Now the remains of animals, especially of aquatic species, are found almost everywhere imbedded in stratified rocks, and sometimes, in the case of limestone, they are in such abundance as to constitute the entire mass of the rock itself.
I shall place before you three kinds of evidence entirely based upon what is known of the forms of animal life which are contained in the series of stratified rocks.
They furnish us with a record, the general nature of which cannot be misinterpreted, of the kinds of things that have lived upon the surface of the earth during the time that is registered by this great thickness of stratified rocks.
Upon the top of the last of this series of stratified rockswe find THE DRIFT.
We live upon the top of a mighty series of stratified rocks, laid down in the water of ancient seas and lakes, during incalculable ages, said, by geologists, to be from ten to twenty miles in thickness.
Such sheets of intruded material cutting across the bedding of stratified rocks, or traversing older igneous or metamorphic terranes, are of common occurrence and are frequently abundant in deeply eroded regions.
Stratified rocks of the ordinary kinds greatly predominate over the igneous and metamorphic rocks, and the strata are in general far less disturbed than those of the Archeozoic and Proterozoic groups.
How does the geologist determine the actual amount of displacement, especially in the case of a large fault in stratified rocks?
A study of stratified rocks of marine origin shows that all, or nearly all, of the earth's surface has at some time, or times, been covered by sea water.
Though the igneous rocks occupy extensive areas in some countries, they nevertheless cover a much smaller part of the whole surface of the land than is taken up by the second division or stratified rocks.
The "sedimentary" or "stratified rocks" form by much the larger part of the dry land of the globe, and they are prolonged to an unknown distance from the shores under the bed of the sea.
But whether any considerable portions of the granitic masses, or of the melted masses now below the surface, have resulted from the fusion of stratified rocks, we have not the means of determining.
We thus have lavas, as well as stratified rocks, of different ages.
The other unstratified rocks have cooled so as to take the solid form below the stratified rocks, as at B.
This is evident, in the case of some mountains, from the existence of stratified rocks reaching to the summits.
They are of definite mineralogical composition, and, like the chemically and organically formed stratified rocks, can be classified chemically.
This group of stratified rocks composed of silicate minerals is of exceptional importance, first, on account of the large number of species which it includes, and, second, on account of the vast abundance of some of the species.
They furnish us with a record, the general nature of which cannot be misinterpreted, of the kinds of things that have lived upon thy surface of the earth during the time that is registered by this great thickness of stratified rocks.
Again, it must be borne in mind that the series of stratified rocks known to geologists is not complete or unbroken.
Another cause interfering with the record is to be found in those important internal changes that have taken place in stratified rocks--often over large areas--which may be ascribed to the influence of heat and pressure combined.
For the present moment it will be enough to consider the two grand divisions--Stratified rocks and Unstratified rocks.
Stratified rocks, on the contrary, which make up a very large part of the earth's crust, are not crystallized.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "stratified rocks" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
