Petrology

Question 1

It is the science concerned with rocks that are made up of definite mineral assemblages from which the earth is built.

Answer 1

Petrology

Question 2

the science that deals with the mode of occurrence, composition, classification and origin of rocks and their relations to geological processes and history.

Answer 2

Petrology

Question 3

a naturally-occurring mixtures of minerals, mineraloids, glass or organic matter. a naturally-occurring solid aggregate of minerals

Answer 3

Rock

Question 4

Places emphasis on the purely descriptive part of the rock science from textural, mineralogical, and chemical points of view.

Answer 4

Petrography

Question 5

It deals with the origin of rocks.

Answer 5

Petrogenesis

Question 6

It is the study of stones, employs knowledge obtained from field exposures or hand specimens and it is almost synonymous with petrology.

Answer 6

Petrogenesis

Question 7

What are the classification of Rocks?

Answer 7

Igneous, Sedimentary, and Metamorphic

Question 8

Are those that ionize less readily and thus tend to form covalent compounds with sulfur.
These elements occur mainly as sulfides.

Answer 8

Chalcophile Elements

Question 9

are those for which metallic bonding is the normal condition and which do not readily form compounds of oxygen or sulfur. The elements occur mainly as native elements.

Answer 9

Siderophile Elements

Question 10

Gaseous and present mainly in the atmosphere

Answer 10

Atmophile Elements

Question 11

How magma forms?

Answer 11

Rock melts and became magma when the temperature is higher than the controlled melting point of the minerals in a rock.

Question 12

Sources of Heat for Melting

Answer 12

Geothermal Gradient, Hot mantle plumes,
Friction, Heat Transfer, Radioactivity

Question 13

Sources of Heat for Melting

Answer 13

Geothermal Gradient, Hot mantle plumes,
Friction, Heat Transfer, Radioactivity

Question 14

Melting point of Lava and Magma

Answer 14

700-1300°C

Question 15

Separate SiO4 groups in which the tetrahedra are not linked directly to each other but are bound together by intervening cations.

Answer 15

Nesosilicate

Question 16

What is Nesosilicate?

Answer 16

separate SiO4 groups in which the tetrahedra are not linked directly to each other but are bound together by intervening cations.

Question 17

Si2O7 may be considered as a condensation of two silica tetrahedra. They are linked by a common oxygen which serves as a bridging ion.

Answer 17

Sorosilicate

Question 18

What is a Sorosilicate?

Answer 18

Si2O7 may be considered as a condensation of two silica tetrahedra.
They are linked by a common oxygen which serves as a bridging ion.

Question 19

Ring structures Si6O18 in which the SiO4 groups are not independent but are united through common oxygen ions in the form of a ring.

Answer 19

Cyclosilicates

Question 20

What is a Cyclosilicate?

Answer 20

Ring structures Si6O18 in which the SiO4 groups are not independent but are united through common oxygen ions in the form of a ring.

Question 21

Has continuous single chains of tetrahedra each sharing two oxygens and continuous double chains of tetrahedra sharing alternately two and three oxygens.

Answer 21

Inosilicate

Question 22

What is an Inosilicate?

Answer 22

continuous single chains of tetrahedra each sharing two oxygens.
– continuous double chains of tetrahedra sharing alternately two and three oxygens.

Question 23

Has continuous sheets of tetrahedra each sharing three oxygens.

Answer 23

Phyllosilicates

Question 24

What is a Phyllosilicate?

Answer 24

continuous sheets of tetrahedra each sharing three oxygens.

Question 25

continuous frameworks of tetrahedra each sharing all four oxygens.

Answer 25

Tectosilicate

Question 26

What is a Tectosilicate?

Answer 26

continuous frameworks of tetrahedra each sharing all four oxygens.

Question 27

Degree of Crystallization

Answer 27

Holocrystalline, Holohyaline and Merocrystalline

Question 28

What is Assimilation?

Answer 28

• is that process of magmatic differentiation whereby ascending magmas evolve chemically by recruiting easily melted or dissolved components(fusibles) from the walls of their conduits.
  A very hot magma may melt some of the country rock and assimilate the newly molten material into the magma. This is like putting a few ice cubes into a cup of hot coffee. The ice melts and the coffee cools as it becomes diluted. Similarly, if a hot basaltic magma, perhaps generated from the mantle, melts portions of the continental crust, the magma simultaneously becomes richer in silica and cooler. Possibly the intermediate magmas that are associated with circum-Pacific andesite volcanoes may derive from assimilation of some crustal rocks by the basalt.

Question 29

Mixing of Magmas

Answer 29

The concept is quite simple. If two magmas meet and merge within the crust, the combined magma will be compositionally intermediate. If you had approximately equal amounts of a granitic magma mixing with a basaltic magma, the resulting magma should consolidate underground as diorite or on the surface as andesite.

Question 30

Granularity

Answer 30

Phaneritic, Aphanitic, Pegmatitic

Question 31

Different types of Textures

Answer 31

F,C,N,B,R,J