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sandstone
10 paragraphs · about 3 minutes
Every paragraph the index cites under sandstone, once, in the order of the book. Beside each stand the entries that cite it.
58:7.9During these times of primitive marine life, extensive areas of the continental shores sank beneath the seas from a few feet to half a mile. Much of the older sandstone and conglomerates represents the sedimentary accumulations of these ancient shores. The sedimentary rocks belonging to this early stratification rest directly upon those layers which date back far beyond the origin of life, back to the early appearance of the world-wide ocean.
59:1.112. Sandstones—deposits made in shallow water but where the waves were sufficient to prevent mud settling.
59:1.12–15 · four paragraphs not cited here ·
59:1.123. Shales—deposits made in the deeper and more quiet water.
59:1.134. Limestone—including the deposits of trilobite shells in deep water.
59:1.14The trilobite fossils of these times present certain basic uniformities coupled with certain well-marked variations. The early animals developing from the three original life implantations were characteristic; those appearing in the Western Hemisphere were slightly different from those of the Eurasian group and from the Australasian or Australian-Antarctic type.
59:1.15370,000,000 years ago the great and almost total submergence of North and South America occurred, followed by the sinking of Africa and Australia. Only certain parts of North America remained above these shallow Cambrian seas. Five million years later the seas were retreating before the rising land. And all of these phenomena of land sinking and land rising were undramatic, taking place slowly over millions of years.
59:1.16The trilobite fossil-bearing strata of this epoch outcrop here and there throughout all the continents except in central Asia. In many regions these rocks are horizontal, but in the mountains they are tilted and distorted because of pressure and folding. And such pressure has, in many places, changed the original character of these deposits. Sandstone has been turned into quartz, shale has been changed to slate, while limestone has been converted into marble.
59:4.7Following these submergences, many of the shore lines were considerably elevated so that the earlier deposits were covered by mud or shale. There is also a red sandstone stratum which characterizes one of the Devonian sedimentations, and this red layer extends over much of the earth’s surface, being found in North and South America, Europe, Russia, China, Africa, and Australia. Such red deposits are suggestive of arid or semiarid conditions, but the climate of this epoch was still mild and even.
59:5.10The deposits of this early Carboniferous age are from 500 to 2,000 feet thick, consisting of sandstone, shale, and limestone. The oldest strata yield the fossils of both land and marine animals and plants, along with much gravel and basin sediments. Little workable coal is found in these older strata. These depositions throughout Europe are very similar to those laid down over North America.
60:1.1The erosion deposits of this period were mostly conglomerates, shale, and sandstone. The gypsum and red layers throughout these sedimentations over both America and Europe indicate that the climate of these continents was arid. These arid districts were subjected to great erosion from the violent and periodic cloudbursts on the surrounding highlands.
60:1.2Few fossils are to be found in these layers, but numerous sandstone footprints of the land reptiles may be observed. In many regions the one thousand feet of red sandstone deposit of this period contains no fossils. The life of land animals was continuous only in certain parts of Africa.
60:1.3These deposits vary in thickness from 3,000 to 10,000 feet, even being 18,000 on the Pacific coast. Lava was later forced in between many of these layers. The Palisades of the Hudson River were formed by the extrusion of basalt lava between these Triassic strata. Volcanic action was extensive in different parts of the world.
60:1.4Over Europe, especially Germany and Russia, may be found deposits of this period. In England the New Red Sandstone belongs to this epoch. Limestone was laid down in the southern Alps as the result of a sea invasion and may now be seen as the peculiar dolomite limestone walls, peaks, and pillars of those regions. This layer is to be found all over Africa and Australia. The Carrara marble comes from such modified limestone. Nothing of this period will be found in the southern regions of South America as that part of the continent remained down and hence presents only a water or marine deposit continuous with the preceding and succeeding epochs.
60:3.9The deposits of chalk and greensand marl give name to this period. The sedimentations of these times are variegated, consisting of chalk, shale, sandstone, and small amounts of limestone, together with inferior coal or lignite, and in many regions they contain oil. These layers vary in thickness from 200 feet in some places to 10,000 feet in western North America and numerous European localities. Along the eastern borders of the Rocky Mountains these deposits may be observed in the uptilted foothills.
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Cited alongside: shale, Europe, limestone, Africa, South America, Australia, conglomerates, fossils