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Southern Great Basin
Saline Valley - Cottonwood Mountains
This subsection is between the Inyo Mountains and Death Valley. It includes the Last Chance Range, Saline Range, Cottonwood Mountains, Nelson Range, Saline Valley, Eureka Valley, and many smaller valleys. It has a hot to temperate, arid climate. MLRA 29f.
Lithology and Stratigraphy. The bedrock is mainly Mesozoic granitic; Paleozoic marine sedimentary; and Tertiary volcanic rocks. Most all of the Paleozoic is represented, at least from Cambrian through Carboniferous. Pliocene volcanic rocks are mostly basalt, but there are other Tertiary volcanic rocks that are silicic. The Quaternary is represented by both alluvial and, in Saline, Eureka, and Racetrack Valleys, lacustrine deposits. Eolian sand deposits are extensive in Saline and Eureka Valleys.
Geomorphology. This subsection contains steep mountains, moderately steep hills, gently to moderately sloping alluvial fans and pediments, and nearly level floodplain and basin floor. Most of the mountains are aligned north-south, but the Nelson Range is aligned toward the northwest. There are high plateaus in the Nelson Range and on Hunter Mountain that appear to be old pediments. The elevation range is from about 1100 feet up to 7063 in the Saline Range, 7701 in the Nelson Range, 7454 on Hunter Mountain, 8456 in the Last Chance Range, and 8953 feet on Tin Mountain in the Cottonwood Mountains. Mass wasting, fluvial and eolian erosion and deposition, and freeze-thaw are the main geomorphic processes.
Soils. The soils on mountains and hills are mostly Lithic Torriorthents and Aridic Argixerolls, plus shallow Typic Torriorthents and shallow Aridic Haploxerolls on granitic rocks and Lithic Haplargids on volcanic rocks. Soils on alluvial fans and basin floors are mostly Typic and Xeric Torriorthents, plus Xerollic Haplargids and shallow Durorthids on older alluvial fans. There are Typic Salorthids on lacustrine deposits. The soils are well drained, except for poorly drained soils on lacustrine deposits. Soil temperature regimes are mostly thermic and mesic, with some frigid at higher elevations. Soil moisture regimes are aridic, except aquic in some lacustrine deposits.
Vegetation. The predominant natural plant communities, from lower to higher elevations, are Desert scrub shrublands and Mixed saltbush series on and around basin floors, Creosote bush series, Black bush series, Big sagebrush series, and Singleleaf pinyon series. Pickleweed series, Saltgrass series, and Greasewood series occur around poorly drained lake plains.
Characteristic series by lifeform include:Climate. The mean annual precipitation is about 5 to 12 inches. Much of the precipitation is snow at higher elevations. Mean annual temperature is about 40° to 70° F. The mean freeze-free period is in the range from 125 to 275 days.
Surface Water. Runoff is rapid from alluvial fans and slow from basin floors. Some of it drains to Death Valley and the remainder drains to closed basins within the subsection. Streams are dry most of each year.< previous Southern Great Basin - next >