Download or read book Engineering Geology of Rocks in Core Hole Eel Point San Clemente Island California written by D. L. Lamar and published by . This book was released on 1968 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A 1,200-foot core hole drilled near Eel Point on the west coast of San Clemente Island, California, penetrated a homogeneous series of andesite flows varying in thickness from 11 to 169 feet. Petrographic examination revealed that textural variations within flows as a result of different cooling rates are more distinct than differences in composition between individual flows. Potassium-argon dates indicate that these flows were extruded in less than one-half million years during Miocene time. The flows are inferred to dip seaward at between 10 and 30 degrees. The rock will provide sound material for excavation. Problems of water leakage can be expected at faults and zones of decomposed rock. (Author).
Download or read book Geologic Evaluation of San Clemente Island as a Location for a Rock site I Installation written by C. F. Austin and published by . This book was released on 1968 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: San Clemente Island has been studied to determine the geologic suitability of employing the island as a candidate site for the construction of a Rock-Site I installation, the land-linked experimental laboratory. The studies of the island consisted of a review of the geologic literature, aerial reconnaissance, geologic mapping, core drilling, borehole pumping, and offshore geophysical studies and sampling operations. Based on the results of these investigations the recommendation is made that the laboratory area beneath the sea floor be located off Mail Point with access tunnels to the laboratory originating at either Mail Point or Lost Point. As a candidate site, San Clemente Island is considered to be feasible but difficult. (Author).
Download or read book Geological Survey Circular written by and published by . This book was released on 1975 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Geological Survey Circular written by and published by . This book was released on 1933 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bathymetry and Structure of San Clemente Island California and Tectonic Implications for the Southern California Continental Borderland written by James Barr Ridlon and published by . This book was released on 1970 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five lithologic units, ranging in age from Middle Miocene to Recent, are defined on the basis of continuous seismic reflection profile records. Two of the units are Miocene sedimentary and volcanic rocks that have been truncated to form a major unconformity (post-orogenic surface) related to the most recent major tectonism of the region. The remaining units are post-orogenic unconsolidated sediments. The fault pattern offshore is generally related to that exhibited on the island. The pattern conforms to a wrench-fault system hypothesized by Moody and Hill (1956) modified by a general north-south tensional fracturing. The San Clemente Fault is assumed to be the primary wrench fault of the system. Anomalies in the thicknesses and the structure of the unconsolidated sediment and rock units tend to confirm the structural model. A canyon (Eel Ridge Canyon) off the west side of San Clemente Island appears to have been caused by pivotal faulting and erosion, and represents a boundary between different structural trends north and south. A prominent terrace around the island is postulated to have been wave-cut during and since the Late Pleistocene. The island has been tilted slightly to the west by Recent tectonism. A steep magnetic gradient off the east side of the island is considered the consequence of faulted volcanic flows comprising the island itself and a deep basic rock mass responsible for a large positive magnetic anomaly off the northwest side. Other magnetic anomalies reflect major structural trends. Earthquake epicenter data suggest a recent and possibly cyclical occurrence of fault activity in the northern Continental Borderland region and the study area. Fault offsets at the sea floor and earthquake epicenters along the San Clemente fault zone imply recent adjustments along the fault. Wrench-fault movement resulting from a simple shear or shear couple is considered to have caused the zone of brecciation along the San Clemente Fault and produced the fault-trace curvature so evident in a series of en echelon, northwest-striking major faults of the Borderland. Tensile release during periods of wrench-fault development has been a fundamental factor in the structural development of the Borderland basins. The entire structure of the Continental Borderland is believed to have developed by right-lateral movement along the series of wrench faults. These faults are believed to have resulted from a translation of force by sea-floor spreading originating on the East Pacific Rise in the Gulf of California region. This force is considered to have moved a northern Continental Borderland crustal plate westward by east to west release along major wrench faults bordering the north and south ends of this plate. Sediments, transported along channels developed along faults in the island block, were deposited in basins developed by faulting and folding of the pre-orogenic rocks. Transportation appears to have been by means of turbidity-current flows, sand flows, and slides. A maximum average depositional rate of 35 to 47 centimeters per 1,000 years is estimated for post-orogenic sediments. The following findings are suggested for inclusion in the Neogene history of the island: (1) the top 365 meters of Miocene andesitic lavas were deposited above sea level and tend to become slightly more basic in composition with depth; (2) subsidence of the island region and temporary sea-level stand(s) occurred after the deposition of the volcanic rocks, with possible periods of foundering to about the Late Pliocene; (3) emergence, lengthy subaerial exposure, and a period of partial submergence took place from about Late Pliocene through Early Pleistocene; (4) a north-south compressive force developed or recurred across the Borderland during Late Pliocene, developing the present northwest-southeast and east-west wrench-fault systems that have been intermittently active to the present time; (5) much of the present Borderland topography formed during the Pleistocene to Recent.
Download or read book Open file Report written by and published by . This book was released on 1986 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selected Geologic Literature on the California Continental Borderland and Adjacent Areas to January 1 1975 written by Albert Eugene Roberts and published by . This book was released on 1975 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aspects of the Geologic History of the California Continental Borderland written by D. G. Howell and published by . This book was released on 1976 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Floods in Indiana written by Albert Eugene Roberts and published by . This book was released on 1949 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geological Society of America Bulletin written by Geological Society of America and published by . This book was released on 1971 with total page 2078 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. 1-44 include Proceedings of the annual meeting, 1889-1933, later published separately.
Download or read book Bulletin written by and published by . This book was released on 1987 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Neogene Symposium written by and published by . This book was released on 1976 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications of the Geological Survey written by and published by . This book was released on 1971 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications of the U S Geological Survey 1971 1981 written by and published by . This book was released on 1986 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book San Clemente Island Rocksite Project Offshore Geology Detailed survey off Eel and Lost Points area written by James Barr Ridlon and published by . This book was released on 1968 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Managing California s Water written by Ellen Hanak and published by Public Policy Instit. of CA. This book was released on 2011 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
