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GEOREF RECORD

Foraminiferal evidence for inner neritic deposition of Lower Cretaceous (upper Aptian) radiolarian-rich black shales on the western Australian margin

David W. Haig
Foraminiferal evidence for inner neritic deposition of Lower Cretaceous (upper Aptian) radiolarian-rich black shales on the western Australian margin
Journal of Micropalaeontology (May 2005) 24, Part 1: 55-75

Abstract

Diverse foraminifera, Lingula-like brachiopods and the geological setting indicate that Aptian radiolarian-rich black shales forming the Windalia Radiolarite were deposited at water depths probably less than 40 m in the Southern Carnarvon Basin. Elsewhere in Australia, coeval radiolarian-rich deposits are widespread in other western-margin basins and in vast interior basins. The organic-rich mudstones containing the radiolaria include the foraminiferal Ammobaculites Association, a sparse benthic macrofauna and kerogens of mainly terrestrial plant origin. The deposits suggest that there was substantial high-nutrient freshwater input into the epeiric seas as well as high levels of dissolved silica resulting from marine flooding of a mature silicate-rich landscape bordered on the eastern and western continental margins by large volcanic provinces. The widespread presence of organic-rich muds through the broad, shallow Southern Carnarvon Basin and through the coeval interior basins suggests that regional geomorphology controlled the distribution of eutrophic facies in the Australian Aptian rather than any global expansion of the oceanic oxygen minimum zone. The foraminiferal assemblage from the Windalia Radiolarite consists of calcareous hyaline benthic types (diverse Lagenida as well as abundant Lingulogavelinella, Epistomina and Coryphostoma) and organic-cemented agglutinated species (including common Ammobaculites humei, Haplophragmoides-Recurvoides spp., and Verneuilinoides howchini). Planktonic foraminifera are very rare and present only in the northern, more open part of the basin. J. Micropalaeontol. 24(1): 55-75, May 2005.


ISSN: 0262-821X
EISSN: 2041-4978
Serial Title: Journal of Micropalaeontology
Serial Volume: 24, Part 1
Title: Foraminiferal evidence for inner neritic deposition of Lower Cretaceous (upper Aptian) radiolarian-rich black shales on the western Australian margin
Author(s): Haig, David W.
Affiliation: University of Western Australia, School of Earth and Geographical Sciences, Crawley, West. Aust., Australia
Pages: 55-75
Published: 200505
Text Language: English
Publisher: British Micropalaeontological Society, London, United Kingdom
References: 84
Accession Number: 2008-119182
Categories: Stratigraphy
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. strat. cols., 4 plates, 2 tables, geol. sketch maps
S26°04'60" - S23°00'00", E113°49'60" - E114°49'60"
Country of Publication: United Kingdom
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute. Reference includes data from The Geological Society, London, London, United Kingdom
Update Code: 200846
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