Download or read book Late Quaternary Slip Histories and Geochronology Within the Southern San Andreas Fault System written by Peter Owen Gold and published by . This book was released on 2018 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geologic slip histories measure the frequency, rate and magnitude of past displacement along active faults. Projected into the near future, they inform potential seismic hazard over human time scales. In this dissertation I describe the results of four projects focused on developing slip histories for active faults within the complex southern San Andreas Fault plate boundary system in southern California and northern Baja California, Mexico. Slip is accommodated through this densely populated region by multiple concurrently active faults. For the Banning Fault, a primary subsidiary strand of the southern San Andreas Fault, I report the first, and only, constraint on recent geologic slip. The ~4-5 mm/a mid-Holocene slip rate shows that the Banning Fault is less dominant than previously thought, significantly clarifying how slip is partitioned between three primary structures along the section of the San Andreas Fault that is most likely to host the next major earthquake. In northern Baja California, I report the first quantitatively constrained slip history for the Agua Blanca Fault, one of two primary structures transferring dextral plate motion from the Gulf of California rift to faults that parallel the Pacific coast. I report rates from three sites along the Agua Blanca Fault that indicate time-invariant slip of 2.8 +0.8/-0.6 mm/a since ~65.1 ka, 3.0 +1.4/-0.8 mm/a since ~21.8 ka, 3.4 +0.8/-0.6 mm/a since ~11.7 ka, and 3.0 +3.0/-1.5 mm/a since ~1.6 ka. I also report the timing of 7 Holocene earthquakes that suggest maximum earthquake recurrence of ~1000 years, and I report geologic evidence of ~2.5 m of slip in the past two earthquakes, which suggests that the Agua Blanca Fault is capable of accommodating >M7 surface rupturing earthquakes. This new, comprehensive slip history significantly clarifies both on- and off-shore slip partitioning within this part of the Pacific-North American plate boundary. Finally, slip rate and earthquake timing measurements critically depend on geochronologic dating of offset geologic landforms that record past displacement. To evaluate the variability between dates measured using different methods, I report a critical comparison of independent geochronometers that informs best dating practices and demonstrates that discordance often quantifies geomorphic process.
Download or read book The San Andreas Fault System in the Vicinity of the Central Transverse Ranges Province Southern California written by Jonathan C. Matti and published by . This book was released on 1992 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The San Andreas Fault System California written by and published by . This book was released on 1990 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of the history, geology, geomorphology, geophysics, and seismology of the most well known plate tectonic boundary in the world.
Download or read book High Geologic Slip Rates Since Early Pleistocene Initiation of the San Jacinto and San Felipe Fault Zones in the San Andreas Fault System Southern California USA written by and published by Geological Society of America. This book was released on 2010-01-01 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The San Jacinto right-lateral strike-slip fault zone is crucial for understanding plate-boundary dynamics, regional slip partitioning, and seismic hazards within the San Andreas fault system of southern California, yet its age of initiation and long-term average slip rate are controversial. This synthesis of prior and new detailed studies in the western Salton Trough documents initiation of structural segments of the San Jacinto fault zone at or slightly before the 1.07 Ma base of the Jaramillo subchron. In Special Paper 475, five new estimates of displacement are developed using offset successions of crystalline rocks; distinctive marker beds in the late Cenozoic basin fill; analysis of strike-slip-related fault-bend folds; quantification of strain in folds at the tips of dextral faults; and gravity, magnetic, and geomorphic data sets."--Publisher's website.
Download or read book Earthquake Geology San Andreas Fault System Palm Springs to Palmdale written by and published by . This book was released on 1992 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Displacement Along the San Andreas Fault California written by John C. Crowell and published by Geological Society of America. This book was released on 1962 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Resolving the Quaternary Slip History of the Santa Susana Fault Western Transverse Ranges Southern California Through U Pb Detrital Zircon Geochronology of Cenozoic Strata written by Jonathan J. Ingram and published by . This book was released on 2018 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Santa Susana fault (SSF) is the western extension of the Sierra Madre fault zone in southern California. It originated as a Miocene normal fault and reactivated as a reverse fault in the Quaternary, uplifting the Santa Susan Mountains. In the current seismic hazard model, the SSF has a poorly constrained slip rate. This study utilized U-Pb detrital zircon geochronology, modal compositions, clast counts, and balanced cross-sections to resolve the Quaternary slip history of the SST. Clast analyses in the footwall Saugus Formation show an upsection transition from dominantly crystalline basement rocks to sedimentary rocks. Modal composition data indicates each sampled sandstone formation is arkosic (>55% feldspar), with few lithic grains (5-15%), derived from a local basement uplift.
Download or read book Where s the San Andreas Fault written by Philip Ward Stoffer and published by . This book was released on 2006 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of the Late Quaternary Slip Rate of the Northern San Andreas Fault at the Vedanta Wind Gap Marin County California written by Tina M. Niemi and published by . This book was released on 1991 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The San Andreas Fault System written by Robert E. Powell and published by Geological Society of America. This book was released on 1993 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors of the ten chapters in this volume critically examine the geologic evidence that constrains timing and magnitude of movement on various faults of the San Andreas system, and they develop and discuss paleogeologic reconstructions based on these constraints. The volume offers new insight into the evolution of the San Andreas fault system,
Download or read book Analysis of Quaternary Faults and Associated Deformation of Sedimentary Basin Fill written by Jonathan Thomas Bennett and published by . This book was released on 2012 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: The San Andreas fault system is distributed across hundreds of kilometers in southern California. This transform system includes offshore faults along the shelf, slope and across the Gulf of Santa Catalina basin (GSCB) - comprising part of the Inner California Continental Borderland. Previously, offshore faults have been interpreted as being discontinuous and striking parallel to the coast between Long Beach and San Diego. Our work, based on several thousand kilometers of deep-penetration industry multi-channel seismic reflection data (MCS) as well as high resolution U.S. Geological Survey MCS, indicates that many of the offshore faults are more geometrically continuous than previously reported including Newport-Inglewood (NI)-San Mateo-Carlsbad(SMC), and Coronado Bank Detachment(CBD)-Descanso faults. We interpret a ~18 km wide step over from the NI-SMC positive flower structure in the north to the CBD-Descanso negative flower structure in the south adjacent to San Diego. These faults and stratigraphic interpretations were gridded and depth converted for modeling slip amounts and orientation on the San Mateo-Carlsbad fault. Stratigraphic interpretations of MCS profiles included the ca. 1.8 Ma Top Lower Pico (TLP), which was correlated from wells located offshore Long Beach (Sorlien et al 2010). Based on this age constraint, four younger (Late) Quaternary unconformities (Q1,Q2,Q3,Q4) are interpreted through much of GSCB. We correlate the Q horizons to core hole data in Los Angeles harbor and constrain their ages: Q1 is 160-300; ka Q2 is 300 ka; Q3 300-450 ka; and Q4 ~600 ka. These ages are an order of magnitude older than interpretations published by Covault and Romans (2009). Assuming the ages that were used to calculate slip are correct, we estimate an average slip rate of ~0.44mm/yr on the San Mateo-Carlsbad with an average azimuth direction of 169° which is significantly less than when calculated with younger interpreted ages and indicates that the SMC fault is a right-lateral strike-slip fault. Our modeling also indicates that the SMC fault is kinematically continuous with a right stepover at its southern extent. This change in SMC strike marks a boundary between transpression in the north and transtension in the south and is significant to understanding future tectonic episodes.
Download or read book Late Quaternary Climate and Tectonics in the San Andreas Fault Valley Near Point Reyes California written by Karen Grove and published by . This book was released on 1998 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Treatise on Geomorphology written by and published by Academic Press. This book was released on 2013-02-27 with total page 6392 pages. Available in PDF, EPUB and Kindle. Book excerpt: The changing focus and approach of geomorphic research suggests that the time is opportune for a summary of the state of discipline. The number of peer-reviewed papers published in geomorphic journals has grown steadily for more than two decades and, more importantly, the diversity of authors with respect to geographic location and disciplinary background (geography, geology, ecology, civil engineering, computer science, geographic information science, and others) has expanded dramatically. As more good minds are drawn to geomorphology, and the breadth of the peer-reviewed literature grows, an effective summary of contemporary geomorphic knowledge becomes increasingly difficult. The fourteen volumes of this Treatise on Geomorphology will provide an important reference for users from undergraduate students looking for term paper topics, to graduate students starting a literature review for their thesis work, and professionals seeking a concise summary of a particular topic. Information on the historical development of diverse topics within geomorphology provides context for ongoing research; discussion of research strategies, equipment, and field methods, laboratory experiments, and numerical simulations reflect the multiple approaches to understanding Earth’s surfaces; and summaries of outstanding research questions highlight future challenges and suggest productive new avenues for research. Our future ability to adapt to geomorphic changes in the critical zone very much hinges upon how well landform scientists comprehend the dynamics of Earth’s diverse surfaces. This Treatise on Geomorphology provides a useful synthesis of the state of the discipline, as well as highlighting productive research directions, that Educators and students/researchers will find useful. Geomorphology has advanced greatly in the last 10 years to become a very interdisciplinary field. Undergraduate students looking for term paper topics, to graduate students starting a literature review for their thesis work, and professionals seeking a concise summary of a particular topic will find the answers they need in this broad reference work which has been designed and written to accommodate their diverse backgrounds and levels of understanding Editor-in-Chief, Prof. J. F. Shroder of the University of Nebraska at Omaha, is past president of the QG&G section of the Geological Society of America and present Trustee of the GSA Foundation, while being well respected in the geomorphology research community and having won numerous awards in the field. A host of noted international geomorphologists have contributed state-of-the-art chapters to the work. Readers can be guaranteed that every chapter in this extensive work has been critically reviewed for consistency and accuracy by the World expert Volume Editors and by the Editor-in-Chief himself No other reference work exists in the area of Geomorphology that offers the breadth and depth of information contained in this 14-volume masterpiece. From the foundations and history of geomorphology through to geomorphological innovations and computer modelling, and the past and future states of landform science, no "stone" has been left unturned!
Download or read book Tectonic Geomorphology and Recency of Faulting of the Northernmost San Jacinto Fault Zone and Implications for Slip Transfer to the San Andreas Fault Zone written by Drake Kerr (Graduate student) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Paleoseismic and geologic data on the southern San Andreas fault zone (SAFZ) show that there is a significant decrease in slip rate on the fault south of Cajon Pass. Transfer of slip from the SAFZ to the San Jacinto fault zone (SJFZ) near the northern terminus of the SJFZ is the likely cause of the decrease in slip rate, and paleoseismic data suggest some ruptures on the SAFZ have diverted down the SJFZ, rather than continuing on the SAFZ. A better understanding of the fault structure and activity on the northern SJFZ is needed to test these hypotheses. To understand where slip is transferred between the SAFZ and the SJFZ in the Cajon Pass, mapping of fault-related geomorphic features was conducted along the three major strands of the SJFZ between the northwestern end of the San Bernardino basin and the fault zone’s northwest termination in the San Gabriel Mountains. Field investigations were complemented by the use of LiDAR imagery to investigate the fault structure and geomorphology. In the San Gabriel Mountains, geomorphic evidence shows a smooth decrease in slip to the northwest. Consultant trench logs along the northern SJFZ reveal the middle strand had a surface rupture between years 1380 AD and 1810 AD. Whereas shallow trenching during this study on the Glen Helen strand of the SJFZ, which is closest to the SAFZ, revealed the last surface rupture occurred between 2960±105 and 1325±20 years ago. This result was unexpected as it was assumed that the Glen Helen strand closest to the SAFZ played a more prominent role in the interaction between the SAFZ and SJFZ. The paleoseismic data from the trenches, combined with the steady decrease in geomorphic evidence for Late Quaternary slip to the northwest on the SJFZ, and the decrease of SAFZ slip rate to the southeast suggest that slip is being transferred between the SAFZ and SJFZ over a zone of at least 20 km from the northwest extent of the SJFZ, southeast into the San Bernardino basin, and the middle strand of the SJFZ has the most active role in slip transfer.
Download or read book Southern San Andreas Crustal Deformation written by J. Beavan and published by . This book was released on 1991 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Holocene Geologic Slip Rate for the Mission Creek Strand of the Southern San Andreas Fault Indio Hills written by Juan José Muñoz Zapata and published by . This book was released on 2017 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Slip on the southern San Andreas fault in the northwestern Coachella Valley in Southern California is partitioned among three fault strands: the Mission Creek, Garnet Hill, and Banning strands. The NW-striking Mission Creek strand extends from the Indio Hills into the San Bernardino Mountains, whereas the Banning and Garnet Hill strands strike W-NW and transfer slip into the San Gorgonio Pass region. Together, these three faults accommodate ~ 20 mm/yr of right-lateral motion based on geodetic slip rate estimates. Determining which strand accommodates the majority of fault slip and how slip rates on these strands have varied over Quaternary timescales is critical to seismic hazard assessment for this region. Here I present a new Holocene geologic slip rate estimate from an offset alluvial fan complex along the Mission Creek fault at the Three Palms site in the Indio Hills. The correlation of offset fans precisely located from a satellite image, confirmed by field mapping and B4 LiDAR indicates that the Three Palms fan complex is offset 50.0 ± 5.0 meters. U-series dating on pedogenic carbonate rinds collected at 25-100 cm depth within the deposit constrain the minimum depositional age to 3.49 ± 0.92 ka (95% CI), yielding a maximum slip rate of 19.2 ± 2.0 mm/yr. Cosmogenic 10Be surface exposure dating on boulders yields a scattered dataset with high apparent inheritance and a median age of 13.6 +6.9/-6.7 ka (1[sigma] error). However, the minimum boulder age of 5.4 ± 1.0 ka (2[sigma] error) was interpreted as the maximum depositional age for the fan. This age, along with the preferred offset of 50.0 meters, yields a minimum slip rate of 7.8 ± 0.8 mm/yr. We therefore estimate a Holocene geologic slip rate of 7-21 mm/yr, with a preferred rate of 9-14 mm/yr. This rate overlaps within error with a previously published late Pleistocene slip rate on the Mission Creek strand of 12-22 mm/yr calculated at Biskra Palms Oasis a few kilometers to the southeast.
Download or read book Paleoseismic Investigations of the Northern San Andreas Fault at the Vedanta Site Marin County California written by Nelson Timothy Hall and published by . This book was released on 1994 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
