Show BG W ROCKS 9 GO FAK W HUGE SCATTERED OVER NORTHERN STATES BY WIDE SWEEP OF 01 acher ICE DECLARED MILES DEEP congealed liau d in baitt quantities flowed far down MIss isis api val ley underlying strata high ly polished by motion BY G FREDERICK WRIGHT A M LL D author of the ice age in north amer lea man and the glacial pe et copyright joseph bowles the story of the glacial period has not been half told its wonders are increasing every day it Is the last of the great geological epochs and has not yet passed away greenland Is still shivering under the rigors of glacial conditions with the etcel tion of a narrow belt of mountains around the southern end the whole continent some square miles in extent is still buried beneath ice from one mile to two miles deep while the antarctic continent with a still greater area is so completely en in ice that explorers have yet been able to penetrate only the merest fringe at two or three points bui during the glac al period prop er the ice to a depth of more than a mile covered 4 square miles of north america and 2 square miles in europe in north america the southern border of this ice field extended into the ocean off the new england coast rising like a great ice wall out of the water and westward the former et ent ot the swiss glaciers agassi went ti great brit ain and came to america and abed those investigations which have shown the spread of glacial ice over the areas already ment lourd boulders bowl ders cover cothern cT thern ger many and are fa and TOO v ties south east at kief in lussia l found at cumbia 60 miles up the caage river which comes down from the uplift to the south they are aasc j found on the south side of the kansas river as far west as lawrence and to peka while windrows of them are found in central dakota which hav been derived from ledges la the vl of lake superior the size of these ice transported boulders bowl ders la certainly surprising sev eral in switzerland which have beet moved more than miles weigh more than a thousand tons apiece the celebrated alerre a bot a above neufchatel switzer land measured 60 by 20 by 40 feet containing about 40 cubic feet while another near monthey contained more than 60 cubic feet ship rock near peabody mass Is a glacially transported boulder bowlder esti mated to weigh 1100 tons while mo began rock in montville conn near norwich would weigh 10 tons at madison N H there Is a boulder bowlder measuring 30 by 40 by 75 feet which can be traced to ledges of conway granite about two miles away the called judge s cave or west rock near new haven conn Is formed by a transported boulder bowlder weighing 1 tons which can be traced to well known dykes of trap 16 miles to the north A granite boulder bowlder near lebanon 0 view of an antarctic ice sheet to a line running through long island across new jersey and pennsylvania to salamanca N Y where it turned southwestward and with many minor variations reached the ohio river 50 or 60 miles above cincinnati crossed kentucky and southern indiana reach ing its farthest extent at carbondale thence northwest it crossed the mississippi river at st louis and tol lowed the missouri and kansas rivers to topeka where it swung northward across the eastern parts of kansas and nebraska and through central dakota to near the canada line thence proceeding with a long loop where it crossed the rocky mountains and the sierras to puget sound and the pacific ocean if one had ap preached pro ached this line during the glacial period anywhere from the south he would hae immediately struck the conditions of greenland and found them continuous for thousands of miles alaska still retains the stumps of this great glacier several hundred square miles being covered by the melr glacier alone and a still larger area by the malaspina glacier which comes down from mount st ellas in europe the ice felds radiated from the scandinavian peninsula extending across the north sea to southern eng land and across the baltic to central germany and southeastern russia in thinking of the glacial period it should be kept clearly in mind that glac al ice is simply compressed snow glaciers are formed wherever there Is a snowfall which exceeds the melting power of the warm season everyone is familiar with the fact that a snow ball may be made as hard as ice by sufficient pressure in the hands that ice in great masses could flow like cold tar or molasses or any other semi fluid seemed until a short time ago impossible and did not enter into the thought of mankind but about 70 years ago it was demonstrated in switzerland that the ice was actually moving down the valleys proceeding not like an avalanche but creeping with a true flow and carrying on its back and frozen into its mass frag ments of rock of varying sizes some of them being as large as a small house under the lee of one of these rock masses on top of the aar glacier aga siz built him a hut and conducted many of his important observations the great extent of this glacial movement in former times was shown by the distance which some of these boulders bowl ders had been carried in north america the transportation of boulders bowl ders by glacial ice has been even more remarkable the back bone of cape cod and long island a line of hills from one h adred to two hundred feet high and two or three miles broad is simply a pile of bowl ders and small fragments transported from new england to canada ply mouth rock Is a glacial boulder bowlder which journeyed from its northern home thousands ot years before the pilgrims set out from holland bowl ders from the adirondack mountains are found upon the summits of the alleghenies in northeastern pennsyl vania in southern ohio there are long belts of canadian boulders bowl ders which can be traced to ledges of north ot lake huron aven in boone county kentucky a few miles south of cincinnati a numb r of rid jasper conglomerate boulders bowl ders some of them two or three feet in di in eter have been found which came from well known ledges in canada north of lake huron boulders Bowl ders of large size from these same ledges have also been found as far southwest as keokuk la boulders Bowl ders from wisconsin and minne sota and dakota abound in northern missouri down to the missouri river s me having recently een uncovered armed with these facts concerning which was brought by the ice from canada measures 17 by 13 feet ditl eight feet out of ground and evident a much larger mass under the ground but prof aiton has described a mass of clinton limestone in freeport war ren county ohio which Is tl ree fourths of an acre in area and 16 fee in thickness which has been broughm several miles the central part northern iowa contains a great num her ot boulders bowl ders ot exceptional size brought from several hundred miles away one of them furnished 1 ulla ing stone enough to construct an en tire church although these transported boulders bowl ders are such striking witnesses to the slow but majestic movement of ice during the glacial period they are a re by no means the only ones As the ice slowly crept over the surface frag ments of rock became frozen anto its lower strata and boulders bowl ders gravel sand and clay were dragged alona be neath it furrowing and scratching and poll hing the surface of the to an degree aimasi anywhere over this glaciated area th removal of the soli will revea scratched and polished rocks under neath the direction of the saratt hes and the grooves shows the direct lor in which the ice was moving at th time they were made this was in the main outward toward the mar gin of the glaciated area which we have described but there were mm curious variations in central ohio the direction of the glacial scratched scra tche Is southeast whereas on the islai ds in the western part of lake erie it Is very nearly west at logansport Logan sport ind extensive grooves and scratch s have been found where the movement Is toward the north this variation in the direction of the grooves and scratches indicates that there were eddies in the ice such as are found 11 the current of a deep stream of water the groove on the islands in the western end of lake erie are among the most remarkable in the world one groove in hard limestone was about 20 feet broad and eight feet deep extend ing for a long distance across kelley island the surface of this groove Is most finely polished corals and other fossils being cut off as sharply as could be done by any graver s tool the direction of these grooves in the bed of lake erie Is evidently due to the tact that the depression of the lal e diverted the ice movement in its closing stages in the diction of its longer diameter toward the natural outlet on tha west |