The Location and Styles of Ice-Free “Oases” during Neoproterozoic Glaciations with Evolutionary Implications
Evidence based on molecular clocks, together with molecular evidence/biomarkers and putative body fossils, points to major evolutionary events prior to and during the intense Cryogenian and Ediacaran glaciations. The glaciations themselves were of global extent. Sedimentological evidence, including...
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ftmdpi:oai:mdpi.com:/2076-3263/2/2/90/ 2023-08-20T04:01:13+02:00 The Location and Styles of Ice-Free “Oases” during Neoproterozoic Glaciations with Evolutionary Implications Daniel Paul Le Heron agris 2012-05-29 application/pdf https://doi.org/10.3390/geosciences2020090 EN eng Molecular Diversity Preservation International Sedimentology, Stratigraphy and Palaeontology https://dx.doi.org/10.3390/geosciences2020090 https://creativecommons.org/licenses/by-nc-sa/3.0/ Geosciences; Volume 2; Issue 2; Pages: 90-108 Neoproterozoic Snowball Earth glaciation evolution Text 2012 ftmdpi https://doi.org/10.3390/geosciences2020090 2023-07-31T20:29:04Z Evidence based on molecular clocks, together with molecular evidence/biomarkers and putative body fossils, points to major evolutionary events prior to and during the intense Cryogenian and Ediacaran glaciations. The glaciations themselves were of global extent. Sedimentological evidence, including hummocky cross-stratification (representing ice-free seas affected by intra-glacial storms), dropstone textures, microbial mat-bearing ironstones, ladderback ripples, and wave ripples, militates against a “hard” Snowball Earth event. Each piece of sedimentological evidence potentially allows insight into the shape and location, with respect to the shoreline, of ice-free areas (“oases”) that may be viewed as potential refugia. The location of such oases must be seen in the context of global paleogeography, and it is emphasized that continental reconstructions at 600 Ma (about 35 millions years after the “Marinoan” ice age) are non-unique solutions. Specifically, whether continents such as greater India, Australia/East Antarctica, Kalahari, South and North China, and Siberia, were welded to a southern supercontinent or not, has implications for island speciation, faunal exchange, and the development of endemism. Text Antarc* Antarctica East Antarctica Siberia MDPI Open Access Publishing East Antarctica Geosciences 2 2 90 108 |
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Open Polar |
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MDPI Open Access Publishing |
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ftmdpi |
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English |
topic |
Neoproterozoic Snowball Earth glaciation evolution |
spellingShingle |
Neoproterozoic Snowball Earth glaciation evolution Daniel Paul Le Heron The Location and Styles of Ice-Free “Oases” during Neoproterozoic Glaciations with Evolutionary Implications |
topic_facet |
Neoproterozoic Snowball Earth glaciation evolution |
description |
Evidence based on molecular clocks, together with molecular evidence/biomarkers and putative body fossils, points to major evolutionary events prior to and during the intense Cryogenian and Ediacaran glaciations. The glaciations themselves were of global extent. Sedimentological evidence, including hummocky cross-stratification (representing ice-free seas affected by intra-glacial storms), dropstone textures, microbial mat-bearing ironstones, ladderback ripples, and wave ripples, militates against a “hard” Snowball Earth event. Each piece of sedimentological evidence potentially allows insight into the shape and location, with respect to the shoreline, of ice-free areas (“oases”) that may be viewed as potential refugia. The location of such oases must be seen in the context of global paleogeography, and it is emphasized that continental reconstructions at 600 Ma (about 35 millions years after the “Marinoan” ice age) are non-unique solutions. Specifically, whether continents such as greater India, Australia/East Antarctica, Kalahari, South and North China, and Siberia, were welded to a southern supercontinent or not, has implications for island speciation, faunal exchange, and the development of endemism. |
format |
Text |
author |
Daniel Paul Le Heron |
author_facet |
Daniel Paul Le Heron |
author_sort |
Daniel Paul Le Heron |
title |
The Location and Styles of Ice-Free “Oases” during Neoproterozoic Glaciations with Evolutionary Implications |
title_short |
The Location and Styles of Ice-Free “Oases” during Neoproterozoic Glaciations with Evolutionary Implications |
title_full |
The Location and Styles of Ice-Free “Oases” during Neoproterozoic Glaciations with Evolutionary Implications |
title_fullStr |
The Location and Styles of Ice-Free “Oases” during Neoproterozoic Glaciations with Evolutionary Implications |
title_full_unstemmed |
The Location and Styles of Ice-Free “Oases” during Neoproterozoic Glaciations with Evolutionary Implications |
title_sort |
location and styles of ice-free “oases” during neoproterozoic glaciations with evolutionary implications |
publisher |
Molecular Diversity Preservation International |
publishDate |
2012 |
url |
https://doi.org/10.3390/geosciences2020090 |
op_coverage |
agris |
geographic |
East Antarctica |
geographic_facet |
East Antarctica |
genre |
Antarc* Antarctica East Antarctica Siberia |
genre_facet |
Antarc* Antarctica East Antarctica Siberia |
op_source |
Geosciences; Volume 2; Issue 2; Pages: 90-108 |
op_relation |
Sedimentology, Stratigraphy and Palaeontology https://dx.doi.org/10.3390/geosciences2020090 |
op_rights |
https://creativecommons.org/licenses/by-nc-sa/3.0/ |
op_doi |
https://doi.org/10.3390/geosciences2020090 |
container_title |
Geosciences |
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2 |
container_issue |
2 |
container_start_page |
90 |
op_container_end_page |
108 |
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1774723533467811840 |