<p> New stratigraphic and geomorphic data from the Santa Maria Basin, California, suggests that the major basin-bounding Little Pine fault system has been acting in a primarily reverse offset fashion since the late Pleistocene. A series of stratigraphic columns in the Plio-Pleistocene Paso Robles Formation measured along the Little Pine fault indicate that there was episodic uplift during the latest Pleistocene. A 20-40% increase in the percent composition of resistive, Franciscan Complex-derived cherts within active drainages indicate that uplift of the San Rafael Mountain front increased rapidly since the deposition of older sediments. The shape of stream profiles created along the Little Pine fault suggest ongoing uplift associated with the central and southeastern segments of the fault, with a lesser amount of uplift occurring further northwest along the Little Pine fault. A number of ridgeline profiles were also created which exhibit significant jumps in topography near, or just northeast of the Little Pine fault, suggesting that recent uplift is responsible. The ridgeline profiles also suggest an increased rate of uplift adjacent to the central and southeastern segments of the Little Pine fault zone, in agreement with the along-strike variations in uplift suggested by the stream profiles. Stream traces were also examined for deflections as they flowed across the Little Pine fault, but most show no significant lateral offset.</p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:1526922 |
| Date | 22 November 2014 |
| Creators | Lee, Richard A. |
| Publisher | California State University, Long Beach |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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