BIKES ALONG COAST WEST OF SANTA CRUZ 



243 



shown in figure 2, plate 24, and in plate 25, and a plan of which is shown 

 in figure 12. 



The dike shown in figure 2, piate 24, and in plate 25, varies in thickness 

 from 2 inches to a foot, and is composed of fine sand highly bituminized 

 in places. It is harder than thie shales about it and consequently stands 

 above them on the beach. 



The intrusion branches several times, as shown in figure 12 and plate 

 25; its dip varies from 10 to 90 degrees, and its strike is also variable. 

 At its western end, dike 30 shows lateral faulting of 20 inches. The 

 shales at this localit}^ dip 5 degrees south, 15 degrees west. 



At 31 there is a veinlet of bituminized sand from one-half inch to one 

 incli thick, standing nearly vertical and having a strike of north 50 

 degrees east. The dike at 31a is 3 

 inches thick, vertical, and has a strike 

 of north 25 degrees east. At 32 the 

 dike is 8 inches thick, vertical, and 

 strikes north 15 degrees east. At 33, 

 veinlets from one half inch to one inch 

 thick are exposed for 50 feet along the 

 top of the wave- washed shale bench. 

 These minute dikes are of bitumin- 

 ized sand, and have a strike of north 

 55 degrees east. 



At 34 there are two small bitumin- 

 ized intrusions dipping 45 degrees 

 north, 45 degrees west. They vary in 

 thickness from one-fourth inch to six 

 inches, becoming thinner and finally 

 disappearing as they approach the top 

 of the sea clifi", which is about forty 

 feet high. The shale here dips 12 de- 

 grees south, 5 degrees east. 



At the point southeast of the mouth of Majors creek, at 35, is a dike of 

 much broken bituminized sandstone along a fault, having a downthrow of 

 4 feet on the east side. There are a number of very small dikes of bitumi- 

 nous sand along joints in the shales at this place. Half way to the top of 

 the clifi", which is 65 feet high, is a thin bed of bituminous sand with 

 which some of the dikes are connected and from which the dikes below 

 have been derived, the injection of sand having been downward. 



Immediately northwest of the mouth of Majors creek is a mass of 

 bituminized sandstone interbedded wdth the shales. Whether this is a 

 bed originally deposited in this position or is an intruded mass is not 



Figure \2,.— Bituminized Satidstone Dikes. 



At 34, figure 10, the mouth of Baldwin creek. 

 Note the influence of the concretion upon the 

 intrusion. 



XXXV— Bull. Geol. Soc. Am., Vol. U. 1902 



