BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



VOL. 15, PP. 29-36 PLS. 1-4 FEBRUARY 10, 1904 



DOMES AND DOME STRUCTURE OF THE HIGH SIERRA 



BY G. K. GILBERT 



{Presented to the Society January 7, 190 If) 

 CONTENTS 



Page 



General character of the domes 29 



Theories of relation between structure and form 29 



Relation of dome structure to plane jointing 31 



The question of cause 32 



Explanation of rounding 33 



Explanation of plates 35 



General Character of the Domes 



In the granite areas of the Sierra Nevada are many hills and other 

 summits having the form of domes. A few of the domes are sym- 

 metric, with approximately circular or oval bases, but the majority are 

 somewhat one-sided or irregular. Associated with these domelike 

 forms are closely related structures. The granite is divided into curved 

 plates or sheets which wrap around the topographic forms. The removal 

 of one discloses another, and the domes seem at the surface to be com- 

 posed, like an onion, of enwrapping layers. 



Theories of Relation Between Structure and Form 



In explanation of these peculiar forms and structures two general 

 theories have been advanced.* According to one theory the separation 

 of the granite into curved plates is an original structure, antedating the 

 sculpture of the country and determining the peculiarities of form. 



*H. W. Turner gives a digest of opinions, with references, in Proc. Cal. Acad. Sci., 3d ser., 

 Geology, vol. 1, pp. 312-315. To his enumeration may be added Muir (Am. Assoc. Adv. Sci. Proc, 

 vol. 23, pp. 61-62) and Le Conte (Elements of Geology, 4th ed., pp. 283-284), both on the side of 

 original structure. 



V— Bur.i,. Geol. Soc. Am. Vol. 15, 1903 (29) 



