Download or read book Surface and Subsurface Geology of the Simi Valley Area Ventura County California written by David Wayne Hanson and published by . This book was released on 1981 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface and subsurface mapping are combined to determine the structure and geologic history of the eastern half of the Simi fault in the Simi Valley area. Upper Cretaceous rocks exposed south and east of the Simi Valley are overlain unconformably by the nonmarine Simi Conglomerate of Paleocene age. The Marine Paleocene unit conformably overlies and is locally interbedded with the Simi Conglomerate; it is composed of Simi Conglomerate clasts that were reworked during a marine transgression. Siltstone of the Santa Susana Formation conformably overlies the Marine Paleocene unit, disconformably overlies the Simi Conglomerate, and was deposited in a deepening marine basin. The overlying Llajas Formation was deposited during a marine regressive-transgressive-regressive cycle. The latter regression continued in late Eocene time with deposition of the overlying nonmarine Sespe Formation. Extension and normal faulting followed deposition of the Sespe, with the early Miocene Vaqueros Formation being deposited unconformably over the Sespe. Formation of the Simi anticline and Simi fault occurred after deposition of the Vaqueros and prior to the deposition of the Conejo Volcanics, and resulted in 3850 feet (1173 m) of separation along the Simi fault in the western part of the study area. The Conejo Volcanics were erupted into a structurally controlled marine basin in the Santa Monica Mountains-Conejo Hills area during the middle Miocene. The flows extended northward over the Simi fault to the southwest flank of Big Mountain. Sedimentary rocks of the Topanga Formation were deposited prior to, during, and after deposition of the Conejo Volcanics. The Neogene Topanga, Modelo, and Pico Formations in the Simi Valley area are thin, discontinuous, and bounded by unconformities, with the late Miocene to early Pliocene Towsley Formation being entirely absent. This implies that the Neogene in the Simi Valley area was characterized by shallow-water sedimentation interrupted by periods of nondeposition and erosion, and is in contrast to the conformable, predominately deep-water Neogene sequence present in the East Ventura basin. The Neogene sequence contains evidence that the Simi Valley became a structural high during the early Miocene and remained elevated through the Pliocene. Formation of the south-dipping Marr, Brugher, Llajas, Ybarra Canyon, and possibly the Corredo faults is assumed to have occurred during Pico deposition, coincident with the formation of the south-dipping Frew fault in the Aliso Canyon area. Movement along the present trace of the Simi fault truncated the Marr fault and is assumed to have occurred subsequent to Pico deposition. The northdipping C.D.L.B., Strathearn, and Joughin faults are inferred to have formed at this time, and ceased movement prior to the deposition of the Saugus Formation. Folding of the Happy Camp syncline occurred after deposition of the Saugus, possibly in response to the same northeast-southwest-oriented stressfield that formed the Santa Susana fault. The Simi fault cuts older alluvium east of Tapo Canyon, but does not cut slump blocks of Conejo Volcanic that overlie the fault north of Tierra Rejada Valley.

Download or read book Surface and Subsurface Geology of the Camarillo and Las Posas Hills Area Ventura County California written by Mary Clare Jakes and published by . This book was released on 1979 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface and subsurface data are combined to determine the structure of the western half of the Simi fault system in the Las Posas and Camarillo Hills area. Cretaceous to Eocene sedimentary rocks, present only in the subsurface, are overlain by late Eocene to early Miocene nonmarine stata (Sespe Formation) and middle Miocene volcanics and sedimentary rocks (Conejo Volcanics and Topanga Formation undifferentiated), in part exposed in the Las Posas Hills. Late Miocene marine beds (Modelo Formation) are present in the subsurface in the Camarillo Hills and may crop out in the eastern Santa Rosa Valley. These rocks are overlain unconformably by marine Pliocene-Pleistocene beds (Saugus Formation), older and younger Quaternary alluvium, and alluvial fan deposits. Normal faults cause the Sespe to subside towards a thick volcanic pile, built up in the Conejo Hills in the middle Miocene. Volcanic rocks buttressed against and later overtopped these Sespe subsidence structures. Reverse faults in the Oxnard plain and the left-lateral Somis fault are truncated by the unconformity at the base of the Saugus. Miocene and older strata were broadly folded in the Las Posas anti-cline and Santa Rosa syncline prior to deposition of the Saugus Formation and displacement on the Simi fault zone. The Bailey fault, a northwest-trending range-front fault, shows reverse separation, commonly follows Sespe subsidence structures and north-dipping normal faults which cut the Sespe. The Camarillo Hills anticline, Springville dome and post-Saugus Las Posas anticline appear to be pressure ridges adjacent to the Simi fault system on the north. Older alluvium deposits are uplifted and warped. The Camarillo fault cut and warped older alluvium.

Download or read book Cenozoic Geology of the Simi Valley Area Southern California written by Richard L. Squires and published by . This book was released on 1983 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Engineering Geology Along the Simi Santa Rosa Fault System and Adjacent Areas Simi Valley to Camarillo Ventura County California written by Thomas F. Blake and published by . This book was released on 1991 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lower Paleogene Geology of the Simi Valley Area Ventura County California written by Jonathan David Parker and published by . This book was released on 1985 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Stratigraphy and Biostratigraphy of a Portion of the Simi Hills on the South Side of the Simi Valley Ventura County California written by Joseph H. Fantozzi and published by . This book was released on 1955 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of Southern California written by California. Division of Mines and Geology and published by . This book was released on 1954 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book U S Geological Survey Professional Paper written by and published by . This book was released on 1962 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book California Geology written by and published by . This book was released on 1988 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology and Tectonics of the San Fernando Valley and East Ventura Basin California written by and published by . This book was released on 2001 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluating Earthquake Hazards in the Los Angeles Region an Earth science Perspective written by Joseph I. Ziony and published by . This book was released on 1985 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: An integrated set of studies describing methods for evaluating geologically controlled earthquake hazards as a basis for reducing future losses.

Download or read book Geology of the Big Mountain Area Santa Susana and Simi Quadrangles Ventura County California written by Quentin Walter Van Camp and published by . This book was released on 1959 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Generalized Subsurface Geology of the Water bearing Deposits Northern San Joaquin Valley California written by W. R. Hotchkiss and published by . This book was released on 1972 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Surface Geologic Effects and Related Land Movement in the City of Simi Valley Resulting from the Northridge Earthquake of January 17 1994 written by Allan G. Barrows and published by . This book was released on 1994 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Subsurface Geology of the Late Tertiary and Quaternary Water bearing Deposits of the Southern Part of the San Joaquin Valley California written by Mark G. Croft and published by . This book was released on 1972 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of the South Mountain Oil Field Ventura County California written by Philip Wingate Reinhart and published by . This book was released on 1928 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geologic Guide of the Central Santa Clara Valley Sespe and Oak Ridge Trend Oil Fields Ventura County California written by Bruce A. Black and published by . This book was released on 1982 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: