The fossils of the Lower San Pedro fauna of the Nob Hill cut, San Pedro, California

T. S. Oldroyd
1925 Proceedings of the United States National Museum  
INTRODUCTION The cut through Nob Hill at San Pedro exposed a large deposit of the Lower San Pedro series of the Pleistocene. In July, 1918, the steam shovel had worked its way down to the bed, uncovering no shells of the upper series in the cut, except a few at the south end. This was especially good, as heretofore in most places where the lower series was exposed, the upper series had cropped out above it; as at Deadman's Island. This made collecting in the latter place from the lower series
more » ... the lower series rather uncertain, as the upper would cave down in quantities from the action of the wind and rain, settle on the edge of the lower, and on becoming packed, looked as if it belonged there. This immense deposit, extending the whole length and breadth of the cut and an unknown distance further, was nearly 6 feet thick, and in the center of the cut, where it had not been graded down, was 20 feet below the surface and dipped to the northeast. The first layer commencing at the bottom was about 15 inches thick and sparsely filled with shells, mostly bivalves. Next above there was a bed of bivalves about 4 inches thick, composed mostly of Macoma nasuta Conrad, and Macoma secta Conrad; these were very plentiful and in a natural condition as they had lived, and had not been disturbed, but were covered up by about 17 inches of sand in which there were no shells. The next layer was about 4 inches thick, composed of Ostrea luinda Carpenter, and Aletes squamigerus Carpenter. Wliile the life of the bed of Macoma was a short one, as none of them had reached a maximum growth, the bed of oysters had apparently lasted for a much longer period of time. This bed, like that of the Macomasŵ as not disturbed but covered up in a natural position. The next layer is a conglomerate mass two feet thick, very compact but not hardened; washed up by some storm, it' contains a great many species from deep Avater, The next and last layer was about 17 inches thick.
doi:10.5479/si.00963801.65-2535.1 fatcat:6nobf5nehrgtvaw7tb4cbh7eee