Mélange

Mélange at the coastal bluffs
Large blocks in the mélange at the coastal bluffs include green serpentinite and basalt in the foreground, graywacke sandstone in the background, and bedded red chert in between.

Will Elder, NPS

Mélange is a mashed-up mixture of rocks, mixed and crushed in a subduction zone. Zones of mélange lie between large areas (miles across) of more coherent rocks of similar type (called terranes) that form larger-scale mixture of rocks that is the Franciscan Complex. Smaller blocks of oceanic crust and sediments and continental marine rocks are mixed together in the mélange and encased in extremely sheared rock that is typically altered to clay.

Last updated: February 28, 2015

Park footer

Contact Info

Mailing Address:

Fort Mason, Bldg. 201
San Francisco, CA 94123

Phone:

415-561-4323
Phone is answered daily from 10 am to 5 pm. Leave a message otherwise and we will get back to you. United States Park Police Dispatch: Non-Emergency: 415-561-5505 Emergency: 415-561-5656

Contact Us