The Bridgeport evening farmer., 1912-11-06
CONNECTICUT RICH IN GRANITE
Interesting Data By Geological
 Survey.

That Connecticut is rich in granite is evident from bulletin recently is- sued by the United States geological survey. in the preparation of data for which the survey co-operated with state authorities and Yale scientists. Sixty three quarries were visited.
 The scientists say that the Connec- ticut granites were once in a molten state and hardened as they became ticUt is dealt with in the bulletin. Enormous pressure in changes of the earth's surface was responsible for the
 broken ridge consisting of masses of lava, extending from Meriden to the Massachusetts line Many of the rocks found in the state were original
 filled by soft material, which later hardened. This gives many of the rocks a banded appearance.
 GeologiStS admit that they do not know whether Connecticut was land or sea at the beginning of geological time. It is thought that some of the g1an1tes of life on the earth. one oasls for this deduction is the fact that in the older rocks no fossile have been found. Certain granite found in northern
 Litchfield county dates back probably billions of years. The limestone and
 marbles of Canaan and Danbury are
 time. After the carboniferous age
 mountains and pIateaus were ground down and compressed into the sand stone of central Connecticut The surface was removed by the forces of nature to the depth of a. mile or more and the present granttes and some oth- stunns of lofty land masses rivaling
 the Alps. That lava overra.n the state at one time is evidenced by the ridge now separating the valleys of Farmington and Connecticut Rivers
 During the cretaceolIs time the high lands of Connecticut were lowered and
 plain sloping from northwest to south
 west. Sediments now seen on Long
 Island originally came from Connect
 vas vas 1sp1ifted ee in places and the streams
 began their work of erosion, which
 cut out valleys and formed features
 of hill and valley. during the millions
 of years comprised in the Tertiary age. Then came the glacial age which
 again rernodeled the scenery and GOV
 cred the state with glacial debris.
 Drainage lines were arranged and the
 lakes, swanps and bogS so character
 iatic of the state were formed De
 composed rock was removed from the
 surface, which is of interest to quar-
 rynen, since the granites and other
 stones have been made easier to get at and less expensive to secure.
 z Four types of rocks are used com n1ercially in Connecticut. The lime stone of the west and northwest is chiefly in making lime. The brown stone of East Haven and Portland is an important structural stone The Portland quarry is said to have been the first sandstone quarry worked in 1 America and it's products went into 1 bridges, monuments and buildings be- | fore the Revolution Trap rock ob- | tained from a section between the l Sound and the Massachusetts line is | widely used for concrete work, road 1 making and railroad ballast, Connec- ticut being one of six states producing | fte, although quarried at relatively few places in the state. has increased in importance until its annual produc- tion exceeds in value the sandstone. limestone and trap. A satisfactory future for the granite industry is promised by the transportation faciii- other large building centers. The wide distribution of pegmatiteS or felspar in the state has given it first rank among the states as a producer of crude feldspar
 There are twenty trade varieties of granite gneiss rocks produced in Con- number of rare minerals of little eco homie consequence The mineral make up of tll0 various granites is desscrib- ed technically in the bulletin as are the qualities of the constituent ele- ments, illustrations are given of .Sev- eral forms and varieties of granite and gneisS. The texture of graniteS is described. Specimens of pegmatite are analysed and their occurrence in veins along the Connecticut River at BranchviIle, Plymouth, Portland, ,Glas- f,,r1h1Tr-v. Cso1linsyiIIe Canton and Mid- dletown is dealt with. PoTpflyry, the other principal form of texture in which Connecticut granibes occur, is found at various points Derby, Hart land, and elsewhere. 1
 The granite gneisses cover large areas of the state, but the so-called gneiss in the granite classif1cation) occupy probably less than one-tHalf of 1 per cent. of the 49e0 square miles of the state The bulletin describes the various granites and gneisses, the na- ture of their formation and their ages As to the latter, it is generally sup dates from the earliest. times, and in fact form part of the original earth's crust. Next are taken up the struc- ture, rock variations, Weathering, and of the granitss and their relatives, their rift and grain. sheets. joints. headings, faults, fractures and technical character, which is extended to deal with the granite dikes, veins, knots, etc. Decomposition Of many of the rock masses was caused by the action of rain and other climatic dis taIrbances.
 The bulletin also contains a dot of geological observations at the various quarries throughout the state The economic discussion is also detailed, the quarTies being taken up by coun- ties, the name and location of each name of owner, name and description of the several varieties of stone char age of quarry and extent of deposits. of the plant, transporta- tfon facilities. use of explosives, uses and chief markets of the product. Quarries at Greenwich, Stony Creek, Waterford, Millstone, Easton, Mason's Island and other points have fine transportation. 1
 The quarries are classified according to the uses of their products, as fol- lows: Constructdona1. monumental. in curbing and trimming, paving and miscellaneous. The quar- ries listed are located at Stonington. Branford, Gui1ford, Bristol, Greenwich, Mfddletown, Lyme Norfolk, Roxbury, Wafe 7Tf7 azf 1