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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ftdoajarticles:oai:doaj.org/article:3d8fa0a28ea5458c9a73447545a86d88 2023-05-15T13:56:49+02:00 The Location and Styles of Ice-Free “Oases” during Neoproterozoic Glaciations with Evolutionary Implications Daniel Paul Le Heron 2012-05-01T00:00:00Z https://doi.org/10.3390/geosciences2020090 https://doaj.org/article/3d8fa0a28ea5458c9a73447545a86d88 EN eng MDPI AG http://www.mdpi.com/2076-3263/2/2/90 https://doaj.org/toc/2076-3263 doi:10.3390/geosciences2020090 2076-3263 https://doaj.org/article/3d8fa0a28ea5458c9a73447545a86d88 Geosciences, Vol 2, Iss 2, Pp 90-108 (2012) Neoproterozoic Snowball Earth glaciation evolution Geology QE1-996.5 article 2012 ftdoajarticles https://doi.org/10.3390/geosciences2020090 2022-12-31T04:42:18Z 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. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Siberia Directory of Open Access Journals: DOAJ Articles East Antarctica Geosciences 2 2 90 108 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Neoproterozoic Snowball Earth glaciation evolution Geology QE1-996.5 |
spellingShingle |
Neoproterozoic Snowball Earth glaciation evolution Geology QE1-996.5 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 Geology QE1-996.5 |
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 |
Article in Journal/Newspaper |
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 |
MDPI AG |
publishDate |
2012 |
url |
https://doi.org/10.3390/geosciences2020090 https://doaj.org/article/3d8fa0a28ea5458c9a73447545a86d88 |
geographic |
East Antarctica |
geographic_facet |
East Antarctica |
genre |
Antarc* Antarctica East Antarctica Siberia |
genre_facet |
Antarc* Antarctica East Antarctica Siberia |
op_source |
Geosciences, Vol 2, Iss 2, Pp 90-108 (2012) |
op_relation |
http://www.mdpi.com/2076-3263/2/2/90 https://doaj.org/toc/2076-3263 doi:10.3390/geosciences2020090 2076-3263 https://doaj.org/article/3d8fa0a28ea5458c9a73447545a86d88 |
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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1766264403742687232 |