CHAPTER XVI. 



litXUMINOUS EFFUSIONS. 



Localities wiieue bitdmen exists. — PfiO.^mixY to the coast. — Scbmarine e.xudations. — Bitcmen found in all stages of con- 

 sistence. — Its abdndance. — Santa cruz bitumen, particulabs of. — Bitumen of san luis valley. — Nature of the asphaltio 

 rock, AND details.— Fluidity of the bitumen. — Subterranean cavities. — Bitumen of napoma. — Op la purissima.— Nature 

 of the strata through which it leaks. — Bitumen of santa Barbara, locality, and extent of the bed. — A solid bitu- 

 men, NO FLUID OUTPOUaiNQ. — EXPOSURE ALONG THE SHORE CLIFF. — ESTIMATE OF THE QUANTITY WHICH THIS LOCALITY AFFORDS. — 



Proprietorship of the land. — Enumeration of the strata at the cliff. — Upraised beach along the terrace. — Evidence 

 OF time afforded by a consideration of the cliff strata. — Bitumen op rincon and san Buenaventura river. — Curve 

 OF the shore line. — Enumeration and thickness of the asphaltic rocks. — Bitumen spring twelve miles up Buenaven- 

 tura river. — Sulphur spring, its temperature. — Liquid overflow op bitumen.— Strata of the neighborhood. — Deposits 



on the SANTA CLARA RIVER. — BiTUMEN OP LOS ANGELES VALLEY. — LOCALITY OF. — ExTENT OF OUTFLOW.- — LlQUIU NATURE OF. — 



Strata of the locality, amount op the bitumen, and co.st at the spring. — Contrast between the supply at los angeles 



AND at SANTA"bARBARA. — DIFFERENT ESTIMATES OF THE VALUE OF ASPHALTUM. — PECUNIARY WEALTH OP LOS ANGELES VALLEY 

 IN THIS MINERAL. — BiTUMEN OF SAN PEDRO, OF SAN JUAN CAPISTRANO, AND SAN DIEGO. — REMARKS ON THE OCCURRENCE OF 

 BITUMEN IN THE STRATA OF CALIFORNIA. — SPECULATION ON THE PROBABLE ORIGIN OF BITUMEN. 



Bitumen is par excellence the mineral of southern California, being found in almost every 

 county south of San Francisco. The localities in which it has been observed hitherto are as 

 follows : 



1. Santa Cruz mountains, southeast spur, Santa Clara county. 



2. San Luis Obispo valley, San Luis Obispo county. 



3. Napoma ranche, San Luis Obispo county. 



4. La Purissima, Santa Barbara county. 



5. Santa Barbara, 6 miles west of Pueblo, Santa Barbara county. 



6. Rincon and San Buenaventura, Santa Barbara county. 



7. Buenaventura river, 12 miles up, Santa Barbara county. 



8. Santa Clara river, 18 miles up, Santa Barbara county. 



9. Sierra Susanna, Los Angeles county. 



10. Los Angeles valley, Los Angeles county. 



11. San Pedro hills, Los Angeles county. 



12. San Juan Capistrano, San Diego county. 



13. San Diego, off shore, San Diego county. 



The survey has traced the mineral in its course from the extremity of the Santa Clara valley 

 to San Diego, a distance of more than four degrees and one-half, or about 300 miles by the 

 travelled roads. It is remarked of most of these deposits that they are situated close to the 

 sea, the most distant being that near Santa Clara river, (No. 8,) being not more than 25 miles 

 inland ; the next most remote is Los Angeles, and then that of the Santa Cruz mountains, 

 being less than 15 miles ; still closer are those of Napoma, Santa Inez, and Susanna hills, while 

 those of San Luis valley, Eincon, and Santa Barbara are on the shore edge and dip under the 

 sea. On the shore at San Diego and at False Bay, north of Point Loma, masses of asphalt 

 are washed ashore by the tidal action. The submarine exudation cannot lie far out, as the 



