Aptian anoxia in the Pacific Basin

Journal Article · Sun Oct 01 00:00:00 EDT 1989 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1989)017<0909:AAITPB>2.3.CO;2· OSTI ID:7135782

Sliter, W V ^[1]

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1. Geological Survey, Menlo Park, CA (USA)

Marine strata of Aptian age in the Pacific Basin include two distinct levels that represent episodes during which sediments rich in organic carbon were deposited. Both episodes lasted less than 1 m.y., as revealed in strata deposited atop submerged topographic highs. One unusually widespread episode of early Aptian age ({approximately}117.5 Ma) correlates with coeval units in Europe and thus is analogous to the Cenomanian-Turonian oceanic anoxic event in its short duration and wide geographic extent. The second episode of late Aptian age ({approximately}116.5 Ma) is restricted to allochthonous pelagic deposits in the Franciscan Complex of California. These results support the concept of widespread and narrowly synchronous anoxic events. Further, they show that organic carbon deposition in the Pacific Basin took place in intermediate water oxygen-minimum zones and thus differed in the mode of deposition, and hence paleoceanography, from that in other middle Cretaceous ocean basins.

• OSTI ID: 7135782
• Journal Information: Geology; (USA), Vol. 17:10; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ORGANIC MATTER
DEPOSITION
PACIFIC OCEAN
STRATIGRAPHY
AGE ESTIMATION
BLACK SHALES
CRETACEOUS PERIOD
DEPTH
GEOLOGIC HISTORY
GEOLOGIC STRATA
OCEANOGRAPHY
OXYGEN
SAMPLING
SEA LEVEL
SEDIMENTATION
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHATTANOOGA FORMATION
DIMENSIONS
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGIC STRUCTURES
GEOLOGY
LEVELS
MATERIALS
MESOZOIC ERA
NONMETALS
OIL SHALES
SEAS
SURFACE WATERS
580000* - Geosciences