Phil's Study Area

The San Marcos Dike Swarm (SMDS) of Northern Baja California

This was the thesis subject for my graduate work at SDSU.
WHERE it is:

TM from Landsat

Approximately within the yellow rectangle

WHAT it is:

oblique view from shuttle STS51F

A densely intruded, northwest-striking, predominantly silicic regional dike swarm exposed over an approximately 100 km-long segment in the west-central portion of the Cretaceous Peninsular Ranges batholith (PRB). Cross-cutting field relationships and a preliminary U-Pb zircon age of 120±1 Ma establish the swarm as an integral feature in the magmatic evolution of the PRB.

Google earth icon Google Earth .kmz file of sample locations: HERE

Roadcut Exposure of Dike
Here's one of the dikes in a roadcut near Ejido San Marcos. Click on the picture below left for a closeup.
Dike ChipRoad Sign to RSM

I gave a poster session to present the on-going research of this dike swarm to the Geological Society of America Cordilleran Section Centennial meeting in Berkeley in June of 1999. In November 2004, I presented the updated version at GSA in Denver.

GSA 2004
GSA 2004
Click here for the poster(s)

Bifurcating Dikes

Photos from a field trip in 1999, source of the image above.

Here's a web version (HTML5/Flash) of my thesis defense 2003.

And here's the final thesis, approved on 30 July 2004.

© 1999-2016, Phil Farquharson, CG-Squared Productions

E-mail: dikeswarm AT (not a "clickable" link)

Latest revision: 24 December 2021 (added 'https' links)