Magnetobiostratigraphic chronology and palaeoenvironmental history of Cenozoic sequences from ODP sites 1165 and 1166, Prydz Bay, Antarctica

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doi: 10.1016/S0031-0182(03)00395-X
Author(s): Florindo, Fabio; Bohaty, Steven M.; Erwin, Patrick S.; Richter, Carl; Roberts, Andrew P.; Whalen, Patricia A.; Whitehead, Jason M.
Author Affiliation(s): Primary:
Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy
Stanford University, United States
Geoscience Australia, Australia
University of California at Santa Cruz, United States
University of Oxford, United Kingdom
Ocean Drilling Program, United States
University of Arkansas, United States
University of Nebraska, United States
Volume Title: Antarctic Cenozoic palaeoenvironments; geologic record and models
Volume Author(s): Florindo, Fabio, editor; Cooper, Alan K.; O'Brien, Philip E.
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 198(1-2), p.69-100; ANTOSTRAT symposium; The geologic record of the Antarctic ice sheet from drilling, coring and seismic studies, Erice, Italy, Sept. 2001, edited by Fabio Florindo, Alan K. Cooper and Philip E. O'Brien. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 86 refs.; illus., incl. sects., 3 tables, sketch map
Summary: A transect of three sites was drilled during Leg 188 of the Ocean Drilling Program (ODP), proximal to the East Antarctic Ice Sheet (EAIS) across the Prydz Bay continental shelf (Site 1166), slope (Site 1167), and rise (Site 1165). We present results of a palaeomagnetic and rock magnetic study of sediments recovered at sites 1165 and 1166. Magnetostratigraphic interpretations are presented for both holes and are mainly constrained by diatom and radiolarian biostratigraphies, interpreted in the light of recent refinements to Southern Ocean zonal schemes and datum calibrations for these microfossil groups. Site 1165 records a history of sedimentation on the continental rise extending back to earliest Miocene times (about 22 Ma). Several long-term changes characterise this record, including an overall trend of decreasing sedimentation rates from the bottom to the top of the hole. There is a progressive decrease in the sedimentation rate above about 308 mbsf (meters below sea floor), which is marked by a transition from dark-grey fissile claystones to greenish-grey diatom-bearing clays. At this transition, ice-rafted debris, sand grains, and total clay content also increase. The chronology presented here indicates a middle Miocene age (∼14.3 Ma) for the lithological transition. Correlation to ODP Hole 747A from the Kerguelen Plateau suggests that this lithological transition coincides with the base of the Mi-3/3a δ18O event, which suggests palaeoclimatic control on middle Miocene sedimentation changes at Site 1165. Core recovery was poor at Site 1166. Consequently, the magnetostratigraphic data are of limited value. The deepest cores recovered at Site 1166 record brief intervals in the early history of the EAIS for the Prydz Bay region, extending back through the early stage of glaciation to pre-glacial times. An Early Cretaceous fluvio-lacustrine unit, lagoonal deposits and sandy fluvio-deltaic units of mid-late Eocene age contain a sporadic record of the transition from humid and mild conditions to cool temperate conditions. Abstract Copyright (2003) Elsevier, B.V.
Year of Publication: 2003
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Anhysteretic remanent magnetization; Antarctic ice sheet; Antarctica; Biostratigraphy; Biozones; Cenozoic; Chronology; Continental shelf; Correlation; Deltaic environment; Depositional environment; Diatoms; East Antarctica; Experimental studies; Faunal list; Floral list; Fluvial environment; Glacial environment; Glaciation; Glaciomarine environment; Grain size; Ice rafting; Invertebrata; Isothermal remanent magnetization; Lagoonal environment; Leg 188; Magnetic minerals; Magnetization; Magnetostratigraphy; Marine environment; Marine sediments; Microfossils; Middle Miocene; Miocene; Neogene; ODP Site 1165; ODP Site 1166; Ocean Drilling Program; Paleoclimatology; Paleomagnetism; Plantae; Protista; Prydz Bay; Radiolaria; Remanent magnetization; Sedimentation rates; Sediments; Shelf environment; Southern Ocean; Tertiary
Coordinates: S642300 S642200 E0671400 E0671300
S674200 S674100 E0744800 E0744700
Record ID: 2003073059
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands