92 



Adventures in Scenery 



Batholith Up -Welled in Region of 

 Coast Ranges 



In late Jurassic time an upheaval of tremendous proportions 

 brought a vast batholith or underground lake of molten granitic 

 rock from the depths of the earth in the Sierra Nevada region 

 and in the region where the Coast Ranges are now. It is 

 thought that this molten rock did not reach the surface, but 



FIG. 27. Geologic map of portion of Inyo County (After Olaf P. Jenkins) . 

 Formations indicated by numbers: 1. Alluvium; 2. Terrace deposits; 3. Vol- 

 canic; 4. Late Palaeozoic (Carboniferous) ; 5. Plutonic (Igneous, granitic) ; 

 6. Pleistocene Lake Beds; 9. Cambrian; 10. Pliocene; 11. Ordovician; 12. Sand 

 Dunes; 13. Oligocene; 14. Caenozoic (undivided); 15. Algonkian; 16. Salt 

 deposits. 



was forced up into and under existing sedimentary rocks, where 

 it slowly cooled. The age of the sedimentary rocks that were 

 intruded by the molten mass in the Coast Range region is not 

 known with certainty, as no fossils have been discovered which 

 make it possible to determine the time of their deposition. 

 They are thought to be very old, possibly dating back as far 

 as the Algonkian. These sedimentary rocks were metamor- 



