DEPARTMENT OF THE INTERIOR TO ACCOMPANY MAP MF-1655-B U.S. GEOLOGICAL SURVEY
MINERAL RESOURCE POTENTIAL OF THE ROADLESS AREAS AND THE SANTA LUCIA WILDERNESS IN THE LOS PADRES NATIONAL FOREST, , SOUTHWESTERN CALIFORNIA
SUMMARY REPORT
By Virgil A. FrizzelL, Jr., and David B. Smith U.S. Geological Survey and Lucia Kuizon and William N. Hale U.S. Bureau of Mines
STUDIES RELATED TO WILDERNESS Under the provisions of the Wilderness Act (Public Law 88-577, September 3, 1964) and the Joint Conference Report on Senate Bill 4, 88th Congress, the U.S. Geological Survey and the U.S. Bureau of Mines have been conducting mineral surveys of wilderness and primitive areas. Areas officially designated as "wilderness," "wild," or "canoe" when the act was passed were incorporated into the National Wilderness Preservation System, and some of them are presently being studied. The act provic^d that areas under consideration for wilderness designation should be studied for suitability for incorporation into the Wilderness System. The mineral surveys constitute one aspect of the suitability studies. The act directs that the results of such surveys are to be made available to the public and be submitted to the President and the Congress. This report discusses the results of a mineral survey of the Santa Lucia Wilderness and 22 roadless area that consist of the Sespe-Frazier, Garcia Mountain, Blsck Mountain, La Panza, Machesna Mountain, Los Machos Hills, Big Rocks, Stanley Mountain, Miranda Pine, Horseshoe Sprinrs, Tepusquet Peak, La Brea, Spoor Canyon, Fox Mountain, Diablo, Matilija, Dry Lakes, Sawmill-Badlands, Cuyama, Antimony, Quatal and Little Pine Roadless Areas. All the roadless areas occur in the Los Padres National Forest, Kern, Los Angeles, San Luis Obispo, Santa Barbara, and Venture Counties, California. The Santa Lucia Wilderness was established by Public Law 95-237 in 1978. The twenty-two roadless areas were classified as further-planning areas during the Second Roadless Area Review end Evaluation (RARE H) by the U.S. Forest Service, January 1979. SUMMARY The study area in the Los Padres National Forest contains mines, prospects, and occurrences that contain identified re sources of antimony, barite, bentonitic clay, building stone (sandstone and marble), copper, gold, gypsum, petroleum, phosphate rock, silver, uranium, and zinc, but geologic and geochemical investigations generally indicate little potential for the presence of these mineral commodities at other localities within the study area. The few areas with potential for additional mineral resources are associated with those containing known resources or are present in similar geologic settings. Anomalies identified from our geochemical study are related to localities previously known for mineralization; no new areas of mineral resource potential were delineated as a result of the geochemical study. Several roadless areas contain resources or reserves (see table 1): the Sespe-Frazier Roadless Area (RA) contains ben tonitic clay, lode gold, gypsum, petroleum, and phosphate rock; the Black Mountain RA contains uranium; the Horseshoe Spring RA contains building stone (sandstone); the La Brea RA contains barite, copper, and zinc; the Fox Mountain RA contains phosphate rock; the Cuyama RA contains gypsum; the Antimony RA contains antimony, building stone (marble), gold, and silver; and the Quatal RA contains bentonitic clay. Phosphate-rock reserves in the Sespe-Frazier RA are minable under 1982 conditions. Bentonitic clay in the Sespe-Frazier RA and sandstone in the Horseshoe Spring RA are marginal reserves because reserves outside the study area meet current marl <*t demands. Marble and other sandstone deposits in the study area are subeconomic resources because of high transportation co^ts and occurrences outside the study area which supply current needs. The deposits of antimony, barite, copper, gold, gypsum, silver, uranium, and zinc contain either marginal reserves or subeconomic resources because of combinations of low commodity prices, generally low grade and tonnage, high mining and benefication costs, and poor access. Petroleum will probably continue to be found in and around the Sespe oil fields and may be present below thrust faults in two parts of the study area in the Sespe-Frazier RA. Low to moderate potential exists for the presence of undiscovered antimony resources in part of the Antimony RA. Low to moderate potential exists for the presence of undiscovered barite resources throughout the study area. Low to moderate potential exists for the presence of additional low-grade lode gold resources in parts of the Sespe-Frazier and Antimony RAs. Low to moderate potential exists for the presence of low-grade mercury resources in part of the Stanley Mountain RA. A low to moder ate potential exists for the presence of undiscovered oil and gas in Miocene and younger rock throughout the study area, and a moderate potential exists for the presence of undiscovered oil and gas at two localities in the Sespe-Frazier RA. A low to moder ate potential exists for the presence of low-grade uranium resources at depth in parts of the Black Mountain RA.
INTRODUCTION Antimony, Quatal and Little Pine Roadless Areas. These roadless areas all occur in the Los Padres National Forest, This report summarizes the results of a mineral survey Kern, Los Angeles, San Luis Obispo, Santa Barbara, rnd in the Santa Lucia Wilderness and 22 roadless areas, consist Venture Counties, California (fig. 1). For purposes of tvis ing of the Sespe-Frazier, Garcia Mountain, Black Mountain, report the individual areas are referred to collectively as the La Panza, Machesna Mountain, Los Machos Hills, Big Rocks, study area. The roadless areas individually range from about Stanley Mountain, Miranda Pine, Horseshoe Springs, 2 to 523 mi2 (fig. 1) and the study area totals some 1336 mi . Tepusquet Peak, La Brea, Spoor Canyon, Fox Mountain, The multidisciplinary study was conducted jointly by Diablo, Matilija, Dry Lakes, Sawmill-Badlands, Cuyama, the U.S. Geological Survey and the U.S. Bureau of Mines in 1980 through 1983. The Bureau of Mines conducted investiga C. M. McDougal eased interpretations of organic and inor tions that included field mapping, sampling of mines, pros ganic geochemistry; Russ Campbell, John Crowell, Tom pects, and mineralized areas, mining-claim searches, and Dibblee, Thane McCulloh, Bob Powell, Jack Vedder, and literature reviews. The Geological Survey studied mineral others participated in conversations that broadened our ized areas and searched for previously unknown mineral understanding of the regional geology. Very importantly, the occurrences using geologic, geophysical, and geochemical cooperation and continuing patience of the supervisors and techniques. staff of the various districts in the Los Padres National Forest are greatly appreciated, %s are the challenging discus Location and accessibility sions offered by Hollis Record, the forest geologist. The study area is in the Los Padres National Forest in GEOLOGY AND STRUCTURE the southern part of the Coast Ranges and western part of the Transverse Ranges of California. It forms an elongate Despite its large size, much of the study area is com curved area between U.S. Highway 101 on the west and posed of similar rock types. Thick sequences of Mesozoic and Interstate 5 on the east. California State Highways 33, 58, Cenozoic sedimentary rocks underlie most of the study area and 166 provide paved approaches to numerous paved and (fig. 2). These sedimentary rocks overlie crystalline base unpaved roads that generally allow access to within a quarter ment rocks composed mostly of pre-Tertiary metamorphic mile of the borders of the various roadless areas. Trails and igneous intrusive rocks. Many maps and articles showing provide access into many parts of most roadless areas. or discussing the geology of the study area are cited by Frizzell and Vedder (1985). Topography and vegetation Large areas underlain by pre-Tertiary metamorphic and intrusive rocks occur in both the extreme northeastern The study area is mostly characterized by steep-walled and northwestern parts of the study area. Included are un- canyons and sharp ridges. Mountain top altitudes vary from differentiated metasedimentary rocks distributed as screens 2,868 ft at Lopez Mountain in the Santa Luca Wilderness to and pendants within the plutonic rocks. These metasedimen 8,831 ft at Mt. Pinos in the Sawmill-Badlands Roadless tary rocks include layered to spotted mica schist, metasand- Area. Although some summit ridges support forests of conif stone, metaquartzite, amphibolite, marble and minor calc- erous trees and riparian woodlands line some valley bottoms, silicate rock, and greenschist. Also included in the unit are impenetrable chaparral covers much of the vegetated portion undifferentiated Precambrian granitic gneisses, Mesozoic of the study area. Mixtures of manzanita, buckbush, chamise granitic and ophiolitic rocks, and minor Tertiary igneous and poison oak characterize the chaparral plant community rocks. and make off-trail traverses quite challenging and slow. Most of .the rest of the study area is underlain by highly folded, in part chaotic, pre-Neogene sedimentary Sources of data rocks. They comprise a thick, heterogeneous, incomplete marine section of interbedded sandstone, siltstone, shale, This report is based upon data derived from various conglomerate and minor marble, ranging in age from Late disciplines involved in the investigation of the study area, Jurassic to Oligocene, with local nonmarine interbeds. which are described in reports on the geology (Frizzell and Neogene (Miocene and Pliocene) marine sedimentary Vedder, 1985), inorganic geochemistry (Smith and others, rocks include organic-rich siltstone and shale, Intel-beaded 1985; Adrian and others, 1984), organic geochemistry sandstone, and lesser conglomerate. These rocks formed (Frizzell and Claypool, 1983; Frederickson, 1985), geophysics mostly from sediments deposited in relatively restricted (Griscom, 1985a, b; Dickinson, 1982; Dickinson and others, marine basins where the organic remains of aquatic flora and 1982), and investigations of mines and prospects (Avery, 1981; fauna living in the water column constituted a relatively Barnes, 1981; Benham, 1983; Benham and McCulloch, 1981; important source of sediment. Neogene non marine rocks Capstick and Hyndman, 1982a, b; Denton, 1982; Gabby, 1981; occur mostly in the Cuyama Badlands, Lockwood Valley, and Hale and others, 1983; Horn, 1983; Kuizon, 1981, 1982, 1983 along the eastern boundary of the study area in the Ridge a, b, c, d; Lambeth, 1982; Lipton, 1981; Longwill, 1982; Basin. These reddish rocks include interbedded arkosic sand McCulloch and Neuman, 1982; Sabine and Esparza, 1981; and stone, clay stone, conglomerate, and bentohitic clay repre White, 1982a, b), which are summarized by U.S. Bureau of senting alluvial-fan, stream, and lacustrine deposits. Mines (1985). Preliminary conclusions based upon all of these Several major and numerous minor faults traverse the data were presented in Frizzell and Hale (1983) and Frizzell study area and exhibit offsets ranging from a few feet to 150 and Kuizon (1983a, b). mi. Some of these faults have created physio-chemical Other mineral resource evaluations have been carried environments that locally control the presence of minerals. out for different parts of the Los Padres. National Forest. For example, the low-grade mercury deposits at the Deer These include a study of mineral resources in the San Rafael Trail mine near the Stanley Mountain RA are in rocks frac Primitive Area (Gower and others, 1966), the Ventana Primi tured in response to movements on nearby faults. Faults tive Area (Pearson and others, 1967), and additions to the create barriers through which fluids, such as oil and gas, Ventana Primitive Area (Seiders and others, 1983). Mineral cannot move; in addition, if the overriding fault block is thick occurrences for the Antimony RA are discussed in a county enough, temperatures can be elevated within the overridden report by Troxel and Morton (1962). Weber and others (1973) block. Faults having some thrust component include the describe mineral occurrences in the southern part of Ventura South Cuyama and the Pine Mountain faults, and the San County. Cayetano thrust. In addition to being faulted, the sedimentary rocks in Acknowledgments the study area are generally much folded. Anticlines tradi tionally are important traps for oil and gas. These structural Numerous colleagues from the U. S. Bureau of Mines features are delineated on maps more detailed than the one (see references table 1) enhanced our understanding of min presented herein (see Vedder and others, 1973; Dibblee, 1973; eral occurrences, including: D. W. Avery; D. J. Barnes; J. R. and numerous references in Frizzell and Vedder, 1985). Benham; D. 0. Capstick; D. K. Denton, Jr.; L. E. Esparza; P. N. Gabby; D. E. Graham; M. C. Horn; P. C. Hyndman; R. H. GEOPHYSICAL STUDIES Lambeth; D. A. Lipton; W. D. Longwill; R. B. McCulloch; T. R. Newmann; C. E. Sabine; W. W. White, ffl; and R. A. Geophysical studies included the compilation and Winters. Likewise, numerous individuals at the U. S. Geolog analysis of gravity, magnetic, and radiometric data (Griscom, ical Survey also supported various aspects of this endeavor: 1985a, b; Dickinson, 1982; Dickinson, and others, 1982). The field, laboratory, and library assistance was provided by Lydia gravity data indicate relatively thin sections of Neogene rock K. Fox, Kathleen M. Ort, Frederika C. Moser, and Theresa in the southern half of the Santa Lucia Wilderness and south Swint; Cathrine R. McMasters provided superb drafting; of the South Cuyama oil field in the northern Fox Mountain George Claypool, Ted Daws, B. M. Adrian, R. B. Vaughn, and RA. It confirms thicker amounts of Neogene sedimentary rocks below the San Cayetano thrust in the southern part of These conclusions corroborate, in part, results of the Sespe-Frazier RA and also may indicate a small amount previous studies. Howell and Claypool (1977) studied Late of Neogene sedimentary rocks below the Pine Mountain fault Cretaceous rocks, and they concluded that those rocks have at Pine Mountain. Magnetic data reflect the presence of poor source and reservoir potential. Link and Smith (If S2, p. granitic bedrock highs and indicate ultramafic rocks, but the 191-197) conclude that the mostly nonnmarine rocks in the data do not provide information on mineral deposits in the Miocene and Pliocene Ridge Basin contain limited numbers of study area. potential source beds with generally immature kerogens Although the radiometric data are equivocal, rather In addition to problems of locating suitable source distinct radiometric anomalies occur over claims on Superior rocks, rocks suitable for reservoir purposes are diffic"lt to Ridge south of the study area and in the Hartman Ranch area delineate. Data for 67 surface and subsurface samp^^s of in the tipper Sespe drainage. Uranium mineralization has sandstone and siltstone, mostly pre-Neogene in age, in o~ near occurred in the lower part of the Sespe Formation in both the study area indicate that the rocks have very low perme these areas. ability and porosity and, thus, have poor reservoir potential (Frizzell and Claypool, 1983). GEOCHEMISTRY COMMODITY INVENTORY AND EVALUATION Inorganic geochemistry Numerous commodities have been mined or prospected A reconnaissance geochemical study was undertaken in for within the study area. For the commodities for whi^h we 1981 and 1982 to assist in the evaluation of the mineral have data or a history of interest, this section brief! ^ de resource potential of the study area (Smith and others, 1985; scribes the mining or prospecting history, the geologic set Adrian and others, 1984). Several sample media were used in ting, any production, workings, sample analyses and identified this study. The initial reconnaissance sampling consisted of resources (see table 1 for occurrences). The areas that have stream sediments and panned concentrates from stream more than a low potential for the presence of undiscovered sediments. Selected rock samples were also taken from some mineral resources are noted (see fig. 3). Numerous additional mines and prospects to determine suites of elements related mines, prospects, and localities for the various commodities to mineralization and also from geologic units to determine are listed in the individual reports by the U.S. Bureau of geoehemical background values. In addition, 16 water sam Mines (see references, table 1) as well as a companion map ples were taken from springs to determine if any mineralizing (U.S. Bureau of Mines, 1985). processes are operating in the ground waters of the region. The assignment of modifiers to the term "potentM" in During followup studies, an additional 47 rock samples were this and the following section involves integrating (F) the taken from areas that showed anomalous (above average for geologic setting of the commodity; (b) knowledge of the the study area) elemental concentrations in stream-sediment presence or absence of occurrences, mines and prospects for and/or panned-concentrate samples. In total, 451 stream- a given commodity in a given geologic setting; and (c) geo sediment, 451 panned-concentrate, 95 rock, and 16 water chemical data. Given the uncertainties involved, the align samples were taken for the geochemical study. ment of "no potential" to an area for a given comirodity Stream sediments were chosen as the primary sample would be highly speculative; therefore this category is not medium for the inorganic geochemical study because they used. "Low potential" indicates that a locality may contain represent a composite of rock and soil exposed in the drain dispersed mineral occurrences, which have few favorable age basin upstream from the sample site. Analysis of the geologic factors and which appear to have little possibility heavy, nonmagnetic fraction of the panned concentrates from for the presence of undiscovered mineral deposits. "Moc^rate stream sediments proved to be useful in evaluating the com potential" indicates favorable geologic factors and localities mon ore-forming sulfide and oxide minerals as well as other that have a reasonable possibility for the presence of undis nonmagnetic minerals, such as barite, zircon, sphene, apatite, covered mineral deposits. rutile, and native gold. The largest anomalies were found in heavy-mineral Antimony concentrates from the Antimony RA. High values of anti mony, arsenic, tungsten, tin, and boron appear to be related Antimony deposits at Antimony Peak in the Antimony to previously recognized mineralization at Antimony Peak RA (location 12, table 1) were rediscovered in 1853 and were (antimony sulfide vein), Black Bob Canyon (the Black Bob gold patented in the late 1800's. These deposits had apparently deposit), and Brush Mountain (uranium prospects). Smaller, been previously mined by Indians and Jesuits. About 600 tons more scattered, and less consistent anomalies for tungsten, of antimony ore was produced from this property between molybdenum, lanthanum, and bismuth from heavy-mineral 1882 and 1941 (Jermain and Ricker, 1949, p. 2). At Antimony concentrates from streams draining igneous and metamorphic Peak, stibnite and antimony oxides occur in siliceous lenses terrain in the Sespe-Frazier RA are believed to be spatially irregularly distributed along a shear zone in quartz diorite- related to numerous known gold occurrences there. tonalite (Troxel and Morton, 1962, p. 56; Jermain and Richer, All anomalies identified from this geochemical study 1949). Strong antimony anomalies (and smaller anomal'^s in seem to be related to areas previously known for mineraliza tungsten, tin, and boron) occur in streams draining the tion. No new areas of mineral resource potential were delin Antimony Peak area, and rocks from the area of the peak eated as a result of the geochemical sampling program. show anomalies in antimony, arsenic, tungsten, mercury, boron, and silver, in addition to small gold values (Smifr and Organic geochemistry others, 1985). The patented Antimony Peak mine contains 470,000 tons of indicated and inferred marginal reserve" and One hundred and sixty samples of siltstone and shale subeconomic resources averaging 1.0 to 2.7 percent antimony were collected, primarily from natural and artificial surface (Kuizon, 1982, p. 4). By comparison, commercial grad? ore exposures, and analyzed for oil-source capability and thermal mined under different economic conditions elsewhere n the maturity of the kerogen. Results of the reconnaissance study United States contains 5 to 10 percent antimony (Goldman, are detailed in Frizzell and Claypool (1983) and summarized 1957, p. 35). Two areas, one near Antimony Peak and another below. just east of Antimony Peak, have low to moderate potential Most samples from pre-Neogene rocks contain less for the presence of additional low-grade anti-nony than one percent organic carbon. The data indicate that most resources. None of our data indicate a potential fo- the of the organic matter present in these rocks has little capa presence of undiscovered antimony resources elsewhere in the city to generate oil and that terrestrial woody humic matter, study area. possible source of natural gas, is the likely source of the organic carbon. Neogene marine rocks, on the other hand, Barite contain organic matter in quantities and qualities conducive to the generation of oil, as well as gas. Barite occurs at the patented White Elephant mine (location 6, table 1) in the La Brea RA where 4,000 tens of ore were produced in 1929 and 1930. The mineral occurs as others, 1983; Dry Lakes RA, White, 1982a; Matilija RA, veins in brecciated Cretaceous sandstone and silts tone. Lambeth, 1982), these have not been shown in table 1 because About 95,000 tons of 73 percent inferred subeconomic barite large amounts of potentially suitable rock are available resources remain on the claims (Benhan and MeCulloch, 1981, thoughout the Transverse Ranges, both inside and outsidi the p. 7). Sustained production at commercial deposits outside study area. Existing quarries have good supplies and are the study area has been from barite deposits with more than located closer to markets. However, other localities in the 17,000 tons of 96 percent barite (Kundert, 1957, p. 73). study area containing sandstone are described in a companion Panned-concentrate samples downstream from the map (U.S. Bureau of Mines, 1985). mine had visible barite and showed high values for barium Marble and dolomitic marble are present in the (greater than 1 percent barium). However, this is not conclu Antimony RA. A total of about 85 million tons of this mate sive evidence for the presence of undiscovered barite veins, rial is identified at the Lebec and White Rock properties because a majority of the panned concentrates from the (locations 13, table 1; Kuizon, 1981, table 1, Nos. 3,17). Hart entire study area had barium values greater than one per (1978, p. 94) describes the Sierra Blanea Limestone, a com cent. The high barium content in the samples of stream mercial-grade rock, which crops out in the study area we-'t of sediments derived from sedimentary rocks and a high content Wheeler Hot Springs. Steeply dipping bands of marble and of sulfate in spring waters sampled may indicate the presence calc-silicate rock 6 mi east of Sespe Hot Springs (Frizzell and of barite veins elsewhere in the study area (Smith and others, Vedder, 1985) are thin and inaccessible. 1984), although no other occurences of vein barite have been found. Therefore, while low to moderate potential exists for Copper and zinc the presence of undiscovered barite resources in the study area, the widespread nature of the barium anomalies makes it A copper and zinc occurrence is present near Wild- impossible to delineate specific localities other than the horse Mountain (location 7, table 1) in the La Brea RA. known occurrence in the La Brea RA. Gabbroic rocks, part of the dismembered Coast Range o?hio- lite (an association of dark-colored igneous and sedimentary Bentonitic Clay rocks formed in oceanic areas), contain vugs and fractures filled with malachite, azurite and associated disseminated Parts of the non marine Neogene Lock wood Clay of sulfide minerals. This mineralization may have occurred by Carman (1964) locally contain rather pure bentonitic clay. remobilization and precipitation of syngenetic copper ir the The clay probably represents the altered remnants of a vol gabbro (Smith and others, 1985). Prospects in a high-grade canic ash layer that became interbedded in the nonmarine zone contain 1,300 tons of gabbro with 1.87 percent ceoper deposits (Carman, 1964, p. 44). A deposit in the eastern part and 3.13 percent zinc. An additional 5,850 tons of grbbro of Lockwood Valley, from which 13 million tons were pro containing 0.18 percent copper and 1.34 percent zinc are duced between 1954 and 1980 (White, 1982b, p. 8), has 7.2 present nearby (Benham and MeCulloch, 1981, p. 4). million tons of bentonitic clay reserves, of which about 4.7 Although copper occurrences are reported in the million tons (location 1, table 1) occur within the Sespe- Sespe-Frazier ,RA (Weber and others, 1973, p. 65), we found Frazier RA (Hale and others, 1983, p. 17, table 2, No. 13). no geochemical indications of a potential for the occurrence Although the Lockwood Clay crops out locally in the Sawmill- of the metal there or elsewhere in the study area. Badlands RA, no resources are estimated there (Longwill, 1982, p. 9, 16). Bentonitic clay resources occur, however, in Geothermal resources the Quatal RA where about 1.6 million tons of subeconomic resources (location 15, table 1) have been identified (White, Thermal springs form a linear pattern in the southern 1982b, p. 14). Because the bentonitic clay is stratabound part of the study area along the Santa Ynez fault system (Carman, 1964; Dibblee, 1973; Vedder and others, 1973) and (Muffler, 1979, map 1). Temperatures of spring waters ir and occurs in well prospected areas, the potential for the pres near the Diablo, Dry Lakes, and Matilija RAs range between ence of undiscovered bentonitic clay resources is low. 62° F and 118° F (White, 1982a; Lambeth, 1982; Godwir and Stephens, 1979), and portions of these RAs have been cl^ssi- Borates fied as lands valuable prospectively for geothermal re sources. Although data are insufficient to estimate reservoir Borates, associated with Miocene basalts and deformed parameters, these springs probably only have potential for lake and playa deposits, were mined within and near the non-electric, or direct heat, purposes. eastern part of the Sawmill-Badlands RA between 1899 and Sespe Hot Springs, in the Sespe-Frazier RA, formf the 1912 (Carman, 1964). Ore at the Russell mine was hand eastern termination of the linear pattern of springs and is sorted to average 29 to 42 percent B2O3 (boron oxide) with classified as a "Known Geothermal Resource Area" (a KGRA; production from the district totalling about 35,000 tons Muffler, 1979, map 1). Temperatures of waters from the four (Longwill, 1982, p. 8-9). Production ceased around 1913 springs in this hot-water hydrothermal convection system because of larger and richer deposits developed further east. range to 194° F (Brook and others, 1979, table 6, No. 61) and The grade of ore required for refining or producing benefi- subsurface temperatures of source aquifers probably r^nge ciated products is probably not less than 20 percent ^^Z between 230° F and 270° F (McCulloh and others, 1981, p. (Ver Planck, 1957, p. 92). No resources were identified in the 359). Although these springs have potential for direct heat Sawmill-Badland RA (Longwill, 1982), but a large boron use, their remote location limits their usefulness for this anomaly marks the locality of the old mines (Smith and purpose. others, 1985). Because no other similar anomaly occurs elsewhere in the study area and because the geologic setting Lode gold is unique to the known boron occurrences, there is no evi dence for the presence of undiscovered boron resources Lode gold was discovered in the late 1800*s at the elsewhere in the study area. Castaic mine (location 2, table 1) and Frazier mine (outside study area) in or near the Sespe-Frazier RA and at the Pack Building stone Bob mine (location 14, table 1) in the Antimony RA. Gold production of about 1300 oz was reported from the late 1800s Active mining is in progress at the Colson quarry, until 1942 from mines in the Sespe-Frazier RA (Hale and adjacent to the Horseshoe Springs RA (location 5, table 1), others, 1983, p. 9). Small amounts of gold, silver, and lead where about 2,000 tons of flagging and rubble are produced were produced from the Black Bob mine in the early 1900's annually from thin-bedded, fine-grained sandstone and inter- (Kuizon, 1982, p. 7). bedded siltstones of the Miocene Monterey Formation. These Gold prospects and former mines are locally found in rocks extend a mile northwest and southeast into the Horse quartz veins along shear zones in Precambrian gneiss ir the shoe Springs RA and include in excess of 50,000,000 tons of Sespe-Frazier RA. The gold in one mine, outside the study raw material (Horn, 1983; p. 4). Although sandstone has been area west of Frazier Mountain and not examined in this study, identified in other roadless areas (Sespe-Frazier RA, Hale and apparently occurs as disseminated particles in gossan-rich shear zones and is associated with iron sulfides (Carman, estimated at $200,000 (Clark, 1970, p. 179). In the early 1964, p. 60). In the Sespe-Frazier RA, similar quartz veins 1840's placer gold was mined from Piru Creek in the Sespe- along shear zones are mostly one to several feet thick and Frazier RA. trend northwesterly (Hale and others, 1983). Many of the generally small and discontinuous Quater Although at least a trace of gold occurs in 12 of the 17 nary!?) and modern terrace and stream gravel deposits were gold prospects and mines examined in or near the Sespe- sampled for placer gold (see various references, table 1; U.S. Frazier RA (Hale and others, 1983), we were able to establish Bureau of Mines, 1985). Calculated grade for individual identified resources for only one locality because many of the samples ranges from none detected to 0.015 oz gold/cu yd workings are caved and not well enough exposed to determine with grades on significant volumes of gravel averaging less resources and reserves. Of the 266 samples collected from 17 than 0.002 oz gold/cu yd. Localities within the study area gold prospects or former gold mines in or near that roadless with appreciable volumes of gravel include: the Lucvy Girl area, about 22 percent (58 samples) con-ained a trace or more placer on the boundary of the La Panza RA with about 15,000 gold (Hale and others, 1983, tables 2, 3. Data discussed below cubic yards of terrace and stream gravel (about 3,00f) cubic resides in this reference.). Thirty of 115 samples from four yards are in the La Panza RA) averaging 0.0002 oz gold/cu yd prospects and mines on the west side of Frazier Mountain (Barnes, 1981); the Jehovah Jireh property in the Mrchesna (Dom Bosco, Esperanza, Jewel, and White Mule) contained Mountain RA with about 27,000 cubic yards of bench gravels from a trace to 0.22 oz gold/ton (all but the one contained that average 0.002 oz gold/cu yd (Kuizon, 1983b, p. 8); and 0.08 oz gold/ton or less). Four of 12 samples from two pros the CIC placer on Piru Creek in the Sespe Frazier KA that pects and mines (Gold Dust and Hidden Value) southeast of contains about 82,000 cubic yards with less than O.C005 oz Frazier Mountain contained from 0.046 to 0.316 oz gold/ton. gold/cu yd (Hale and others, 1983). The general low grade Eight of 28 samples from an unknown prospect in Lockwood and discontinuous occurrence of placer gold within the study Creek contained from 0.026 to 0.072 oz gold/ton. Of ten area probably precludes recovery of the gold by commercial samples from the Brown prospect, nine yielded no significant ventures, but does not necessarily preclude recovery by values, and one contained 0.31 oz gold/ton; of 40 samples hobbyists. Low potential exists for the presence of undis collected from the Gold Hill Group, 36 yielded no significent covered placer gold resources in the study area. gold values, three contained trace to 0.012 oz gold/ton, and one contained 0.122 oz gold/ton. Eight of 24 samples from Gypsum the Castaic mine (location 2, table 1) yielded gold values: six samples from a massive quartz vein assayed 0.02 to 1.2 Gypsum was discovered in the Guyana RA ir 1892. oz/ton. This quartz vein contains about 8,000 tons of indi Subsequently, other gypsum deposits were discovered in and cated and inferred subeconomic resources averaging 0.38 oz near the Cuyama, Sawmill-Badlands, Sespe-Frazie", and gold/ton (Hale and others, 1983, table 1, No. 26). Although Quatal RAs. Two deposits (Frenchman's Point and Burgess the gold bearing veins in the Frazier mine may extend into Canyon) in the Sawmill-Badlands RA contain thin, impure the roadless area (Hale and others, 1983, table 2, No. 52), and gypsum-bearing zones, but no resources were identified although the Harris mine contains anomalous gold values (Longwill, 1982). Several claims for gypsum were filed in or (Smith and others, 1985), we are unable to establish identified near the Fox Mountain RA as early as 1901 (McCullcch and resources with significant gold values for any other mine or Neumann, 1982), but no resources were identified. The Mono prospect within the Sespe-Frazier RA except the Castaic lith Quarry, just west of the Quatal RA, produced about 1.7 mine. Potential is low to moderate for the presence of million tons of gypsum and gypsite between 1939 and 1980 additional undiscovered lode gold resources in this roadless (White, 1982b, p. 7). A small amount of gypsum of the ala area. baster variety was mined for local use in the 1950's through Gold at the Black Bob and Cedar mines (location 14, 1970's from the Cuyama and Sawmill-Badlands RAs. table 1) in the Antimony RA is found in quartz veins along Gypsum occurs as discontinuous beds or lenses inter- shear zones, but these shears are in Mesozoic biotite grano- bedded in Neogene sandstone and siltstone sequences inter diorite, not in Precambrian rocks as they are in the Sespe- preted to have been deposited in hypersaline lagoonal to very Frazier RA. Heavy-mineral concentrates taken downstream shallow marine environments (Thor, 1978, p. 52-54) and saline from the mines show strong arsenic and tin anomalies (ele lakes. Three prospects in the Cuyama RA (locations 9, 10, ments often associated with gold), but rock sampling indi 11, table 1) are estimated to collectively contain about cates only the known gold locality in that drainage (Smith and 370,000 tons of subeconomic gypsum resources that average others, 1985). These mines contain 1,600 tons of marginal between 83 to 90 percent CaSO4 (calcium sulfate) (I'uizon, reserves averaging 0.13 oz/ton gold and 11,000 tons of sub- 1981, p. 9). Gypsum-bearing beds occur both insHe and economic resources averaging 0.034 oz/ton (Kuizon, 1982, p. outside the Sespe-Frazier RA near Pine Mountain (location 3, 4, 13). table 1). About 8 million tons of subeconomic gypsum re Anomalies in antimony, arsenic, tungsten, mercury, sources, averaging 76 percent CaSO^ occur within the latter boron, silver, and gold from Antimony Peak (location 12, roadless area (Hale and others, 1983, p. 16). table 1) indicate the previously known antimony deposits and Because the gypsum is stratabound and occurs in well suggest possible gold mineralization (Smith and others, prospected areas, the potential for the presence of undis 1985). Jermain and Ricker (1949, p. 5) reported gold and covered gypsum resources is low. silver values of $0.60 per ton. Seven chip samples contained gold ranging from trace to 0.29 oz/ton (Lucia Kuizon, unpub. Mercury report, 1982). Low to moderate potential exists for the presence of undiscovered gold resources in the vicinity of Mercury was discovered north of the Santa Lucia Antimony Peak. Wilderness (at the Rinconada mine) in 1872 and adjacent to From a total of 74 chip samples collected from the the Stanley Mountain RA (at the Deer Trail mine) ir 1914. Deer Trail mine just outside the Stanley Mountain RA, two Total production from the Rinconada and Deer Trail mines samples contained gold values of 0.014 and 0.026 oz/ton was about 3,000 and 200 flasks of mercury (a flask contains (Kuizon, 1983d, p. 6). Four chip samples from the Clyde's 76 pounds of mercury), respectively (U.S. Bureau of Mines, Saylor prospect in the Machesna Mountain RA contain gold 1965, p. 165). ranging from 0.01 to 0.06 oz/ton (Kuizon, 1983b, p. 9). Mercury deposits in California are generally associated Low potential exists for the presence of undiscovered with major fault zones and, in many places, with young vol lode gold resources elsewhere in the study area. canic systems. Hot fluids containing mercury apparently move through the crushed rock and fill openings or replace Placer gold host rocks as local changes in pressure, temperature, and chemistry permit. Placer gold mining by Spanish settlers and Indians The Rinconada mine produced mercury from silica- began in the region in the early 1800's in the La Panza mining carbonate rock, an altered form of serpentinite, that formed district, partly within the La Panza, Machesna Mountain, and prior to the mercury mineralization (Eckel and others 1941, Black Mountain RAs. Total gold production in this district is p. 531). This mine was one of the largest producers in San Luis Obispo County and yielded ore containing about 5 to 10 favorable settings, which have moderate potential for the Ibs of mercury per ton (Eckel and others, 1941, p. 536). presence of oil and gas, exist below the San Cayetano, and, Rocks similar to those at the mine do not occur in the Santa perhaps, the Pine Mountain faults. Late Eocene marine, Lucia Wilderness (Sabine and Esparza, 1981). Mercury occurs Oligocene nonmarine, and Neogene marine rocks near existing as cinnabar which fills fractures in brecciated calcite at the oil and gas fields in and near the southern part of the Sespe- Deer Trail mine. The mine contains about 32,000 tons of vein Frazier RA still probably contain additional oil and gas. calcite and sandstone averaging 1.71 Ibs mercury/ton (Kuizon, 1983d, p. 10). Low to moderate potential exists for the Phosphate rock presence of low-grade mercury resources in and adjacent to this mine. Low potential exists for the presence of undis Phosphate-rock occurrences were first reported in covered mercury resources in other parts of the study area. Ventura County in 1925 and Santa Barbara County in If 31. In the 1960's, two phosphate deposits, one at Pine Mountain Petroleum (location 3, table 1) adjacent to and in the Sespe-Fraz'^r RA and the second at the Cuyama deposit (location 8, table 1) Oil and gas exploration began in the region in the adjacent to the Fox Mountain RA, were extensive'y ex 1860's, and the first wells were drilled in the Sespe Creek plored. The Cuyama phosphate mine produced 18,000 tons of area in 1887 (Kew, 1924, p. 121). The Sespe oil field, part of phosphate rock between 1965 and 1970 (McCulloch and which is in the Sespe-Frazier RA, has produced 24 million Newmann, 1982, p. 6). barrels of oil and 22 billion cubic feet of gas since it's dis Phosphate pellets were probably precipitated in a covery, and it currently produces 96 percent of the produc Neogene offshore muddy shelf environment that had both a tion within the boundaries of the Los Padres National Forest low sedimentation rate and optimal chemical environment (700,000 barrels of oil and 900 million cubic feet of gas in (Thor, 1978, p. 47-48). The Fox Mountain RA may contain 1981, Hollis Record, written commun., 1982). more than 300 million tons of phosphatic pellet-bearing rocks Wildcat drilling and oil and gas production in and near (Fedewa and Hovland, 1981, p. 72), but most of these rocks the study area have not been very successful. Of the approx are covered by thick overburden. The area (location 8, table imately 222 classifiable holes completed outside known oil 1) does, however, contain more than 21 million tons of sub- and gas fields through 1981, about 214 were dry holes, and economic phosphate-rock resources with 4.84 percent VftOc less than 80,000 barrels of oil were pumped from the eight (phosphorous pentoxide), which are not as deeply buried producing wells, all of which are now abandoned or idle (McCulloch and Neumann, 1982, p. 4). (Frizzell and Claypool, 1983). These statistics are not sur Phosphate-bearing beds occur both inside and outside prising when the organic geochemistry of the rocks in the the Sespe-Frazier RA near Pine Mountain (location 3, table study area is reviewed. These data indicate that most pre- 1). About 51 million tons of phosphate- rock reserves, aver Miocene rocks sampled contain less than 1 percent total aging 10 percent ^2®$* occur within the study area (Hrle and organic matter (Frizzell and Claypool, 1983), most of which others, 1983). This phosphate rock deposit is minable under has little capacity to generate oil (although it may generate 1982 conditions, assuming a hypothetical one million ton per natural gas). year open-pit mining operation utilizing advanced technology Samples from Miocene and younger marine rocks, in the processing operation. By comparison, 18 percent ^2®$ however, indicate that they have about 2 percent organic represented the minimum grade of phosphate-bearing rock for matter of a type that does produce oil and gas. Most local earlier resource estimates with different economic conditions ities underlain by Miocene and younger marine rocks, though, in the Permian phosphate fields in Wyoming where more than are either composed of relatively thin sequences of these 25 billion tons of reserves occur (Sheldon, 1963, p. 148, table rocks or contain sections that have been breached by erosion, 20). Because the phosphate is stratabound and occurs in well thus allowing the escape of any entrapped oil and gas. (Hy prospected areas, the potential for the presence of undis drocarbon-bearing fluids generally travel upward through covered phosphate-rock resources in the study area is low. minute holes in rocks. They can be trapped against various types of impermeable zones or layers, but if the porous rocks Rock products crop out at the earth's surface, any fluids that may have been using the rock as a conduit will be lost.) A variety of unconsolidated materials, including rela For instance, the southern two-thirds of the Santa tively well sorted alluvial gravel, sand, and silt, underlie Lucia Wilderness is underlain by Miocene marine rocks that major river and sidestream valley bottoms throughout the appear to be about 5,000 ft thick in which canyons as deep as study area. Although these materials can be used for con 1600 ft have been cut. Similarly, the Miocene rocks exposed struction purposes, they are not specifically identified here at the surface in the Tepusquet Peak, La Brea, and Little in. Because there are abundant deposits of these materials Pine RAs are apparently relatively thin (about 2,000 to 4,000 outside the study area, deposits in the study area cannot ft) and generally have been deeply dissected by erosion. compare favorably with those closer to major markets. Although the Miocene rocks at the surface in the Fox Mountain RA are relatively thin and have been deeply dis Silver sected, similar rocks have been projected to occur below the low angle South Cuyama fault northwest of the roadless Although silver does not occur as the primary m?.tal of area. However, if this fault is present in the roadless area, interest at any prospect in the study area, it does occur gravity data do not support the presence of appreciable associated with gold-bearing veins in both the Sespe-r-azier thicknesses of Neogene rocks below it (Griscom, 1985b). and Antimony RAs. Selected samples from prospects in or An elongate, east-west negative-gravity anomaly near the Sespe-Frazier RA contain silver values rangin-r from confirms the presence of Miocene rocks below the San 0.4 to 0.6 oz silver/ton, but since many workings are caved Cayetano thrust in the southernmost part of the Sespe- and not well enough exposed, no tonnages are assigned (Hale Frazier RA. South of the line labled A-A' (fig. 3), the fault and others, 1983). The 1,600 tons of marginal reserves at the may be less than 12,000 ft below sea level (Griscom, 1985b). Black Bob and Cedar mines in the Antimony RA (locat'on 14, Another, smaller, negative-gravity anomaly may indicate that table 1) average 0.5 oz/ton silver and the 11,000 tons of Miocene and younger rocks are present below the Pine subeconomic resources average 0.27 oz/ton silver (Fuizon, Mountain fault, and a small part of this anomaly is present in 1982). the roadless area near Pine Mountain (Griscom, 19855). From a total of 74 chip samples collected, two simples In summary, drilling experience and organic geo- from the Deer Trail mine adjacent to the Stanley Mountain chemical data indicate a low potential for the presence of RA contained silver values of 2.4 and 3.3 oz/ton silver undiscovered oil and gas in pre-Miocene rocks outside known (Kuizon, 1983d, p. 6). Two chip samples from Clyde's Saylor fields. A low to moderate potential for the presence of prospect in Machesna Mountain RA contained silver ranging undiscovered oil and gas in marine Miocene and Pliocene from 0.1 to 0.3 oz/ton (Kuizon, 1983b, p. 9). Low potential sedimentary rocks is indicated by favorable organic geo- exists for the presence of undiscovered silver resource? in the chemical data but variable physical settings. The most study area. Uranium prospected since 1964, and a phosphate prospecting permit extends into the roadless area near Pine Mountain (Ha1*? and Uranium minerals were first reported in the Antimony, others, 1983). Petroleum has been produced at the Sespe Sawmill-Badlands, Machesna Mountain, and Black Mountain Canyon Field since before the turn of the century. RAs in the 1950's. In the Black Mountain RA, biotite schist, which has been intruded by granitic rocks, locally shows Although the gold bearing veins in the Frazier mine scintillometer readings four to five times regional back may extend into the roadless area and although twelve farmer ground. The uranium associated with these schists locally mines or prospects contain greater than trace amounts of averages 90 ppm uranium while the sfBeffied granitic rocks gold (Hale and others, 1983, tables 2 and 3), gold resources average 6 ppm uranium (Smith and others, 1985). The Black could only be identified at one locality mainly because many Widow prospect (location 4, table 1) has produced about 400 workings were caved and not well enough exposed to deter IDS of UoO8 (uranium oxide); it and two nearby prospects mine resources. Eight thousand tons of indicated and inferred contain about 153,000 tons of subeconomie uranium resources subeconomie gold resources averaging 0.38 oz gold per ton averaging 0.02 - 0.047 percent U30g and 2,900 tons indicated occur at the Castaic mine (location 2, table 1) (Hal^ and and inferred uranium resources averaging B.I 8 percent UjOg others, 1983, table 1, No. 26). Identified subeconomie lode (Gabby, 1981, table 1). Low to moderate potential exists lor gold resources at the Castaic mine do not contain enough the presence of undiscovered low-grade uranium resources at gol
10 AasMem«nt of mineral-resource potential in U.S. Kuizon, Lucia, 1981, Mineral resources of the Cuyama RARE Forest Service lands studied 1964-1984: U.S. n Area (No. 5135), Santa Barbara and Ventura Geological Survey Professional Paper 1300, v. 1, p. Counties, California: U.S. Bureau of Miner MLA 363-366. Open-File Report 9-81,11 p. Frizzell, V. A. Jr., and Kuizon, Lucia, 1983a, Santa Lucia 1982, Mineral investigation of the Antimony RARE n Wilderness, and Garcia Mountain, Black Mountain, La Area (No. 5136), Kern and Ventura Counties, Panza, Machesna Mountain, Los Machos Hills, Big California: U.S. Bureau of Mines MLA Open-File Rocks, and Stanley Mountain Roadless Areas, Report 71-82,14 p. California, jn Marsh, S. P., Kropschot, S. J., and 1983a, Mineral investigation of the Big Rocks RARE n Dickinson, R. G., eds., Wilderness mineral potential- Area (No. 5112), San Luis Obispo County, California: Assessment of mineral-resource potential in U.S. U.S. Bureau of Mines MLA Open-File Report 12-83, 8 Forest Service lands studied 1964-1984: U.S. P. Geological Survey Professional Paper 1300, v. 1, p. 1983b, Mineral investigation of the Machesna Mountain 356-359. RARE n Area (No. 5110), San Luis Obispo County, 1983b, Miranda Pine, Horseshoe Springs, Tepusquet Peak, California: U.S. Bureau of Mines MLA Open-File La Brea, Spoor Canyon, Fox Mountain, and Little Pine Report 13-83, 11 p. Roadless Areas, California, in Marsh, S. P., Kropschot, 1983c, Mineral investigation of the Miranda Pine Rock S. J., and Dickinson, R. G., eds., Wilderness mineral RARE H Area (No. 5114), Santa Barbara County, potential Assessment of mineral-resource potential in California: U.S. Bureau of Mines MLA Open-File U.S. Forest Service lands studied 1964-1984: U.S. Report 19-83, 8 p. Geological Survey Professional Paper 1300, v. 1, p. 1983d, Mineral investigation of the Stanley Mountain 293-296. RARE n Area (No. 5113), San Luis Obispo County, Frizzell, V. A., Jr. and Vedder, J. G., 1985, Geologic map of California: U.S. Bureau of Mines MLA Open-File roadless areas and the Santa Lucia Wilderness in the Report, 57-83,13 p. Los Padres National Forest, southwestern California: Kundert, C. J., 1957, Boron, in Wright, J. A., ed., Mineral U.S. Geological Survey Miscellaneous Field Studies commodities of California: California Division of Map MF-1655-A, scale 1:250,000 [in press]. Mines Bulletin 176, p. 71-74. Gabby, P. N., 1981, Mineral resources of the Black Mountain Lambeth, R. H., 1982, Mineral resources of the Matilija RARE H Area (No. 5108), San Luis Obispo County, RARE n Area (No. (5129), Ventura and Santa Farbara California: U.S. Bureau of Mines MLA Open-File Counties, California: U.S. Bureau of Mines MLA Report 21-82, 12 p. Open-File Report 64-82, 13 p. Godwin, L. H., and Stephens, E. V., 1979, Lands valuable for Link, M. H., and Smith, P. R., 1982, Organic geochemistry of geothermal resources, southern California: U.S. Ridge Basin, southern California, jn Crowell, J. C., and Geological Survey, Conservation Division, Office of Link, M. H., eds., Geologic history of Ridge Basin, the Area Geologist, Pacific Region, scale 1:500,000. southern California: Society of Economic Paleontolog Goldman, H. B., 1957, Antimony, jn Wright, J. A., ed., Min ists and Mineralogists, Pacific Section, p. 191-1S7. eral commodities of California: California Division of Lipton, D. A., 1981, Mineral resources of the Garcia Mountain Mines Bulletin 176, p. 35-44. RARE n Area (No. 5107), San Luis Obispo County, Gower, H. D., Vedder, J. G., Clifton, H. E., and Post E. V., California: U.S. Bureau of Mines MLA Open-File 1966, Mineral resources of the San Rafael primitive Report 8-82, 9 p. area, California: U.S. Geological Survey Bulletin Longwill, W. D., 1982, Mineral resources of the Sawmill- 1230-A, p. A1-A28. Badlands RARE H Area (No. 5134), Ventura and Kern Griscom, Andrew, 1985a, Aeromagnetic map of part of the Counties, California: U.S. Bureau of Mines MLA Los Padres National Forest in the southern Coast and Open-File Report 51-82,18 p. western Transverse Ranges, California: U.S. Geologi McCulloch, R. B., and Neumann, T. R., 1982, Mineral investi cal Survey Miscellaneous Field Studies Map MF-1658- gation of the Fox Mountain RARE H Area (No. 5120), A, scale 1:250,000 [in press]. Santa Barbara County, California: U.S. Bureau of 1985b, Bouguer gravity map of part of the Los Padres Mines MLA Open-File Report 128-82, 9 p. National Forest in the southern Coast and western McCulloh, T. H., Frizzell, V. A., Jr., Stewart, R. J., and Transverse Ranges, California: U.S. Geological Survey Barnes, Ivan, 1981, Precipitation of laumontit^ with Miscellaneous Field Studies Map MF-1658-B, scale quartz, thenardite, and gypsum at Sespe Hot Springs, 1:250,000 [in press]. western Transverse Ranges, California: Clay and Clay Hale, W. N., Winters, R. A., Graham, D. E., and Neumann, T. Minerals, v. 29, no. 5, p. 353-364. R., 1983, Mineral investigation of the Sespe-Frazier Muffler, L. J. P., ed., 1979, Assessment of geotheriral re RARE H Area (No. 5002), Ventura County, California: sources of the United States 1978: U.S. Geological U.S. Bureau of Mines MLA Open-File Report, 78-83, Survey Circular 790, 163 p. 30 p. Nagle, H. E., and Parker, E. S., 1971, Future oil a-rd gas Hart, E. W., 1978, Limestone, dolomite, and shell resources of potential of onshore Ventura Basin, California: the Coast Ranges province, California: California American Association of Petroleum Geologists Memoir Division of Mines and Geology Bulletin 197,103 p. 15, p. 254-296. Horn, M. C., 1983, Mineral investigation of the mineral Pearson, R. C., Hayes, P. T., and Fillo, P. V., 1967, Mineral resources of the Horseshoe Spring RARE n Area (No. resources of the Ventana primitive area, Mcnterey 5115), Santa Barbara County, California: U.S. Bureau County, Calif ornia: U.S. Geological Survey Bulletin of Mines MLA Open-File Report, 18-83, 9 p. 1261-B, 42 p. Howell, D. G., and Claypool, G. E., 1977, Reconnaissance Sabine, Charles, and Esparza, L. E., 1981, Mineral resources petroleum potential of Mesozoic and Cenozoic Rocks, of the Santa Lucia Wilderness, San Luis Obispo County, Coast Ranges, California, in Howell, D. G., Vedder, J. California: U.S. Bureau of Mines MLA Open-File G., and McDougall, Kristin, eds., Cretaceous geology Report 16-82, 6 p. of the California Coast Ranges, west of San Andreas Seiders, V. M., Esparza, L. E., Sabine, Charles, Spear, J. M., fault: Pacific Section, Society of Economic Stebbins, Scott, and Benham, J. R., 1983, Mineral Paleontologists and Mineralogist, Pacific Coast resource potential map of part of the Ventana Wilder Paleogeography Field Guide 2, p. 85-90. ness and the Black Butte, Bear Mountain, and Bear Jermain, G. D., and Ricker, S., 1949, Investigation of Canyon Roadless Areas, Monterey County, Antimony Peak, Kern County, California: U.S. Bureau California: U.S. Geological Survey Miscellaneous Field of Mines Report of Investigations 4505, 5 p. Studies Map MF-1559-A, scale 1:50,000. Kew, W. S. W., 1924, Geology and oil resources of a part of Sheldon, R. P., 1963, Physical stratigraphy and mineral re Los Angeles and Ventura Counties, California: U.S. sources of Permian rocks in western Wyoming; U.S. Geological Survey Bulletin 753, 202 p. Geological Survey Professional Paper 313-B, 273 p.
11 Smith, D. B., Frizzell, V. A., Jr., Adrian, B. M., Vaughn, R. U.S. Bureau of Mines, 1965, Mercury potential of the Un;ted B., and McDougal, C. M., 1985, Geochemical map of States: Bureau of Mines Information Circular 1C 8252, roadless areas and the Santa Lucia Wilderness Area in 376 p. the Los Padres National Forest, southwestern Vedder, J. G., Dibblee, T. W., Jr., and Brown, R. D., Jr., 1973, California: U.S. Geological Survey Miscellaneous Field Geologic map of the upper Mono Creek-Pine Mountain Studies Map MF-1655-E, scale 1:250,000 [in press]. area, California: U.S. Geological Survey Miscellansous Taylor, J. C., 1976, Geologic appraisal of the petroleum Geologic Investigations Map 1-752, scale 1:48,000. potential of offshore southern California: the Border Ver Planck, W. E., 1957, Boron, jn Wright, L. A., ed., Miniral land compared to onshore coastal basins: U.S. Geolog commodities of California: California Division of ical Survey Circular 730, 43 p. Mines Bulletin 176, p. 87-95. Thor, D. R., 1978, Depositional environments and paleogeo- Weber, F. H., Jr., Cleveland, G. B., Kahle, J. E., Kiessling, E. graphic setting of the Santa Margarita Formation, F., Miller,i R. V., Mills, M. F., and Morton, D. M., 1973, Venture County, California, in Fritsche, A. F., ed., Geology and mineral resources study of soutt ^rn Depositional environments of Tertiary rocks along Ventura County, California: California Division of Sespe Creek, Ventura County, California: Society of Mines and Geology Preliminary Report 14,102 p. Economic Paleontologists and Mineralogists, Pacific White, W. W., m, 1982a, Mineral investigation of the Dry Section, Pacific Coast Paleogeography Field Guide 3, Lakes RARE H Area (No. 5131), Ventura County, p. 42-59. California: U.S. Bureau of Mines MLA Open-File Troxel, B. W., and Morton, P. K., 1962, Mines and mineral Report 84-82,17 p. resources of Kem County, California: California 1982b, Mineral investigation of the Quatal RARE n /rea Division of Mines and Geology, County Report 1, 370 (No. 5268), Ventura County, California: U.S. Bureau of P. Mines MLA Open-File Report 68-82, 15 p. Tucker, W. B., and Sampson, R. J., 1932, Ventura County, in Yeats, R. S., 1983, Large-scale quaternary detachment* in Mining in California: California Division of Mines Ventura Basin, southern California: Journal of Geo Report of the State Mineralogist; 28, p. 247-277. physical Research, vol. 88, no. Bl, p. 569-583. U.S. Bureau of Mines, 1985, Mines and prospects map of roadless areas and the Santa Lucia Wilderness in the Los Padres National Forest, southwestern California: U.S. Geological Survey Miscellaneous Field Studies Map MF-1655-C, scale 1:250,000 [in press].
12 [Numerous additional mines, prospects, and occurrences are noted In referenced reports and in U. S. Bureau of Mines (19tS)]
Map Area Mineral Quantity location No. Roadless area No. occurrence (tons) Grade Classification Reference
1 Sespe-Frazler 5002 Benotonltlc clay 4,700,000 Suitable for light-: Marginal reserves Hale and others, 1983 weight aggregate 2 Gold, lode2 8,000 0.38 oz/ton Subeconomlc resources do. 3 Gypsum 8,000,000 76% CaS04 do. do. Petroleum - - - Frizzell and Claypool, 1983 3 Phosphate' 51,000,000 10% P205 Reserves Hale and others, 1983 Garcla Mountain 5107 None identified - - - Llpton, 1981 4 Black Mountain 5108 Uranium 2,900 0.18% U30g Subeconomlc resources Gabby, 1981 75,000 0.047% UoOo do. do. 78,000 0.02% U308 do. do. La Panza 5109 None identified - - - Barnes, 1981 Machesna Mountain 5110 None identified - - - Kulzon, 1983b Los Machos Hills 5111 None identified - - - Denton, 1982 Big Rocks 5112 None Identified - - - Kuizon, 1983a Stanley Mountain 5113 None identified - - - Kulzon, 1983d Miranda Pines 5114 None identified - - - Kuizon, 1983c 5 Horseshoe Springs 5115 Building stone* 50,000,000 Suitable for Marginal reserves Horn, 1983 (sandstone) building stone Tepusquet Peak 5116 None identified - - - Avery, 1981 6 La Brea 5117 Barite2 95,000 73% barite Subeconomlc resources Benham and McCulloch, 1981 7 Copper , zinc 1,300 1.87% Cu, 3.13% Zn do. do. 5,850 0.18% Cu, 1.34% Zn do. do. Spoor Canyon 5118 None identified - - - Benham, 1983 8 Fox Mountain 5120 Phosphate rock 21,400,000 4.84% P205 Subeconomlc resources McCulloch and Neumann, 1982 Diablo 5127 None identified - - - Caps tick and Hyndman, 1982 Matlllja 5129 None identified - - - Lambeth, 1982 Dry Lakes 5131 None identified - - - White, 1982a Sawmill Badlands 5134 None identified - - - Longwill, 1982 9 Cuyama 5135 Gypsum 61,000 90% gypsum Subeconomlc resources Kulzon, 1981 10 276,000 85% gypsum do. do. 11 o 30,000 83% gypsum .do. do. 12 Antimony 5136 Antimony 240,000 2.73% antimony Marginal reserves Kulzon, 1982 230,000 1.02% antimony Subeconomlc resources do. 13 Building stone 85,000,000 Suitable for do. do. (marble) building stone 14 Gold2 , silver2 1,600 0.13 oz/ton gold Marginal reserves do. 0.5 oz/ton silver do. do. 11,000 0.034 oz/ton gold Subeconomlc resources do. 0.27 oz/ton silver do. do. 15 Quatal 05268 Bentonlte2 1,600,000 Suitable for light do. White, 1982b weight aggregate Lltte Pine 05278 None identified - - - Caps tick and Hyndman, 1982b Santa Lucia NF 905 None Identified - - Sabine and Esparza, 1981 Wilderness
Marginal reserves because reserves outside the study area are closer to markets and meet current market demand. Deposits of antimony, barite, copper, gold, gypsum, phosphate rock, silver, uranium, and zinc are probably marginal reserves or subeconomic resources because of combinations of commodity prices, generally low grade and tonnage, high mining and beneficiation costs, and inaccessibility. Probably minable under 1982 conditions. 120 C Area numbers and gross square miles of roadless areas and the Santa Lucia Wilderness, Los Padres National Forest, California
Square miles Square miles (gross) (gross)
San Luis 05002 Sespe-Frazier 05117 La Brea Obispo 05107 Garcia Mountain 05118 Spoor Canyon 05108 Black Mountain 05120 Fox Mountain 05109 La Panza 05127 Diablo 05110 Machesna Mountain 05129 Matilija 05111 Los Machos Hills 05131 Dry Lakes 05112 Big Rocks 05131 Sawmill-Badlands 05113 Stanley Mountain 05135 Cuyama 051 It Miranda Pine 05136 Antimony 05115 Horseshoe Springs 05268 Quatal 05116 Tepusquet Peak 05278 Little Pine NF905 Santa Lucia Wild 35°- Bakersfield Total square miles (gross) Santa Maria
Santa Barbara
AREA OF MAP Figure 1 Index map showing approximate locations of roadless areas and the Santa Lucia Wilderness, Los Padres National Forest, California. 120°
MAP UNITS
Qs I SURFICIAL DEPOSITS (HOLOCENE AND PLEISTOCENE)
Ns SEDIMENTARY ROCKS NEOCENE)
SEDIMENTARY ROCKS (PRE-NEOGENE) AREA OF MAP IGNEOUS AND METAMORPHIC ROCKS PRE-TERTIARY)
EXPLANATION CONTACT FAULT Dotted where concealed THRUST FAULT Dotted where concealed. Sawteeth on upper plate - APPROXIMATE BOUNDARY OF WILDERNESS AND ROADLESS AREAS 119°
35° -
Figure 2 Simplified geologic map of roadless areas and the Santa Luoia Wilderness, Los Padres National Forest, California. Geology from Frizzell and Vedder (1985). See figure 1 for names and locations of roadless areas. 120° EXPLANATION Black Widow prospect : -- (uranium) LOCATION OF IDENTIFIED MINERAL RESOURCES See table I, pamphlet 58 LOCALITY DISCUSSED IN PAMPHLET Clyde's^aylor prospect MODERATE POTENTIAL FOR THE PRESENCE OF UNDISCOVERED PETROLEUM RESOURCES--See Frizzell and CloypooKl9833, Griscom Deer Trail mine See discussion of Sespe-Frazier Roadless Area in pamphlet (mercury) APPROXIMATE BOUNDARY OF WILDERNESS AND ROADLESS AREAS 119° Brush Mountain 35°- QUL prospect / ProsPect 166; (bentonitic clay) / White Rock (marbl White B'rush Fence I / / Antimony Peak\5/'Black Bob Cedar mines Elephant mine Cuyama Phosphate prospect (gypsum)J__/_/._ /...(antimony) ~\/ (gold, silver) /mine (barite) (Au, Ag) Lebec (marble) Wildhorse Mountain Frazier mine prospects (copper, zinc) Santa Barbara Canyon Dom Bosco prospect (gypsum) White Mule Wagon Road prospect (gypsum) Harris-Long Dave mines Frenchmans Point old Hill Group Burgess Canyon prospect ,.-.. (phosphate, gypsurn) artman Ranch Sespe Oil f Wheeler Hot Springs AREA OF MAP Figure 3 Mineral resource potential map of roadless areas and the Santa Lucia Wilderness, Los Padres National Forest, California. See figure 1 for names and locations of roadless areas, figure 2 for simplified geology, and table 1 for identified mineral resources.