Geology of the Virgin and Beaverdam Mountains, Arizona - AZGS ...

ABSTRACT
The Virgin and Beaverdam Mountains form an arcuate range in
northwestern Mohave County, Arizona, which extends northeasterly from
the Nevada State line and swings to a northerly trend near the Utah
boundary. The range lies on the eastern edge of the Basin-and-Range
province, adjacent to the Plateau province, and has a maximum
topographic relief of nearly 6,500 feet.
Rocks ranging in age from Precambrian to Tertiary are exposed in
the Virgin and Beaverdam Mountains. Precambrian rocks consist of a
metamorphic and igneous complex. The Paleozoic Era is represented by
marine carbonate rocks with subordinate, fine-grained clastic material.
Mesozoic and Cenozoic rocks are for the most part clastic units of
continental origin.
Structural elements that have played a major part in the development
of the range include a large anticlinal fold and a zone of reverse faulting
that extends for nearly 20 miles along the eastern flank of the range. The
basic pattern established by these structures has been modified by highangle
faults of large displacement which strike substantially parallel with
the line of reverse faulting, and by transverse faults of less displacement.
In the northern part of the range low-angle thrust faulting is locally
prominent.
The structural elements can be divided temporally into three episodes
of deformation: (I) post Jurassic to mid-Cretaceous(?) folding and thrustfaulting
along north-trending axes, (2) late Cretaceous to pre-Middle
Miocene folding and steep reverse faulting along northeast trending axes,
and (3) Late Pliocene(?) to Recent normal faulting striking northeasterly.