by the advance of a stack of allochthonous units formed previously in an accretionary prism. Below this unit, the Lower Parautochthon is a less pervasively deformed tectonic slice including two lithostratigraphic units (Travanca and Vila Chã formations) composed of Culm-type synorogenic low-grade metasediments deposited in a tectonic trench located between the accretionary prism and a peripheral bulge, with detrital zircon age populations pointing to a Late Devonian–Early Carboniferous age. These sediments were subsequently detached from the Autochthon along mechanically weak Silurian carbonaceous slates. The provenance study on the detrital zircons implies that this basin was fed mainly from the active margin.
DOI: 10.6084/m9.figshare.3453821.v1
title: Detrital zircon and tectonostratigraphy of the Parautochthon under the Morais Complex (NE Portugal): implications for the Variscan accretionary history of the Iberian Massif

description: Zircon geochronology using laser ablation inductively coupled plasma mass spectrometry, combined with a new detailed geological map and a stratigraphic study of the Parautochthon at the eastern rim of the Morais Allochthonous Complex, has provided new insights into the evolution of the Iberian Variscan belt. The data confirmed that the Parautochthon is composed of two structural units. The higher and more deformed, called the Upper Parautochthon, consists of recumbently folded pre-Variscan low-grade metasediments deposited in the northern Gondwana passive margin during the opening of the Rheic Ocean. It represents the Variscan tectonic duplication of the NW Iberian autochthonous sedimentary sequence triggered by the advance of a stack of allochthonous units formed previously in an accretionary prism. Below this unit, the Lower Parautochthon is a less pervasively deformed tectonic slice including two lithostratigraphic units (Travanca and Vila Chã formations) composed of Culm-type synorogenic low-grade metasediments deposited in a tectonic trench located between the accretionary prism and a peripheral bulge, with detrital zircon age populations pointing to a Late Devonian–Early Carboniferous age. These sediments were subsequently detached from the Autochthon along mechanically weak Silurian carbonaceous slates. The provenance study on the detrital zircons implies that this basin was fed mainly from the active margin.
DOI: 10.6084/m9.figshare.3453818
title: The source of Proterozoic anorthosite and rapakivi granite magmatism: evidence from combined <em>in situ</em> Hf–O isotopes of zircon in the Ahvenisto complex, southeastern Finland

description: The isotope compositions of massif-type anorthosites in Proterozoic anorthosite–mangerite–charnockite–granite (AMCG) complexes are commonly dominated by crustal values. Olivine-bearing anorthositic rocks in several AMCG suites have, however, been shown to display juvenile character, suggesting that variably depleted mantle reservoirs were involved in their genesis. A coupled <em>in situ</em> zircon Hf–O isotope dataset from the 1.64 Ga Ahvenisto AMCG complex in the 1.54–1.65 Ga Fennoscandian rapakivi granite–massif-type anorthosite province reveals correlated juvenile isotope signals (δ<sup>18</sup>O<sub>zrn</sub> = 5.4–6.6‰; initial ϵ<sub>Hf</sub> = −1.1 to +3.4) in the most primitive gabbroic rock type of the suite suggesting a depleted mantle origin for the anorthositic rocks. This signal is not as prominent in the more evolved co-magmatic anorthositic rocks (δ<sup>18</sup>O<sub>zrn</sub> = 6.3–7.8‰; initial ϵ<sub>Hf</sub> = −0.8 to +2.0), most probably owing to contamination of the mantle-derived primary magma by crustal material. A rapakivi granite associated with the anorthositic rocks has different isotope composition (δ<sup>18</sup>O<sub>zrn</sub> = 7.4–8.6‰; initial ϵ<sub>Hf</sub> = −2.1 to +0.5) that points to a crustal source.