United States or Trinidad and Tobago ? Vote for the TOP Country of the Week !
As a deduction, it was also attempted to be shown, first, that the want of close sequence in the fossils of successive formations, and of successive stages in the same formation, would follow from the improbability of the same area continuing slowly to subside from one whole period to another, or even during a single entire period; and secondly, that certain epochs having been favourable at distant points, in the same quarter of the world for the synchronous accumulation of fossiliferous strata, would follow from movements of subsidence having apparently, like those of elevation, contemporaneously affected very large areas.
If, now, the modern fossiliferous deposits of Australia were to be examined by one ignorant of the existing Australian Fauna; and if he were to reason in the usual manner; he would be very unlikely to class these deposits with those of the present time.
By reference to the tables given at the end of the last chapter the reader will see that when the fossiliferous rocks are arranged chronologically, we have first to consider the Post-tertiary and then the Tertiary or Cainozoic formations, and afterwards to pass on to those of older date. Laurentian. 2. Cambrian. 3. Silurian. 4. Devonian. 5. Carboniferous. 6. Permian. 7. Triassic. 8. Jurassic. 9.
During these latter periods there will probably be more variability in the forms of life; during periods of subsidence, more extinction. With respect to the absence of fossiliferous formations beneath the lowest Silurian strata, I can only recur to the hypothesis given in the ninth chapter.
I. Primary Plutonic rocks. II. Secondary Plutonic rocks. III. Tertiary Plutonic rocks. IV. Post-tertiary Plutonic rocks. 1. Primary fossiliferous or Palaeozoic strata. 2. Secondary or Mesozoic strata. 3. Tertiary or Cainozoic strata. 4. Post-tertiary strata. The oldest Plutonic rock, No. I, has been upheaved at successive periods until it has become exposed to view in a mountain-chain.
In this latter case, as long as the rate of subsidence and supply of sediment nearly balance each other, the sea will remain shallow and favourable for many and varied forms, and thus a rich fossiliferous formation, thick enough, when upraised, to resist a large amount of denudation, may be formed.
The meridian altitude of the fourth day must have been reached where for the first time the covering of vapor and clouds of the earthly atmosphere permanently parted, and sun, moon, and stars became visible: and geology finds this time in the period which lies between the carboniferous period and the trias in the Permian period, as it is called in England, in the dyas of the fossiliferous and of cupriferous slate and Zechstein, as we call it in Germany.
In other words, our problem is palaeontological, and the method pursued must be the same as that employed in dealing with other fossil remains. Among the richest of the fossiliferous strata to which I have alluded are the books of Judges and Samuel.
However, no such progress from more to less generalized types has been demonstrated, although many trained investigators have searched the fossiliferous rocks for such evidence of evolution.
The general adoption by geologists of the term stratified, as applied to these rocks, sufficiently attests their division into beds very analogous, at least in form, to ordinary fossiliferous strata.
Word Of The Day