Muller, Pamela Hallock; Sheps, Kathryn; Chamroniere, George; Howell, Michael W. (2006): Larger benthic foraminifers of the Marion Plateau, northeastern Australia (ODP Leg 194); comparison of faunas from bryozoan (Sites 1193 and 1194) and red algal (Sites 1196-1198) dominated carbonate platforms. Texas A&M University, Ocean Drilling Program, College Station, TX, United States, In: Anselmetti, Flavio S., Isern, Alexandra R., Blum, Peter, Andresen, Nils, Birke, Tesfaye Kidane, Bracco Gartner, Guido L., Burns, Stephen J., Conesa, Gilles A. R., Delius, Heike, Dugan, Brandon, Eberli, Gregor P., Ehrenberg, Stephen N., Fuller, Michael D., Muller, Pamela Hallock, Hine, Albert C., Howell, Michael W., John, Cedric M., Karner, Garry D., Kindler, Pascal F., Olson, Brooke E., Sasaki, Keiichi, Stewart, Duncan, Wei, Wuchang, White, Timothy S., Wood, Jason L., Yamada, Tsutomu, Proceedings of the Ocean Drilling Program; constraining Miocene sea level change from carbonate platform evolution, Marion Plateau, northeast Australia; covering Leg 194 of the cruises of the drilling vessel JOIDES Resolution; Townsville, Australia, to Apra Harbor, Guam; Sites 1192-1199; 3 January-2 March 2001, 194, georefid:2006-075592

Abstract:
Two Neogene carbonate platforms on the Marion Plateau, off northeastern Australia, were drilled during Ocean Drilling Program Leg 194. Approximately 510 m of mixed shelf and slope sediments were penetrated at Site 1193, and approximately 672 m of shallow-water platform sediments were penetrated at Site 1196. Shallow-water carbonates at Site 1193 were dominated by bryozoans. At Site 1196, coralline red algae dominated, though stony corals were common to abundant in some intervals. Larger benthic foraminifers (LBF) were abundant at both sites, with common genera including Amphistegina, Cycloclypeus, Lepidocyclina, Miogypsina, and Operculina. Five LBF assemblages were distinguished using thin sections cut from recovered cores. Assemblage A was found in mixed carbonate-terrigenous clastic neritic facies (<100 m) associated with basement flooding. Operculina complanata was common in terrigenous mud-rich facies, whereas Lepidocyclina spp. with relatively primitive, nonstellate morphologies dominated in more carbonate-rich facies. These taxa are characteristic of larger foraminiferal (LF) Associations 1-5, indicative of latest Oligocene to early Miocene ages. Nannofossil dates are similar ( approximately 18-24 Ma) for the units immediately above basement. Depositional environments ranged from deltaic muds with oyster and Operculina shells to a striking interval of in situ, large, flat Lepidocyclina badjirraensis at Site 1198, indicating a deep oligophotic ( approximately 100-150 m) paleoenvironment. Assemblage B was found in platform facies at Sites 1193 and 1196 and in corresponding slope sediments at Sites 1197 and 1198. This assemblage is characterized by predominantly nonstellate lepidocyclinids and ovate miogypsinids. Units containing this assemblage are interpreted to be late early Miocene ( approximately 16-18 Ma) and indicate deposition in a range of euphotic paleodepths, as interpreted from LBF morphologies. Assemblage C, found at Site 1196 (183-326 meters below seafloor), is characterized by Flosculinella, Austrotrillina, soritids, and smaller miliolid foraminifers. This LF 8 association is considered middle Miocene ( approximately 13.3-15.2 Ma), an assumption consistent with nannofossil dates from the interval. The assemblage and associated sediments indicate shallow (<12 m), somewhat restricted platform conditions, including seagrass meadows. Assemblage D was found in platform facies at Sites 1193, 1194, and 1196 and in corresponding slope sediments at Sites 1197 and 1198. This assemblage is characterized by the transition from mixed concentric and stellate lepidocyclinid morphologies to predominantly stellate forms, as well as by vermiform miogypsinids. Units containing this assemblage are interpreted to be middle Miocene ( approximately 11.9-16.4 Ma). At Sites 1193 and 1194, the middle Miocene regression is recorded by changes in foraminiferal taxa and LBF morphologies. Assemblage E was found in upper platform facies at Site 1196, in corresponding periplatform sediments at Sites 1197 and 1198, and also in transported sediments at Sites 1193 and 1194.
Coverage:
West: 151.4500 East: 153.0500 North: -20.1000 South: -21.0500
Relations:
Expedition: 194
Site: 194-1193
Site: 194-1194
Site: 194-1196
Site: 194-1197
Site: 194-1198
Supplemental Information:
Available only on CD-ROM in PDF format and on the Web in PDF or HTML
Data access:
Provider: SEDIS Publication Catalogue
Data set link: http://sedis.iodp.org/pub-catalogue/index.php?id=10.2973/odp.proc.sr.194.009.2006 (c.f. for more detailed metadata)
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