ABSTRACT
Since 1963 geologists and engineers have been intensively investigating this crack and several similar ones nearby, all known to be surface expressions of deep, near-vertical faults of Pleistocene or greater age. The Baldwin Hills, site of the Inglewood oil field and the failed reservoir, form part of an interrupted chain of low hills that rise in striking contrast to the surrounding flat terrain of the Los Angeles basin. The near-parallel, north-striking faults that splay outward from the Inglewood fault south of the Baldwin Hills Reservoir were probably formed as an array of tear faults developed in response to strike-slip displacement along the dominant Inglewood fault. The Inglewood oil field occupies an irregularly oval area that extends diagonally across the trend of the hills along the axis of the faulted Inglewood anticline. Subsurface fluid injection has been practiced less widely than fluid withdrawal, and theoretical and empirical understanding of the mechanical effects of high-pressure fluid injection has lagged accordingly.
