By Judith Fenley, Pepperwood Member
Pepperwood Rocks: Indeed it is so! Reflections on a rockin’ day, at Pepperwood Preserve, Saturday, September 6, 2014
A glimpse of how to see with a geologist’s eye opened up the Pepperwood landscape in new ways.
We traveled far enough back in geological time to see an image of earth with only one land mass. An animated time warp, on-screen, journeyed through the continental shift to the “Super Continent, Pangaea” to “Laurasia” and on to our current, yet ever-shifting global territory map.
Variations of the Teutonic plates -- the divergent plate boundary, the convergent plate boundary, and the transform plate boundary, are all present in California, making our state an exceptional geological study area.
Our Mayacama region is resplendent with rocks of all types as well. Before our hike, we partook of a visual and tactile rock feast. No, we did not eat any rocks. Fondling variations of each type of rock, readied us to head out of doors.
Identification challenged everyone. Even our instructor admitted most all rocks looked alike, once covered with lichen and earth debris. A handy geo-hammer cracked through to a clean surface, as needed. Igneous rock like basalt, tuff, and granite, sedimentary rock of chert, sandstone, and shale, metamorphic rock of greenschist, and serpentine all made their appearance. It was a rocking-out afternoon!
No fault of the rocks, fault lines made their debut as well. A flat area with a sudden rise demonstrated an earthquake upheaval (not of our recent jolt). Riparian areas gave evidence of a fault line that allowed underground moisture to nourish maple and willow trees.
Our rolling California hills tell their geological story to a trained professional. Rebecca Perlroth, our geology instructor and guide, was true to her promise, covering an introductory semester of geology in a two-hour lecture. A gifted and captivating Instructor, her power point presentation, as well as the guided hike, tested our assimilation of her material, and held us captive.
Our geologist-eye view sparked my deeper curiosity. If it intrigues you as well, I suggest you attend next year’s repeat of this offering, along with me.
We rocked out! Here are some pictures to prove it.