Question

This assignment is for historical Geology class :

Use the geologic time scale from your book and create a scaled geologic time scale that includes the Eons, Eras (of the Phanerozoic only), and one Period (you choose which one).

The length of your time scale should be 20cm (that means the scale is 20cm=4.6Ga). Be sure to include the ages for the boundaries of each unit you include. Label and color in each unit

Question 2/ Choose five units from the geologic time scale. What is the origin or meaning of each name?

Please answer all the questions. Thank You

Answer 1

The assignment is given by:

Solution 2: 1. Precambrian: The Precambrian eon represents that part of geological time which is older than Cambrian period, the oldest period of the Paleozoic Era. The Precambrian eon is divided into three era as Headean, Archaen and Proterozoic. The Cambrian name is derived from the old name of Welsh province of Great Britain ( Cambria).

Eon Era Period Present 66 my- Cenozoic Mesozoic Phanerozoic 251 my 14 SMY 201my CAPE COUS SOISSIS TGSSIS Paleozoic 540 my Precambrian 20cm 146oomy

2. Phanerozoic: Phanerozoic denotes the presence of forms of life with preservable hard parts. It is divided into three era as Paleozoic, Mesozoic and Cenozoic contain remain of past life because the organism living during these eras had developed hard parts.

3. Triassic: It is period of Mesozoic era. The name of triassic signifies its three fold division in its type locality in Germany.

4. Jurassic: It is period of Mesozoic era. Jurassic name is derived from the Jura mountains of Switzerland.

5. Cretaceous: It is also period of Mesozoic era. Cretaceous name is derived from it's typical lithology in the type area as Chalk( creta) in case of Cretaceous.