514 EMMONS AND MERRILL — SKETCH OF LOWER CALIFORNIA. 



mediate coast. From cape Colnett the flanks of the buried range appear 

 to follow a due southeast course, leaviiio* a gradually widening belt of 

 Cretaceous beds betw^een them and the coast, which has been protected 

 from recent erosion by the lavas of San Quentin and similar phenomena. 

 South of Canoas point, if the southeast direction were strictly followed, 

 the flanks of the buried range would approach nearer to the present 

 coast-line as Viscaino bay widens landward, and the shore topography 

 given on the hydrographic charts would indicate that this is the case. 

 The character of the southeastern shores of Viscaino bay indicate that 

 the depression extends for a considerable, though unknown, distance in 

 that direction. On the southwest of Viscaino bay is another uplift of 

 older rocks, the projecting summits of a second buried ridge whose 

 culminating points form Benito and Cerros islands and the coastline at 

 point San Eugenio and for some distance southward. 



In the next reentering curve, around and beyond Ballenas bay, the 

 coast is again a low mesa country, presumably of Cretaceous and more 

 recent beds, wdiich may be part of the Viscaino bay depression or an 

 independent one set off a little to the south westward. Gabb's descrip- 

 tions indicate that the depression extends a long distance southeastward, 

 and the map shows it to be on the line with the bay on the Gulf coast 

 north of La Paz. 



At cape San Lazaro and in the islands outside of Magdalena bay is a 

 third projecting ridge of older rooks which may form part of the uplift 

 at the extreme end of the peninsula south of La Paz. 



Diller and Stanton * have shown that the Chico and Tejon formations, 

 formerly considered conformable and part of a continuous series, are sep- 

 arated by a marked unconformity in northern California and Oregon. 



Whether representatives of these lower formations exist in Lower 

 California can only be determined by further exploration. The Todos 

 Santos beds of the Chico would seem from their fauna to be of low^er 

 horizon than those between Bluff and Canoas points. On the other 

 hand, probably several hundred feet of these beds are below scale vel at 

 the latter locality and probably form the floor of Viscaino bay. 



The fact that since Cretaceous times these formations seem not to have 

 been flexed and altered, as they have been in the Coast range of Califor- 

 nia, but occur almost in the attitude of deposition, renders the peninsula 

 a most favorable point for their study, except for its inaccessibility. 



Since the great depression near the close of Tertiary times our observa- 

 tions go to show that the whole peninsula has taken part in the consecu- 

 tive movements of elevation which have been outlined by Mr Lawson 

 for southern California, though they were not sufficiently exact to de- 

 termine an actual corre3[)ondence in the number or altitude of the dif- 

 ferent terraces formed during the progress of this elevation. 



* Bull. Geo! Soe. of Am., vol v, p. 436. 



