Physiography 



Knowledge of the topography of a region 

 is essential to an understanding of the en- 

 vironment and its processes. When topo- 

 graphic data are organized into physiographic 

 units they become still more useful. In this 

 respect the sea floor off" southern California 

 is better known than are most other parts of 

 the ocean. Its basins, banks, and islands are 

 essentially unique for the sea floor, and they 

 really belong neither to continental shelf nor 

 to continental slope nor to abyssal sea floor. 

 Instead, they are similar to features of the 

 nearby land area, which itself is unique in 

 the world. Farther north and south of 

 southern California both land and sea floor 

 change to more typical forms. Although 

 the region is of unusual physiography, its 

 very complexity has resulted in a concentra- 

 tion of environments of such varied nature 

 that elsewhere it would require long cruises 

 to visit them. Since the detailed knowledge 

 obtained off" southern California can be 

 extrapolated to more distant regions, this 

 area might be thought of as a large model 

 useful for easy testing of many ideas about 

 general oceanic processes. 



Exploration 



The earliest explorations of the shores of 

 southern Cahfornia, lost in the mists of 

 time, were doubtlessly made by primitive 



immigrants from Asia via Bering Strait. 

 Their antiquity is shown by the finding of 

 artifacts near the shores of former lakes, on 

 the sea floor, and under soils that date from 

 some unknown part of the Pleistocene 

 Epoch, but probably from the last glacial 

 age and possibly the preceding interglacial 

 (Clements and Clements, 1953; Carter, 

 1957a). Radiocarbon dating of charcoal 

 and bones from hearth sites on Santa Rosa 

 Island (Orr, 1956) showed the presence of 

 man in the area at least as long ago as 

 29,650 ± 2500 years. On the same island is 

 the oldest dated midden of the West coast, 

 7400 years (Orr, 1958). No record remains 

 of the explorations of these people other 

 than what can be inferred from the distribu- 

 tion of debris and occasional tools which 

 they left behind. On the mainland and most 

 of the islands many bowls made of steatite 

 quarried on Santa Catalina Island have been 

 found, indicating that extensive boat travel 

 and trading occurred during at least a late 

 stage of the Indian culture. Indian canoes 

 seen by the Spaniards in 1602 and 1770 were 

 so well made and so seaworthy that they 

 were given special mention in the diaries of 

 Vizcaino (Bolton, 1916, p. 87) and Fray 

 Crespi (Bolton, 1927, pp. 34, 159). 



Even more hazy is a record of a series of 

 Chinese visits, possibly to western North 

 America about 2250 b.c. This record, the 

 Shan Hai King, was compiled by Emperor 



