Ransome. 1 



Eruptive Rocks of Point Bonita: 



77 



the ellipsoidal forms predominate. Upon descending the steps to 

 the landing, the spheroidal rock may be seen continuing down to 

 the water, and showing conspicuous spheroidal forms on the wave- 

 washed surfaces. A notable feature of the rock at this place, and 

 for some two hundred yards northward, is the abundance of in- 

 cluded fragments of unmistakable red jasper. Such pieces seem to 

 have suffered little alteration beyond having their usual dark red 

 or chocolate color changed to a bright vermilion — a change which 

 was constantly observed wherever such included fragments were 

 found. 



About one hundred yards directly south from the old tower, the 

 path makes an abrupt turn to the east, after running for a few paces 

 along a very narrow ridge of rock. On the steep slope just above 

 and to the north of the turn, occur the curious spheroidal masses 

 shown in Plate 7, Fig. 2. As the illustration shows, they are of 

 various sizes up to three feet in diameter, and appear to be imbedded 

 in a shattered mass of rock similar to that of which they are formed. 

 The view shown unfortunately affords only one aspect of these 

 masses, making it appear that they are really spherical in form; but 

 upon going around to the ground in the left of the illustration, it is 

 at once evident that these bodies are not true spheroids. The one 

 depicted is seen to be lying upon a similar rounded mass under- 

 neath, and to present the appearance shown in Fig. 2, as though it 



Figure 2. — Side view of large spheroid shown in PI. 7, Fig. 2. 

 had been laid there in a pasty or viscous state, and had assumed its 



