Question

1) Provide six (6) compelling reasons to study Geology?

2) Describe the evidence Aldred Wegener provided to introduce the concept of Confidential Drift. Explain why he could NOT provide this thesis.

3) Describe procedures to identify a mineral specimen.

4) Describe the chemical composition and physical appearance (texture) of Basaltic (MAFIC) vs. Granitic (FELSIC) igneous rocks, and Explain how cooling history and cooling environment affects crystal formation and growth patterns (crystalline mass vs. perfect crystal).

5) Explain how differences in composition, variations in age of Igneous Rocks (Basaltic rock generally younger then Granitic rock), and differences in the thickness of oceanic Plate versus Continental Plate, all support current Global Tectonic Theory (Think formation and destruction of ocean basins at plate boundaries and age differences in the Hawaiian Islands!)

Answer 1

1) Provide six (6) compelling reasons to study Geology?

Ans. The reasons are as following -

1. To know the history of the earth

2. to understand the interior of the earth that helps us in understanding the other planets

3. to understand various rocks on the earth and their formation

4. to relate phenomenon like earthquake, landslide etc with the formation of rocks

5. to understand how the continents are formed and how they are drifting

6. To know the geological processes occurring on the earth and how they shape the nature

2) Describe the evidence Aldred Wegener provided to introduce the concept of Confidential Drift. Explain why he could NOT provide this thesis.

Ans. The evidences are as following -

1. jig saw fitting of south america and africa

2. similar ages of coal found in north america and europe

3. similar kind of fossil fuels of both the sides of continents

4. when we join the continents to make Pangea, the mountain ranges also so a sort of connection

But he could not make a valid statement about the force acting on the earth for all such movements. He said that the continents are making two types of movements - (a) westward due to gravitational pull and (b) equator wards (due to force of byoyancy) but both these forces are not enough to pull such a huge block of continents and thus his theory failed.

3) Describe procedures to identify a mineral specimen.

Look at the grains texture of that specimen

Try to find out whether it is a metamorphic, igneous or sedimentayr rock, looking at the texture

find out its streak property, malleability, ductility etc.

4) Describe the chemical composition and physical appearance (texture) of Basaltic (MAFIC) vs. Granitic (FELSIC) igneous rocks, and Explain how cooling history and cooling environment affects crystal formation and growth patterns (crystalline mass vs. perfect crystal).

Mafic rocks are rich in magnesium and iron while FELSIC are rich in feldspar, silica.

Mafic rocks will have lowest silica content, color is dark and relative viscosity is low. Volcanic rock type is biotite while plutonic rock type is Gabbro. While Felsic rocks have high silica content, high viscosity and light color. Volcanic rock type example is quartz and plutonic rock type is granite.

When a rock cools down at slower rate, it has enough time to develop crystals and thus it will develop crystal while if the rock gets cooled rapidly, it does not have enough type to develop crystals.