SU0006291 - Laserfiche WebLink

Home Browse Search

1 KRC's sand and gravel deposits are included in .the Laguna Formation. . ' Underlying the Laguna is the Tertiary-age Mehrten Formation. The Mehrten Formation,consists of well rounded'andesitic'conglomerate, sandstone, siltstone, ;and•claystone of n.onmarine,,typically.fluvial origins. The units are stint fled but discontinuous over,large areas;'with.cut and fill channeling. Mudflow-.idepoits r denved from the Sierra Nevada occur`as mterbeds.. The'- t � pnncipal source of:the 'La rocks. They are though .toha been dewed fr �ments �s eroded metamorphic ornm tarnorphics in the Sierra Nevada Mountains to the east by glacial erosion and washed.to the>r :present Location by:glacial melt water:' Pebbles and:cobbles of the'LUguna Formation are hrghly siliceous .metamorphic.' quartzite, which: are extremely tough and very durable .Finer fractions of the-Lagtina Formation include sand,silt; and clays. The California Division,of Mines roand Geology (DMG) classifies .mostof the deposits in the project area as"Mineral Resource Zone 2 (MRZ-2). MRZ-2 areas have adequate information'indicating that sigriificant mineral deposits are present, or a highlikelihood for their presence exists. .This zone is. applied to known mineral deposits or where it can be demonstrated that the likelihood for occurrence of significant mineral deposits is high. The remainder is classified as MRZ-3. MRZ-3 areas contain aggregate deposits, the significance of which could not,be evaluated from the data available at the time of the DMG's report (1988). However, KRC has explored these areas and found deposits of aggregates similar to the MRZ-2 areas. According to the initial study for the existing KRC permit, the project will not result in, or be subject to, potentially hazardous geologic or soil conditions on or immediately adjacent to the site including slides, liquification or earthquake faults. c. Hydrology-Describe surface and ground water resources. There are several manmade surface water features on the Permit Area. These ponds are used primarily as stock ponds for cattle ranching(see Exhibit II). In the existing permit area there are also manmade reservoirs used in the aggregate processing operations that are located at the processing plant. Aggregate mined in the new permit area will be transported to the existing plant for processing, including crushing, screening, sorting, and stockpiling. Several ephemeral drainages are located within the proposed Permit Area (see Exhibit II). These drainages are tributaries to Bear Creek to the northwest, but only flow in response to seasonal precipitation during the winter and spring and are dry during the rest of the year. Some portions of the drainages support a noticeable variation in flora compared to surrounding areas_ KRC is not proposing any excavation activities along those portions of the drainages that contain higher concentrations of Blue Oak trees. These avoidance areas are shown on Exhibit II. Other smaller ephemeral drainages are located within the Distribution Copy Page 2 of 14 August 2, 2006