In 1669, Steno, a Danish physician residing in Italy, wrote a work on organic petrifactions which are found enclosed in solid rocks, and showed by his dissection of a shark which had been recently captured and by a comparison of its teeth with those found fossil in the cliffs, that they were identical. The same author also pointed out the resemblance between the shells discovered in the Italian strata and those living on the adjacent shores. It was not until the close of the eighteenth century, however, that the study of fossil remains received a decided impetus. It is curious to note that many of these later authors maintained the occurrence of a universal flood to account for the presence of fossil shells and bones on the dry land.
Fig. 4—William Smith (1769-1839.)
“The Father of English Geology,” at the age of 69.
(From Brit. Mus. Cat.)
Fossils an Index to Age.—
A large part of the credit of showing how fossils are restricted to certain strata, and help to fix the succession and age of the beds, is due to the English geologist and surveyor, William Smith ([Fig. 4]). “The Father of English Geology,” as he has been called, published two works[1] in the early part of last century, in which he expressed his view of the value of fossils to the geologist and surveyor, and showed that there was a regular law of superposition of one bed upon another, and that strata could be identified at distant localities by their included fossils. Upon this foundation the work of later geologists has been firmly established; and students of strata and of fossils work hand in hand.
[1] “Strata identified by Organised Fossils,” 1816-1819; and “Stratigraphical System of Organised Fossils,” 1817.
Stratigraphy.—
That branch of geology which discusses the nature and relations of the various sediments of the earth’s crust, and the form in which they were laid down, is called Stratigraphy. From it we learn that in bygone times many of those places that are now occupied by dry land have been, often more than once, covered by the sea; and thus Tennyson’s lines are forcibly brought to mind—