Brief:

During this field trip, we will make 5 stops: 1) The Steinbeck Ranch, where we will examine the typical lithology and stratification of the WGF. The underlying Franciscan Complex, Tolay Volcanics, as well as the interbedded Roblar Tuff (one of the best marker beds in the formation) will be observed at this stop. 2) Stony Point Rock Quarry, where the lower and middle members of the PF, as well as underlying and interbedded Tolay Volcanics will be examined. Particular attention will be paid to the gravel composition of the middle PF. 3) Stony Point Road, north of the Stony Point Rock Quarry, where a road cut exposure of the upper member of the PF will be examined. The gravel composition of the upper member will be discussed. 4) Taylor Mountain landslide, where the head scarp exposes Tolay Volcanics thrust over PF. Active landslide features will also be observed. 5) Matanzas Creek in Bennett Valley, where we will observe the PF east of the RCF and compare it with the PF west of the RCF.

Field trip focused on the thrust fault system along the northeastern topographic range front of the Santa Cruz Mountains. The primary objectives of the field trip, and papers in the field trip guidebook, were to provide a forum for discussion of the fault hazard, to compile recent published and unpublished fault data, and initiate a discussion toward a consensus regarding a formal name designation for the range front fault system. Field trip co-leaders included Glenn Borchardt, Tom Bullard, Bill Cole, Steve Connelly, Reid Fisher, Jim Hengesh, Christopher Hitchcock, Drew Kennedy, Bob McLaughlin, Ron Rubin, Ted Sayre, John Wakabayashi, and Carl Wentworth.

Download a PDF copy of the field trip guidebook (49MB file). The guidebook includes 11 individual papers focused on the range front fault system.

Seismic Hazard of the Range Front Thrust Faults, Northeastern Santa Cruz Mountains/Southwestern Santa Clara Valley: An Overview
Drew G. Kennedy and Christopher S. Hitchcock

Coexistence of Thrusting, Extension, and Opportunistic Landsliding on the Berrocal Fault, Los Gatos, Santa Clara County, California
G. Reid Fisher

Geology and Paleoseismology of the Blossom Hill Fault: Holocene Activity on a Range Front Fault in Los Gatos, California
Ron S. Rubin, Glenn Borchardt, and Steven F. Connelly

Range Front Thrust Faults - Saratoga and Los Altos Hills, Santa Clara County, California
Ted Sayre, William F. Cole, John M. Wallace, and William Cotton

Updated Assessments of the Activity and Slip Rate for the Stanford Fault Zone and Pulgas Faults, Frontal Thrust Fault System, Palo Alto Region, California
Tom Bullard, Kathryn Hanson, Hans AbramsonWard, Michael Angell, and John Wesling

Geomorphic Evidence of Late Quaternary Deformation along the Western Margin of the Santa Clara Valley, California: Characterization of the Monte Vista, Shannon, and Cascade Faults
Christopher Hitchcock, Keith Kelson, and Steve Thompson

Seismic Hazards Associated with the Serra Fault, San Francisco Peninsula, California
James V. Hengesh, Jeffery M. Nolan, and John Wakabayashi

Evidence for Holocene Activity on the Serra Fault at Fort Funston, San Francisco, California
Drew G. Kennedy

The Monta Vista Fault, Foothill Community College, Los Altos Hills, California
J. Michael Cleary and David F. Hoexter

The Cañada-Hermit Fault Zone, Woodside, San Mateo County, California
Robert H. Wright

Progressive Evolution of Step-Overs and Bends: A Process that has Influenced Development of Fold and Thrust Belts and Inverted Basins in the San Francisco Bay Region, California
John Wakabayashi, James V. Hengesh, Thomas L. Sawyer

• History and Geology of the Caldecott Tunnel, Trip leaders - Ray Mailhot, Grant Wilcox, and Chris Risden, Caltrans (June 2001)
• Hydrogeology and Environmental Restoration of the Presidio of San Francisco (April 1997)
• Engineering Geology and Tectonic Setting of the Point San Pedro - Devil's Slide Area, Trip leaders - Joan Van Velsor, Caltrans, and Dr. John Wakabayashi, Independent Consultant (November 1996)
• Welch Creek Paleoseismic Trench Site, Trip leaders - Gary Simpson and John Baldwin, William Lettis & Associates (August 1996)
• Cool Under Pressure: An Exploration of High P/T Metamorphism - the Franciscan Complex of the San Francisco Bay Area, Trip leader - Dr. John Wakabayashi, Independent Consultant (May 1996)
• Point Reyes National Seashore - Family Picnic, Leader - Nancy Barnes, Montgomery Watson (September 1995)
• The Geology and Sequence Stratigraphy of Black Diamond Mines Regional Preserve, Trip leaders - Dr. Raymond Sullivan, San Francisco State University, and John Waters, East Bay Regional Park District/Keller Canyon Landfill, Pittsburg, Trip leader - Gregory Bartow (April 1995)
• Angel Island - First Annual Picnic (October 1990)

Pictures from the Caldecott Tunnel Field Trip, June 2, 2001 - ( photos courtesy of Keil Albert and Drew Kennedy)

Caldecott Field Trip Pics