Last Updated：2025/12/30
Sentence
The
whole
history
of
the
earth
is
divided
into
five
eras,
with
corresponding
rock-systems.
These
are:
1.
Archæan
or
Eozoic¹
era,
embodied
in
the
Laurentian
system;
2.
Palæozoic²
era,
embodied
in
the
Palæozoic
or
Primary
system;
3.
Mesozoic³
era,
recorded
in
the
Secondary
system;
4.
Cenozoic,⁴
recorded
in
the
Tertiary
and
Quaternary
systems;
and,
5.
The
Psychozoic
era,
or
era
of
Mind,
recorded
in
the
recent
system.
Quizzes for review
The whole history of the earth is divided into five eras, with corresponding rock-systems. These are: 1. Archæan or Eozoic¹ era, embodied in the Laurentian system; 2. Palæozoic² era, embodied in the Palæozoic or Primary system; 3. Mesozoic³ era, recorded in the Secondary system; 4. Cenozoic,⁴ recorded in the Tertiary and Quaternary systems; and, 5. The Psychozoic era, or era of Mind, recorded in the recent system.
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