32 



level and at a distance of twenty miles to the north we find the same group ex 

 isting, and each bed holding its precise relative position, which it is found occu 

 pying at the coast, with this exception, that the bituminous shales is no where 

 seen to crop out in any of the hills lying at the base of the mountains. The ab 

 sence of this out-crop, however, is no evidence that the bituminous shales does 

 not exist there, but on the contrary we have strong proof of their continuation 

 and underlying position here as on the coast, from the fact that the principal 

 springs of bitumen are found among the lower hills in the immediate vicinity of 

 the outcrops of their associated rocks as found near the sea. As the organic 

 forms in each bed of the rocks are precisely identical, we have good reason to 

 believe that the rocks on the coast line are continuously from that line to the 

 mountains inclusive, and as a consequence form the basis of all the superficial 

 deposits of the intervening plains. The thickness of these deposits, as deter 

 mined by their outcrop amounts to nearly 200 feet, and it is hardly to be sup 

 posed that they much exceed that depth. 



The dip of these beds on the south base of the mountains being much higher 

 than those at San Pedro, it is probable that they would not be reached by 

 boring so soon as in any other part of the valley. The dip of the stratified 

 rocks near the edge of the plains, and at the point selected for sinking an arte 

 sian well, ranges from 48 to 53 degrees, and it will be probably impossible to 

 reach them below the surface at that point at any distance less than 375 feet, 

 presuming that their dip is the same, or nearly so at the distance of 1000 feet 

 from the outcrop. It is more than probable that the inclination of the strata 

 decreases as the distance from hills increases, and that at some point a little 

 more than midway between the City and San Pedro these rocks have a horizon 

 tal position. This must certainly be the case or we shall be forced to the sup 

 position that the equivalent group on the coast to the south lie unconformably, 

 and that the two overlap each other. This would be contrary to all reasoning 

 upon similar cases, as there are no evidences that there has been any volcanic 

 disturbances which could have produced a false position of such a character. 



The opposite inclination of the two extremes of the group favor the above 

 presumption, and if this be true, then the superficial deposits upon the beds 

 must be much thinner than at that point where the rocks assume a horizontal 

 line. From the inclination of the surface of the plain from both margins, to 

 wards its centre, we should be induced to suppose that near the points of hori 

 zontal position of the basis of the plains, not only would be found a corres 

 ponding depression upon the surface, but also other attendant circumstances 

 which might have lead us to infer that if water was percolating even among the 

 superficial strata of clays and other earthy semi-indurated masses, resting upon 

 the rocks above referred to. Such should be the case if water exists among any of 

 these strata, and this is the fact, thus furnishing the best evidence which we can ob 

 tain on this and similar points. We find the water leaking out of the lamina 

 of the deep clayey sub-soil in quantities sufficient to form small lagunas and per 

 ennial springs for several miles, and at a point not less than 200 feet below the 

 level of the City of Los Angeles and twelve miles to the south from the town. 

 It is to be greatly doubted that anything approaching a constant supply will 

 be found in any of the superficial material resting upon the rocks, notwith 

 standing wells of this character may be sufficient for the supply of local de 

 mands, and although they may rise above the surface at first, still it will ultimately , 

 be found that mechanical means will have to be employed in obtaining water in 

 sufficient quantities for the supply of agricultural purposes. 



It will most probably be necessary to pierce the stratified rocks before a su 

 ficient amount of water will be obtained for the ample irrigation of farming lands, 

 and to accomplish this will require heavy expenses to be laid out, for labor at 



