This raster layer contains a 30-meter seamless digital elevation model for Monterey County, California in 1999. This layer is part of a collection of data and maps containing geologic information prepared for the Monterey County General Plan Update. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data.

This poygon shapefile contains a geologic model of Monterey County, California. For geologic and seismic hazard evaluation, the most important factor is the geologic model. In this study, the geologic model is a digital compilation of stratigraphic formations and faults in Monterey County. T.W. Dibblee, Jr. mapped most of the geology in Monterey County for the U.S. Geological Survey in the 1960s and 1970s. Other major contributors of mapping include J.C. Tinsley, III, W.R. Dupré, V.M. Seiders, D.C. Ross, J.C. Clark, and C.A. Hall. To provide a logical framework for the many geologic units in Monterey County, T.W. Dibblee, Jr. prepared a countywide correlation of map units, with emphasis on the Tertiary and Cretaceous age sedimentary rocks. Cretaceous plutonic and metamorphic rocks follow the nomenclature of Ross (1972, 1976). Quaternary deposits are classified based on the work of Tinsley and Dupré. This data set presents a unified, seamless geologic coverage for the seventy-nine 1:24,000 scale quadrangles that cover Monterey County. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
The purpose of this map is to provide a seamless, regionally consistent geologic database for regional planning studies in Monterey County.

This digital raster graphic (DRG) is a composite raster image of two scanned 1974 USGS topographic maps including the collar information, georeferenced to the Calfornia State Plane grid. The DRG shows the area of Monterey County, California. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
A DRG is useful as a source or background layer in a GIS, as a means to perform quality assurance on other digital products, and as a source for the collection and revision of DLG data. DRG's can also be merged with other digital data, e.g. DEM's or DOQ's, to produce a hybrid digital file.

This point shapefile contains records of historical seismicity (1931-2001) recorded by the Northern California Earthquake Data Center. These data show clustered earthquakes along many of the faults in Monterey County. The largest concentration of events is along the San Andreas fault. Other faults with clustered seismicity include the San Gregorio fault zone (Rocky Creek segment), the Reliz fault, and the Nacimeinto fault. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
Epicenters occurring from 1931 to April 2001 with magnitudes of 3 or greater are plotted to provide a perspective on the historical seismicity of Monterey County.

This polygon shapefile contians classifies bedrock and surficial geologic units into soil profile types delineated in table 16-J of the 1997 Uniform Building Code (UBC). This layer is part of a collection describing Geology resources and constraints Monterey County, California.
The data in this set are intended to provide an approximate value of the UBC site class for planning purposes. Because they were derived from regional scale mapping, they are not appropriate for site-specific use.

This line shapefile depicts the relative activity of faults in Monterey County, California. Fault rupture is a seismic hazard that affects structures sited above or nearby an active fault (fault showing movement within the past 11,000 years). The only known historically active fault in Monterey County is the San Andreas fault, which ruptured during the 1966 Parkfield earthquake. The State of California has not zoned other faults within Monterey County as active; however, other studies document Holocene activity on local faults. These include the offshore parts of the Navy and Chupines faults (McCulloch and Greene, 1989); the Tularcitos, Sylvan thrust, Hatton Canyon (Rosenberg and Clark, 1994); the Garrapata/Palo Colorado and Rocky Creek fault segments of the southern San Gregorio fault zone (Clark and Rosenberg, 1999); the San Gregorio fault offshore of Point Sur (Eittreim and others, 1998), and the Zayante/Vergeles fault (Coppersmith, 1979). Other faults such as the Reliz/Rinconada, the Sur fault zone, the Laureles, the Cachagua, and the Miller Creek faults show indications of late Pleistocene activity (750,000 to 11,000 years before present). Detailed work on these faults may show that they are more recently active than currently known. Most of the faults in Monterey County are classified as pre-Quaternary (latest movement more than 1,600,000 years before present). This classification is a result of a lack of information, rather than conclusive evidence as to the timing of fault movement because the majority of geologic mapping did not focus on the activity assessment of faults. Faults classified as pre-Quaternary should not necessarily be regarded as inactive. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
The purposes of this data set are to show the location of faults and to provide a comparison of relative fault rupture hazard for regional planning studies in Monterey County. This map does not take the place of fault-rupture hazard zones designated by the California State Geologist (Hart and Bryant, 1999).

This point shapefile shows areas that liquefied in the 1906 San Francisco or 1989 Loma Prieta earthquake as mapped by Youd and Hoose (1978) and Tinsley and others (1998). This layer is part of a collection describing Geology resources and constraints Monterey County, California.
The purpose of this data set is to document sites of previous liquefaction.

This polygon shapefile contains the distribution of Mineral Resource Zones for Monterey County, California. Construction minerals such as sand, gravel, and stone are classified by the State Geologist into four mineral resource zones based on the likelihood of the presence of mineral deposits and their economic value. The areas that contain minerals that can be economically extracted are classified as MRZ 2 and are essential for supplying aggregate used in residential, commercial, and industrial building projects, as well as in public-works projects such as roads, bridges, and pipelines. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
The intended use of this map is to provide a mineral resource zonation for regional planning studies.

This point shapefile contains locations of active, historic, and inactive mines as within Monterey County, California. Data from the mines database at the California Department of Conservation, Division of Mines and Geology were extracted for use in the Monterey County 21st Century General Plan Update Program. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
These data are kept by the Division of Mines and Geology to help track mining activities in the state. They are used in Monterey County for identifying sites of current and historical mining to aid in natural resource evaluation and planning.

This point shapefile contains locations, operational status, and lease information, for oil wells in Monterey County. The information was extracted from a database of oil wells on the central coast created by the California Department of Conservation, Division of Oil, Gas, and Geothermal Resources. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
This database is useful for finding locations of active, inactive, and abandoned oil wells. It also lists the total well depth.

This polygon shapefile depicting relative landslide susceptibility from earthquakes was created using a simplified version of the methodology developed for San Mateo County, California by the USGS (Wieczorek and others, 1985). This approach is based on analysis of geologic and topographic data. Geologic units shown on sheets 1 and 2 were reclassified into three categories based on their assumed strength characteristics. The vector strength polygons were then converted into a raster grid with a 200-foot cell size. Slope inclination was derived from U.S. Geological Survey 30-m Digital Elevation Model files using ArcView Spatial Analyst software. The resultant values of geologic strength grid and the slope inclination were calculated for each cell and reclassified into the three categories as shown on the susceptibility matrix. Finally, the raster map was converted into a vector map. The resulting data set shows that the areas of highest susceptibility include Carmel Valley, the southern Big Sur coast, the Arroyo Seco district, and the foothills of the southern Salinas Valley. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
The purpose of this map is to provide a comparison of relative landslide hazards for regional planning studies in Monterey County. The focus of the map is large (hundreds to thousands of feet in length or width) deep-seated landslides caused by strong shaking. Shallow landslides such as debris flows and rock falls are strongly dependent on local site conditions and therefore are not included on this map.

This polygon shapefile contains areas of relative liquefaction suceptability in Monterey County, California. A common type of ground failure associated with moderate and large earthquakes is liquefaction in which water-saturated fine-grained cohesionless sediments lose strength and may fail during strong ground shaking. Liquefaction susceptibility depends on the age and type of material, relative density of the material, and the depth to first (shallowest) water. Generally, younger sediments (especially latest Holocene that are less than 1,000 years old) such as loose fill, river channel, and flood plain deposits are more likely to liquefy than older Pleistocene terrace deposits. Relative liquefaction susceptibility was evaluated using a simplified version of the methodology developed for the Monterey Bay area by the USGS (Dupré and Tinsley, 1980; Dupré, 1990; Pike and others, 1994). The resulting data set shows that the areas of highest susceptibility include the Salinas, Carmel, San Antonio, and Peachtree Valleys. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
This map depicts the relative liquefaction susceptibility of sediments in Monterey County. The purpose of this map is to provide a comparison of relative liquefaction susceptibility for regional planning studies in Monterey County.

This polygon shapefile depicts the seismic shaking level (peak ground acceleration) with a 10% probability of being exceeded in 50 years for Monterey County, California. Probabilistic seismic shaking maps are prepared using consensus information on historical earthquakes, faults, and geologic materials. A probabilistic seismic hazard map is a map that shows the hazard from earthquakes that geologists and seismologists agree could occur in California. It is probabilistic in the sense that the analysis takes into consideration the uncertainties in the size and location of earthquakes and the resulting ground motions that can affect a particular site. Historic earthquakes, areas damaged, the slip rates of major faults, and geologic materials were combined to calculate the shaking hazard for the peak ground acceleration. The shaking hazard maps show the level of ground motion that has 1 chance in 475 of being exceeded each year, which is equal to a 10% probability of being exceeded in 50 years. These levels of ground shaking are used primarily for formulating building codes and for designing buildings. Information used in preparing the data set was developed in cooperation with the U. S. Geological Survey. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
This purpose of this data set is to provide a regional perspective of earthquake ground shaking hazards in Monterey County. It is no tintended for site-specific hazard analysis,

This line shapefile contains isohyetal contours showing the average rainfall in inches per year for the Monterey County, California. Contours were mainly developed from countywide rainfall records collected by the Monterey County Water Resources Agency and in the area north of Salinas from research by the Santa Clara Valley Water District. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
The purpose of this data set is to aid in evaluating the countywide rainfall amounts, which in turn influence other processes such as aquifer recharge potential.

This point shapefile depicts paleontological resources within Monterey County, California. Fossils provide important evidence to help determine what happened in Earth history and when it happened. Today the animals and plants that live in the ocean are very different from those that live on land, and the animals and plants that live in one part of the ocean or on one part of the land are very different from those in other parts. Similarly, fossil animals and plants from different environments are different. It becomes a challenge to recognize rocks of the same age when one rock was deposited on land and another was deposited in the deep ocean. Scientists must study the fossils from a variety of environments to build a complete picture of the animals and plants that were living at a particular time in the past (Edwards and Pojeta, 1999).
Because fossils are so useful to science, they need to be considered a resource and properly managed. The purpose of this database is to provide information on the type of fossil and the location so that these fossils may be preserved for science.

This polygon shapefile contains areas for potential recharge of high to moderate infiltration capacity and low to moderate water holding capacity soils that overlie proven alluvial aquifers. These areas include Fort Ord/Seaside, parts of northern Monterey County, Carmel Valley, and the alluvial deposits along the Salinas River. Other areas include the alluvial fan deposits near Arroyo Seco. The alluvial fill in the San Antonio Valley area was also identified as highly favorable for recharge. Overlain on recharge areas are isohyetals (rainfall contours) of average annual precipitation. Blaney (1933) suggested threshold rainfall amounts that must occur to result in meaningful amounts of recharge for semi-arid climates similar to Monterey County. Blaney suggested a value of 17 inches per year of rainfall on native soils and 11 inches per year on irrigated fields. However, Blaney's analysis does not account for the anomalous distributions of annual rainfall (for example, a year where the rainfall total was 9 inches but it all fell in January), modeling efforts have shown the generalization relatively accurate. With the exception of the northern portion of North County and the San Antonio area, most of the identified recharge areas in Monterey County receive less than 17 inches of rainfall. In consideration of Blaney's generalizations, in these areas, even if soils are favorable, recharge from rainfall must be considered a rare occurrence and the importance of these areas as recharge areas is therefore limited. This layer is part of a collection describing Geology resources and constraints Monterey County, California.
This map depicts areas of potential aquifer recharge for Monterey County, California. The intended use of this map is to provide a guide for use in regional planning studies of areas that provide recharge to aquifers.