Page 5 - muehlberger1954
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The date of the folding and metamorphism of the Pelona schist
is not known, but it assuredly is pre-Tertiary. Tertiary rocks have
been either tilted or deformed into broad open folds, although locally
near the major faults nearly isoclinal folds are found. Almost with-
out exception, these folds plunge to the west or southwest.
The numerous faults are the most prominent structural
features of the Soledad basin. Normal faults which trend generally
east were formed in post-Martinez, pre-Vasquez time. Displacements
occurred throughout Vasquez time and ceased prior to Tick Canyon
time. The Pelona fault may have been reactivated just prior to Mint
Canyon time. Offsets on these normal faults are as much as 10,000 to
15, 000 feet. The normal faults indicate that the minimum compressive
stress was oriented nearly north-south. On the other hand, the post-
Mint Canyon, pre-Saugus faults indicate a maximum compressive
stress oriented north-south, which resulted in a number of northeast-
trending left-hand faults with displacements up to 10, 000 feet. None of
the faults of the Soledad basin have been reactivated in spite of Pleisto-
cene and Recent offsets along the San Andreas fault.
