Paleontology and geochronology of the Long Beach core sites and monitoring wells, Long Beach, California

Open-File Report 2011-1274

In cooperation with the Los Angeles County Department of Public Works and the Water Replenishment District of Southern California
, , , , ORCID iD , and



The U.S. Geological Survey's Focus on Quaternary Stratigraphy in Los Angeles (FOQUS-LA) project was a cooperative coring program between Federal, State, and local agencies. It was designed to provide a better understanding of earthquake potentials and to develop a stratigraphic model of the western Los Angeles Basin in California. The biostratigraphic, geochronologic, and paleoecologic analyses of eight wells drilled during the FOQUS-LA project are presented. These analyses are based on microfossils (benthic and planktic foraminifers), macrofossils, paleomagnetic stratigraphy, optically stimulated luminescence, thermoluminescence, radiocarbon dating, and tephrochronology. A geochronologic framework (incorporating paleomagnetism, luminescence, and tephrochronology) was used to calibrate the sequence stratigraphic units in the FOQUS-LA wells and also was used to calibrate the ages of the microfossil stage and zonal boundaries. The results of this study show that (1) the offshore California margin zones can be used in a nearshore setting, and (2) the California margin zonal scheme refines the chronostratigraphic resolution of the benthic foraminiferal biostratigraphic framework for the Pacific Coast. Benthic foraminiferal stages are modified by the recognition of an early Hallian substage, which is a faunal change recognized throughout the Los Angeles Basin. Although no detailed macrofossil zonations exist for the Quaternary of southern California, several species, whose distribution is regulated by the climatic conditions, are useful as secondary marker species in the shallower water deposits of the Los Angeles Basin.

Additional publication details

Publication type:
Publication Subtype:
USGS Numbered Series
Paleontology and geochronology of the Long Beach core sites and monitoring wells, Long Beach, California
Series title:
Open-File Report
Series number:
Year Published:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Western Region Geology and Geophysics Science Center
xi, 223 p.; Plates Folder; All Files Folder
United States
Other Geospatial:
Long Beach;Los Angeles Basin
Online Only (Y/N):
Additional Online Files (Y/N):