Research Article DOI:10.2110/jsr.2014.4 ICE-KEEL SCOUR MARKS IN THE GEOLOGICAL RECORD: EVIDENCE FROM CARBONIFEROUS SOFT-SEDIMENT STRIATED SURFACES IN THE PARANA ́ BASIN, SOUTHERN BRAZIL
ABSTRACT: Soft-sediment glacially striated surfaces are common structures in ancient glacial successions, such as the Gondwanic Paleozoic record, and document ice erosion on non lithified beds. In most cases, they have been interpreted as the product of subglacial erosion beneath advancing marine or...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.1029.246 2023-05-15T16:41:15+02:00 Research Article DOI:10.2110/jsr.2014.4 ICE-KEEL SCOUR MARKS IN THE GEOLOGICAL RECORD: EVIDENCE FROM CARBONIFEROUS SOFT-SEDIMENT STRIATED SURFACES IN THE PARANA ́ BASIN, SOUTHERN BRAZIL Fernando F. Vesely Mario L. Assine The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1029.246 http://jsedres.geoscienceworld.org/content/jsedres/84/1/26.full.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1029.246 http://jsedres.geoscienceworld.org/content/jsedres/84/1/26.full.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://jsedres.geoscienceworld.org/content/jsedres/84/1/26.full.pdf text ftciteseerx 2016-10-30T00:07:49Z ABSTRACT: Soft-sediment glacially striated surfaces are common structures in ancient glacial successions, such as the Gondwanic Paleozoic record, and document ice erosion on non lithified beds. In most cases, they have been interpreted as the product of subglacial erosion beneath advancing marine or terrestrial glaciers, although direct evidence for glacial sedimentation in associated strata is infrequent. In this paper we document soft-sediment striated surfaces of Carboniferous age occurring in cross-laminated sandstones of the lower Itarare ́ Group, southern Parana ́ Basin, Brazil, and interpret them as scour marks generated by keels of floating ice. Striated surfaces occur in closely spaced, multiple stratigraphic horizons in the lower half of a deglacial sequence, whose facies characteristics indicate sedimentation in subaqueous outwash and deltaic settings. Surfaces are laterally discontinuous, commonly bordered by marginal berms, and in some cases capped by mudstones with dropstones; they have orientations that deviate from the regional paleo-ice flow indicated by glacial grooves carved on the pre-glacial basement. The characteristics observed are consistent with modern and Pleistocene ice-keel scour marks. In addition, soft-sediment striated surfaces from other Gondwanic localities have similar attributes, suggesting that ice-keel scour marks may be more common in the geological record than previously considered and that vertically repeated striated surfaces do not necessarily indicate multiple ice-sheet advances. Therefore, paleo-ice flow reconstructions based on soft-sediment striated surfaces need to be revaluated considering that the movement of free-floating ice masses is controlled by phenomena other than glacier advance. Text Ice Sheet Unknown |
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ftciteseerx |
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ABSTRACT: Soft-sediment glacially striated surfaces are common structures in ancient glacial successions, such as the Gondwanic Paleozoic record, and document ice erosion on non lithified beds. In most cases, they have been interpreted as the product of subglacial erosion beneath advancing marine or terrestrial glaciers, although direct evidence for glacial sedimentation in associated strata is infrequent. In this paper we document soft-sediment striated surfaces of Carboniferous age occurring in cross-laminated sandstones of the lower Itarare ́ Group, southern Parana ́ Basin, Brazil, and interpret them as scour marks generated by keels of floating ice. Striated surfaces occur in closely spaced, multiple stratigraphic horizons in the lower half of a deglacial sequence, whose facies characteristics indicate sedimentation in subaqueous outwash and deltaic settings. Surfaces are laterally discontinuous, commonly bordered by marginal berms, and in some cases capped by mudstones with dropstones; they have orientations that deviate from the regional paleo-ice flow indicated by glacial grooves carved on the pre-glacial basement. The characteristics observed are consistent with modern and Pleistocene ice-keel scour marks. In addition, soft-sediment striated surfaces from other Gondwanic localities have similar attributes, suggesting that ice-keel scour marks may be more common in the geological record than previously considered and that vertically repeated striated surfaces do not necessarily indicate multiple ice-sheet advances. Therefore, paleo-ice flow reconstructions based on soft-sediment striated surfaces need to be revaluated considering that the movement of free-floating ice masses is controlled by phenomena other than glacier advance. |
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The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Fernando F. Vesely Mario L. Assine |
spellingShingle |
Fernando F. Vesely Mario L. Assine Research Article DOI:10.2110/jsr.2014.4 ICE-KEEL SCOUR MARKS IN THE GEOLOGICAL RECORD: EVIDENCE FROM CARBONIFEROUS SOFT-SEDIMENT STRIATED SURFACES IN THE PARANA ́ BASIN, SOUTHERN BRAZIL |
author_facet |
Fernando F. Vesely Mario L. Assine |
author_sort |
Fernando F. Vesely |
title |
Research Article DOI:10.2110/jsr.2014.4 ICE-KEEL SCOUR MARKS IN THE GEOLOGICAL RECORD: EVIDENCE FROM CARBONIFEROUS SOFT-SEDIMENT STRIATED SURFACES IN THE PARANA ́ BASIN, SOUTHERN BRAZIL |
title_short |
Research Article DOI:10.2110/jsr.2014.4 ICE-KEEL SCOUR MARKS IN THE GEOLOGICAL RECORD: EVIDENCE FROM CARBONIFEROUS SOFT-SEDIMENT STRIATED SURFACES IN THE PARANA ́ BASIN, SOUTHERN BRAZIL |
title_full |
Research Article DOI:10.2110/jsr.2014.4 ICE-KEEL SCOUR MARKS IN THE GEOLOGICAL RECORD: EVIDENCE FROM CARBONIFEROUS SOFT-SEDIMENT STRIATED SURFACES IN THE PARANA ́ BASIN, SOUTHERN BRAZIL |
title_fullStr |
Research Article DOI:10.2110/jsr.2014.4 ICE-KEEL SCOUR MARKS IN THE GEOLOGICAL RECORD: EVIDENCE FROM CARBONIFEROUS SOFT-SEDIMENT STRIATED SURFACES IN THE PARANA ́ BASIN, SOUTHERN BRAZIL |
title_full_unstemmed |
Research Article DOI:10.2110/jsr.2014.4 ICE-KEEL SCOUR MARKS IN THE GEOLOGICAL RECORD: EVIDENCE FROM CARBONIFEROUS SOFT-SEDIMENT STRIATED SURFACES IN THE PARANA ́ BASIN, SOUTHERN BRAZIL |
title_sort |
research article doi:10.2110/jsr.2014.4 ice-keel scour marks in the geological record: evidence from carboniferous soft-sediment striated surfaces in the parana ́ basin, southern brazil |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1029.246 http://jsedres.geoscienceworld.org/content/jsedres/84/1/26.full.pdf |
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Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
http://jsedres.geoscienceworld.org/content/jsedres/84/1/26.full.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1029.246 http://jsedres.geoscienceworld.org/content/jsedres/84/1/26.full.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766031682097381376 |