The Lava Flows-Gassaway Complex, 2 to 15 percent slopes map unit is found along the northeastern shoreline of Big Lake at the northeastern edge of the site. Special attention shall be provided to erosion prone hillside areas, including extremely erodible soils types such as those evolved from decomposed granite. Holocene faults such as the, McArthur, Mayfield, Pittville, Hat Creek, and Rocky Ledge faults are located within a 20-mile radius of the site. Mountain goats inhabit high elevations in the central and northern part of the ecoregion in Washington, but are largely absent from the southern portion of their range, and absent from Oregon. The Shasta County General Plan provides the following policies for properties outside of the FERCs jurisdiction as they relate to seismic and geologic hazards: Policy SG-c - Shasta County shall coordinate with state and federal agencies monitoring volcanic activity and shall periodically review and update the Shasta County Emergency Plan with respect to volcanic hazards. These soils formed on stream terraces from alluvium derived from extrusive igneous rocks. [14]. During the Jurassic, many sediments shed into the region from the rising proto-Sierra Nevada. Upper Klamath Lake is Oregons largest lake and is the biggest remnant of this wetland system. It is in northeastern California about 50 km (31 mi) south of Klamath Falls, Oregon. Additionally, each of the properties lie within or adjacent to an Alquist-Priolo Fault-Rupture Study Zone. The Poway Formation has rounded metavolcanic pebbles with no known source nearby, suggesting an original source somewhere in Sonora before a major offset to the north by faults. In fact volcanic rocks are 10,000 feet thick in the western part of the Santa Monica Mountains. These different regions are called geological provinces. They have a low shrink-swell potential, low to moderate water erosion hazard, and a low wind erosion hazard in bare areas (see TableVI-1). [12] They are small in area and are thought to represent a higher-grade metamorphic environment than the slate belt, and may have formed through subduction, when one plate slid beneath another. The East Cascades in Washington and northern Oregon resulted from tectonic uplift and subsequent erosion by alpine glaciers and landslides. In the southern part of the range, between the Nacimiento and San Andreas fault zones, the metamorphic rocks and granite plutons of the Salinian block make up the basement rock. . Ash-flow tuff, lava flows, pumice-lapilli tuff, coarse pumicite, flow breccia, and domal complexes of rhyolitic, rhyodacitic, and dacitic composition; in places includes peralkaline rhyolite and some andesite and andesite breccia. Additionally, the Burney Falls area could be affected by regional volcanic events originating within the Mt. Geological Survey of Canada, Open File 5529. MODOC PLATEAU The Modoc Plateau is a volcanic table land (elevation 4,000- 6,000 feet above sea level) consisting of a thick accumulation of lava ows and tu beds along with many small volcanic cones. It is also known for scores oflava-tubecaves and for well-preserved young volcanic features. Furthermore, the McArthur Fault bisects the property and is designated as an Alquist-Priolo Fault-Rupture Study Zone. Condado de Modoc, California, Estados Unidos The northeastern-most county in California with a total area of 4,203.37 square miles, but with a population under 10,000. By contrast, the Trinity ophiolite is found in the east, known for its numerous ultramafic rocks and being one of the most extensive ophiolites in the US. In the Modoc Plateau, Douglas-fir becomes less important, western white pine (Pinus monticola) woodlands dominate many areas, and Jeffrey pine (Pinus jeffreyi) and Washo pine (Pinus washoensis) occur with or replace ponderosa pine. Numerous lakes, reservoirs and marshes characterize the East Cascades, providing exceptional habitat for waterfowl, shorebirds and wading birds, aquatic mammals, amphibians, fish, aquatic plants and invertebrates. Tertiary volcanic flow rocks; minor pyroclastic deposits. Each of the proposed transfer properties are located within a seismically active region and could experience significant groundshaking and/or earthquake induced landslides resulting from displacement along one of the following Holocene Faults including the, McArthur, Mayfield, Pittville, Hat Creek, and Rocky Ledge faults. This property could potentially be subjected to ground motion from displacement along any of these local and regional faults. The volcano is positioned at a kink where northwest-trending faults entering the volcano from the south turn to the northeast, and then back to northwest. Additionally, the banks of the levees could experience localized landslides and slumps. The area formed as a series of small island arcs, deep-ocean sediments and mafic oceanic crust accreted to the western edge of North America, producing a series of deep basins and high mountain ranges. Adherence to appropriate engineering, design, and construction practices, such as dust control, seasonal considerations, and rapid revegetation, would minimize impacts involving these improvements at the McArthur Swamp property, resulting in a less than significant impact. Volcanism continued through the Holocene, forming the 300 foot thick basalts of the Cima Volcanic Field or the Barstow-Amboy axis of volcanic craters, which have protected underlying granite from erosion. California has 435 recognized alliances and within those more than 1,200 vegetation associations exist. The geomorphology of the Sierra Nevada is comparatively recent, dating to as recently as the Quaternary. Eruptions relatively quiet, but spectacular. Roadside Geology of Northern and Central California, "Second Edition", 2016, Alt/Hyndman Roadside Geology of Oregon, "Second Edition", 2016, Marli B. Miller These soils have a Capability Class rating of III to IV, due to erosion hazards and are not considered to be Prime Farmland (NRCS, 2000). Major uplift was going on in Pleistocene, with some marine terraces raised 1000 feet. Much of the remainder of the East Cascades to the north in Oregon is drained by the Deschutes River system, which includes a series of large lakes and reservoirs near its headwaters. They have a moderate to high hazard of erosion by water and a low to moderate erosion hazard from wind in exposed, bare areas (refer to TableVI-1). In spite of low rainfall, the numerous lava tubes and volcanic fractures in the plateau produce the Fall River Springs, one of the largest springs in the US. In places includes flows of platy olivine andesite or basaltic andesite. The Alquist-Priolo Earthquake Fault Zoning Act (formerly the Alquist-Priolo Special Studies Zone Act), signed into law December 1972, requires the delineation of zones along active faults in California. The Golden State includes both the highest and lowest point in the continental US and practically every conceivable geological feature known. Extensive marine and nonmarine sand deposits, generally near the coast or desert playas. Modoc Plateau: Average elevation 1370 m (4500 feet) Predominant rocks: Late Cenozoic volcanics, especially basalts in the Modoc Plateau, andesites and dacites in the Cascades Plate tectonic setting: Andean-style volcanic arc in the Cascades, Basin and Range volcanoes in the Modoc Plateau Most recent eruptions: Lassen, 1914-1921 The purpose of the Alquist-Priolo Act is to regulate development on or near active fault traces to reduce the hazard of fault rupture and to prohibit the location of most structures for human occupancy across these traces. The Transverse Ranges are poorly drained by streams, but subject to periodic intense flooding, typically every 20 to 25 years. Polygons from the 1978 State map unit Qp were added where no playa was shown on the county maps. The Ventura Avenue field, north of Ventura is one of the largest fields in California, producing since 1903. Thick Pliocene marine rocks up to 14,000 feet thick are found on the edges of the Santa Clara River Valley and parts of the San Fernando Valley, stretching to Fillmore. Lava lakes. LavaBeds National Monument encompasses about 188 km2(73 mi2) on the northern flank of Medicine Lake volcano and displays mostlybasalticand someandesiticlavas. Roadside Geology of Northern and Central California - David D. Alt 2016 Sierra Nevada -- Klamath mountains -- Coast range -- The great valley -- High Cascades on the Modoc plateau -- Basin and range. The east side of the Warner Mountains in particular has exposed rock in the many canyons, including finds of petrified wood and assorted gemstones. Miners extracted placer gold or dug up fossil placers in the Weaverville Formation and Hornbrook Formation. Elevations vary from 650 to 1300 feet and the bedrock consists of sandstone, siltstone, shale, some limestone and coal. The southern portion of the ecoregion has extensive valleys and flatlands between the forested mountains and foothills, which include large marshes, irrigated meadows and pastures, and arid juniper and sagebrush steppes. Surface fault rupture is not necessarily restricted to the area within an Alquist-Priolo Zone. The oldest rock in this part of the range is the Santa Monica Slate. The Burney Falls properties are located to the northwest of the Rocky Ledge Fault-Rupture Zone. The Santa Ynez Mountains extend up the coast of Santa Barbara County and contain Franciscan basement rocks (also referred to as the Franciscan basement complex) like the Coast Ranges. The water erosion hazard on these soils is low, while the wind erosion hazard is moderate, due to the high percentage of silt (refer to TableVI-1). Share sensitive information only on official, secure websites. Abstract. Rockhounding. Many of the ash--flow tuffs exhibit flow features and only obscure vitro-clastic textures. Soils comprising the Burney-Arkright Complex, two to nine percent slopes mapping unit, occupy smaller areas in the eastern portion of the transfer property and are underlain by basaltic lava flows. The Modoc Plateau is part of the larger Columbia Plateau which extends into eastern Oregon and Washington, southern Idaho, northern Nevada and western Wyoming. Selected large landslides, such as Blackhawk slide on north side of San Gabriel Mountains; early to late Quaternary. Both of these provinces have substantial geothermal resource base and resource potential. Read more Print length 384 pages The soil lacks a substantial proportion of clay and therefore, has a low shrink-swell potential (refer to TableVI-1). The actual distribution of these ten mapping units is complex, and therefore, will be described by bisecting the site into two northern quadrants and a southern half. [5][6], The distinctive Coronado Island in San Diego County helps to create the large sheltered harbor of San Diego. The river drains a 612-square mile area, but due to the porous volcanic nature of the region, most of the stream flow originates from springs within the valley. These rocks are rich in plagioclase, quartz and chlorite mica (which gives them a greenish color) and range up to 25,000 feet thick. These soils developed in basins from stratified alluvium of ash and lacustrine deposits. In places contains mollusks or vertebrate fossils indicating Pleistocene age; mostly deposits of late Pleistocene age, but locally includes some deposits of early Holocene age. The Bowman Ditch is located on soils mapped as the Pastolla Muck, drained, zero to two percent slopes. The Upper Klamath Basin and the Modoc Plateau are large land forms that characterize the southern portion of the ecoregion.