STRUCTURE AND CONDITIONS AFFECTING PRESENCE OF OIL. 79 
CONCLUSIONS REGARDING FUTURE DEVELOPMENT. 
On account of the greater intensity of the folding and the lack of 
the thick, more or less unaltered diatomaceous deposits which are 
found associated with all the proved productive fields in this dis¬ 
trict, the indications are not so encouraging for good wells in the 
territory northeast of the head of the Santa Maria Valley as they are 
in certain other portions of the Lompoc and Guadalupe quadrangles. 
The areas in the region of the San Rafael Mountains which offer the 
most inducements for testing by the drill are as follows: 
1. North and northwest of Sisquoc post-office, along the anticlines 
shown on the map (PI. I, in pocket). There are one or two local 
anticlines not shown, which might also be prospected with good 
results. The hard shales exposed in this region are probably lower 
Monterey and, if such, do not offer as much promise of great accu¬ 
mulations of oil at their base as if they were overlain by the upper 
part of the formation. The strata in the region above the head¬ 
waters of Round Corral Canyon and Asphaltum Creek are too sharply 
folded to give much hope of the retention of large deposits of petro¬ 
leum. The asphaltum deposits here and to the southeast indicate 
that the Miocene was at one time highly petroliferous, but that at 
least a considerable portion of the oil has escaped. 
2. In the Monterey area bordering the head of the Santa Maria 
Valley on the northeast, both west and east of Tepusquet Creek, 
wherever the anticlines are not so sharply folded as to give indica¬ 
tions of probable loss of their petroleum content by excessive frac¬ 
turing. The surface evidence of petroleum in this general Monterey 
area is greatest in the southeastern or more sharply folded portion, 
but for obvious reasons it seems likely that the chances for the 
accumulation of economically important deposits of petroleum are 
greatest in the less compressed area northwest of Labrea Creek. 
3. The region about Fugler Point and thence southward and 
southeastward toward Sisquoc. This territory is doubtless under¬ 
lain by the oil-bearing beds, but at what depth it is not possible to 
calculate owing to the fact that the Monterey and Fernando are cov¬ 
ered by later sediments. The occurrence of asphaltum at Fugler 
Point is analogous to that at the east end of Graciosa Ridge, near 
which very productive territory has been developed. The local dip 
at the point (25° SW.) would indicate that the best places to drill 
would be east of the asphaltum deposit; but the uncertainty whether 
this dip is anything more than a local tilting of the Fernando is so 
great that conclusions regarding the best localities for exploitation 
in this immediate vicinity are extremely hazardous. Southwest of 
Fugler Point, however, there is evidence of the presence of a low 
