Gold Mine Creek - Tectonic Block

Looking at the tectonic block that sits between the historic and Quaternary traces of the San Andrea fault near Gold Mine Creek.

The hill shade maps really help to show the land forms, especially when combined with the USGS fault maps on Google Earth.

Paper: ENVIRONMENTAL GEOLOGIC ANALYSIS OF THE MONTEBELLO RIDGE MOUNTAIN STUDY AREA:
https://babel.hathitrust.org/cgi/pt?id=mdp.39015042059330&seq=38
"TECTONIC BLOCKS - Large angular to rounded, commonly elliptically shaped masses of relatively hard rocks surrounded by a clay-rich. sheared matrix. Occurs within shear zones and fault gouge. In the shear zones of the Franciscan' rocks, these' blocks range from fist size to masses more than one mile long."

USGS National Map Viewer w/ Hill Shade:
https://apps.nationalmap.gov/viewer/

USGS Quaternary Faults data:
https://earthquake.usgs.gov/education/geologicmaps/qfaults.php
Download the "qfaults.kmz" file from the link on the page, then import that into Google Earth.
Tip: Zoom into your area of interest BEFORE turning on one of the layers. I recall this file has the fault traces, landslide areas and geologic units for a large area and it'll bring your device to a crawl if you enable one of these layers zoomed way out.
You can see how the Canyon Trail, that's mostly built on an old ranch road, follows the historic trace of the San Andreas fault.

If you check out this previous video:
https://youtu.be/_7jxPb-Cvmw?t=366
You can see what this area looked like prior to the road being built.

Montebello Open Space history page:
https://www.openspace.org/preserves/monte-bello#history

More to come...
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And as always, thanks for watching
#USGS #HillShade