ABSTRACTS AND DISCUSSIONS OF PAPERS 407 



No extensive faultiug or folding has occurred since the post-Eocene period 

 of deformation, although uplift and some tilting has taken place. The most 

 conspicuous uplift, presumahly during Pliocene times, was followed by at least 

 local depression, and since Glacial times there has been a very general uplift 

 of from 250 to 600 feet. 



Presented by title in the absence of the author. 



STUDY OF yiXETY THOl'SAXD POUNDS OF MAMMOTH TUSKS FROM LENA 



RIVER, SIBERIA 



BY GEORGE F. KUNZ 



Presented by title in the absence of the author. 

 The Society then adjourned sine die. 



EXCURSIONS 



On Thursday, Aug-ust 5, an excursion, in charge of A. C. Lawson, of 

 the University of California, was made to Hunter^s Point to see a contact 

 of variolitic and ellipsoidal basalt, intrusive in radiolarian cherts of the 

 Franciscan, and incidentally the intrusive relations of serpentinized 

 peridotite to the Franciscan. 



On Friday, Augiist 6, an excursion, in charge of A. C. Lawson and 

 E. P. Davis, of the University of California, was made to San Andreas 

 fault and rift. Point Reyes Station, Marin County, to see the most pro- 

 nounced phenomena of the horizontal slip on the San Andreas fault ; 

 also the rift topography. 



On Saturday, August 7, an excursion, in charge of E. S. Holway, of 

 the University of California, v/as made to the Santa Cruz Ocean beaches 

 to see the finely preserved series of old ocean beach terraces which occur 

 u]) to 1.200 feet ahove present sealevel. The three major terraces are 

 broad, the maximum width of the lowest terrace being one mile. Fifteen 

 to twenty terraces arc found in ]ilnces between Santa Cruz and Daven- 

 port, 12 miles westward. 



On Monday, August 9, an excursion, in charge of A. C. Lawson and B. L. 

 Clai-k, of the University of California, was marie from Berkeley to Mount 

 Diablo. This ti'ip enabled tlie excursionists to s^ee a fairly complete 

 section of the strata imolved by the great geosynclino which lies between 

 tlx' valley of tlie r)ay of San Francisco and ^Mount Diablo. The lowest 

 ' strata of the section, the Franciscan, are exposed on the two flanks of the 

 geosyiieline. Resting on the Franciscnn in ascending order are the Knox- 

 ville shales, the Oakland conglomerate, and Chico s^andstone and shale. 

 extending from Tiower to T^titter Cretaceous. The Tertiarv formations 



