The San Gabriel Mountains have been subject to quite a bit of deformation in their past. Some of which is still ongoing, such as the movements along the Sierra Madre and San Andreas Faults. Here, near Mt Wilson, the rocks exhibit multiple instances of deformation. The white vein is mostly composed of quartz, which has been offset by multiple faults. Slickensides can be seen as the reddish areas on the right side of the photo. The surrounding materials are complex metamorphic rocks.
Near the southern end of the Salton Sea in the Imperial Valley, you can find some very interesting geological features. Mud volcanoes, slowly “erupting” a fine muddy ooze, are some of the evidence of the extreme heat not far below the surface here. Gases, usually carbon dioxide, also emanate from the ground here. These mud volcanoes are more active in winter and spring, when groundwater is a little higher and the surface temperatures are a bit lower. I highly recommend a visit sometime.
Looking toward South Mount Hawkins in the West Fork San Gabriel Canyon from State 39. This road was planned to be improved but landslides prevented this work from being completed. In the case of this area, almost all of the low lying areas not covered in snow are landslides in one form or another. Even Crystal Lake, where this roadway is headed, exists because of landslides.
Back in the 1970’s, California was “all about the freeway” it seemed. Build them so that people could go anywhere using one. Anywhere, at times, meant an offshore causeway (Pacific Coast Freeway) or over high mountain ranges where even a two-lane roadway has problems (Angeles Crest Expressway), regardless of the costs or necessity. One of these plans, the Pacific Coast Freeway, never really came to fruition. Portions were indeed built, such as the interchange with I-5 near Dana Point and through the Oxnard Plain. The section that was proposed to go through Newport Beach would be the end of the plan. Local opposition was quite heavy, which cascaded to every city along the path also saying no to the project. The image above is an artists rendering of what would have been the State 1 and State 55 interchange near the present intersection of Newport Blvd (State 55) and Hospital Road.
