Resolving the Late Paleozoic Ice Age in Time and Space
Late Paleozoic cyclic strata of Euramerica: Recognition of Gondwanan glacial signatures during periods of thermal subsidence
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Published:January 01, 2008
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CiteCitation
M.R Gibling, M.C Rygel, 2008. "Late Paleozoic cyclic strata of Euramerica: Recognition of Gondwanan glacial signatures during periods of thermal subsidence", Resolving the Late Paleozoic Ice Age in Time and Space, Christopher R. Fielding, Tracy D. Frank, John L. Isbell
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In paleoequatorial parts of Europe and North America, late Paleozoic cyclic successions are widely inferred to reflect glacio-eustasy. However, many of these successions accumulated in basins in the Pangean collisional zone, where variations in tectonics and sediment supply could also have generated cyclic successions. Cyclic successions are ubiquitous in the Maritimes Basin of Atlantic Canada but are especially prominent in the Visean and Bolsovian to Cantabrian, when subsidence rates on coastal plains were low and probably steady during periods of thermal subsidence. During relatively humid climatic conditions in the Bolsovian to Cantabrian, fluvial systems generated clastic cyclic successions with deep valleys and mature interfluve paleosols, providing strong evidence for alternate rise and fall of sea level—a characteristic glacio-eustatic feature. Under arid conditions in the Visean, with few rivers, carbonate-evaporite rhythms formed with little evidence for incision. Comparisons with near- and far-field records for Gondwanan glacial activity suggest that these two periods correspond to sea-level changes on the order of a few tens of meters, probably due to melting and accumulation of small ice caps rather than continent-wide ice sheets. Cyclic successions that formed in basins undergoing steady thermal subsidence may provide the most reliable evidence for glacio-eustasy in the paleoequatorial realm.
- Canada
- Carboniferous
- cyclothems
- Eastern Canada
- eustasy
- glaciation
- Gondwana
- Joggins Formation
- lithostratigraphy
- Maritime Provinces
- Maritimes Basin
- Mississippian
- Morien Group
- Nova Scotia
- paleoclimatology
- Paleozoic
- Pennsylvanian
- planar bedding structures
- sea-level changes
- sedimentary structures
- sequence stratigraphy
- subsidence
- tectonics
- Windsor Group
- Boss Point Formation