Holocene sediment dynamics on a cool-water carbonate shelf: Otway, southeastern Australia

Journal Article · Thu Jul 01 04:00:00 EDT 1993 · Journal of Sedimentary Petrology; (United States)

OSTI ID:6113154

Boreen, T D; James, N P ^[1]

---

1. Queen's Univ., Kingston, Ontario (Canada)

The Otway Shelf is covered by cool waters and veneered by bryozoan-dominated carbonate sediments. Radiocarbon dating and stratigraphy of shelf vibracores and slope gravity cores document late Pleistocene/Holocene deposition. Shelf sediments of the late Pleistocene high-stand are rare, either never having been deposited or having been removed during the following sea-level fall. During the subsequent lowstand the shelf was exposed, facies shifted basinward, and beach/dune complexes were constructed near the shelf edge. The deep shelf was characterized by nondeposition and hardground formation, and the shelf margin became locally erosional. Upper-slope bryozoan/sponge assemblages continued to grow actively, and lower-slope foraminifera and nannofossil ooze was increasingly enriched in hemipelagic terrigenous mud swept off the wide shelf. Coarse shelf debris and lowstand dune sands were erosively reworked and transported onto the upper slope and redistributed to deep-slope aprons during early transgression. The late Quaternary shelf record resembles that of flat-topped, warm-water platforms with Holocene sediment overlying Pleistocene/Tertiary limestone, but for different reasons. The slow growth potential, uniform profile of sediment production and distribution, and inability of constituent organisms to construct rigid frameworks favor maintenance of a shallow ramp profile and makes the cool-water carbonate system an excellent modern analog for interpretation of many ancient ramp successions.

• OSTI ID: 6113154
• Journal Information: Journal of Sedimentary Petrology; (United States), Journal Name: Journal of Sedimentary Petrology; (United States) Vol. 63:4; ISSN 0022-4472; ISSN JSEPAK
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
ANIMALS
AQUATIC ORGANISMS
AUSTRALASIA
AUSTRALIA
BRYOZOA
CARBONATE ROCKS
CENOZOIC ERA
CONTINENTAL MARGIN
CONTINENTAL SHELF
DEPOSITION
DEVELOPED COUNTRIES
FORAMINIFERA
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
INVERTEBRATES
ISOTOPE DATING
MICROORGANISMS
PALEONTOLOGY
PROTOZOA
QUATERNARY PERIOD
REEFS
ROCKS
SARCODINA
SEDIMENTARY ROCKS
SEDIMENTATION
STRATIGRAPHY