cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.3453380.v1
title: <sup>40</sup>Ar/<sup>39</sup>Ar hornblende provenance clues about Heinrich event 3 (H3)

description: Iceberg discharges into the North Atlantic are important sources of fresh water, and the sediments they deposit can provide constraints on which sectors of different ice sheets were contributing icebergs. <sup>40</sup>Ar/<sup>39</sup>Ar ages of sand-sized hornblende grains provide useful constraints on IRD (ice-rafted detritus) source areas. Heinrich events are intervals of anomalously high percentages of IRD in marine sediment cores of the North Atlantic IRD belt. In contrast to the others, Heinrich event 3 (H3) records a significantly lower flux of IRD. This study compares <sup>40</sup>Ar/<sup>39</sup>Ar hornblende age distributions from the interval around and including H3 in giant gravity core EW9303-GGC31 from Orphan Knoll, in the southern part of the Labrador Sea, with piston core V28-82 in the eastern part of the North Atlantic IRD belt. Collectively, these results confirm that H3 represents a Hudson Strait IRD event, but that it was smaller than during H1, H2, H4 and H5, and therefore comprises only a small fraction of the detritus at the eastern North Atlantic location of V28-82. These results support a previously published interpretation of across-strait ice flow during H3 at Hudson Strait.
DOI: 10.6084/m9.figshare.3453374
title: Thick-skin orogen–foreland interactions and their controlling factors, Northern Andes of Colombia

description: The study draws from reflection seismic, <em>in-situ</em> stress and low-temperature geochronology data on the Eastern Cordillera–Llanos foreland basin system of Colombia, which is an example of the retro-wedge of the orogen with an advancing subduction zone. The system was obliquely converging during deposition of the Lower Oligocene–Lower Miocene Carbonera to recent Guayabo formations, recording it by the northeastward depocentre shift in the proximal Llanos Basin. While the southern portion of the foreland did not flex and undergo flexural normal faulting after Carbonera deposition, the northern portion did. The earthquake data indicate that the northern Eastern Cordillera undergoes strengthening by internal deformation, while the southern segment is already strong enough to undergo significant displacements dominantly along its bounding fault systems. Furthermore, the southern segment initiated detachment of the first thick-skin blocks from the proximal Llanos Basin. Such co-existence of different convergence maturity stages along the orogen strike allows unravelling of its development starting with internal deformation and foreland flexure, followed by mountain building and large-scale boundary fault displacements, to the large-scale foreland deformation. The onset of new foreland accretion seems to be controlled by the resistance of the foreland plate to flexing, given that the orogenic engine continues to drive convergence.
DOI: 10.6084/m9.figshare.3453374.v1
title: Thick-skin orogen–foreland interactions and their controlling factors, Northern Andes of Colombia

description: The study draws from reflection seismic, <em>in-situ</em> stress and low-temperature geochronology data on the Eastern Cordillera–Llanos foreland basin system of Colombia, which is an example of the retro-wedge of the orogen with an advancing subduction zone. The system was obliquely converging during deposition of the Lower Oligocene–Lower Miocene Carbonera to recent Guayabo formations, recording it by the northeastward depocentre shift in the proximal Llanos Basin. While the southern portion of the foreland did not flex and undergo flexural normal faulting after Carbonera deposition, the northern portion did. The earthquake data indicate that the northern Eastern Cordillera undergoes strengthening by internal deformation, while the southern segment is already strong enough to undergo significant displacements dominantly along its bounding fault systems. Furthermore, the southern segment initiated detachment of the first thick-skin blocks from the proximal Llanos Basin. Such co-existence of different convergence maturity stages along the orogen strike allows unravelling of its development starting with internal deformation and foreland flexure, followed by mountain building and large-scale boundary fault displacements, to the large-scale foreland deformation. The onset of new foreland accretion seems to be controlled by the resistance of the foreland plate to flexing, given that the orogenic engine continues to drive convergence.
DOI: 10.6084/m9.figshare.3453371
title: Basin compartmentalization and drainage evolution during rift inversion: evidence from the Eastern Cordillera of Colombia

description: The Cenozoic stratigraphic infill of hinterland and foreland basins in central Colombia holds the record of basin development during tectonic inversion of rift in the context of subduction orogenesis. A comprehensive review of detrital U–Pb geochronologic and thermochronologic data reveals that activation of interconnected fault systems in the hinterland Magdalena Valley and the Eastern Cordillera occurred coevally since Paleocene time. Longitudinal basins were fed by detritus shed from the Central Cordillera carried along axial drainage systems in open basins in times where slow deformation rates prevailed. Faster deformation since Oligocene resulted in the transient formation of internally drained basins. Differential along-strike exhumation and subsidence patterns in the Eastern Cordillera and the foredeep, respectively, document tectonic acceleration since late Miocene, which we attribute to superimposed collision of the Panama arc leading to oroclinal bending in the Cordillera. Our data documents that the inherited structural grain led to the formation of longitudinal drainage patterns, even in closed basins, which seem to be a general feature of early stages of inversion. We hypothesize that the presence of more humid climatic conditions and faster tectonic rates along the range’s eastern margin favoured the development of internally drained basins, as has also been shown in the Central Andes.
DOI: 10.6084/m9.figshare.3453371.v1
title: Basin compartmentalization and drainage evolution during rift inversion: evidence from the Eastern Cordillera of Colombia

description: The Cenozoic stratigraphic infill of hinterland and foreland basins in central Colombia holds the record of basin development during tectonic inversion of rift in the context of subduction orogenesis. A comprehensive review of detrital U–Pb geochronologic and thermochronologic data reveals that activation of interconnected fault systems in the hinterland Magdalena Valley and the Eastern Cordillera occurred coevally since Paleocene time. Longitudinal basins were fed by detritus shed from the Central Cordillera carried along axial drainage systems in open basins in times where slow deformation rates prevailed. Faster deformation since Oligocene resulted in the transient formation of internally drained basins. Differential along-strike exhumation and subsidence patterns in the Eastern Cordillera and the foredeep, respectively, document tectonic acceleration since late Miocene, which we attribute to superimposed collision of the Panama arc leading to oroclinal bending in the Cordillera. Our data documents that the inherited structural grain led to the formation of longitudinal drainage patterns, even in closed basins, which seem to be a general feature of early stages of inversion. We hypothesize that the presence of more humid climatic conditions and faster tectonic rates along the range’s eastern margin favoured the development of internally drained basins, as has also been shown in the Central Andes.
DOI: 10.6084/m9.figshare.3453365
title: Development history of the foreland plate trapped between two converging orogens; Kura Valley, Georgia, case study

description: Structural, sedimentological, well and seismic data from the Kura basin show that the geometry of deformation has been largely determined by thick-skin structures occurring along margins of depressions filled with upper Oligocene–lower Miocene Maykop formation, flanked by highs without Maykop record. Thin-skin structures are detached inside the shaly Maykop formation and inside shale horizons of the Sarmatian–Pontian section. The main shortening took part during Sarmatian–Pontian, followed by subordinate shortening during Akchagylian–present. The thick-skin architecture formed first, reactivating pre-existing rift grain on the foreland plate that refused to flex underneath the load of advancing orogens. The thin-skin architecture developed subsequently, deforming thick-skin structures. During the Oligocene–early Miocene, the foreland basin behaved as a flexural basin, reacting by prominent fill asymmetry to Oligocene loading by the advancing Lesser Caucasus and earliest Miocene–early Sarmatian loading by advancing Greater Caucasus. Subsequently, the basin recorded only vertical movements responding to new orogen loading events. Each loading event was recorded by a shift of marine depositional environments northwestwards, up the SE-plunging Kura Valley. Conversely each quiescence period was recorded by their retreat southeastwards, towards the Caspian Sea.
DOI: 10.6084/m9.figshare.3453365.v1
title: Development history of the foreland plate trapped between two converging orogens; Kura Valley, Georgia, case study

description: Structural, sedimentological, well and seismic data from the Kura basin show that the geometry of deformation has been largely determined by thick-skin structures occurring along margins of depressions filled with upper Oligocene–lower Miocene Maykop formation, flanked by highs without Maykop record. Thin-skin structures are detached inside the shaly Maykop formation and inside shale horizons of the Sarmatian–Pontian section. The main shortening took part during Sarmatian–Pontian, followed by subordinate shortening during Akchagylian–present. The thick-skin architecture formed first, reactivating pre-existing rift grain on the foreland plate that refused to flex underneath the load of advancing orogens. The thin-skin architecture developed subsequently, deforming thick-skin structures. During the Oligocene–early Miocene, the foreland basin behaved as a flexural basin, reacting by prominent fill asymmetry to Oligocene loading by the advancing Lesser Caucasus and earliest Miocene–early Sarmatian loading by advancing Greater Caucasus. Subsequently, the basin recorded only vertical movements responding to new orogen loading events. Each loading event was recorded by a shift of marine depositional environments northwestwards, up the SE-plunging Kura Valley. Conversely each quiescence period was recorded by their retreat southeastwards, towards the Caspian Sea.
DOI: 10.6084/m9.figshare.3453362
title: Anatectic reworking and differentiation of continental crust along the active margin of Gondwana: a zircon Hf–O perspective from West Antarctica

description: The Fosdick migmatite–granite complex of West Antarctica preserves evidence of two crustal differentiation events along a segment of the former active margin of Gondwana, one in the Devonian–Carboniferous and another in the Cretaceous. The Hf–O isotope composition of zircons from Devonian–Carboniferous granites is explained by mixing of material from two crustal sources represented by the high-grade metamorphosed equivalents of a Lower Palaeozoic turbidite sequence and a Devonian calc-alkaline plutonic suite, consistent with an interpretation that the Devonian–Carboniferous granites record crustal reworking without input from a more juvenile source. The Hf–O isotope composition of zircons from Cretaceous granites reflects those same two sources, together with a contribution from a more juvenile source that is most evident in the detachment-hosted, youngest granites. The relatively non-radiogenic εHf isotope characteristics of zircons from the Fosdick complex granites are similar those from the Permo-Triassic granites from the Antarctic Peninsula. However, the Fosdick complex granites contrast with coeval granites in other localities along and across the former active margin of Gondwana, including the Tasmanides of Australia and the Western Province of New Zealand, where the wider range of more radiogenic εHf values of zircon suggests that crustal growth through the addition of juvenile material plays a larger role in granite genesis. These new results highlight prominent arc-parallel and arc-normal variations in the mechanisms and timing of crustal reworking v. crustal growth along the former active margin of Gondwana.
DOI: 10.6084/m9.figshare.3453362.v1
title: Anatectic reworking and differentiation of continental crust along the active margin of Gondwana: a zircon Hf–O perspective from West Antarctica

description: The Fosdick migmatite–granite complex of West Antarctica preserves evidence of two crustal differentiation events along a segment of the former active margin of Gondwana, one in the Devonian–Carboniferous and another in the Cretaceous. The Hf–O isotope composition of zircons from Devonian–Carboniferous granites is explained by mixing of material from two crustal sources represented by the high-grade metamorphosed equivalents of a Lower Palaeozoic turbidite sequence and a Devonian calc-alkaline plutonic suite, consistent with an interpretation that the Devonian–Carboniferous granites record crustal reworking without input from a more juvenile source. The Hf–O isotope composition of zircons from Cretaceous granites reflects those same two sources, together with a contribution from a more juvenile source that is most evident in the detachment-hosted, youngest granites. The relatively non-radiogenic εHf isotope characteristics of zircons from the Fosdick complex granites are similar those from the Permo-Triassic granites from the Antarctic Peninsula. However, the Fosdick complex granites contrast with coeval granites in other localities along and across the former active margin of Gondwana, including the Tasmanides of Australia and the Western Province of New Zealand, where the wider range of more radiogenic εHf values of zircon suggests that crustal growth through the addition of juvenile material plays a larger role in granite genesis. These new results highlight prominent arc-parallel and arc-normal variations in the mechanisms and timing of crustal reworking v. crustal growth along the former active margin of Gondwana.
DOI: 10.6084/m9.figshare.3453359
title: Reconstruction of the early Mesozoic plate margin of Gondwana by U–Pb ages of detrital zircons from northern Victoria Land, Antarctica

description: Detrital zircons of eight sandstone samples from the Triassic–Early Jurassic Section Peak Formation (Victoria Group, Beacon Supergroup) in northern Victoria Land, Antarctica, were investigated by U–Pb LA–ICPMS dating. The basin was flanked by the East Antarctic craton, and by a magmatic arc at the palaeo-Pacific margin of Gondwana. It accommodated sandstones ranging from quartzo-feldspathic to volcaniclastic in composition. The detrital zircon age spectra yield pronounced concentrations at <em>c.</em> 190–250 Ma, 500–700 Ma and 800–1200 Ma. The proportion of Triassic–Early Jurassic zircons increases from base to top of the formation, and correlates positively with the abundance of detrital volcanic rock fragments. The youngest zircon ages are close to the stratigraphic age of each sample, indicating contemporaneous magmatic activity along the active margin of Gondwana. Igneous rocks that formed during the Ross Orogeny (<em>c.</em> 470–545 Ma) were a minor source only, suggesting that the Ross Orogen became progressively covered by sediments as the basin expanded. Pan-African (<em>c.</em> 500–700 Ma) and Grenville (<em>c.</em> 800–1200 Ma) age zircons may have been derived from crustal sources currently covered beneath the polar ice sheet, although recycling from Cambro-Ordovician units provides an alternative explanation.
DOI: 10.6084/m9.figshare.3453359.v1
title: Reconstruction of the early Mesozoic plate margin of Gondwana by U–Pb ages of detrital zircons from northern Victoria Land, Antarctica

description: Detrital zircons of eight sandstone samples from the Triassic–Early Jurassic Section Peak Formation (Victoria Group, Beacon Supergroup) in northern Victoria Land, Antarctica, were investigated by U–Pb LA–ICPMS dating. The basin was flanked by the East Antarctic craton, and by a magmatic arc at the palaeo-Pacific margin of Gondwana. It accommodated sandstones ranging from quartzo-feldspathic to volcaniclastic in composition. The detrital zircon age spectra yield pronounced concentrations at <em>c.</em> 190–250 Ma, 500–700 Ma and 800–1200 Ma. The proportion of Triassic–Early Jurassic zircons increases from base to top of the formation, and correlates positively with the abundance of detrital volcanic rock fragments. The youngest zircon ages are close to the stratigraphic age of each sample, indicating contemporaneous magmatic activity along the active margin of Gondwana. Igneous rocks that formed during the Ross Orogeny (<em>c.</em> 470–545 Ma) were a minor source only, suggesting that the Ross Orogen became progressively covered by sediments as the basin expanded. Pan-African (<em>c.</em> 500–700 Ma) and Grenville (<em>c.</em> 800–1200 Ma) age zircons may have been derived from crustal sources currently covered beneath the polar ice sheet, although recycling from Cambro-Ordovician units provides an alternative explanation.
DOI: 10.6084/m9.figshare.3453356
title: Contrasting metamorphic records and their implications for tectonic process in the central Sør Rondane Mountains, eastern Dronning Maud Land, East Antarctica

description: Metamorphic rocks in the central part of Sør Rondane Mountains, eastern Dronning Maud Land, East Antarctica, are classified into three types based on petrological characteristics. (i) The Austkampane area preserves <em>c.</em> 800 °C and 0.5–0.6 GPa peak metamorphic conditions followed by decompression and subsequent isobaric cooling and later hydration (A-type). (ii) The Brattnipene and eastern Menipa area preserve peak <em>P–T</em> conditions of <em>c.</em> 800 °C and 0.7–0.8 GPa with subsequent isobaric cooling and later hydration (B-type). (iii) The area including Lunckeryggen, southern Walnumfjella and western Menipa preserves an amphibolite–facies peak metamorphic condition with signatures of prograde metamorphism (L-type), which are typically unaffected by the retrograde hydration event. Peak granulite–facies metamorphism of A- and B-type rocks are contemporaneous at <em>c.</em> 640–600 Ma, but a difference in the <em>P–T</em> paths between these rocks can be explained by thrusting of the A-type rock unit onto the B-type rock unit. By contrast, the timing of the metamorphism of the L-type rocks is significantly younger at <em>c.</em> 550 Ma, possibly related to the intrusion of pegmatites and granitoids. These metamorphic records in the central part of the Sør Rondane Mountains can be a test ground for the regional tectonic processes proposed for the orogeny related to Gondwana formation.
DOI: 10.6084/m9.figshare.3453356.v1
title: Contrasting metamorphic records and their implications for tectonic process in the central Sør Rondane Mountains, eastern Dronning Maud Land, East Antarctica

description: Metamorphic rocks in the central part of Sør Rondane Mountains, eastern Dronning Maud Land, East Antarctica, are classified into three types based on petrological characteristics. (i) The Austkampane area preserves <em>c.</em> 800 °C and 0.5–0.6 GPa peak metamorphic conditions followed by decompression and subsequent isobaric cooling and later hydration (A-type). (ii) The Brattnipene and eastern Menipa area preserve peak <em>P–T</em> conditions of <em>c.</em> 800 °C and 0.7–0.8 GPa with subsequent isobaric cooling and later hydration (B-type). (iii) The area including Lunckeryggen, southern Walnumfjella and western Menipa preserves an amphibolite–facies peak metamorphic condition with signatures of prograde metamorphism (L-type), which are typically unaffected by the retrograde hydration event. Peak granulite–facies metamorphism of A- and B-type rocks are contemporaneous at <em>c.</em> 640–600 Ma, but a difference in the <em>P–T</em> paths between these rocks can be explained by thrusting of the A-type rock unit onto the B-type rock unit. By contrast, the timing of the metamorphism of the L-type rocks is significantly younger at <em>c.</em> 550 Ma, possibly related to the intrusion of pegmatites and granitoids. These metamorphic records in the central part of the Sør Rondane Mountains can be a test ground for the regional tectonic processes proposed for the orogeny related to Gondwana formation.
DOI: 10.6084/m9.figshare.3453353
title: Pb isotopic domains from the Indian Ocean sector of Antarctica: implications for past Antarctica–India connections

description: New feldspar lead isotope compositions of crystalline rocks from the Indian Ocean sector of East Antarctica, in conjunction with the review of data from elsewhere within the continent and from continents formerly adjacent within Gondwana, refine boundaries and evolutionary histories of terranes previously inferred from geological mapping and complementary isotope studies. Coastal Archaean Vestfold and Napier complexes have overlapping compositions and had Pb isotopes homogenized at 2.5 Ga sourced from or within already fractionated protoliths with high and variable U–Pb. Identical compositions from the Dharwar Craton of India support a correlation with these Antarctic terranes. The Proterozoic–Palaeozoic Rayner Complex and Prydz Belt yield more radiogenic compositions and are broadly similar and strongly suggest these units correlate with parts of the Eastern Ghats Belt of India. A strikingly different signature is evident from the inboard Ruker Complex, which yielded unradiogenic compositions. This complex is unlike any unit within India or Australia, suggesting that these rocks represent exposures of an Antarctic (Crohn) Craton. Compositions from the enigmatic Rauer Terrane are consistent with a shared early history with the Ruker Complex but with a different post-Archaean evolution.
DOI: 10.6084/m9.figshare.3453353.v1
title: Pb isotopic domains from the Indian Ocean sector of Antarctica: implications for past Antarctica–India connections

description: New feldspar lead isotope compositions of crystalline rocks from the Indian Ocean sector of East Antarctica, in conjunction with the review of data from elsewhere within the continent and from continents formerly adjacent within Gondwana, refine boundaries and evolutionary histories of terranes previously inferred from geological mapping and complementary isotope studies. Coastal Archaean Vestfold and Napier complexes have overlapping compositions and had Pb isotopes homogenized at 2.5 Ga sourced from or within already fractionated protoliths with high and variable U–Pb. Identical compositions from the Dharwar Craton of India support a correlation with these Antarctic terranes. The Proterozoic–Palaeozoic Rayner Complex and Prydz Belt yield more radiogenic compositions and are broadly similar and strongly suggest these units correlate with parts of the Eastern Ghats Belt of India. A strikingly different signature is evident from the inboard Ruker Complex, which yielded unradiogenic compositions. This complex is unlike any unit within India or Australia, suggesting that these rocks represent exposures of an Antarctic (Crohn) Craton. Compositions from the enigmatic Rauer Terrane are consistent with a shared early history with the Ruker Complex but with a different post-Archaean evolution.