388 University of California Publications in Geology [Vol. 7 



These excavations were made possible through the generosity of 

 the late Madam Ida Hancock Ross and Mr. G. Allan Hancock, 

 who kindly granted a concession to work the deposits. The 

 work was carried on between September, 1912, and April, 1913, 

 under the direction of Dr. John C. Merriam and under the 

 immediate supervision of the writer. An average of about ten 

 men were employed. As our knowledge of the accumixlation of 

 the deposits was increased somewhat by the results of these 

 excavations it seems desirable to record such information as 

 relates to origin of the bone beds. 



DESCRIPTION OF THE LOCALITIES INVESTIGATED 



Locality 2050. — This locality was chosen for the first work 

 in 1912. as it was known that excellent material had been obtained 

 here in a pocket opened by Dr. L. H. Miller in excavating for 

 the State Normal School of Los Angeles some years ago. 



The bones exposed at this point covered an area not larger 

 than four feet square. The larger part of the pocket was cov- 

 ered with green and brown clays. The bones found on the 

 surface were embedded in a hard asphalt and were very much 

 decayed from weathering. Two feet under the surface valuable 

 material in perfect state of preservation was encountered. In 

 the western half of the pocket the bones were embedded in a 

 soft, sandy asphalt, which also contained many sticks and a few 

 large branches of trees. In the other half of the pocket the 

 asphalt was mixed with green clay, which in places was filled 

 with coarse quartz grains. The area of bone-bearing asphalt 

 within two feet of the surface was small, probably about sixteen 

 square feet. At a depth of ten feet the area covered was about 

 fifty square feet. The majority of the bones were taken from 

 soft, sticky asphalt, and in this matrix they were the most 

 numerous and best preserved. Around the edge of the pocket 

 where clay tended to overlap the asphalt few bones were found 

 in the clay. In some eases where the asphalt was soft small 

 bones had been forced into cracks in the clay, forming veins of 

 bones which could be followed for two or three feet. Only a 

 small percentage of the total number of bones obtained came 

 from the fillings of these fissures. It should be noted that the 



