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16 DIVISION OF MINES AND GEOLOGY SR 160
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<br /> the apex.The general composition of Sector A-I is 55 percent A-2v and A-2w because of the proximity to the Delta-Mendota
<br /> - gravel, 30 percent sand, 15 percent silt/clay, which is consistent Canal.As a compromise, Lone Star Industries, Inc. was
<br /> with its location at the apex of the fan where coarse material has allowed by San Joaquin County to mine below the water table
<br /> been deposited by Corral Follow Creek. The other sectors(A-2, in their existing pits.
<br /> A-3,A4)contain higher percentages of clay because Corral
<br /> Hollow Creek has carried finer sediment to their locations in Teichert Aggregates has holdings in Sector A-2 which they
<br /> the distal portions of the fan. Due to the erratic nature of allu- are not presently mining.
<br /> vial fan sedimentation,clay lenses occur throughout the Corral
<br /> Hollow Creek deposit and certain areas of Sector A-I can con- SECTOR A-3
<br /> tain clay in amounts as high as 50 percent.
<br /> Sector A-3 contains three subsectors, each composed of 60
<br /> Currently,Granite Construction is the only operator produc- percent PCC-grade aggregate. All three subsectors are permitted
<br />` ing aggregate in Sector A-1. Lone Star Industries,Inc. has ob- by Teichert Aggregates,which has been mining in the Corral.
<br /> tained a mining permit in this sector, but is not in production Hollow Creek deposit since 1955..Teichert Aggregates'reserves
<br /> yet- Mining in this sector averages 70 to 120 feet below the contain 40 percent clay, 30 percent gravel and 30 percent sand.
<br /> surface,depending on whether or not isolated clay lenses are Teichert Aggregates, Inc. is permitted to mine to the water table,
<br /> encountered at the mine site, which is approximately 90 to I00 feet below the surface in this
<br /> sector.
<br /> SECTOR A-2
<br /> SECTOR A-4
<br /> Sector A-2, which has been divided into 26 subsectors,
<br /> contains approximately 68 percent PCC-grade aggregate and 32 Sector A4, which is divided into two subsectors,contains
<br /> percent clay and silt. Lone Star Industries, Inc. is producing Iand with 50 percent PCC-grade aggregate. Both subsectors,
<br /> PCC-grade aggregate from portions of this sector. Most of the which have not been previously mined,are permitted by Lone
<br /> available aggregate resources in Sector A that are not currently Star Industries,Inc. The material in Lone Star's property has a
<br /> permitted for mining are contained within Sector A-2. Large high clay content of 50 percent. The property immediately to the
<br /> portions of land in the north-central portion of Sector A-2 are east of this sector is zoned MIZZ-3 because of high percentages
<br /> not sectorized because f inclusion s o m sfon in the City of Tracy's spe- of clay.
<br /> cificP lan.
<br /> SECTOR B--LONE TREE CREEK ALLUVIAL FAN
<br /> n{ti Lone Star Industries, Inc. has been mining in this sector since
<br /> 1947. Due to previous mining, large portions of Lone Star's Sector B (Lone Tree Creek alluvial fan)covers 2.5 square
<br /> holdings are depleted and are classified MRZ-1.The clay content miles- Sector B has never been mined and was classified on
<br /> in these gravel pits varies from 15 to 50 percent. The high clay the basis of Caltrans test data, water well-log data and geologic
<br /> percentages occur below the 20-foot-thick clay lens. The average similarity with the Hospital Creek alluvial fan which contains
<br /> clay content is approximately 32 percent, with 34 percent sand proven deposits of PCC-grade aggregate. Geologic mapping by
<br /> and 34 percent gravel. Lone Star Industries, Inc. is permitted to Lettis(1976)delineated the general shape of the fan and water
<br /> mine 40 to 50 feet below the water table. The water table occurs well-logs provided depth control. An average depth of 25 feet
<br /> approximately 97 feet below the surface. Lone Star Industries, was used in our calculations. The waste factor of 10 percent,
<br /> Inc. was not permitted to mine their property in Subsectors used for resource calculations,was extrapolated from Sector C.
<br /> Table 3. Aggregofe resources in Sector A-7.
<br /> THICK-
<br /> NESS PERCENT
<br /> SUB- TOTAL ACRES (feet) PCC RESERVES RESOURCES
<br /> SECTOR ACRES PERMITTED [reserve] GRADE (tons) (tons)
<br /> A-lo 4 135 85 1,000,000
<br /> A-1 b 3 135 85 800,000
<br /> A-lc 3 3 [501 85
<br /> A-ld 9 9 [601 85
<br /> A-le 24 135 85 4,500,000
<br /> A-If 16 135 85 2,500,000
<br /> A-19 37 135 85 7,300,000
<br /> A-lh 144 144 [125] 85 '
<br /> A-1i 46 105 85 8,100,000
<br /> A-1i 28 28 135[301 85 '
<br /> A-lk 68 68 105[60] 85 '
<br /> A-11 16 135 85 2,100,000
<br /> A-lm 37 135 85 7,800,000
<br /> A-In 22 22 1321871 85 '
<br /> A-lo 42 42 1341601 85
<br /> A-lp 53 53 132167] 85 '
<br /> A-lq 28 135 85 5,700,000
<br /> SUBTOTALS
<br /> 580 369 97,600,000
<br /> 'Prapr7eiary data -
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