Norwich bulletin., 1917-10-20
THE GRANTEES OF CONNECTICUT
But the Stumps of Lofty Land Masses RivaIins The Alps in Height and Rueeedness.

: The United States Geological Sur <ey, department of the interior, has i published a valuable report on. The Granites of Connecticut, copies of ! which can be had on application. The ] magnitude of the granite industry of l New England lends special interest ! and importance to this publication, 1 which describes not only the geologic origin of the granites and their dis ! trtbution, but also the principal fea- 1 lures of the granite industry. New England granite in the form of statu- ary, monuments, bridges. and build tngs is found in almost every part of the United States and even in foreign , countries. In nearly all the eastern states, as we'll as in cities as distant from New England as Vicksburg. Spo- kane, and San Francisco, in Montreal, and in Cuba these granites may be seen in statues or in permanent struc- lures.
 Though the granites are by no means the oldest rocks. they furnish by far the hardest and most durable construction stone, though they differ greatly in hardness among them pressure of 15,00O pounds to the square inch; otkers withstand pres sures exceeding 10000 pounds. The granttes are of plutonic origin, re- sulttng from the cooling of molten rock matter-the magma-which was forced upward from the earth's interior. Be- fore its intrusion this magma existed as fused mass heavily charged with gases and therefore under immense pressure through and among the older rocks it was changed from a fused li- qutd mass to a plastic paste, finally soHdifytng and combining at some places with the older rocks and at these places forming granite rocks such as the gneisses.
 Granitss of Many Kinds and coIors.
 These profound disturbances in ear ly geologic time produced over much of New England deposits of granite and granite rock that is suitable for economic uses, ranging from statue making to road building. The rocks are of many colors-black, white, red, purple, pink. and yellow. The authors of the bulletin, T. Nelson Dale and Herbert E. Gregory. believe that when these granites were formed New En- gland was a mountainous region that stood several thousand feet higher Gregory says: "We may be reasonably sure that mountains of folded strata once occupied Connecticut and that the granttes and gneisses and schists which we see are but the stumps of lofty land masses rivaling the Alps in height and ruggedness."
 Thousands of Feet of Rock Worn
 Away.
 The great cap of overlying rock in to which the granites were intruded has since been largely removed by erosion, so that the grenate is now ex- posed at many places. Some concep- ton of the age of these rocks may be gained from the statement of the Geo. logical Survey that the present rate oS erosion in New England is less than an inch in a thousand years. A good example of the remnant of this an cient capping can he seen at the Wal doboro quarry in Maine. The presence of this great cover, which prevented the rapid cooling of the magma, per mftted the formation of the granite Had the molten masses been forced to the surface and exposed to the air they would have cooled so quickly that the slow process of crystalliza- tfon by which granite is formed would have been arrested by the sudden passage of the material into the solid state, a change that forms a dense glass similar to that in the obsidian cliffs in Yellowstone Park. Instead, the molten masses, forced upward by great pressure against a capping of enormous weight, cooled and solif1ed specialization of the liquor or plas- ttc matter, allowing the molecules of the minerals to arrange themselves in the crystalline form in which, as the microscope shows, they appear in granite. The heat of this molten mass must have been very great, as granite melts at a temperature of 2,000 de- Erees to 2.500 degrees Fahrenheit