Earth's Statistics and Earth Materials

Question 1

Geology comes from the two greek words ___ which means ______ and ___ which means _____.

Answer 1

geo (earth) and logos (discourse)

Question 2

Give the two main branches of geology.

Answer 2

Physical or Dynamic Geology and Historical Geology

Question 3

This theory states that rocks were formed by heat concealed within the Earth’s interior. Who proposed this theory?

Answer 3

Plutonism - James Hutton

Question 4

Who proposed the following theory? Neptunism, Catastrophism, and Uniformitarianism

Answer 4

Neptunism (Abraham Gottlob Werner), Catastrophism (Baron Georges Cuvier), and Uniformitarianism (James Hutton)

Question 5

Life started when atmosphere was modified due to the appearance of the _______.

Answer 5

Blue-green Algae

Question 6

Earth’s circumference was first
calculated by ______.

Answer 6

Eratosthenes

Question 7

What is the age of the Earth and who established it?

Answer 7

4.543 billion years - Clair C. Patterson

Question 8

Who and when was the Nebular Hypothesis proposed?

Answer 8

Immanuel Kant and Pierre Simon de Laplace in the 18th century

Question 9

Enumerate the make-up of solid matter on Earth from smallest to largest.

Answer 9

Atoms - Elements - Compounds - Minerals - Rocks

Question 10

Enumerate the particles that make up an atom and their corresponding charges.

Answer 10

Protons (+), Neutrons (no charge), Electrons (-)

Question 11

Atoms that have different numbers of neutrons.

Answer 11

Isotopes

Question 12

What is the polymorph of Pyrite (FeS2)

Answer 12

Marcasite

Question 13

It is a method of predicting the relative stability or weathering rate of common igneous minerals on the Earth’s surface, with minerals that form at higher temperatures and pressures less stable on the surface than minerals that form at lower temperatures and pressures.

Answer 13

Goldich Dissolution Series

Question 14

What is the specific gravity of pure gold (Au).

Answer 14

19.3

Question 15

Temperature which the mineral loses its magnetism.

Answer 15

Curie Point

Question 16

Differentiate Pratt’s Isostacy Theory from Airy’s Isostacy Theory.

Answer 16

PRATT’S THEORY
- Elevation is inversely proportional to density. Thus, the higher the mountain, the lower is its density; that is, light rocks “float” higher. AIRY’S THEORY (after G.B. Airy, 1855)
- Mountains have “roots” which extend down into the mantle. Thus, elevation is proportional to the depth of the underlying “root”.

Question 17

Enumerate the Major Minerals in the Mesosphere
(660km to ~2900km depth) and their chemical formula.

Answer 17

Perovskite and Periclase [(Mg,Fe)O] - Magnesiowustite
[(Mg,Fe)O] - Ilmenite [(Fe,Mg)TiO2] - Stishovite (SiO2) - Ferrite [(Ca,Na,Al)Fe2O4]

Question 18

Enumerate the minerals formed in the mantle as depth increases.

Answer 18

410km depth (Olivine and Wadleysite/Beta Spinel), Transition Zone (Ringwoodite and Garnet), 660km depth (Perovskite and Periclase).

Question 19

Enumerate the distinct layers of the Earth’s Atmosphere and their corresponding thickness. From highest to lowest.

Answer 19

Exosphere (very thin ~500 km), Thermosphere (>90 km), Mesosphere (50-90 km)
, Stratosphere (12-50 km), Tropopause (11-12 km), Troposphere (0-11 km)

Question 20

Enumerate the 7 major tectonic plates from largest to smallest.

Answer 20

Pacific Plate, North American Plate, Eurasian Plate, African Plate, Antarctic Plate, Indo-Australian Plate, and South American Plate.

Question 21

Enumerate the chemical composition of Earth by mass.

Answer 21

34.6% Iron, 29.5% Oxygen, 15.2% Silicon,12.7% Magnesium

Question 22

Define the Goldschmidt Classification and enumerate the host phases for each group.

Answer 22

It is a geochemical classification which groups the chemical elements within the Earth according to their preferred host phases into lithophile (rock-loving), siderophile (iron-loving), chalcophile (sulfide ore-loving or chalcogen-loving), and atmophile (gas-loving) or volatile

Question 23

Enumerate the elements abundant in the Earth’s crust and their percentage.

Answer 23

O (46.6%), Si (27.7%), Al (8.1%), Fe (5.0%), Ca (3.6%), Na (2.8%), K (2.6%), Mg (2.1%), all others (1.5%)

Question 24

Enumerate the polymorphs of Aluminum Silicate (Al2SiO5).

Answer 24

Kyanite (High Pressure, Low Temperature), Andalusite (Low Pressure, High Temperature), Sillimanite (High Pressure, High Temperature)

Question 25

Give the chemical formula for Fayalite and Fosterite respectively.

Answer 25

Fe2SiO4 and Mg2SiO4

Question 26

Differentiate Ferromagnetism, Paramagnetism, and Diamagnetism and give corresponding examples.

Answer 26

Ferromagnetism (strong attraction; magnetite), Paramagnetism (weak attraction but most are strongly magnetic when heated; hematite), and Diamagnetism (repelled from magnetic fields; bismuth)

Question 27

Enumerate the Udden-Wentworth grain size classification in detail.

Answer 27

(table)

Question 28

Enumerate the water distribution of Earth.

Answer 28

Oceans (96.5%), Saline groundwater and lakes (0.9%), Freshwater (2.5%) - Glaciers (1.72%), Groundwater (0.75%), All other freshwater (0.03%)

Question 29

Define cratons and explain how it can be called stable “platform” or “shield”.

Answer 29

Continents consist of relatively flat, stable areas called cratons. Where a craton is blanketed by a relatively thin layer of sediment or sedimentary rock, it is called a stable platform. Where a craton is exposed at the surface, it is known as a shield.

Question 30

Explain the difference between the terms silicon and silicate.

Answer 30

Silicon is one of the elements that makes up silicates but silicates is made up of silicon and many other elements. Silicate is made up of silicon, oxygen, and other elements (metals) such as aluminium, etc. Silicon is made up of different compounds

Question 31

Define geocryology.

Answer 31

It is the study of permafrost.

Question 32

Following the uniformitarian principle, the same physical processes that operate today operated throughout geologuc time, although not necessarily with the same ____ as now.

Answer 32

C. INTENSITY

Question 33

This refers to the geographic location of a stratigraphic unit in which the unit-strato-type is situated.

Answer 33

Type Locality

Question 34

What makes up the lithosphere?

Answer 34

Continental and Oceanic Crust

Question 35

What modern continents were derived from Gondwanaland?

Answer 35

Some 200 million years ago, Antarctica was joined to South America, Africa, India, and Australia.

Question 36

Enumerate the Earth’s Internal Structure and their corresponding depth and density.

Answer 36

Continental Crust (20-60km thick, 2.7 g/cm^3). Oceanic Crust (3-15km thick, 3 g/cm^3). Upper Mantle (70-660km, 3.4-4.4 g/cm^3). Lower Mantle (660-2890km, 4.4-5.6 g/cm^3). Outer Core (2890-5150km, 9.9-12.2 g/cm^3). Inner Core (5150-6371km, 12.8-13.1 g/cm^3)

Question 37

Enumerate the Discontinuities on the Earth’s Internal Structures, define their boundaries and the mineral/s their rich of or anything that makes them special.

Answer 37

Conrad (Upper-Lower Crust, transition zone between SIAL and SIMA). Moho/Mohorovicic (Lower Crust-Upper Mantle, composed of ultramafic rock peridotite). Repetti (Upper-Lower Mantle, increased seismic velocities). Gutenberg (Lower Mantle-Outer Core, mantle is rich in perovskite and outer core is in liquid Fe and Ni composition). Lehmann (Outer-Inner Core, inner core is in solid Fe and Ni composition).

Question 38

Enumerate and explain the soil horizons.

Answer 38

• O – (humus or organic)
• A - (topsoil)
• E – (eluviated/zone of leaching)
• B – (subsoil/zone of accumulation)
• C – (parent material)
• R – (bedrock) This is not soil.

Question 39

Differentiate Benthonic realm from Pelagic realm.

Answer 39

1. Benthonic realm
   -a collective designation for all the bottom of the sea.
2. Pelagic realm
   - all the ocean water lying seaward of low— tide level. The pelagic realm consists of two major provinces:
   a. Neritic province: the coastal—ocean water overlying the continental shelves.
   b. Oceanic province: the blue—water regions overlying the deep sea basins.

Question 40

Differentiate frost wedging, root wedging, and salt wedging.

Answer 40

• Frost wedging: water fills cracks, freezes, expands, and forces cracks to open causing them to grow. Can lift large blocks.
• Root wedging: same as frost wedging except that roots pry open the cracks.
• Salt wedging: salt crystals form when evaporating water flows through rocks. The salt crystals pry open the cracks.

Question 41

Between what geologic era was the Chicxulub Impact Crater in Yucatan Peninsula, Mexico formed?

Answer 41

Mesozoic and Cenozoic

Question 42

Define decollement.

Answer 42

These are low angle faults (<30degrees) characterized by upward movement of the hanging wall relative to the footwall.

Question 43

Differentiate thrust fault from reverse fault.

Answer 43

A thrust fault has a fault angle of less than 45°, whereas the angle of a reverse fault is greater.

Question 44

Differentiate the following types of K-feldspars: microcline, orthoclase, and sanidine in terms of the temperature where they form and their crystal system.

Answer 44

Microline (Low Temperature - Triclinic), Orthoclase (Medium Temperature - Monoclinic), Sanidine (High Temperature - Monoclinic)

Question 45

Enumerate the types of elements based on their weight percentage.

Answer 45

Major Element (>/= 1% ppm), Minor Element (0.1% - 1% ppm), Trace Element (<0.1% ppm)

Question 46

Enumerate and explain the processes involve in Pseudomorphs.

Answer 46

1. Replacement- pre-existing atoms are replaced by new mineral retaining its external crystal form. 2. Loss of Constituent from original crystals. (i.e., dissolution of carbonate from) 3. Encrustation – the new mineral mimic the original mineral’s crystal form.

Question 47

Laurasia was made of what present day continents?

Answer 47

North America (Greenland), Europe, and Asia