Columbia River / Modoc Plateau basalt. 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. Glacial till and moraines. [11]. These two locations are located approximately 30 miles east of the Park and less than a mile south of the Bowman Ditch and Ahjumawi Property. These soils are moderately deep, moderately well drained and have slow permeability. Most of these wetlands have been drained and converted to agriculture. The three interconnected Suisun, San Pablo and San Francisco bays occupy a structural depression dating to the Pliocene which flooded several times due to Pleistocene glaciations. 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). It is composed of layers of volcanic flows and periodic volcanic uplifts. The Santa Monica Mountains and the Channel Islands are different than the mountains to the north because they have granitic and metamorphic basement rocks more like the Sierra Nevada. It is the only coastal mountain range in the USand potentially North Americawith rocks older than the Phanerozoic. In Washington, much of the ecoregion is within the ceded lands and usual and accustomed fishing areas of tribes. Older alluvium, lake, playa, and terrace deposits. Its landform is volcanic table land ranging from 4,000 to 6,000 feet above sea level, cut by many northsouth faults. Most of the gold historically mined in California originated in the Mother Lode belt, located in the foothills of the western Sierras. The Western Paleozoic and Triassic Plate is the most common unit of the Klamath Mountains and is up to 50 miles wide at the Oregon state line. California was the first place in the US to develop offshore oil drilling in the Summerland field, first found in 1896. Rockhounding. The highest point on the rim of Medicine Lake volcano'scalderais 2,412 m (7,913 ft). Geothermal systems with evidence of magmatic heat . Shasta, Lassen Peak, or Medicine Lake volcanic centers, all of which have experienced activity within the last 500 years (CDMG, 1994). LavaBeds National Monument encompasses about 188 km2(73 mi2) on the northern flank of Medicine Lake volcano and displays mostlybasalticand someandesiticlavas. The San Onofre Breccia also formed during this period with distinct glaucophane schist, gabbro, limestone and greenschist. The Seismic Hazards Mapping Act was developed to protect the public from the effects of strong groundshaking, liquefaction, landslides, or other ground failure, and from other hazards caused by earthquakes. Like the Sierra Nevada, the Peninsular Ranges have gentle western slopes and steep eastern faces. The oldest rocks in California date back 1.8 billion years to the Proterozoic and are found in the San Gabriel Mountains, San Bernardino Mountains, and Mojave Desert. MOD - Modoc Plateau, CA, USA. Locally includes soils containing abundant organic material, and thin peat beds. Per square mile of drainage, the Eel River has the highest suspended sediment load of any river in the US, exceeding the Colorado River and Mississippi River. The oldest rock in this part of the range is the Santa Monica Slate. Lava lakes. They are associated with the Whipp-Cupvar Complex, slightly saline, 0 to 2percent slopes mapping unit which occupies a flanking position to the south. 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). Thick sequences of marine rocks from the Late Cretaceous through the Paleocene and Eocene are common in the mountains and on San Miguel Island. [4]. For much of the Cenozoic the region was filled with lakes and brackish swamps. . In 1873, 53 Modoc men held off 650 US troops, killing 70 of them in heavy weather in the lava plateau to the south of Tule Lake. As indicated by Special Publication 42, Fault-Rupture Zones in California, each of the transfer properties are located in areas with delineated fault-rupture zones. An official website of the United States government. As described under item (a), while various areas of the project site do consist of unstable soils, there are no facilities proposed as part of the project which have the potential to be impacted by these soils, therefore this is a less than significant impact. It formed as a sandspit filled in to the north from sediment deposited by the Tijuana River and sheltered from wind and waves by the Cretaceous uplands of Point Loma. Use the interactive map to zoom smoothly from a national view to state and local perspectives anywhere across the country. 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 Clear Lake National Wildlife Refuge and Long Bell State Game Refuge are located on the plateau as well. The East Cascades in Washington and northern Oregon resulted from tectonic uplift and subsequent erosion by alpine glaciers and landslides. It is also known for scores oflava-tubecaves and for well-preserved young volcanic features. Policy SG-f - Shasta County shall pursue preparation of development standards based on topography and soil erosion potential in revising its land capability standards pursuant to Policy CO-h. Policy SG-g - Shasta County should comply with the requirements of the Seismic Hazards Mapping Act, when the Seismic Hazards Maps for the County are completed and made available by the State Geologist. Their hazard for water and wind erosion is none to low when bare. Official websites use .gov Find many great new & used options and get the best deals for Roadside Geology of Northern and Central California (paperback) at the best online prices at eBay! The vast tableland between the Cascades and the Warners is referred to as the Modoc Plateau. Mineral materials found on the forest include obsidian and obsidian needles, petrified wood and assorted gemstones. New Idria, New Almaden and mines in the Mayacmas Mountains have been the main sources throughout history. and late Miocene in age (see Fiebelkorn and others, 1983), flows of Deer Butte Formation of Kittleman and others (1967), and extensive unnamed flow sequences in the Basin-Range and Owyhee Upland Provinces of southern Lake, Harney, and Malheur Counties that are younger than Steens Basalt, dated at about 15 Ma (Baksi and others, 1967) and the Owyhee Basalt, dated at about 14 Ma (Bottomley and York, 1976; see also Fiebelkorn and others, 1983), and older than 7 or 8 Ma. It is in northeastern California about 50 km (31 mi) south of Klamath Falls, Oregon. The Marble Mountain Cambrian quartzite lies unconformably atop Proterozoic granites. The southern portion of the McArthur Swamp property is comprised of numerous soil mapping units, which include the Cupvar, Whipp, Pittville, Dugan, and Graven soil series. True. Broad valleys occupy the lowlands between the mountain ridges. Britton Silt Loams, 30 to 50 percent slopes soils are characterized as being relatively shallow (10 to 20inches), and well drained with moderately slow permeability. See table of contents below. However some areas are virtually devoid of vegetation, due to deficient nutrient supplies (NRCS, 2000). Soils located on the Ahjumawi Property consist of the Pastolla muck, 0 to 1 percent slopes, which are similar to those located along the Bowman Ditch, except that it is not artificially drained (NRCS, 2000). Much more recent Pliocene terrestrial sedimentary rocks are also common in the northern Peninsular Ranges like the San Timoteo Canyon and Mount Eden conglomerate, sandstone and siltstone which are up to 7000 feet thick. Kokanee (Oncorhynchus nerka) can be found in lakes in the northern and central portions of this ecoregion in Washington. Water erosion hazard for bare soil is low to moderate, while the wind erosion hazard is low (refer to TableVI-1). Large mammals are emblematic of the ecoregion, which supports populations of elk, blacktail deer, mule deer, bighorn sheep, mountain lions, and black bears. Reviews aren't verified, but Google checks for and removes fake content when it's identified. The Bowman Ditch and adjacent area are underlain by Quaternary lacustrine deposits composed of alluvial sediments derived from volcanic materials, water-lain ash deposits, and local diatomaceous detritus (CDMG, 1968). The plateau is thought to have been formed approximately 25 million years ago. The Pastolla Muck, drained, 0 to 2 percent slopes and Pastolla muck, 0 to 1 percent slopes occupy a large portion of the area of the northern quadrants along the Tule River. Flows like water in many cases. This project could not have been undertaken without the financial support of The Nature Conservancy's Oregon, Washington and California offices, and the Washington Department of Fish and Wildlife (WDFW). "Modoc County has an area of 3823 square miles. The rugged terrain of the Modoc Plateau played an important role in the Modoc War. Lava Beds National Monument is on the Modoc Plateau in Modoc and Siskiyou Counties. Most of the Modoc National Forest is covered by basaltic lava flows. The only significant difference is attributed to the continued maintenance of the McArthur Levee, which has kept these soils drained and suitable for grazing. [4] and Modoc Cypress (Cupressus bakeri).[5]. Since the active McArthur fault traverses the site, any displacement along this segment of the fault could result in potential fault rupture at the surface. Bull trout occur within the ecoregion but their range has been significantly reduced. The soils are moderately to strongly alkaline and have a very high shrink-swell potential (refer to TableVI-1). 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 Historically, fires occurred at irregular intervals from under 10 years in the lowland foothills to 150 years or more at high elevations. California has 435 recognized alliances and within those more than 1,200 vegetation associations exist. 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). 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. These soils contain a very deep profile and are somewhat poorly drained with moderately slow permeability. [J Curtis Kramer; Geological Society of Sacramento. They have a moderate hazard for water and wind erosion when bare. Quaternary pyroclastic and volcanic mudflow deposits. Dugan and Graven soils are comprised of soils formed on mounds and stream terraces from alluvium of extrusive igneous rocks. Starting on p. 15, this book is divided into seven chapters dealing with the gold-bearing provinces: 1) Sierra Nevada, 2) Klamath Mountains, 3) Basin Ranges, 4) Mojave Desert,S) Transverse and Peninsular Ranges, 6) Modoc Plateau . They are very deep, poorly drained soils with slow permeability and a high shrink-swell potential (see TableVI-1). Ships from Sacramento, CA. Groundwater quality in the 39,000-square-kilometer Cascade Range and Modoc Plateau (CAMP) study unit was investigated by the U.S. Geological Survey (USGS) from July through October 2010, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program's Priority Basin Project (PBP). The Modoc Plateau has both active volcanoes and faults. They are shallow, well drained cobbly loams of moderate permeability and are neutral to mildly acidic. [10], At the edge of the Los Angeles coastal plain and just west of the San Joaquin Hills, Newport Bay is a major hub of boating. This property could potentially be subjected to ground motion from displacement along any of these local and regional faults. Typical rock formations in the area include volcanic breccia, mud and ash flows, lava flows, lacustrine (lake) deposits, and cinder cone pyroclastic rocks. Geologists have interpreted the bay as the drowned channel of the Santa Ana River. Source: US geologic names lexicon (USGS Bull. Dominant land uses are forestry, livestock grazing, recreation and conservation. Soils of the Pittville Sandy Loam, 0 to 5 percent slopes mapping unit occur at the southern fringe of the site. The western pond turtle is listed as an endangered species in Washington, although it has more robust populations in the Oregon and California portions of its range. Subsequently, sandstone and shale deposited while the region was still underwater. Geology. Get this from a library! Mercury was first discovered in Santa Barbara County in 1796. The Modoc Plateau Region (Figure MOD-1) encompasses 22,858 km of the volcanic tablelands east of the Cascade and northern Sierra Nevada ranges in Modoc, Lassen, and Siskiyou counties. Technicians will serve vegetation management and fuels reduction efforts, supporting initiatives for healthy, productive, and resilient forest landscapes and resources. Both of these provinces have substantial geothermal resource base and resource potential. Whitebark pine (Pinus albicaulis), lodgepole pine, and western larch (Larix occidentalis) are common components of many of these forests. Reference: Chorlton, L.B. Pahoehoe vs. aa lavas. These basins steadily filled with sediment, with one famous example preserved as the Great Valley beds in the Coast Ranges. The plateau consists of a thick accumulation of lava flows and tuff beds along with many small volcanic cones. This area lies along the northwestern-most flank of the Sierra Nevada Geomorphic Province. Polygons from the 1978 State map unit Qp were added where no playa was shown on the county maps. 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. The Southern unglaciated Allegheny Plateau is a maturely dissected plateau characterized by high hills, sharp ridges and narrow valleys. Andesite and dacite typically have plagioclase, hornblende, and clinopyroxene phenocrysts; some flows aphyric. Age, mostly Oligocene; may include some rocks of early Miocene age. [15] However, a bulge in the bay's sand spit records offshore presence of the Newport submarine canyon. In places includes flows of platy olivine andesite or basaltic andesite. The ecoregion includes a large pumice zone in central Oregon, dominated by lodgepole pine (Pinus contorta), one of the very few places where the species is the climax tree (not replaced by other conifers if fire is suppressed). The majority of the PG&E property is underlain by Quaternary Lake deposits comprising alluvial sediments derived from volcanic lands and water-lain ash deposits. Both of these provinces have substantial geothermal resource base and resource potential. [9]. Hill*s work, however, is of little value in understanding the areal . The West Shasta district has a long history of copper and zinc production out of chalcopyrite and sphalerite. It is exposed in the Smith River drainage to the north of US Highway 199 in Del Norte County. The Modoc National Forest has four obsidian mines in the Warner Mountains near Davis Creek, Calif. on the east side of the forest where it is legal to collect obsidian with a free permit available from the Forest Supervisor's office in Alturas.
