As discussed under the Bowman Ditch subheading, numerous faults are located in the immediate vicinity of the McArthur Swamp. During the Pleistocene, the mountains had a large number of glaciers and cirques and glacially-carved U-shaped valleys are remaining features from that time period. Therefore, a less-than-significant impact is expected. 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. The eastern portion of the property is underlain by Plio-Pleistocene olivine basalt flows such as those exposed by the falls on Burney Creek (CDMG, 1994). Much of the north-eastern part of the state is actively stretching apart, creating numerous faults, all capable of producing earthquakes. The western gray squirrel is at-risk within the ecoregion in Washington as it is restricted to two isolated populations, but populations in Oregon and California are more robust. Flow in and out of the estuary has been controlled with a man-made structure since heavy silting in 1915. Project work may include post fire recovery efforts. 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. Additionally, borate deposited during arid conditions, with mining after 1926. They have a high shrink-swell potential and have a low water erosion hazard and low wind erosion hazard when bare (see TableVI-1). These deposited as part of a series of small island arcs, "rafted" against the coast of the proto-North American continent Laurentia. The exception to this is where the natural drainage regime is altered, as is the case for areas immediately adjacent to the channeled ditch. The region surrounding the Modoc Plateau, encompassing parts of northeastern California, southern Oregon, and northwestern Nevada, lies at an intersection between two tectonic provinces; the Basin and Range province and the Cascade volcanic arc. Miners extracted placer gold or dug up fossil placers in the Weaverville Formation and Hornbrook Formation. Sign In Skip to Main Content Requires ability to work and study under rigorous conditions. Oil is also abundant in the San Joaquin Valley, but almost non-existent in the Sacramento Valley. 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. Kokanee (Oncorhynchus nerka) can be found in lakes in the northern and central portions of this ecoregion in Washington. The east side of the Warner Mountains in particular has exposed rock in the many canyons, including finds of petrified wood and assorted gemstones. These basins steadily filled with sediment, with one famous example preserved as the Great Valley beds in the Coast Ranges. 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 New Almaden mine opened in 1824, ultimately extending 2,450 feet below ground. Compared with the Sierra Nevada, rocks from this time period tend be more calcic than silicic. Shelf and slope deposits would ultimately become Great Valley rocks, while the trench deposits became the Franciscan subduction complex. Plateau in the northeast corner of California, United States, List of plants on the Modoc National Forest, California Geologic Provinces, Note 36, page 2, https://en.wikipedia.org/w/index.php?title=Modoc_Plateau&oldid=1106243134, California placenames of Native American origin, Wikipedia articles needing clarification from May 2016, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 23 August 2022, at 20:13. Furthermore, the McArthur Fault bisects the property and is designated as an Alquist-Priolo Fault-Rupture Study Zone. [2] The plateau is thought to have been formed approximately 25 million years ago as a southern extension of the Columbia Plateau flood basalts. As with its flora, this diversity arises as a result of topography, unique climate, geology, and ecological isolation. What people are saying - Write a review. 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). Occasional lakes, marshes, and sluggishly owing streams meander across the plateau. In the 19th century, a railroad pier was built out into the canyon to avoid waves closer in to shore when loading and unloading ships. They are shallow, moderately well drained soils with slow permeability and have a high shrink-swell potential (see TableVI-1). Older alluvium, lake, playa, and terrace deposits. Pillow structures from rapid cooling water indicate underwater volcanism that produced basalt, andesite and diabase flows during the Miocene. Borehole Conditions The vault is a horizontal tunnel, located beneath 5 meters of overburden to maintain thermal stability. The California Coast Ranges extend from the Oregon line southward 600 miles to the Santa Ynez River. [5][6], The distinctive Coronado Island in San Diego County helps to create the large sheltered harbor of San Diego. Henhill Silt Loams are classified as neutral to slightly alkaline and have moderate shrink-swell potential. These soils formed in basins of mixed alluvium and are moderately deep, poorly drained soils with slow permeability and a high shrink-swell potential (see TableVI-1). This property could potentially be subjected to ground motion from displacement along any of these local and regional faults. The Transverse Ranges extend from Point Arguello to Joshua Tree National Park, bounded by the San Andreas Fault to the north. In Washington and the rapidly developing areas around Bend in Oregon, timber companies have recently begun to sell their lands in the mid-elevation forest and transition zones to developers. The Maps will include liquefaction hazard zones and earthquake-induced landslide hazard zones. Uplift took place into the Pliocene and Pleistocene, slowly reducing sea levels inland in the Central Valley. The Modoc Plateau has a diverse geography, with portions draining into closed basins such as Goose Lake and Surprise Valley, and most of the remainder draining into the Pitt River, a tributary of the Sacramento River. Some Great Valley rocks are exposed in the Coastal Ranges as well, like the Jurassic Knoxville Formation shale. Click here to use the California geological interactive map Source: California Geological Survey This produced major crustal stretching, volcanism and displacement of up to 125 miles. Finally, the Modoc Plateau, a volcanic table ranging from 4,000 to 6,000 feet (1,200 to 1,800 m) in elevation, separates the Medicine Lake Highlands in the west from the Warner Mountains in the east, covering roughly 1,000,000 acres (400,000 ha) of the forest. The plateau consists of a thick accumulation of lava flows and tuff beds along with many small volcanic cones. Discovering the Colorado Plateau - Bill Haggerty 2021-04-01 The Colorado Plateau is America's western treasure, home to the country's highest concentration of national parks, monuments, wilderness areas, and state parks, and a near-endless bounty of wild, stunning landscape. The Ahjumawi Property is located immediately adjacent to the southeast of the Bowman Ditch and therefore the subsurface is comprised of similar alluvial sediments and water-lain ash deposits. 12201 Sunrise Valley Drive Reston, VA 20192, Region 2: South Atlantic-Gulf (Includes Puerto Rico and the U.S. Virgin Islands), Region 12: Pacific Islands (American Samoa, Hawaii, Guam, Commonwealth of the Northern Mariana Islands). Study with Quizlet and memorize flashcards containing terms like 11, Cascade Range, Great Valley, Transverse Range, Peninsular Range, Colorado Desert, Coast Ranges, Sierra Nevadas, Mojave Desert, Modoc Plateau, Klamath Mountains, Basin and Range, Mount Whitney, Sierra Nevadas and more. Tertiary pyroclastic and volcanic mudflow deposits. 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. Below the bays, is the Merced Formation, with 45000 feet of marine rocks overlain by 500 feet of terrestrial sedimentary rocks and capped with more modern sediments from the Sacramento River. GitHub export from English Wikipedia. The Marble Mountain Cambrian quartzite lies unconformably atop Proterozoic granites. Therefore, aside from naturally occurring erosional processes, no impact is anticipated. ADVERTISEMENT Modoc Plateau, and West Cascades Ecoregional Assessments. In the 1960's, NASA astronauts trained for future moon landings in the pumice fields of the highlands. As shown, may include some rocks older than Oligocene, correlative with upper parts of unit Tea. The Modoc Plateau is characterized as a transitional region between the Basin and Range Geomorphic Province to the east and the Cascade Range Geomorphic province to the west and north. Most areas are vegetated by such plants as western juniper, ponderosa pine, antelope bitterbrush, manzanita, and Modoc cypress. Whipp soils account for approximately 60 percent of these map units, while Cupvar soils account for approximately 25 percent. The Peninsular Ranges are a group of mountain ranges that extend 900 miles (1,400km) from the Los Angeles basin and Transverse Ranges southward the entire length of Baja California. These activities include periodic maintenance of levees and roadways, recreational use, and grazing. The McArthur Swamp, Bowman Ditch, and the Ahjumawi Property are located within or adjacent to the McArthur Fault-Rupture Zone. MOD - Modoc Plateau, CA, USA. Its main production ran from 1892 to the 1940s, supplying lubricating oil for other refineries. Halemaumau, Mauna Loa Even moderate shaking . North of the San Joaquin River, the mountains have a tilted-block pattern caused the Sierra Nevada fault, which is interpreted as being similar to the more common Basin and Range terrain to the east. Additionally, the banks of the levees could experience localized landslides and slumps. Also includes isolated masses of dacitic and rhyodacitic flows, breccia, and ash-flow tuff along eastern slope of Cascade Range that are lapped by flows and sediments of the Madras (or Deschutes) Formation. Over 40 different oil and gas fields are found in association with the Transverse Ranges and their surrounding basins.