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Rh parts of the world there resulted a distinct break in the sequence of fossil remains. Great tracts of our modern continental land areas gradually emerged, and several mountainous tracts began to be elevated, such as the Appalachians, parts of the Cordilleras, and the Rocky Mountains, and their northern continuation, and indeed the greater part of the western N. American continent was intensely affected; the uplifting was associated with extensive faulting. Volcanic activity was in abeyance in Europe and in much of Asia, but in America there were many eruptions and intrusions of igneous rock towards the close of the period. Diabases and peridotites had been formed during the Lower Cretaceous in the San Luis Obispo region. Great masses of ash and conglomerate occur in the Crow’s Nest Pass in Canada; porphyries and porphyritic tuffs of later Cretaceous age are important in the Andes; while similar rocks are found in the Lower Cretaceous of New Zealand. It is, however, in the Deccan lava flows of India that we find eruptions on a scale more vast than any that have been recorded either before or since. These outpourings of lava cover 200,000 sq. m. and are from 4000 to 6000 ft. thick. They lie upon an eroded Cenomanian surface and are to some extent interbedded with Upper Cretaceous sediments.

Economic Products of Cretaceous Rocks.—Coal is one of the most important products of the rocks of this system. The principal Cretaceous coal-bearing area is in the western interior of N. America, where an enormous amount of coal—mostly lignitic, but in places converted into anthracite—lies in the rocks at the foot of the Rocky Mountains; most of this is of Laramie age. Similar beds occur locally in Montana. Coal seams of Lower Cretaceous age are found in the Black Hills (S. Dakota), Alaska, Greenland, and in New Zealand; and the “Upper Quader” of Löwenberg in Silesia also contains coal seams. Coals also occur in the brackish and fresh-water deposits of Carinthia, Dalmatia and Istria, while unimportant lignitic beds are known in many other regions. The Fort Pierre beds are oil-bearing at Boulder, Colorado; and the Trinity formation bears asphalt and bitumen. Important clay deposits are worked in the Raritan formation of New Jersey, &c., and pottery clays are found in the Löwenberg district in Germany. The Washita beds yield the well-known hone stone. Great beds of gypsum exist in the Cretaceous rocks of S. America. Near Salzburg a variety of the hippuritic limestone is quarried for marble. Lithographic stone occurs in the Pyrenees. The economic products peculiar to the chalk are mentioned in the article. Beds of iron ore are found in the Lower Cretaceous of Germany and England.

The Life of the Cretaceous Period.—The fossils from the Cretaceous series comprise marine, fresh-water and terrestrial animals and plants. Foremost in interest and importance is the appearance in the Lower Potomac (Lower Cretaceous) of eastern and central N. America of the earliest representatives of angiospermous dicotyledons, and undoubted monocotyledons, the progenitors of our modern flowering plants. The angiosperms spread outward from the Atlantic coast region of N. America, and first appeared in Europe in the Aptian of Portugal; towards the close of the Lower Cretaceous period they occupied parts of Greenland, the remaining land areas of N. America, and were steadily advancing in every quarter of the globe. At first the Jurassic plants, the Cycads, ferns and conifers, lived on and were the dominant plant forms. Gradually, however, they took a subordinate place, and by the close of the Cretaceous period the angiosperms had gained the upper hand. The earliest of these fossil angiosperms is not in a true sense a primitive form, and no records of such types have yet been discovered. Some of the early forms of the Lower Cretaceous are distinctly similar to modern genera, such as Ficus, Sassafras and Aralia; others bore leaves closely resembling our elm, maple, willow, oak, eucalyptus, &c. Before the close of the period many other representatives of living genera had appeared, beech, walnut, tamarisk, plane, laurel (Laurus), cinnamon, ivy, ilex, viburnum, buckthorn, breadfruit, oleander and others; there were also junipers, thujas, pines and sequoias and monocotyledons such as Potamogeton and Arundo. This flora was widely spread and uniform; there was great similarity between that of Europe and N. America, and in parts of the United States (Virginia and Maryland) the plants were very like those in Greenland. The general aspect of the flora was sub-tropical; the eucalyptus and other plants then common in Europe and N. America are now confined to the southern hemisphere.

The marine fauna comprised foraminifera which must have swarmed in the Chalk and some of the limestone seas; their shells have formed great thickness of rock. Common forms are