Report on the geology of the state of Maine . yke in the quarry, three feet wide, but not of sufficient powerto have induced all the changes that have taken place. Crocketts quarry, adjacent to the one above noticed, ismore interesting. There the lines of stratification are seenonly in the different shades of color the rock presents, andthe limestone is a mixture of blue, white and crystallineparticles. The coloring matter, as ascertained by analysis,is chiefly carbon and oxide of iron. By measurement, it wasascertained by Dr. Purrington, that this quarry was 272 feetlong, 80 feet broad, 27 fe
Report on the geology of the state of Maine . yke in the quarry, three feet wide, but not of sufficient powerto have induced all the changes that have taken place. Crocketts quarry, adjacent to the one above noticed, ismore interesting. There the lines of stratification are seenonly in the different shades of color the rock presents, andthe limestone is a mixture of blue, white and crystallineparticles. The coloring matter, as ascertained by analysis,is chiefly carbon and oxide of iron. By measurement, it wasascertained by Dr. Purrington, that this quarry was 272 feetlong, 80 feet broad, 27 feet deep, and yields 30,000 casks oflime annually. The lines of stratification run N. E. and S. most remarkable object, at this locality, is its trap dyke,which stands like a wall in its centre, rising to the height of30 feet, and the excavations have been made from eitherside. This dyke is 10 feet in thickness at its widest part,and it narrows at either extremity to an edge. The followingdiagram exhibits a section of this quarry. a b a. 30 feet. W. N. W. <« E. c c Trap dyke, Crocketts Quarry, Thomaston. a a Strata of blue limestone. b Dyke of greenstone trap-rock,c c White crystalline limestone. 52 TOPOGRAPHICAL GEOLOGY. The limestone, at its junction with the dyke, is closelycemented to it, and is converted into a perfectly white crys-talline variety, which loses this character in proportion toits distance from the dyke. The same fact was observed inall the quarries thus intersected. The Meadow quarries are generally marked by exactlysuch appearances as I have above described. They aresituated in the midst of a plain, and are wrought to the depthof 10 or 15 feet. They are in the possession of about 60individuals, and the particular quarries are named accordingto their proprietors. These quarries bear a general resem-blance to each other, so that there would be no advantagein separating them for particular description. They are allcut across by a series of zig-za
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