STRATIGRAPHY OF THE CHIKKIM AND FATU LA FORMATIONS IN THE ZANGLA AND ZUMLUNG UNITS (ZANSKAR RANGE, INDIA) WITH COMPARISONS TO THE THAKKHOLA REGION (CENTRAL NEPAL) : MID-CRETACEOUS EVOLUTION OF THE INDIAN PASSIVE MARGIN
Detailed biostratigraphic study of mid-Cretaceous Tethys Himalayan pelagic units shed new light on the evolution of the northern India passive continental margin. After a major episode of alkaline magmatism recorded from Zanskar to Nepal in the Early Cretaceous, condensed glauco-phosphorites were de...
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ftunivmilriv:oai:ojs.riviste.unimi.it:article/8961 2023-12-31T10:22:14+01:00 STRATIGRAPHY OF THE CHIKKIM AND FATU LA FORMATIONS IN THE ZANGLA AND ZUMLUNG UNITS (ZANSKAR RANGE, INDIA) WITH COMPARISONS TO THE THAKKHOLA REGION (CENTRAL NEPAL) : MID-CRETACEOUS EVOLUTION OF THE INDIAN PASSIVE MARGIN PREMOLI SILVA, ISABELLA GARZANTI, EDUARDO GAETANI, MAURZIO 1991-12-30 application/pdf https://riviste.unimi.it/index.php/RIPS/article/view/8961 https://doi.org/10.13130/2039-4942/8961 eng eng Milano University Press https://riviste.unimi.it/index.php/RIPS/article/view/8961/8526 https://riviste.unimi.it/index.php/RIPS/article/view/8961 doi:10.13130/2039-4942/8961 Copyright (c) 2017 ISABELLA PREMOLI SILVA, EDUARDO GARZANTI, MAURZIO GAETANI RIVISTA ITALIANA DI PALEONTOLOGIA E STRATIGRAFIA Vol. 97 No. 3-4 (1991) Rivista italiana di Paleontologia e Stratigrafia; V. 97 N. 3-4 (1991) 2039-4942 0035-6883 Stratigraphy Cretaceous Tethys Himalaya Planktonic foraminifera info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 1991 ftunivmilriv https://doi.org/10.13130/2039-4942/8961 2023-12-05T23:14:14Z Detailed biostratigraphic study of mid-Cretaceous Tethys Himalayan pelagic units shed new light on the evolution of the northern India passive continental margin. After a major episode of alkaline magmatism recorded from Zanskar to Nepal in the Early Cretaceous, condensed glauco-phosphorites were deposited during the Rotalipora subticinensis Subzone, and were overlain unconformably by pelagic mudstones during the Rotalipora ticinensis to Rotalipora appenninica Zones (Fatu La Formation in Zanskar and Muding Formation in Nepal). Throughout the Tethys Himalaya drowning of clastic shelves thus occurred with the same modalities and synchronously in Late Albian time. The base of the Chikkim Formation in Zanskar is younger, and overlies palimpsest arenites and reworked glauco-phosphorires deposited during the latest Cenomanian Whiteinella archaeocretacea Zone. Hiatuses several million years long, mainly coeval and similar in duration in the Chikkim and Fatu La Formations, characterize the Cenomanian and the Late Turonian to Campanian sections throughout the Zanskar Range. These hiatuses are ascribed to continuous resuspension of pelagic sediments on the upper slope, caused by the action of strong eastbound oceanic currents. Much higher accumulation rates were recorded in the early-middle Turonian, when deposition occurred at grearer depths below the mudline. Accumulation rates increased greatly in the Maastrichtian, when offshore marls with sparsc phosphate nodules were gradually rcplaced by inner shelf carbonate facies at the close of the Cretaceous. The studied succession shows a mirrorlike repetition of sedimentary facies, interpreted as part of a 65 to 70 my long Cretaceous supersequence. Sedimentary evolution reflected a complex interplay of global and regional phenomena, including the extensional and magmatic episodes leading to thc final fragmentarion of Gondwana-Land and opening of the Indian Ocean, a long-term tendency to eustatic rise, changing paleooceanographic circulation, and oceanic anoxic events. Article in Journal/Newspaper Planktonic foraminifera University of Milan: Riviste UNIMI |
institution |
Open Polar |
collection |
University of Milan: Riviste UNIMI |
op_collection_id |
ftunivmilriv |
language |
English |
topic |
Stratigraphy Cretaceous Tethys Himalaya Planktonic foraminifera |
spellingShingle |
Stratigraphy Cretaceous Tethys Himalaya Planktonic foraminifera PREMOLI SILVA, ISABELLA GARZANTI, EDUARDO GAETANI, MAURZIO STRATIGRAPHY OF THE CHIKKIM AND FATU LA FORMATIONS IN THE ZANGLA AND ZUMLUNG UNITS (ZANSKAR RANGE, INDIA) WITH COMPARISONS TO THE THAKKHOLA REGION (CENTRAL NEPAL) : MID-CRETACEOUS EVOLUTION OF THE INDIAN PASSIVE MARGIN |
topic_facet |
Stratigraphy Cretaceous Tethys Himalaya Planktonic foraminifera |
description |
Detailed biostratigraphic study of mid-Cretaceous Tethys Himalayan pelagic units shed new light on the evolution of the northern India passive continental margin. After a major episode of alkaline magmatism recorded from Zanskar to Nepal in the Early Cretaceous, condensed glauco-phosphorites were deposited during the Rotalipora subticinensis Subzone, and were overlain unconformably by pelagic mudstones during the Rotalipora ticinensis to Rotalipora appenninica Zones (Fatu La Formation in Zanskar and Muding Formation in Nepal). Throughout the Tethys Himalaya drowning of clastic shelves thus occurred with the same modalities and synchronously in Late Albian time. The base of the Chikkim Formation in Zanskar is younger, and overlies palimpsest arenites and reworked glauco-phosphorires deposited during the latest Cenomanian Whiteinella archaeocretacea Zone. Hiatuses several million years long, mainly coeval and similar in duration in the Chikkim and Fatu La Formations, characterize the Cenomanian and the Late Turonian to Campanian sections throughout the Zanskar Range. These hiatuses are ascribed to continuous resuspension of pelagic sediments on the upper slope, caused by the action of strong eastbound oceanic currents. Much higher accumulation rates were recorded in the early-middle Turonian, when deposition occurred at grearer depths below the mudline. Accumulation rates increased greatly in the Maastrichtian, when offshore marls with sparsc phosphate nodules were gradually rcplaced by inner shelf carbonate facies at the close of the Cretaceous. The studied succession shows a mirrorlike repetition of sedimentary facies, interpreted as part of a 65 to 70 my long Cretaceous supersequence. Sedimentary evolution reflected a complex interplay of global and regional phenomena, including the extensional and magmatic episodes leading to thc final fragmentarion of Gondwana-Land and opening of the Indian Ocean, a long-term tendency to eustatic rise, changing paleooceanographic circulation, and oceanic anoxic events. |
format |
Article in Journal/Newspaper |
author |
PREMOLI SILVA, ISABELLA GARZANTI, EDUARDO GAETANI, MAURZIO |
author_facet |
PREMOLI SILVA, ISABELLA GARZANTI, EDUARDO GAETANI, MAURZIO |
author_sort |
PREMOLI SILVA, ISABELLA |
title |
STRATIGRAPHY OF THE CHIKKIM AND FATU LA FORMATIONS IN THE ZANGLA AND ZUMLUNG UNITS (ZANSKAR RANGE, INDIA) WITH COMPARISONS TO THE THAKKHOLA REGION (CENTRAL NEPAL) : MID-CRETACEOUS EVOLUTION OF THE INDIAN PASSIVE MARGIN |
title_short |
STRATIGRAPHY OF THE CHIKKIM AND FATU LA FORMATIONS IN THE ZANGLA AND ZUMLUNG UNITS (ZANSKAR RANGE, INDIA) WITH COMPARISONS TO THE THAKKHOLA REGION (CENTRAL NEPAL) : MID-CRETACEOUS EVOLUTION OF THE INDIAN PASSIVE MARGIN |
title_full |
STRATIGRAPHY OF THE CHIKKIM AND FATU LA FORMATIONS IN THE ZANGLA AND ZUMLUNG UNITS (ZANSKAR RANGE, INDIA) WITH COMPARISONS TO THE THAKKHOLA REGION (CENTRAL NEPAL) : MID-CRETACEOUS EVOLUTION OF THE INDIAN PASSIVE MARGIN |
title_fullStr |
STRATIGRAPHY OF THE CHIKKIM AND FATU LA FORMATIONS IN THE ZANGLA AND ZUMLUNG UNITS (ZANSKAR RANGE, INDIA) WITH COMPARISONS TO THE THAKKHOLA REGION (CENTRAL NEPAL) : MID-CRETACEOUS EVOLUTION OF THE INDIAN PASSIVE MARGIN |
title_full_unstemmed |
STRATIGRAPHY OF THE CHIKKIM AND FATU LA FORMATIONS IN THE ZANGLA AND ZUMLUNG UNITS (ZANSKAR RANGE, INDIA) WITH COMPARISONS TO THE THAKKHOLA REGION (CENTRAL NEPAL) : MID-CRETACEOUS EVOLUTION OF THE INDIAN PASSIVE MARGIN |
title_sort |
stratigraphy of the chikkim and fatu la formations in the zangla and zumlung units (zanskar range, india) with comparisons to the thakkhola region (central nepal) : mid-cretaceous evolution of the indian passive margin |
publisher |
Milano University Press |
publishDate |
1991 |
url |
https://riviste.unimi.it/index.php/RIPS/article/view/8961 https://doi.org/10.13130/2039-4942/8961 |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_source |
RIVISTA ITALIANA DI PALEONTOLOGIA E STRATIGRAFIA Vol. 97 No. 3-4 (1991) Rivista italiana di Paleontologia e Stratigrafia; V. 97 N. 3-4 (1991) 2039-4942 0035-6883 |
op_relation |
https://riviste.unimi.it/index.php/RIPS/article/view/8961/8526 https://riviste.unimi.it/index.php/RIPS/article/view/8961 doi:10.13130/2039-4942/8961 |
op_rights |
Copyright (c) 2017 ISABELLA PREMOLI SILVA, EDUARDO GARZANTI, MAURZIO GAETANI |
op_doi |
https://doi.org/10.13130/2039-4942/8961 |
_version_ |
1786833292539985920 |