3° WiiP. JENNY 
their magnetic behavior. From the magnetic vectors at Bradley, San 
Lucas, Soledad, and Salinas it seems, however, permissible to conclude 
that the Santa Lucia “blocks”? would act somewhat neutral magneti- 
cally. If this should be the fact, then these ‘“‘blocks”’ could not possibly 
reach great depths. 
It is interesting to note that the two pronounced magnetic high 
trends occur where they are least expected, that is, along the east 
flank of the Santa Lucia “blocks” and along the west flank of the 
Sierra Nevada ‘‘block.”’ If we interpret these high trends in the usual 
way, we should expect an anticlinal trend in the Basement complex 
below the California Valley, or along the west edge of the Sierra 
Nevada “block,” and another anticlinal trend in the Basement com- 
plex approximately below the San Andreas fault, or along the east 
edge of the Santa Lucia ‘‘blocks.” 
To interpret the magnetic data properly, we have to assume that 
the Santa Lucia “blocks” and the Sierra Nevada “block” are floating 
on a Basement complex, which is greatly depressed below the “blocks” 
and elevated along the edges of the “‘blocks.’”’ This might be explained 
either by assuming that these two “blocks” are laccoliths, or by the 
assumption of huge overthrusts. 
The mechanics of the ‘‘progressive breaking down of the crystal- 
line Pacific borderland,” as explained by the arrows in Figure 2 and. 
in the text of ‘‘Decline of Great Basin,’” are not sufficiently free from 
possible objections, to speak plainly against the foregoing interpreta- 
tion.” 
In connection with a detail geologic map and scattered magneto- 
meter surveys, the vector map of California may prove of value also 
for the study of local anomalies. 
SUMMARY OF REGIONAL ANOMALIES 
Figure 10 summarizes the regional magnetic trends and areas of 
magnetic anomalies, which have been mentioned before in the dis- 
cussion of the respective states. We have discriminated between 
probable and possible anomalies. The probable anomalies are fairly 
well established by the magnetic vectors; the possible anomalies, how- 
ever, may upon more detailed investigations prove to be more local- 
ized and not as continuous as shown on the map, though the vectors 
1 J. Edmund Eaton, op. cit. 
? Friedrich Noelke, ‘“‘Geotektonische Hypothesen,” Sammlung geophysikalischer 
Schriften, No. 2 (Berlin, 1924), p. 70, b. 
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