Paleontologic investigations of the uppermost Santa Susana Formation, south side of Simi Valley, southern California

Conference · Fri Feb 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5170944

Squires, R L ^[1]

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1. California State Univ., Northridge (United States)

Strata assignable to the provincial macroinvertebrate Meganos stage, equivalent to the calcareous nannofossil CP8 zone (late Paleocene) to CP9 zone (early Eocene), are uncommon on the Pacific coast of North America. This stage has been recognized in southern California only in the uppermost Santa Susana Formation, north side of Simi Valley. Although early workers reported meganos stage strata from the south side of Simi Valley, most of these deposits have since been assigned to younger or older stages. Intensive collecting by the author now proves that Meganos stage fossils are present in the upper 100 m of the Santa Susana Formation on the south side of the Simi Valley, east of the Runkle Canyon fault. This 100-m-thick interval consists of gray, very fine-grained sandstone that has a gradational lithology from the underlying gray mudstone. Calcareous nannofossils were found only near the bottom of the 100-m-thick interval, and they are suggestive of the late Paleocene Discoaster multiradiatus (CP8) zone. Rare, macrofossil-bearing lenses near the bottom of the 100-m-thick interval contain the solitary coral Trochocyathus zitteli, the gastropods Turritella subuvasana and the Velates californicus( ), and the bivalve Fimbria susanensis. Sparsely occurring, macrofossil-bearing lenses in the upper 20 m of the 100-m-thick- interval contain the colonial coral Archohelia clarki and the gastropod Turritella andersoni susanae (= T. andersoni n. subsp. of authors). Turritella andersoni susanae indicates the early Eocene part of the Meganoz stage because it is found just above the earliest Eocene Discoaster diastypus (CP9) zone in the upper Santa Susana Formation on the north side of Simi Valley.

• OSTI ID: 5170944
• Report Number(s): CONF-9103128-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:2; Conference: American Association of Petroleum Geologists (AAPG)/Society of Economics, Paleontolgists, and Mineralogists (SEPM)/Society of Exploration Geophysicists (SEG)/Society of Professional Well Log Analysts (SPWLA) Pacific Section annual meeting, Bakersfield, CA (United States), 6-8 Mar 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CALIFORNIA
GEOLOGIC FORMATIONS
GEOLOGIC STRATA
PALEONTOLOGY
SANDSTONES
AGE ESTIMATION
CORALS
EOCENE EPOCH
FOSSILS
LITHOLOGY
MOLLUSCS
PETROLOGY
ANIMALS
AQUATIC ORGANISMS
CENOZOIC ERA
CNIDARIA
COELENTERATA
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC STRUCTURES
GEOLOGY
INVERTEBRATES
NORTH AMERICA
ROCKS
SEDIMENTARY ROCKS
TERTIARY PERIOD
USA
580000* - Geosciences