Cenozoic Ash Layers on the Vøring Plateau (ODP Leg 104)
Numerous fresh ash layers comprise about 0.3% by volume of Neogene to Holocene sediments drilled at Leg 104 Sites 642 and 643 (Wring Plateau, North Atlantic). Median grain sizes of the ashes are about 100 /xm and maximum grain sizes range up to 1200 fim. Rhyolitic pumice shards dominate, with minor...
Main Authors: | , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
1989
|
Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/46704/ https://oceanrep.geomar.de/id/eprint/46704/1/sr104_18.pdf https://doi.org/10.2973/odp.proc.sr.104.129.1989 |
id |
ftoceanrep:oai:oceanrep.geomar.de:46704 |
---|---|
record_format |
openpolar |
spelling |
ftoceanrep:oai:oceanrep.geomar.de:46704 2023-05-15T16:51:34+02:00 Cenozoic Ash Layers on the Vøring Plateau (ODP Leg 104) Bitschene, P. R. Schmincke, Hans-Ulrich Viereck, L. 1989 text https://oceanrep.geomar.de/id/eprint/46704/ https://oceanrep.geomar.de/id/eprint/46704/1/sr104_18.pdf https://doi.org/10.2973/odp.proc.sr.104.129.1989 en eng https://oceanrep.geomar.de/id/eprint/46704/1/sr104_18.pdf Bitschene, P. R., Schmincke, H. U. and Viereck, L. (1989) Cenozoic Ash Layers on the Vøring Plateau (ODP Leg 104). Open Access Proceedings of the Ocean Drilling Program: Scientific Results, 104 . pp. 357-366. DOI 10.2973/odp.proc.sr.104.129.1989 <https://doi.org/10.2973/odp.proc.sr.104.129.1989>. doi:10.2973/odp.proc.sr.104.129.1989 info:eu-repo/semantics/openAccess Article NonPeerReviewed 1989 ftoceanrep https://doi.org/10.2973/odp.proc.sr.104.129.1989 2023-04-07T15:45:40Z Numerous fresh ash layers comprise about 0.3% by volume of Neogene to Holocene sediments drilled at Leg 104 Sites 642 and 643 (Wring Plateau, North Atlantic). Median grain sizes of the ashes are about 100 /xm and maximum grain sizes range up to 1200 fim. Rhyolitic pumice shards dominate, with minor bubble wall shards. Basaltic shards are poorly vesicular and blocky or round. Phenocrystic plagioclase, zircon, and clinopyroxene occur in the rhyolitic, plagioclase, and clinopyroxene phenocrysts and basaltic lithics in the basaltic tephra. Quartz, amphibole, clinozoisite, and rutile are interpreted as xenocrysts. All ash layers are well-sorted and represent distal fallout from major explosive eruptions. Most ashes are rhyolitic (high-K and low-K) in composition, some are bimodal (tholeiitic and rhyolitic). Early Miocene tephra is dominantly basaltic. Iceland is inferred to be the likely source region for most ashes. Late Miocene high-K rhyolites may have originated from the K-rich Jan Mayen magmatic province. One Quaternary layer with biotite and alkali feldspar phenocrysts may have been derived from Jan Mayen Island. Four individual Pliocene to Holocene ash layers from Sites 642 and 643 can be correlated fairly well. Upper Miocene layers are tentatively correlated as a sequence between Sites 642 and 643. Average calculated layer frequencies are about three layers/m.y. through the Pliocene and Pleistocene and five to eight layers per m.y. through the middle and late Miocene, suggesting rather continuous volcanic activity in the North Atlantic. Episodic magmatic activity during Neogene epochs in this part of the North Atlantic, as postulated in the literature, cannot be confirmed. Article in Journal/Newspaper Iceland Jan Mayen Jan Mayen Island North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Jan Mayen Vøring Plateau ENVELOPE(4.000,4.000,67.000,67.000) |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Numerous fresh ash layers comprise about 0.3% by volume of Neogene to Holocene sediments drilled at Leg 104 Sites 642 and 643 (Wring Plateau, North Atlantic). Median grain sizes of the ashes are about 100 /xm and maximum grain sizes range up to 1200 fim. Rhyolitic pumice shards dominate, with minor bubble wall shards. Basaltic shards are poorly vesicular and blocky or round. Phenocrystic plagioclase, zircon, and clinopyroxene occur in the rhyolitic, plagioclase, and clinopyroxene phenocrysts and basaltic lithics in the basaltic tephra. Quartz, amphibole, clinozoisite, and rutile are interpreted as xenocrysts. All ash layers are well-sorted and represent distal fallout from major explosive eruptions. Most ashes are rhyolitic (high-K and low-K) in composition, some are bimodal (tholeiitic and rhyolitic). Early Miocene tephra is dominantly basaltic. Iceland is inferred to be the likely source region for most ashes. Late Miocene high-K rhyolites may have originated from the K-rich Jan Mayen magmatic province. One Quaternary layer with biotite and alkali feldspar phenocrysts may have been derived from Jan Mayen Island. Four individual Pliocene to Holocene ash layers from Sites 642 and 643 can be correlated fairly well. Upper Miocene layers are tentatively correlated as a sequence between Sites 642 and 643. Average calculated layer frequencies are about three layers/m.y. through the Pliocene and Pleistocene and five to eight layers per m.y. through the middle and late Miocene, suggesting rather continuous volcanic activity in the North Atlantic. Episodic magmatic activity during Neogene epochs in this part of the North Atlantic, as postulated in the literature, cannot be confirmed. |
format |
Article in Journal/Newspaper |
author |
Bitschene, P. R. Schmincke, Hans-Ulrich Viereck, L. |
spellingShingle |
Bitschene, P. R. Schmincke, Hans-Ulrich Viereck, L. Cenozoic Ash Layers on the Vøring Plateau (ODP Leg 104) |
author_facet |
Bitschene, P. R. Schmincke, Hans-Ulrich Viereck, L. |
author_sort |
Bitschene, P. R. |
title |
Cenozoic Ash Layers on the Vøring Plateau (ODP Leg 104) |
title_short |
Cenozoic Ash Layers on the Vøring Plateau (ODP Leg 104) |
title_full |
Cenozoic Ash Layers on the Vøring Plateau (ODP Leg 104) |
title_fullStr |
Cenozoic Ash Layers on the Vøring Plateau (ODP Leg 104) |
title_full_unstemmed |
Cenozoic Ash Layers on the Vøring Plateau (ODP Leg 104) |
title_sort |
cenozoic ash layers on the vøring plateau (odp leg 104) |
publishDate |
1989 |
url |
https://oceanrep.geomar.de/id/eprint/46704/ https://oceanrep.geomar.de/id/eprint/46704/1/sr104_18.pdf https://doi.org/10.2973/odp.proc.sr.104.129.1989 |
long_lat |
ENVELOPE(4.000,4.000,67.000,67.000) |
geographic |
Jan Mayen Vøring Plateau |
geographic_facet |
Jan Mayen Vøring Plateau |
genre |
Iceland Jan Mayen Jan Mayen Island North Atlantic |
genre_facet |
Iceland Jan Mayen Jan Mayen Island North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/46704/1/sr104_18.pdf Bitschene, P. R., Schmincke, H. U. and Viereck, L. (1989) Cenozoic Ash Layers on the Vøring Plateau (ODP Leg 104). Open Access Proceedings of the Ocean Drilling Program: Scientific Results, 104 . pp. 357-366. DOI 10.2973/odp.proc.sr.104.129.1989 <https://doi.org/10.2973/odp.proc.sr.104.129.1989>. doi:10.2973/odp.proc.sr.104.129.1989 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.2973/odp.proc.sr.104.129.1989 |
_version_ |
1766041686430973952 |