Editing Transverse Ranges (section)

===Rocks===
Rocks of the Transverse Ranges exhibit extreme differences in geologic age and composition, varying from sedimentary rocks in the western Santa Ynez and volcanic rocks in the Santa Monica Mountains to primarily granitic and metamorphic rock in the central and eastern segments, including the San Gabriel and San Bernardino Mountains.

The oldest basement (deepest) rocks are of [[Proterozoic]] age, and are found in the San Gabriel Mountains and the San Bernardino Mountains. The [[Jurassic]]-[[Cretaceous]] [[Franciscan Assemblage]] is found in the western section of the ranges and is the presumed basement in this segment. Exposed plutonic rocks from the [[Mesozoic]], mostly granites, can be found on [[Mount Pinos]] and generally in regions east of [[Tejon Pass]]. The youngest rocks are [[Cenozoic]] sedimentary and volcanic rocks that can be found throughout the ranges.

The western segment is distinctive for the large thickness of Cretaceous and Cenozoic sedimentary rocks, estimated to be up to 10 kilometers.<ref name=":1" /> The thickest deposits of these are in the Santa Barbara Channel and Ventura basin. These are mostly marine in origin with a marked change to [[red beds]] of river systems of [[Oligocene]] age in the western and central segments.

[[Limestone]]s and [[Dolomite (rock)|dolomite]]s of the marine Miocene [[Monterey Formation]] are found in the Santa Ynez Mountains and in the Coast Ranges to the north.