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- 42 - <br /> <br />' Coal is currently being mined mainly from the D seam at a depth of more than <br />150 feet underground and in a horizontal N-S direction west of the main incline access <br />' to the Sunlight Mine. The seam is 9 feet thick and appears to be uniform within the <br />mine. The coal is high volatile A or B bituminous (Table G.1) The Sunlight Mine <br />produced 471 tons of coal in 1979, and has an average work force of five. At a depth <br />' of about 130 feet, a horizontal adit branches off_to the south from the main incline <br />access for about 30 feet at which point work on a rock tunnel, opening down to the <br />lower seam C was in progress. <br />The D seam and overlying and underlying strata were sampled at the horizontal <br />' adit. Details of the stratigraphy at this level are given on the STRAT Format, Table <br />' G.2, the general features, from top to bottom, being as follows: <br />Shale, black, carbonaceous, thinly bedded, thickness not determined <br />Coal (D seam); 9 feet thick <br />Shaly sandstone or sandy shale, grey, fossiliferous, massive, thickness not <br />' determined. <br />' Analysis of the physical properties of these rocks (Table G.3), shows that the <br />overlying stratum consists of 41% silt, 33%sand, and 26% clay fractions while the <br />' underlying stratum is composed of 77% sand, 14% silt, and 9% clay. The coal gives R6% <br />sand, 8% clay and 6% silt fractions. <br />' Saturated water extract analysis (Table G3) indicates a calcium <br />' -magnesi~im-sulphate composition for the coal seam and the overburden shale, while the <br />underlying stratum appears to give calcium-magnesium-bicarbonate composition. The <br />' carbonate content is ~~niformly low in all three strata as is also the bicarbonate in the <br />coal seam. The low contents in carbonate and bicarbonate ions and the relatively high <br />' concentrations of iron and sulfate probably account for the acidity (3.8 pH) of the <br />extract from the coal seam. The same may be true for the relatively lower pH of the <br />' shale o~~erburden. <br />' Fluoride is higher in the coal seam than in the overburden and underlying strata. <br />1 <br />-' 24 <br />