1.7 (218.8) | Turn left, STOP 8, Manzanar Relocation Camp. Here we will take a few moments to view the memorial and be reminded of one of the insanities of World War II. The high peak directly west is Mt. Williamson (14,384'). |
0.6 (219.4) | Reward-Manzanar Road on right. To the left at 9:00, the base of the Sierra is marked by a well-exposed scarp along the Independence Fault (Fresno Map Sheet). |
3.7 (223.1) | On the crest of the Inyo Mountains at 3:00, at the low point on the skyline, is the Paiute Monument, a natural monolith of granite 80 feet high. This is in the center of the Paiute Monument pluton, one of several plutons making up this part of the southern Inyo Mountains. |
1.4 (224.5) | Enter Independence, the county seat of Inyo County. |
0.5 (225.0) | The rock in front of the Independence Court House, on the right, is not a movie rock, but rather a bizzarly weathered bit of the Bishop rhyolite tuff which we will see on the second day of the trip. |
1.8 (226.8) | On the Inyo Mountains to the right, the barren, rocky exposures are the Santa Rita Flat pluton. Beyond, the wooded area is underlain by a westward dipping succession of rocks from upper Cambrian to Pennsylvanian in age. |
2.0 (228.8) | The Poverty Hills lie ahead in the distance; the Big Pine Volcanic Field at 10-12:00. |
4.0 (232.8) | Sawmill Canyon at 9:00. If the light is right, you may be able to discern a black basalt filling part of the lower canyon. The basalt has been dated at about 100,000 years. It is of special interest as the flow rests upon glacial moraine material and is overlain by a younger moraine. |
1.0 (233.8) | Here the highway passes across very recent lavas, which are apart of the Big Pine Volcanic field. For the next several miles, we can see basaltic flows and cones on both sides of the valley, and along the center. Those along the sides are closely related to the faults bounding the Sierra Nevada and the Inyo Mountains, suggesting that these faults extend deep within the crust, and have tapped deep-seated sources. The youth of the flows is suggested by their essentially unweathered surfaces and the fact that several have been poured out over alluvial fans. |
Plate 4 is a photo mosaic of the volcanic rich part of the Owens Valley from here to Big Pine. | |
1.6 (235.4) | Rest area on right. |
3.9 (239.3) | Enter Mariposa Geologic Map Sheet, just beyond Taboose Creek. Red Mountain at 10:00. |
0.9 (240.2) | To the right at approximately 3:00, several volcanic cones and a large basalt flow are related to the intersection of the Inyo Mountains frontal fault and a major northwest trending fault within the range. |
East of the volcanics, Papoose Flat occupies the lowest part of the mountain crest. | |
1.6 (241.8) | The Poverty Hills lie ahead at 10-12:00. The Poverty Hills are in a sense similar to the Alabama Hills, in that they are a block of bedrock isolated from the Sierran front, although they are not so clearly marked by a bounding fault. They comprise a block of Mississippian to Permian argillites and marbles intruded by the Jurassic Tinemaha granodiorite (Plate 5). |
1.1 (242.9) | Wild Life Viewpoint. The sign refers to a herd of seldom seen Tule Elk, which were introduced into the Owens Valley in 1933.The size of the herd is managed by controlled hunts in an attempt to maintain a population of near 300. |
1.1 (244.0) | Tinemaha Reservoir at 3:00; Crater Mountain at 10-11:00. At the south end we can see the granite bedrock core upon which Crater Mountain has been built. The prominent 1872 earthquake scarp is visible along the east flank of the volcano. |
Across the Tinemaha Reservoir, the west flank of the Inyo Mountains exposes rather complex geology. The dark colored exposures at the base of the range are middle to late Paleozoic sedimentary rocks representing the lower plate of the Last Chance thrust, of which we will hear more later. Rocks higher on the mountain front range in age from late Precambrian to middle Cambrian in complex fold and fault relationships and represent the upper plate of the thrust. | |
1.0 (245.0) | Pleistocene Waucobi Lake beds (white), and the Waucobi embayment (Plate 7) at 1:00. |
As we approach Big Pine, the Sierran front is more subdued than farther south (Plate 6). | |
1.5 (246.5) | The Coyote Warp (Fig. 9) , of which we will hear more on the second day, can be seen at 11:00. |
4.4 (250.9) | Upon entering Big Pine, turn left at intersection of 395 and Crocker Street (at the Chevron Station). Proceed west on Glacier Lodge Road. |
0.7 (251.6) | Glacier Lodge Road turns left and ascends the sharp 1872 fault scarp. |
1.0 (252.6) | Turn right onto Sugar Loaf Road (stay on paved road) to Camp Inyo. |
Camp Inyo is a former fruit ranch (called the Owens Valley Ranch) which was purchased by the Los Angeles Department of Water and Power. They have leased it to the Inyo County Schools, who in turn make it available to other educational units. We will have the use of the amphitheater (for cooking), the shower and toilet facilities, and the meadow (for sleeping). We do not have use of the dormitory facilities. | |
Depending on your inclination, you may wish to explore Sugar Loaf, which is the striped hill just west of Camp Inyo. For that purpose, a copy of a geologic map (Fig. 17, ahead) is enclosed in the guidebook. Sugar Loaf is of interest because recent fossils found there have allowed direct correlation of these Sierran metasedimentary pendant rocks with early Cambrian rocks across Owens Valley in the White-Inyo Range. | |
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For tomorrow morning, we will be divided into two groups. Group A will be the larger and will examine surface geology between Big Pine and the Pine Creek Mine, by way of Bishop Canyon. Group B, limited to 15 persons, will travel directly from Big Pine to the mine and spend several hours touring the mill and mine. | |