If what has been stated above be true then for an interval of time almost incalculable the surface of Vertnont lay exposed to erosional agencies by which it must have been greatly modified, for, except the narrow band of Terti ary mentioned, there are no strata between the Ordovician and the Pleistocene. These latter deposits are everywhere the conspicuous fea tures of the surface below the hills and moun tains.
The great ice-sheet of the Early Pleistocene sold the flood*. dust followed' its melting have left abundant evidence of their activity every where. Whether there was a single movement of the ice over the surface or several cannot be determined. There was one so great that if there were others before it, as in many parts of the country, all traces of them have been obliterated and we have traces of but one, that of Later Wisconsin time. By the age-long erosion before the Pleistocene and the more rapid wearing and tearing of the rocks during glacial activity enormous quantities of solid rock were crushed, ground, worn to small bits and this loose material was seized by the tor rents that followed the melting of the ice and distributed in sand hills, plains and deltas, gravel mounds, clay banks and all the rest of the many and plain evidences of the work of ice, water and atmospheric forces during long geological periods.
Museral Resourees.—Although mines of iron, copper, gold, manganese have in past years been opened and worked more or less in Ver mont, none of them have in the long run been profitable, though iron and especially copper mines have for a time paid- for working and there are still a few deposits of copper (Chalcopyrite) which are active. Asbestos has been mined to some extent. Talc is now mined more than ever before. There is good promise of increased work at these mines and during the last few years Vermont has produced more talc than any other State. Kaolin, ochre and fire day are dug and purified, ready for market at Brandon, Bennington and several other lo calities. These industries are small when com pared with the very large amount of marble, granite and slate which is annually quarried and sold. For more than a century Vermont has produced these materials in far greater quan tity than any other State except Pennsylvania, which has exceeded this in slate. For many years the marble sold from Vermont was from 80 to 85 per cent of the entire sales for the whole country and, though latterly other lo calities have produced considerable amounts of good marble, Vermont still produces 43 per cent of the country's total.
Marble was quarried in Vermont at least as early as 1785, but only a few blocks were taken from small quarries in Dorset and West Rut land in the early days and the business did not become very important before 1850. Since this thne the production and sale of marble has in creased until at the outbreak of the war (1917) the annual sales reached a million cubic feet or more. While there are a few quarries out side of Rutland County, most of the marble comes from that region and is generally known as Rutland marble. Here the stone is a very pure
lime carbonate and is mainly the result of more or less completely metamorphosed Ordovician limestone. The marble is mostly light in color and the variety in shade and tint is well nigh endless from pure white statuary to almost black. Blue, pink, yellow, gray and black veins, clouds and blotches are seen in different layers. These shades are distributed through a lighter mass and in varying proportion so that hardly two pieces of what are called ufancy marbles* are exactly alike. There tnay be more than 20 varieties, all fine, in a single quarry. On the other hand the standard varieties can readily be matched, if necessary, in color and shade.
More than 100 shades of marble can be ob tained in the quarries of the Vermont Marble Company, which controls by far the greater part of the marble of the State, but about 50 are as many as are usually kept on the market. The others are quarried when called for. At Swanton, in northern Vermont, a red and white dolomite is quarried and sold largely for floor tiling as it is very hard and durable and in Roxbury a very handsome serpentine marble, verde antique, is obtained, both by this com pany. These are not true marbles, but they are very beautiful for interior finish. The granite industry is of more recent development and it is only within a few years that Vermont has led the world in the production of this stone, but it has now a pre-eminence which seems certain to remain. The granite quarries are far more numerous and widely distributed than those of marble. As all the producing marble quarries are in the western part of the State, so all the granite is quarried east of the Green Mountains. It is of igneous origin and geologically later than the marble or slate. Barre, Hardwick, Wood bury and Bethel are the most important granite centres, but there are many other localities that produce smaller quantities. All Vermont gran ite is of lighter or darker shades of gray, no red granite being quarried, though there is a little in the State. The claim of Barre that it is the greatest granite centre in the world appears well-founded. At this place the an nual payroll is reported by the board of trade as not less than $4,000,000. Mount Ascutney in Windsor, near the Conhecticut River, is a pe culiar intrusive mass and on its slopes there has been quarried the 4Windsor Green Gran ite,* which is a dark syenite of various shades of olive green. Columns in the library of Columbia University and the sarcophagi of President McKinley and his wife are examples of this stone. In normal business years the mineral products of the State reach an aggre gate value of about $9,000,000. Slate is found on both sides of the Green Mountains, but for a long time all that has been sold has been taken from quarries in the extreme western border in Rutland County. Though not a very close second, Vermont produces more slate than any other State except Pennsylvania. The colors are mostly shades of green and purple, though gray slate is found.