GEOLOGY OF THE SANTA MONICA MOUNTAINS
The Santa Monica Mountains Education Consortium and the Resource Conservation District of the Santa Monica Mountains worked together to prepare a field trip about the geology of the Santa Monica Mountains. On October 18, about 35 interested individuals met at 9:30 AM at King Gillette Ranch. Stephen Vodantis greeted everyone and introduced the guest speaker retired Professor William “Bill” Selby.
Professor Selby gave a brief overview of what to expect during the field trip and introduced us to a number of well-written books that would be excellent follow-up reading material on geology as well as other wildlife topics. We then boarded the bus for the daylong event.
We discovered that the Santa Monica Mountain range is one of the youngest in the world and encompasses 344 square miles. It seems that each rock, crevice, and layer tells a story packed with millions of years of history. Professor Selby discussed climate and temperature changes, how that affects erosion, and how various land mass form. The field trip included a bit of hiking where he talked about the various types of plants and trees and explained why some mountains facing certain directions are almost barren while other mountains are full of plants. Everyone learned a great deal of the technical terminology associated with geology. Various types of rocks were passed around during the bus ride as well as at several stops along the way. Sometimes he would quiz the group and at other times explain the composition of each rock. It was all so interesting and exciting to learn.
We stopped in Malibu taking a break for lunch and after we resumed the travel to end the trip he provided everyone with a handout that also gave data and images. His explanations were very clear so that even though the material could be highly technical it was brought to a level where everyone attending could understand.
During the late summer and fall, hot and arid Santa Ana east winds blow from the deserts and this develops into extreme fire conditions. I might add that on September 25, 1970 my home burned completely to the ground during one of these dangerous conditions so I know what type of experience that can be.
Towards the end of the field trip, Professor Selby spoke about the upcoming large earthquake that is actually overdue and expressed concern that everyone should prepare to have on hand emergency supplies to carry them for at least two weeks. He spoke about the motion of the Earth’s crust in Southern California. It is usually north-northwest except where the southerly group of blocks meets the deep roots of the Sierra Nevada. At that point, the blocks go to the west so that there are transverse ranges and a big bend in the San Andreas Fault System. This helped us to better understand this upcoming dire situation.
Thank you to the Staff at the Consortium and to Stephen Vodantis for arranging this event. A special thank you goes to Professor William Selby for sharing his knowledge and expertise with us. Some useful links and good source material including images that he recommends are:
Note: This blog was contributed by Marilyn Fordney