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At least 19 recordsLinked to original sources
USGS1989

Tectonically controlled fan delta and submarine fan sedimentation of late Miocene age, southern Temblor Range, California

The Santa Margarita Formation in the southern Temblor Range, composed of conglomerate and subordinate sandstone, evolved as a large complex of fan deltas and submarine fans in late Miocene time. An 80 to 90-m.y.-old granitic basement of the Salinian block and an accompanying 23.5-m.y.-old volcanic field now located in the northern Gabilan Range and the Pinnacles area, respectively, were the primary source terranes. In general, the fan deltas crop out along the west side of the southern Temblor Range, whereas the proximal parts of the submarine fans crop out along the east side of the range. The fan deltas consist of subaerial topset beds and low-angle basinward-dipping subaqueous foreset beds. Strata interpreted to be topset beds are composed largely of conglomerate with thick to very thick horizontal beds and matrix-supported clasts. Most of the thick to very thick conglomerate beds are internally massive and disorganized. Strata interpreted as foreset beds are composed of thick-bedded, large-scale, low-angle, cross-stratified conglomerate and sandstone units which commonly are internally massive. Abundant molluskan macrofossils such as Ostrea and Pecten are present in the subaqueous foreset beds; many have been displaced downslope from their original site of deposition. Conglomerate- and sandstone-filled submarine canyons, through which coarse-grained detritus was transported to the adjacent submarine fans, locally have cut into the foreset beds of the fan deltas. These submarine canyon deposits are generally better stratified than adjacent foreset-bed deposits, and they consist of thick horizontal beds, internally massive or normally graded, arranged in fining- and thinning-upward sequences. Isolated and composite conglomerate- and sandstone-filled channels, which crop out on the east flank of the southern Temblor Range, are interpreted as proximal submarine-fan channel deposits. These channel-form conglomerate and sandstone deposits are characterized by thick, horizontal beds which are internally massive or normally graded containing division T a , and locally T b , of the Bouma sequence. Sparse calcareous foraminifers collected from diatomaceous interbeds suggest that these fan channels were deposited in upper bathyal water depths. Subaerial and regenerated subaqueous debris flows probably formed the bulk of the Santa Margarita fan delta and submarine fan system. Santa Margarita debris flows ranged from the mudflow variety to the cataclysmic debris-avalanche variety. The cogenetic Republic and Williams sandstones of local usage, located on the east side of the southern Temblor Range, are slightly older and finer grained than the Santa Margarita Formation. These units, containing well-graded sandstones, fining- and thinning-upward and coarsening- and thickening-upward sandstone sequences, thick-bedded tabular and channel-shaped sandstones, a mixture of shallow- and deep-water foraminifers, and a fan-shaped geometry in the subsurface, are interpreted as submarine fan deposits. Sedimentation associated with the Santa Margarita Formation was intimately related to the growing southern Temblor Range anticlinorium and the right-laterally shifting Salinian block along the San Andreas fault. Examples of control exerted on Santa Margarita sedimentation by the southern Temblor Range anticlinorium include the preferential accumulation of sediments along the flanks of the anticlinorium, thickening of strata on the downthrown side of the Recruit Pass fault and on flanks of selected anticlines, intraformational unconformities, and possible partial blockage of the eastward-prograding fan deltas by the Recruit Pass fault. East of the growing southern Temblor Range anticlinorium, the distal ends of the Santa Margarita submarine fans were deflected northwestward by the growing Buena Vista Hills anticline. Several examples of well-defined diachronous sedimentation, where conglomerates and sandstones of the Santa Margarita Formation occupy progressively higher stratigraphic levels in a northwest direction subparallel to the trace of the San Andreas fault, strongly imply that the Salinian basement terrane was shifting in a right-lateral sense during Santa Margarita sedimentation. Regional factors of importance in focusing conglomerate sedimentation on the southern Temblor Range locale for a 2- to 3-m.y. period in the late Mohnian were right-lateral oblique slip on the San Andreas fault, formation of the "big bend" in the San Andreas fault by left-lateral slip along the Garlock and White Wolf faults, and the partial overlap of the Salinian and Franciscan assemblage basement rocks.

California↗
USGS2024

Digging into detectability: Uncovering how temperature influences detection probability of the fossorial Temblor legless lizard

Knowledge of species distributions is critical for conservation, but surveying for rare, understudied species presents many challenges. A two-phase occupancy study can increase knowledge gained from early occupancy studies of a species by quickly using data from the first survey period to revise the study design for a second period. The Temblor legless lizard Anniella alexanderae is a recently described fossorial species found in the southwestern San Joaquin Valley, California, and its status is currently under review by state and federal wildlife agencies. As a fossorial species that is rarely surface active, Temblor legless lizards might be unavailable for detection at certain times of year or under inhospitable conditions (e.g., hot, dry weather), indicating the importance of accounting for false-negative surveys when determining its distribution. We used a multiscale occupancy model to disentangle detection probability, availability for detection, and occupancy for Temblor legless lizards. Focusing our effort from mid-February to mid-April when temperatures are mild and soil moisture is expected to be higher near the surface, we surveyed a total of 89 sites in 2022 ( n = 60) and 2023 ( n = 68) and detected Temblor legless lizards at 12 sites, including 5 new localities. Detection probability was positively related to temperature during our late winter-early spring survey period, and availability for detection was consistently high with minimal fluctuation within each year. Nevertheless, repeated surveys with nondetection can increase confidence that this fossorial lizard does not occur at a site. Temblor legless lizards were more likely to occur at sites near ephemeral streams and in areas without high clay soil content, but more investigation could help to discern drivers of occurrence. Our study provides valuable information for optimizing surveys for Temblor legless lizards and suggests promising directions for future research on this species’ ecology.

California↗
USGS1979

Origin of dolomite in Miocene Monterey Shale and related formations in the Temblor Range, California

Dolomites in thick sections of Miocene Monterey Shale and related formations in the Temblor Range of California acquired their isotopic compositions as they formed at shallow depth in the original sediment rich in organic matter, and retained the composition against the vicissitudes of burial diagenesis. The oxygen isotopes of dolomites of successive beds record changes in temperature of bottom water while the carbon isotopes of the same samples indicate changes in the kind of microbial activity (sulfate reduction vs carbohydrate fermentation) that prevailed at shallow depths in the sediment. In an auxiliary study, two samples of dolomite from sediments of Cariaco Basin off Venezuela (DSDP site 147) were found to have ??5C13 of -14.1 and -9.8 per ml PDB, although they occur in a heavy-carbon zone containing bicarbonate as heavy as +8.4 per ml. These dolomites probably originated at shallow depth in the light-carbon zone of microbial sulfate reducers and were buried under later sediments down into the heavy-carbon zone of microbial fermenters of carbohydrates without losing their original light-carbon composition. ?? 1979.

Geochimica et Cosmochimica Acta↗
USGS1975

Diagenesis of Miocene siliceous shales, Temblor Range, California

Siliceous Monterey Shale and related shales of the Temblor Range, Calif., are subdivided into three depth-controlled zones characterized by different forms of silica. These are, in descending stratigraphic order: (1) Biogenic opal zone, with remains of diatoms and other siliceous organisms, (2) diagenetic cristobalite zone, and (3) diagenetic quartz zone. Using the top of the youngest marine unit, the overlying Etchegoin Formation, as datum, the transition from biogenic opal to disordered cristobalite occurs within the Monterey Shale of Chico Martinez Creek at -730 m, and the ordered cristobalite-to-microquartz transition at about -2,030 m. Temperatures that prevailed at these transition depths while the sedimentary pile lay at the bottom of the sea are estimated at about 50° and 110°C, respectively. Diagenetic cristobalite manifests, downward through a 1,300-m interval of section, a progressive decrease in its d (101) spacing because of a gradual ordering of its internal structure through adjustments in the solid state. Diagenetic microquartz forms only from well-ordered cristobalite that provides the most appropriate concentration of dissolved silica for precipitation of microquartz. Scanning electron micrographs of the silica mineral in pores of rocks made up of disordered cristobalite show aggregates of well-formed bladed crystals, like those described from deep-sea cherts. The pore silica minerals in rocks made up of ordered cristobalite occur as dendritic growths of poorly formed stubby crystals, and the change in crystal habit could be an external expression of the internal ordering process.

California↗
USGS1977

Occurrence of bloedite and related minerals in marine shale of Diablo and Temblor Ranges, California

Bloedite, epsomite, and related minerals occur in small amounts throughout the arid eastern foothills of the Diablo and Temblor Ranges, as efflorescences on siliceous shale and as deposits around small springs and a brine pond. These minerals ultimately are products of weathering of underlying organic shale, and they are reminders that the chemistry of weathering of reduced organic shale is largely a reversal of the chemistry of its early diagenesis.

California↗
USGS1987

Structure contour map of the top of the Oligocene to Middle Miocene Temblor Formation in the Kettleman Hills and Lost Hills areas, Fresno, Kings, and Kern counties, California

This structure contour map shows the general structural configuration of the Cenozoic section in the area surrounding Kettleman Hills and Lost Hills. It was compiled from electric well-log data available through April 1982 (Ammann Map Services, 1978; Petroleum Information Corporation, 1982; California Division of Oil and Gas, 1982) and from surface geology (Dibblee, 1971; 1973).

California↗
USGS1999

Regional geologic map of San Andreas and related faults in Carrizo Plain, Temblor, Caliente and La Panza Ranges and vicinity, California: A digital database

This Open-File Report is a digital geologic map database. The report serves to introduce and describe the digital data. There is no paper map included in the Open-File Report. The report includes PostScript and PDF plot files that can be used to plot images of the geologic map sheet and explanation sheet. This digital map database is prepared from a previously published map by Dibblee (1973). The geologic map database delineates map units that are identified by general age, lithology, and clast size following the stratigraphic nomenclature of the U.S. Geological Survey. For descriptions of the units, their stratigraphic relations, and sources of geologic mapping, consult the explanation sheet (of99-14_4b.ps or of99-14_4d.pdf), or the original published paper map (Dibblee, 1973). The scale of the source map limits the spatial resolution (scale) of the database to 1:125,000 or smaller. For those interested in the geology of Carrizo Plain and vicinity who do not use an ARC/INFO compatible Geographic Information System (GIS), but would like to obtain a paper map and explanation, PDF and PostScript plot files containing map images of the data in the digital database, as well as PostScript and PDF plot files of the explanation sheet and explanatory text, have been included in the database package (please see the section 'Digital Plot Files', page 5). The PostScript plot files require a gzip utility to access them. For those without computer capability, we can provide users with the PostScript or PDF files on tape that can be taken to a vendor for plotting. Paper plots can also be ordered directly from the USGS (please see the section 'Obtaining Plots from USGS Open-File Services', page 5). The content and character of the database, methods of obtaining it, and processes of extracting the map database from the tar (tape archive) file are described herein. The map database itself, consisting of six ARC/INFO coverages, can be obtained over the Internet or by magnetic tape copy as described below. The database was compiled using ARC/INFO, a commercial Geographic Information System (Environmental Systems Research Institute, Redlands, California), with version 3.0 of the menu interface ALACARTE (Fitzgibbon and Wentworth, 1991, Fitzgibbon, 1991, Wentworth and Fitzgibbon, 1991). The ARC/INFO coverages are stored in uncompressed ARC export format (ARC/INFO version 7.x). All data files have been compressed, and may be uncompressed with gzip, which is available free of charge over the Internet via links from the USGS Public Domain Software page (http://edcwww.cr.usgs.gov/doc/edchome/ndcdb/public.html). ARC/INFO export files (files with the .e00 extension) can be converted into ARC/INFO coverages in ARC/INFO (see below) and can be read by some other Geographic Information Systems, such as MapInfo via ArcLink and ESRI's ArcView.

California↗
USGS1989

Oligocene and Miocene paleogeography of central California and displacement along the San Andreas fault

Recently completed sedimentologic and petrologic studies of Oligocene and Miocene strata in the Temblor Range (San Joaquin basin) and Santa Cruz Mountains (La Honda basin) permit detailed reconstructions of paleogeography, as well as new estimates of displacement along the San Andreas fault. During the Oligocene and Miocene, the San Joaquin and La Honda basins were contiguous. The southwestern margin of the San Joaquin-La Honda basin was tectonically unstable and paleogeographically complex, with several small deep-sea fans fed by sediment derived from nearby subaerial uplifts of Franciscan and granitic basement. One of these deep-sea fans, represented by the Temblor Formation of the southern Temblor Range and the Vaqueros Sandstone of the central Santa Cruz Mountains, apparently has been displaced about 315 to 320 km by post-early Miocene (post-Zemorrian, about 23 Ma) right-lateral slip along the San Andreas fault. This new estimate of displacement places an additional constraint on interpretations of San Andreas slip history, but ambiguities remain. The time of initiation of San Andreas displacement is poorly known, and available data do not permit discrimination between a history of relatively continuous slip versus a history of episodic slip.

California↗
USGS1973

Isotopic composition of oil-field brines from Kettleman North Dome, California, and their geologic implications

Deuterium and O 18 analyses were made on 25 formation-water samples from Miocene (Temblor Formation) and Eocene (McAdams Formation) reservoir rocks at Kettleman North Dome oil field, California, and on three surface water samples from Reef Ridge located about three miles to the west of the field. The δO 18 values obtained generally increase with depth and most probably are due to temperature controlled exchange reactions with carbonate cement and dissolved carbonate species. The δD values obtained seem to be controlled primarily by the membrane behavior of shales modifying the assumed original values. The contribution of isotopic exchange between water and clays cannot be evaluated at present. The isotopic data support the conclusions based on a detailed study of geology, hydrodynamics, and formation water geochemistry ( Kharaka , 1971) which indicate that: 1. The Temblor Formation waters are probably meteoric in origin concentrated chemically and isotopically by shale membranes, and 2. The McAdams Formation waters were most probably obtained by squeezing the original interstitial marine connate waters of deposition from the underlying Mesozoic sediments.

California↗
USGS1967

The geohydrology of Pinnacles National Monument, California

Water supplies for Pinnacles National Monument are obtained from a collection gallery in alluvium and from a flowing well which obtains water from fractured breccia and tuff near a fault. Rocks other than alluvium, in all but the northern fourth of the monument, are dense igneous or metamorphic types that, unless fractured, have little potential for development of ground water. However, in some areas near faults these rocks probably will yield small supplies of water. The alluvium along Chalone Creek contains water of good chemical quality in quantities sufficient to supply the monument's needs. The Temblor Formation, a fanglomerate in the northeastern part of the monument, seems to be capable of absorbing and transmitting water but has not been drilled. A test well to determine the potential of the Temblor is suggested.

California↗
USGS2009

Petroleum systems used to determine the assessment units in the San Joaquin Basin Province, California

For the San Joaquin Basin Province in California (fig. 8.1), six petroleum systems were identified, mapped, and described to provide the basis for the five total petroleum systems (TPS) and ten related assessment units (AU) used in the 2003 U.S. Geological Survey (USGS) National Oil and Gas Assessment (table 8.1; Gautier and others, 2004; Hosford Scheirer, 2007). The petroleum pools in the province were allocated to each petroleum system on the basis of (1) geochemical composition as described by Lillis and Magoon (this volume, chapter 9) and Lillis and others (this volume, chapter 10), (2) reservoir rock nomenclature (fig 8.2; appendix 8.1 and appendix 8.2) as described by Hosford Scheirer and Magoon (this volume, chapter 5), and (3) the volume of oil and gas discovered for each petroleum system by system, flank, and trap type (tables 8.2, 8.3 and 8.4). For this assessment, each petroleum system was determined, followed by the TPS from one or more petroleum systems. For example, the Miocene TPS includes two petroleum systems, the McLure-Tulare(!) and Antelope-Stevens(!) (notation described in Petroleum System Name section, below). Magoon and Schmoker (2000) describe how the TPS is used in this and the USGS world assessments. This chapter describes the six petroleum systems used to make five total petroleum systems in this San Joaquin Basin Province assessment. The figures and tables for each petroleum system and TPS are as follows: (1) the San Joaquin(?) petroleum system or the Neogene Nonassociated Gas TPS is a natural gas system in the southeast part of the province (figs. 8.3 through 8.8; table 8.5; this volume, chapter 22); (2) the Miocene TPS (this volume, chapters 13, 14, 15, 16, and 17) includes the McLure-Tulare(!) petroleum system north of the Bakersfield Arch (figs. 8.9 through 8.13; table 8.6), and the Antelope-Stevens(!) petroleum system south of the arch (figs. 8.14 through 8.18; table 8.7), and is summarized in figure 8.19; (3) the Eocene TPS (this volume, chapters 18 and 19) combines two petroleum systems, the Tumey-Temblor(.) covering much of the province (figs. 8.20 through 8.24; table 8.8) and the underlying Kreyenhagen-Temblor(!) (figs. 8.25 through 8.29: table 8.9), and is summarized in figure 8.30; (4) the Eocene-Miocene Composite TPS, formed by combining the Miocene and Eocene TPS (this volume, chapter 20); and (5) the Moreno-Nortonville(.) is both a petroleum system and a TPS consisting mainly of natural gas in the northern part of the province (figs. 8.31 through 8.36: table 8.10; this volume, chapter 21). Oil samples with geochemistry from surface seeps and wells used to map these petroleum systems are listed in table 8.11. Finally, the volume of oil and gas expelled by each pod of active source rock was calculated and compared with the discovered hydrocarbons in each petroleum system (figs. 8.37 through 8.39; tables 8.12 and 8.13).

California↗
USGS2013

Chemometric differentiation of crude oil families in the San Joaquin Basin, California

Chemometric analyses of geochemical data for 165 crude oil samples from the San Joaquin Basin identify genetically distinct oil families and their inferred source rocks and provide insight into migration pathways, reservoir compartments, and filling histories. In the first part of the study, 17 source-related biomarker and stable carbon-isotope ratios were evaluated using a chemometric decision tree (CDT) to identify families. In the second part, ascendant hierarchical clustering was applied to terpane mass chromatograms for the samples to compare with the CDT results. The results from the two methods are remarkably similar despite differing data input and assumptions. Recognized source rocks for the oil families include the (1) Eocene Kreyenhagen Formation, (2) Eocene Tumey Formation, (3–4) upper and lower parts of the Miocene Monterey Formation (Buttonwillow depocenter), and (5–6) upper and lower parts of the Miocene Monterey Formation (Tejon depocenter). Ascendant hierarchical clustering identifies 22 oil families in the basin as corroborated by independent data, such as carbon-isotope ratios, sample location, reservoir unit, and thermal maturity maps from a three-dimensional basin and petroleum system model. Five families originated from the Eocene Kreyenhagen Formation source rock, and three families came from the overlying Eocene Tumey Formation. Fourteen families migrated from the upper and lower parts of the Miocene Monterey Formation source rocks within the Buttonwillow and Tejon depocenters north and south of the Bakersfield arch. The Eocene and Miocene families show little cross-stratigraphic migration because of seals within and between the source rocks. The data do not exclude the possibility that some families described as originating from the Monterey Formation actually came from source rock in the Temblor Formation.

AAPG Bulletin↗