human
or
gpt
or
human
in scattered deposits of stones, clay, gravel and _débris_ of all kinds, brought down from the northward as the ice moved along, and irregularly dumped upon the surface, thickly in some places and thinly in others, with many boulders, some of enormous size. It abraded all the rock surfaces crossed, and transported and rounded and striated the fragments torn off in its resistless passage. The line of farthest southern advance of the ice is shown by the
gpt
Terminal Moraine, stretching across country, which put the obstructions into the
human
Foul Rift. A glacier always pushes up at its foot a mound of material composed of fragments of rocks of all shapes and sizes, which the ice has taken up at various points along its flow and carried to its terminus, thus forming the moraine. This
gpt
Terminal Moraine has been traced and carefully studied for four hundred miles across Pennsylvania, showing throughout a remarkable accumulation of drift materials and boulders, heaped into irregular hills and hollows over a strip of land nearly a mile wide. The action of the Delaware River currents at the
human
Foul Rift
gpt
upon the rocks of the Kittatinny near the Water Gap, where some ponderous fragment, imbedded in the ice, as it moved along has gouged out a great scratch six feet wide and seventy feet in length. Although this ice had evidently resistless power in its slow motion, yet it seems to have had small influence upon the topography of the country. It appears to have merely
human
the surfaces of the rocks. It passed bodily across the sharp edges of the upright sandstone strata of the Kittatinny, yet has not had appreciable effect in cutting the ridge down, the glaciated portion east of the
gpt
Wind Gap appearing as high and as sharply defined as the unglaciated part to the westward of the moraine. The glacier made many lakes north of the moraine, due to the
human
and obstruction of streams by unequal deposits of drift. It is inferred in the estimates of the duration of the glacier, from astronomical data, that the cold period began two hundred and eighty thousand years ago, the greatest cold being many thousand years later. The intense cold began moderating eighty thousand years ago, but the sea of ice remained long afterwards, and steadily diminished under the increasing heat. So many thousand years being required for melting, there are data inducing the belief that the ice-cap did not retreat from this part of the country back to Greenland until within ten thousand or fifteen thousand years ago. Then came the floods of water from the melting glacier, and it is significant that the Indians in the spacious valley northwest of the Kittatinny called that fertile region the
gpt
Minisink, meaning