Into the Breach Craft Unseen

OYSTER SHELL: Emeryville Shellmound, Emeryville, CA

Photos: Vanessa Lim/, symbionspacesuit/

Cartographer's note: I did not know oyster shells were used to make cement until this project but I've known about the Emeryville shellmound for many years before the development of the Bay Street Mall. It used to be a much larger grassy mound that traffic swerved around on the way to the freeway. Even at that time, though, it represented only a tiny portion of the largest shellmound in the area.

"Industries in the vicinity of San Francisco make use of two types of natural lime-bearing raw materials. The first, seashells, have been calcined to lime for as long as the process has been known to the human race. It is exceedingly uncommon, however, to find seashells in sufficient concentration to form source material upon which to justify erection of a modern industrial plant. Nevertheless, the Pacific Portland Cement Company's mill at Redwood City, which produces cement far in excess of a million barrels annually, utilizes seashell accumulations from San Francisco Bay as its sole source of lime. There are shell deposits on certain parts of the bay floor large enough to support such a plant for many decades."1

"Across the state there are statues of Native dancers in front of a Walmart, a bronze cast of an Indian leader at a strip mall, and a shellmound that is a replica of the one that was destroyed during a century of ignorance. At the Bay Street Mall, there is such a memorial next to the Old Navy retail store. It is a small place of respite with a concrete pathway to protect visitors’ feet from dirt. There is an artificial creek that forms a water feature to soothe shoppers and guests. It is a replica shellmound, facing a hotel located across the street. One section of the mound is exposed, much like the depiction of the Emeryville shellmound in old photographs of the excavations by Nels Nelson. Shells are embedded in the bottom of the mound for visitors to gaze upon, and a fountain sprays water from artistically rendered boulders into a small pool lined with rocks. People now have a monument to what was once there that has now largely been erased."2

1 Olaf P. Jenkins. "Geologic Guidebook of the San Francisco Bay Counties: History, Landscape, Geology, Fossils, Minerals, Industry, and Routes to Travel, Bulletin 154." California Division of Mines, December, 1951.
2 Gould, Corrina and Michelle LaPena. “Buried in Shells.” Grantmakers in the Arts. Accessed February 28, 2022.