Relationship among latest Miocene oxygen isotopic enrichment, antarctic ice volume, and the Messinian salinity crisis

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6321199

Hodell, D A; Elmstrom, K M; Kennett, J P

An interval of high variable, enriched benthic /sup 18/O values was found to bracket the Miocene/Pliocene boundary, between 5.6 and 5.1 Ma, in five sites from the Southwest Pacific and Atlantic Oceans. The duration of this enrichment event was less than 500,000 years, and is shown by paleomagnetic correlation to be equivalent in time with the deposition of Messinian evaporites. The /sup 18/O enrichment occurred in two main stages separated by a brief interval of relatively depleted /sup 18/O values. Between 5.5 and 5.3 Ma, glacioeustatic lowering of sea level due to increased Antarctic ice volume isolated the Mediterranean basin, and resulted in the deposition of the lower evaporite unit (Main Salt unit). A temporary decrease in ice volume occurred between 5.3 and 5.2 Ma, and corresponded to the intra-Messinian transgression where evaporite deposition ceased temporarily. Between 5.2 and 5.1 Ma, a second Antarctic glacial advance lowered sea level again and resulted in the deposition of the upper evaporite unit. A rapid decreased in delta/sup 18/O values occurred in all sites during the early Pliocene at 5.0 Ma. This depletion marks a glacial retreat and marine transgression, which refilled the Mediterranean Basin and permanently terminated evaporite deposition.

• Research Organization: Univ. of Rhode Island, Narragansett (USA)
• OSTI ID: 6321199
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
580400 -- Geochemistry-- (-1989)
580500 -- Oceanography-- (1980-1989)
ATLANTIC OCEAN
CENOZOIC ERA
CHEMICAL COMPOSITION
CHEMISTRY
DEPOSITION
EVAPORITES
EVEN-EVEN NUCLEI
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GLACIERS
ICE
ICE CAPS
ISOTOPE RATIO
ISOTOPES
LEVELS
LIGHT NUCLEI
MAGNETISM
MELTING
MIOCENE EPOCH
NUCLEI
OXYGEN 18
OXYGEN ISOTOPES
PACIFIC OCEAN
PALEOCLIMATOLOGY
PALEOMAGNETISM
PALEONTOLOGY
PHASE TRANSFORMATIONS
ROCKS
SALT DEPOSITS
SEA LEVEL
SEAS
SEDIMENTARY ROCKS
STABLE ISOTOPES
SURFACE WATERS
TERTIARY PERIOD
VARIATIONS
WATER CHEMISTRY