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We'll be exploring Sunol Wilderness's Little Yosemite (now named *Alameda Creek Overlook--*I'm guessing they changed the name because there is no granite there), and other rocks in the area. AllTrails lists this hike as 3.7 miles and 860 ft. We seem to average 2 MPH, plus a brief lunch, so we'll probably take three hours.

### Geological Highlights

  • The Franciscan Complex at Little Yosemite: Our first stop is the iconic gorge where Alameda Creek has carved through 150-million-year-old oceanic crust. We’ll examine massive outcrops of greenstone and basalt, looking for water-carved "potholes" and hydrothermal mineral veins.
  • The Stratigraphic Leap: As we ascend Cerro Estes Road, we leave the metamorphic basement behind and move into the Great Valley Sequence. These are younger sandstones and shales that once sat at the bottom of a vast inland sea.
  • Fault Line Vistas: From the Lower McCorkle Trail, we’ll have a "bird’s-eye" view of the Sunol-Calaveras Fault. We’ll discuss how fault "gouge" (pulverized rock) creates the long, linear valleys that define our local landscape.

Restrooms, food. and water:
There are restrooms at the start, but I don't think there is running water there. There is no food sold in the park, so bring plenty of water and a lunch. We'll have lunch somewhere near the top of our climb.
Weather
In the event of light rain, we'll start up to Little Yosemite (on a fire road), then decide when we get there if it's too wet to continue, or if we want to slog it out in the drizzle and mud. 10 day forecast.
Past hikes here (with photos and comments):

Etc:

  • From 10:15-10:30 will be a brief background talk about the geology of California, if you've heard this before you're welcome to show up at 10:00.
  • $5/car entrance fee (may have gone up; carpooling encouraged, leave a comment at the bottom if you can ride/drive).
  • Kids are welcome.
  • Dogs not allowed
  • $2 donation requested to help with Meetup fees and buys me lunch or a cup of coffee :-)

Other resources:

Related topics

Events in Sunol, CA

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