Geology of the Tujunga region, Southwestern San Gabriel Mountains

• Main Author: Sharp, Robert Phillip
• Format: Others
• Published: 1934
• Online Access: https://thesis.library.caltech.edu/5711/1/Sharp_rp_1934.pdf; https://thesis.library.caltech.edu/5711/2/Sharp_rp_1934_plate.PDF; Sharp, Robert Phillip (1934) Geology of the Tujunga region, Southwestern San Gabriel Mountains. Bachelor's thesis, California Institute of Technology. doi:10.7907/6D8Y-3G83. https://resolver.caltech.edu/CaltechTHESIS:04082010-130714281 <https://resolver.caltech.edu/CaltechTHESIS:04082010-130714281>

<p> The Tujunga area offers a wide variety of rocks, igneous plutonics, lavas, metamorphics, and Tertiary and Quaternary marine and terrestrial sediments from middle Miocene up to Recent in age. The entire span of all the rocks of the area ranges quite certainly from Jurassic up to Recent and possibly from Pre-Cambrian(?) up to Recent.</p> <p> The Tertiary sediments have all been deformed and are folded into a medium large syncline, the Merrick Syncline, with several smaller attendant folds. Faulting has uplifted the underlying basement to the north. The Tertiary sediments abut sharply against this basement scarp.</p> <p> The faulting of the Tujunga area is of two types, reverse and normal, with the normal faulting being younger than the reverse faulting. This idea differs from the ideas generally held about the Tujunga area and is the most important contribution of this paper. The faulting has all occurred in late Pleistocene or Recent time and evidence of movements are fresh.</p> <p>Collections and determinations of fossils from the so called Topanga of the Tujunga area have definitely fixed the age of this series of beds as middle Miocene.</p>