http://oaklandgeology.wordpress.com/2009/06/26/dunsmuir-ridge-and-the-irvingtonian-gravels/ focused on, near and under Oakland, California Sat, 18 May 2013 23:16:21 +0000 hourly 1 http://wordpress.com/ http://oaklandgeology.wordpress.com/2009/06/26/dunsmuir-ridge-and-the-irvingtonian-gravels/#comment-1202 Tue, 05 Jan 2010 03:09:07 +0000 http://oaklandgeology.wordpress.com/?p=488#comment-1202 There have been several reports made on the geology of Dunsmuir Ridge. Trenching was done in the 80′s when a developer wanted to build several hundred units on the site. Do y’all have access to those reports? Where did your map come from? I’m very interested in the botany and zoology of Dunsmuir Ridge, and how it relates to the geology.

]]> http://oaklandgeology.wordpress.com/2009/06/26/dunsmuir-ridge-and-the-irvingtonian-gravels/#comment-813 Sat, 11 Jul 2009 05:30:06 +0000 http://oaklandgeology.wordpress.com/?p=488#comment-813 Yes, I found those same rounded gravels (in a sand matrix) while I was trenching on that ridgeline a few years ago. Some of the rocks are high-pressure metamorphics.
Those gravels appear to be a fossil of a previous drainage regime, that existed prior to the uplift of the East Bay Hills. How else do you ger this classic level-ground alluvium (looks just like the Niles cone deposits), way up on the hillside ? The creek that deposited those sands and gravels surely did not flow down the face of the current slopes!

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