Stable isotopic, assemblage, and paleoenvironmental investigations of juvenile-ocean sediments recovered on Leg 122, Wombat Plateau, northwest Australia

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

A sedimentary sequence documenting the early history of the proto-Indian Ocean was drilled at Site 761. Directly above the post-rift unconformity, two lithologic units were recovered which reflect deposition in incipient oceanic environments. The lower unit, composed of sandstone, contains abundant belemnites and a few lenses composed of low-diversity coccolith assemblages. The second unit, composed of chalk, contains abundant calcispheres, thoracospheres, low-diversity coccolith assemblages, and a few radiolarians. Belemnites and organisms that produced calcispheres and thoracospheres are thought to be opportunistic. Their abundance, and the absence of a normal marine fauna and flora, reflects an unstable early ocean environment. Stable oxygen and carbon isotopic data for the two units fall into almost separate fields. Heavy δ18O values for the belemnites indicate that they have not been affected by recrystallization. Instead, these isotopic values are thought to indicate either the deep, cool habitat of the belemnites or strong vital effects. -from Author

Original languageEnglish (US)
Pages (from-to)569-585
Number of pages17
JournalUnknown Journal
StatePublished - Jan 1 1992

Fingerprint

coccolith
plateau
ocean
chalk
sedimentary sequence
unconformity
sediment
flora
sandstone
oxygen
carbon
habitat
history
organism
Indian Ocean
effect
marine fauna

All Science Journal Classification (ASJC) codes

  • Environmental Science(all)
  • Earth and Planetary Sciences(all)

Cite this

@article{a73893fa6a7d4a328db1228e0a5cc946,
title = "Stable isotopic, assemblage, and paleoenvironmental investigations of juvenile-ocean sediments recovered on Leg 122, Wombat Plateau, northwest Australia",
abstract = "A sedimentary sequence documenting the early history of the proto-Indian Ocean was drilled at Site 761. Directly above the post-rift unconformity, two lithologic units were recovered which reflect deposition in incipient oceanic environments. The lower unit, composed of sandstone, contains abundant belemnites and a few lenses composed of low-diversity coccolith assemblages. The second unit, composed of chalk, contains abundant calcispheres, thoracospheres, low-diversity coccolith assemblages, and a few radiolarians. Belemnites and organisms that produced calcispheres and thoracospheres are thought to be opportunistic. Their abundance, and the absence of a normal marine fauna and flora, reflects an unstable early ocean environment. Stable oxygen and carbon isotopic data for the two units fall into almost separate fields. Heavy δ18O values for the belemnites indicate that they have not been affected by recrystallization. Instead, these isotopic values are thought to indicate either the deep, cool habitat of the belemnites or strong vital effects. -from Author",
author = "Timothy Bralower",
year = "1992",
month = "1",
day = "1",
language = "English (US)",
pages = "569--585",
journal = "[No source information available]",
issn = "0042-1215",

}

TY - JOUR

T1 - Stable isotopic, assemblage, and paleoenvironmental investigations of juvenile-ocean sediments recovered on Leg 122, Wombat Plateau, northwest Australia

AU - Bralower, Timothy

PY - 1992/1/1

Y1 - 1992/1/1

N2 - A sedimentary sequence documenting the early history of the proto-Indian Ocean was drilled at Site 761. Directly above the post-rift unconformity, two lithologic units were recovered which reflect deposition in incipient oceanic environments. The lower unit, composed of sandstone, contains abundant belemnites and a few lenses composed of low-diversity coccolith assemblages. The second unit, composed of chalk, contains abundant calcispheres, thoracospheres, low-diversity coccolith assemblages, and a few radiolarians. Belemnites and organisms that produced calcispheres and thoracospheres are thought to be opportunistic. Their abundance, and the absence of a normal marine fauna and flora, reflects an unstable early ocean environment. Stable oxygen and carbon isotopic data for the two units fall into almost separate fields. Heavy δ18O values for the belemnites indicate that they have not been affected by recrystallization. Instead, these isotopic values are thought to indicate either the deep, cool habitat of the belemnites or strong vital effects. -from Author

AB - A sedimentary sequence documenting the early history of the proto-Indian Ocean was drilled at Site 761. Directly above the post-rift unconformity, two lithologic units were recovered which reflect deposition in incipient oceanic environments. The lower unit, composed of sandstone, contains abundant belemnites and a few lenses composed of low-diversity coccolith assemblages. The second unit, composed of chalk, contains abundant calcispheres, thoracospheres, low-diversity coccolith assemblages, and a few radiolarians. Belemnites and organisms that produced calcispheres and thoracospheres are thought to be opportunistic. Their abundance, and the absence of a normal marine fauna and flora, reflects an unstable early ocean environment. Stable oxygen and carbon isotopic data for the two units fall into almost separate fields. Heavy δ18O values for the belemnites indicate that they have not been affected by recrystallization. Instead, these isotopic values are thought to indicate either the deep, cool habitat of the belemnites or strong vital effects. -from Author

UR - http://www.scopus.com/inward/record.url?scp=0026448832&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026448832&partnerID=8YFLogxK

M3 - Article

SP - 569

EP - 585

JO - [No source information available]

JF - [No source information available]

SN - 0042-1215

ER -