_mesos_, intermediate; _zoe_, life); the organic remains of
this "Middle-Life" period being, on the whole, intermediate in
their characters between those of the palaeozoic epoch and those
of more modern strata. Lastly, the Eocene, Miocene, and Pliocene
formations are grouped together as the _Tertiary_ or _Kainozoic_
rocks (Gr. _kainos_, new; _zoe_, life); because they constitute
a "New-Life" period, in which the organic remains approximate in
character to those now existing upon the globe. The so-called
_Post-Tertiary_ deposits are placed with the Kainozoic, or may
be considered as forming a separate _Quaternary_ system.
CHAPTER IV.
THE BREAKS IN THE GEOLOGICAL AND PALAEONTOLOGICAL RECORD.
The term "contemporaneous" is usually applied by geologists to
groups of strata in different regions which contain the same
fossils, or an assemblage of fossils in which many identical
forms are present. That is to say, beds which contain identical,
or nearly identical, fossils, however widely separated they may
be from one another in point of actual distance, are ordinarily
believed to have been deposited during the same period of the
earth's history. This belief, indeed, constitutes the keystone
of the entire system of determining the age of strata by their
fossil contents; and if we take the word "contemporaneous" in a
general and strictly geological sense, this belief can be accepted
as proved beyond denial.
Pages:
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99