Geologic Trips, San Francisco and the Bay Area, by Ted Konigsmark, GeoPress

Geologic Trips, Sierra Nevada, by Ted Konigsmark, GeoPress

Geologic Trips, Sea Ranch and Bowling Ball Beach, by Ted Konigsmark (pdf)





Sierra Nevada



Fort Rock




Bowling Ball


Sea Ranch

San Francisco

Bowling Ball Beach concretions that are shaped like large bowling balls are lined up along bowling lanes on the beach.


Fort Rock a volcanic ring, the shape of a round fort, was formed by a volcanic eruption in a large ice-age lake.


Rogue Valley Area a large valley that was carved from sedimentary rocks is sandwiched between the Klamath Mountains and Cascade Range. Trips: Klamath Mountains, Cascade Range, Rogue Valley.


San Francisco a city that is built on rocks that were forged in the Franciscan subduction zone. The rocks are now being torn apart by the San Andreas fault. Trips: San Francisco, Marin Headlands, Angel Island, Ring Mountain, Fort Funston, Bay Area Faults, and Point Reyes Peninsula.


Sea Ranch a scenic coastline etched by beach erosion of sedimentary rocks brought here from southern California by San Andreas fault. Trips: Bluff, Meadow and Hillside, San Andreas fault.


Sierra Nevada a large west-tilted fault block that collects rain and snow from Pacific storms, uses the ice and water to sculpture magnificent mountain scenery, and then distributes the water to San Francisco, Los Angeles, and the Great Valley for further use. Trips: Lone Pine, Mammoth, Mono Lake, Lake Tahoe, Northern Sierra, Mother Lode, Yosemite Valley, Sequoia and Kings Canyon National Parks.


Steens Mountain drive to the top of a large, west-tilted fault block of basalt that has been dissected by ice-age glaciers.