Skip to Main Content
Skip Nav Destination

Paleogeography and sedimentology of Upper Cretaceous turbidites, San Diego, California

Tor H. Nilsen and Patrick L. Abbott
Paleogeography and sedimentology of Upper Cretaceous turbidites, San Diego, California
AAPG Bulletin (July 1981) 65 (7): 1256-1284


Upper Cretaceous (Campanian and Maestrichtian) marine strata of the Rosario Group in the San Diego area include the Point Loma Formation and overlying Cabrillo Formation. These units contain six facies associations: (1) shelf and lagoonal sandstone, (2) slope and basin-plain(?) mudstone, (3) outer-fan lobe sandstone, (4) middle-fan channel-fill sandstone, (5) middle-and inner-fan interchannel and channel-margin thin-bedded turbidites and mudstone, and (6) inner-fan channel-fill conglomerate and sandstone. The facies associations define a deep-sea fan deposited by westward-flowing sediment gravity flows that transported sediments derived chiefly from batholithic and prebatholithic metamorphic rocks of the Peninsular Ranges. The sedimentary basin initially deepened abruptly, partly aided by eustatic sea-level rise. The fan then prograded westward into the basin, with a retrogradational phase recorded in the uppermost part of the sequence, which is erosionally truncated by transgressive lower Eocene conglomerate. The fan was deposited along the eastern edge of a forearc basin similar to that of the Great Valley sequence in northern California. The western part of the fan, which probably contained mostly outer-fan lobe and associated basin-plain deposits, appears to have been truncated by late Cenozoic strike-slip faulting associated with the San Andreas fault system. The fan and remnants of the western part of the basin and associated subduction complex may be present on the northwest in the Channel Islands region or still farther north.

ISSN: 0149-1423
EISSN: 1558-9153
Coden: AABUD2
Serial Title: AAPG Bulletin
Serial Volume: 65
Serial Issue: 7
Title: Paleogeography and sedimentology of Upper Cretaceous turbidites, San Diego, California
Affiliation: U. S. Geol. Surv., Menlo Park, CA, United States
Pages: 1256-1284
Published: 198107
Text Language: English
Publisher: American Association of Petroleum Geologists, Tulsa, OK, United States
References: 84
Accession Number: 1981-066441
Categories: Stratigraphy
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables, strat. cols., sketch maps
N32°45'00" - N32°45'00", W117°10'00" - W117°10'00"
Secondary Affiliation: San Diego State Univ., USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute.
Update Code: 1981
Close Modal

or Create an Account

Close Modal
Close Modal