Guide to Finding Fossils at Shark Tooth Hill

One of the most well known and prolific fossil sites in California, Shark Tooth Hill is a reliable source of shark teeth and the fossils of over 175 marine species.

Geology of the Area:

The area was a shallow extension of the Pacific extension during the Miocene epoch, or approximately 12-15 mya, and thus harbored a variety of marine mammals, sharks, birds, rays, skates and even land mammals.

Theories for the strata’s dense fossil record include 1) neighboring volcanic activity poisoned the bay with ash and noxious gases, causing a mass extinction of the organisms, and 2) the bay became landlocked during the Miocene epoch, rendering the inhabitants unable to escape as the waters slowly evaporated in the Pliocene epoch.



Where to Find Fossils on Gaviota Beach

Geological History of the Area:

The area of the Gaviota and El Capitan State Beaches contain a series of folds such as the Gaviota Offshore Fold trend which suggests the area is by the Eagle fault and has experienced pressure. Six hydrocarbon (oil) seeps have been found at the El Capitan- Gaviota shelf. During early Miocene time, calcareous plankton dominated this basin fill, but by the middle Miocene, the expansion of the East Antarctic ice sheet led to intense upwelling in eastern boundary current areas. The shelf from which the specimens were collected from is part of the Monterey formation and is riddled with a series of marine gullies. The beach-bordering segments are part of the El-Capitan-Gaviota Continental Shelf.