Marine magnetic survey and onshore gravity and magnetic survey, San Pablo Bay, northern California

Open-File Report 2016-1150
By: , and 

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Introduction

From November 2011 to August 2015, the U.S. Geological Survey (USGS) collected more than 1,000 line-kilometers (length of lines surveyed in kilometers) of marine magnetic data on San Pablo Bay, 98 onshore gravity stations, and over 27 line-kilometers of ground magnetic data in northern California. Combined magnetic and gravity investigations were undertaken to study subsurface geologic structures as an aid in understanding the geologic framework and earthquake hazard potential in the San Francisco Bay Area. Furthermore, marine magnetic data illuminate local subsurface geologic features in the shallow crust beneath San Pablo Bay where geologic exposure is absent.

Magnetic and gravity methods, which reflect contrasting physical properties of the subsurface, are ideal for studying San Pablo Bay. Exposed rock units surrounding San Pablo Bay consist mainly of Jurassic Coast Range ophiolite, Great Valley sequence, Franciscan Complex rocks, Miocene sedimentary rocks, and unconsolidated alluvium (Graymer and others, 2006). The contrasting magnetic and density properties of these rocks enable us to map their subsurface extent.

Suggested Citation

Ponce, D.A., Denton, K.M., and Watt, J.T., 2016, Marine magnetic survey and onshore gravity and magnetic survey, San Pablo Bay, northern California: U.S. Geological Survey Open-File Report 2016–1150, 14 p., http://dx.doi.org/10.3133/ofr20161150.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Introduction
  • Magnetic Data
  • Gravity Data
  • Discussion
  • Acknowledgments
  • References Cited

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Marine magnetic survey and onshore gravity and magnetic survey, San Pablo Bay, northern California
Series title Open-File Report
Series number 2016-1150
DOI 10.3133/ofr20161150
Year Published 2016
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center
Description Report: iv, 14 p.; 3 Tables; Metadata
Country United States
State California
Other Geospatial San Pablo Bay
Online Only (Y/N) Y
Additional Online Files (Y/N) Y