Volcanogenic sediment distributions in the Indian Ocean through the Cretaceous and Cenozoic, and their paleoenvironmental implications

Author(s): Sykes, Tim J. S.; Kidd, Robert B.
Author Affiliation(s): Primary:
University of Wales College at Cardiff, Department of Geology, Cardiff, United Kingdom
Volume Title: Marine Geology
Source: Marine Geology, 116(3-4), p.267-291. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0025-3227 CODEN: MAGEA6
Note: In English. 97 refs.; illus. incl. sketch maps
Summary: Volcanogenic sediments are significant components of the cores that have been drilled over the past two decades by the Deep Sea Drilling Project (DSDP) and the Ocean Drilling Program (ODP). The spatial distribution of these sediment components were used, in connection with paleogeographical reconstructions, to determine the primary dispersal processes (direct air fall input, surface circulation or atmospheric circulation) for volcanic material across the Indian Ocean. The identification of volcanic-rich intervals in cores is based on the recognition of primary and secondary (authigenic) components or, where sediment samples have not been obtained, from analysis of downhole logging results e.g. spectral gamma-ray and whole core magnetic susceptibility. The data generated from DSDP cores by Vallier and Kidd (1977) have been upgraded in this study to fit a new integrated timescale that has been adopted for synthesis of ODP and DSDP drilling data (Kidd et al., 1992). It is now possible to map the distributions of volcanic-rich sediments on paleogeographic reconstructions at 1 Ma intervals. Through a review of its tectonic development the timing of accumulations of volcanic components in the Indian Ocean can be related to rifting of continents, formation of new crust at ridge crests and at hotspots, and to landmass volcanism, linked to subduction along the Indonesian Arc. The Kerguelen and Réunion hotspots were the dominant sources of volcanogenic sediments to the Indian Ocean since the early Cretaceous. The main accumulations of volcanogenic sediments occur within the basal sequences of drillholes, immediately above basement. Controls on the transport of volcanic components were linked to atmospheric, surface and, possibly deeper, water circulation patterns. The opening Indian Ocean experienced a change from westerly surface currents, generated by the high latitude westerly winds, during the Mesozoic to a gyral circulation pattern in the Cenozoic. The northwest Indian Ocean has also experienced seasonal reversal of winds since the development of the monsoon system during the late Miocene to Recent. These changes in the wind and water circulation patterns are reflected in the distribution patterns of volcanogenic sediments in the Indian Ocean. The Kerguelen hotspot led to the development of Kerguelen Plateau which was formed above sea level during the Albian (110 Ma) and remained above sea level for the next 30-40 Ma. Volcaniclastic material from this source was mainly distributed to the northeast. In contrast, the Réunion hotspot has contributed volcanic material mainly to the northwest during much of its evolution. Volcanism related to the Réunion and Kerguelen hotspots has apparently influenced volcanogenic sediment distributions in the developing Indian Ocean basins more than the regional rates of sea floor spreading, which were previously thought to exert a major control (Valluer and Kidd, 1977).
Year of Publication: 1994
Research Program: DSDP Deep Sea Drilling Project
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Asia; Broken Ridge; Cenozoic; Chronostratigraphy; Cretaceous; Crust; Deep Sea Drilling Project; Distribution; Evolution; Far East; Hot spots; Indian Ocean; Indonesia; Kerguelen Plateau; Mesozoic; Ninetyeast Ridge; Ocean Drilling Program; Paleo-oceanography; Paleoenvironment; Paleogeography; Plate tectonics; Provenance; Rates; Reconstruction; Rifting; Sea-floor spreading; Sediments; Spatial distribution; Subduction; Volcaniclastics; Volcanism; Wharton Basin
Record ID: 1994025680
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands

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