The Curran Quarry

Maple Avenue, in the upper Dimond neighborhood, used to be called Quarry Street. It was an old county road that served at least two quarries, starting with the Fruit Vale White Cement Gravel quarry in the 1870s. The road entered a small valley that cut through the southern tail of the Piedmont crustal block and over a small saddle in the ridgetop to the quarry, which exploited the light-colored fault gouge along the Hayward fault. Here it is on the digital elevation map based on a lidar survey of the fault zone a few years back.

This post is about the second quarry, which has had various names over the years. Its old scar is in the center of the image.

It was opened by James O’Brien some time before 1883 and was known as the O’Brien quarry. Later, when John F. Curran took it over, it became the Curran quarry, but it was also called the Fruitvale Red Gravel quarry, probably to differentiate it from the nearby white gravel quarry. Curran, a Canadian-born resident who died in 1912 aged 72, owned land around present-day Curran Avenue.

Like nearly all Oakland quarries, it produced crushed rock. Some jobs, like roadbeds for trains and cars, demanded hard “blue rock,” but there was also a good market for crummier stuff, and that’s what was here. Being so near the fault, the rock was pervasively shattered, which left it open to weathering and alteration. The area is mapped as mixed Franciscan rocks, which doesn’t tell us much because “Franciscan” is a grab-bag term.

Qpoaf is really old gravel, KJf is undivided Franciscan rocks, and Jsv is Leona volcanics. Find it on the main geologic map toward the middle.

In 1904, the county was asked to give Quarry Street the more appealing name of Maple Avenue. (At that time Oakland had not yet annexed it.) Later that year the owner of the 22-acre parcel the quarry sat on offered the “Crescent View Tract” to the county for use as a hospital, but nothing came of it. The state mineralogist took note of the Curran Quarry in 1906: “The rock is termed ‘red cement gravel,’ and is a very much altered rock, recemented by a red clay. Used as a top dressing for roads and walks.”

The area got annexed in 1909 and developed by the 1920s, but the quarry pit was abandoned at an unknown date and sat vacant until after World War II. It’s visible at the top of this photo from the winter of 1945, at which time the city owned it.

Original photo from Oakwiki

The pit was subdivided and filled with homes over the following decade, and today it looks like anywhere else up there.

The house on the corner has a wonderful exposure of serpentinite that deserves its own post some time.

From the street, everything looks green and lush and fine. From across the valley, though, there are spots visible where that “red cement gravel” has been freshly exposed by our recent hard rains.

Quarry pits are wounds to the land that Earth tries to heal.

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