Wk6_Geological Interpretations_Josiah Freeman

Caption: Franciscan Complex
IMAGE CREDIT: Wikipedia

This week I decided to visit the Franciscan Complex in Northern California. The Franciscan Complex is a geological term for a late Mesozoic terrane of heterogeneous rocks found throughout California’s Coastal Ranges; particularly the San Francisco Peninsula.

The first piece of information I would request is the mineral composition of the complex. This information would allow me to come to a suitable hypothesis of how this peculiar rock formation might have come to be. If metamorphism has taken place, what the rocks may have been exposed to, pressure and temperature wise.

The second piece of information I would request is if any fossils have been discovered embedded in the complex. This information would be instrumental in estimating the age of the complex.

The final piece of information I would request is where else do Franciscan Rocks occur in California, if anywhere? This would allow me to consider what relation the formation has to other geological areas in California. How did such a formation of rocks occur? What kind of plate tectonic activity is suggested?

What history is hidden in the Franciscan Complex?