Sources
The best overview of the geology of the Caldecott Tunnel region is available in the book: The Geology and Natural History of the San Francisco Bay Area: A Field-Trip Guidebook, edited by Philip W. Stoffer and Leslie C. Gordon, published by USGS. The information you want is found in the second field trip, “A Geologic Excursion to the East San Francisco Bay Area”, stop #3, “Caldecott Tunnel between Oakland and Orinda”. The entire guide with other excellent field trips throughout the Bay Area may be downloaded from the USGS website.
Professor Steven Dutch of the University of Wisconsin, Green Bay has put together an excellent series of photos of the road cut near the Tunnel.
To learn more about the Caldecott Tunnel itself, the California Department of Transportation has a website with a historical timeline of the tunnel and information about current projects. In addition, engineers J. David Rogers and Ralph Peck describe the geologic engineering for the BART system (Bay Area Rapid Transit).
For an even broader discussion of the geology in the Bay Area, the USGS has assembled a treasure trove of information about the geology of the San Francisco Bay Area.
Finally, to pan back even further to view the geology of the entire state of California, legendary science writer John McPhee’s book Assembling California provides an in depth, highly accessible discussion of the geologic history of California. READ IT! And read McPhee’s other works such as Basin and Range. I personally disliked geology as a science until I read McPhee and suddenly fell in love with the field.
Standards
Grade 6
Plate Tectonics and Earth's Structure
Plate tectonics accounts for important features of Earth's surface and major geologic events. As a basis for understanding this concept:
e Students know major geologic events, such as earthquakes, volcanic eruptions, and mountain building, result from plate motions.
f Students know how to explain major features of California geology (including mountains, faults, volcanoes) in terms of plate tectonics.
Shaping Earth's Surface
Topography is reshaped by the weathering of rock and soil and by the transportation and deposition of sediment. As a basis for understanding this concept:
a Students know water running downhill is the dominant process in shaping the landscape, including California's landscape.
b Students know rivers and streams are dynamic systems that erode, transport sediment, change course, and flood their banks in natural and recurring patterns.
Investigation and Experimentation
Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will:
e Recognize whether evidence is consistent with a proposed explanation.
f Read a topographic map and a geologic map for evidence provided on the maps and construct and interpret a simple scale map.
g Interpret events by sequence and time from natural phenomena (e.g., the relative ages of rocks and intrusions).
Grade 7
Earth and Life History (Earth Sciences)
Evidence from rocks allows us to understand the evolution of life on Earth. As a basis for understanding this concept:
a Students know Earth processes today are similar to those that occurred in the past and slow geologic processes have large cumulative effects over long periods of time.
c Students know that the rock cycle includes the formation of new sediment and rocks and that rocks are often found in layers, with the oldest generally on the bottom.
