Cerrito de San Antonio
So, try as I might, I was unable to find geological maps of the East Bay that showed Albany hill, otherwise known as Cerrito de San Antonio. However I found this explanation from the Berkeley Paths website helpful:
A good place to begin is in fairly recent geologic history, with the sideways friction of the North American and Pacific Plates, cause of our area’s famous earthquakes. Just a few million years ago, the ruptures resulting from this friction led a longish block of crust to tilt downward to the east. Its higher west portion formed what became the hills of San Francisco and Marin; its eastern portion formed a long valley. More recently, perhaps as little as a million years ago, the sharp scarp on the block just east of this valley was similarly tilted, with the uplifted edge forming the Berkeley Hills – probably still rising today. These rocks -- a mix of old sediments, volcanic outpourings, and scrapings from the clash of the great plates – was already deeply fractured, and eroded rapidly into the valley as they rose.
Some 10,000 years ago, as the last Ice Age released water from glaciers, sea level rose. The valley between the San Francisco and Berkeley Hills was flooded, forming today’s San Francisco Bay. A few hilltops on the down-tilted edge of the long block remained dry, forming El Cerrito del Sur (Fleming Point), Cerrito de San Antonio (Albany Hill), Brooks Island, and Potrero San Pablo (the hills of Point Richmond).
A good place to begin is in fairly recent geologic history, with the sideways friction of the North American and Pacific Plates, cause of our area’s famous earthquakes. Just a few million years ago, the ruptures resulting from this friction led a longish block of crust to tilt downward to the east. Its higher west portion formed what became the hills of San Francisco and Marin; its eastern portion formed a long valley. More recently, perhaps as little as a million years ago, the sharp scarp on the block just east of this valley was similarly tilted, with the uplifted edge forming the Berkeley Hills – probably still rising today. These rocks -- a mix of old sediments, volcanic outpourings, and scrapings from the clash of the great plates – was already deeply fractured, and eroded rapidly into the valley as they rose.
Some 10,000 years ago, as the last Ice Age released water from glaciers, sea level rose. The valley between the San Francisco and Berkeley Hills was flooded, forming today’s San Francisco Bay. A few hilltops on the down-tilted edge of the long block remained dry, forming El Cerrito del Sur (Fleming Point), Cerrito de San Antonio (Albany Hill), Brooks Island, and Potrero San Pablo (the hills of Point Richmond).
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