Granite and Associated
Landforms Exam
Questions with Correct
Answers
Denning [Date] [Course title]
, Granite - Correct Answer: one of the most common rocks found on earth and is associated with
landforms vastly different from those found in karsts regions and different climatic zones tend to
produce different granite landforms due to their distinct climate regimes.
Formation of Granite - Correct Answer: intrusive igneous rock formed from the solidification of granitic
magma. When granitic magma is viscous and moves slowly, it seldom travels far enough to reach the
surface but solidifies underground to form granitic plutonic structures such as batholiths (that form core
of mountains). Since the rock is usually relatively more resistant to weathering and erosion than the
surrounding rocks, it will be exposed after denudation (erosion). As it is formed underground under high
pressure and heat, it is prone to the weathering process of pressure release.
Characteristics and Weathering of Granite - Correct Answer: Includes how chemical composition, rock
texture and rock structure affect how it is broken down.
Chemical composition of granite - Correct Answer: made up of 25-35% quartz, >50% feldspar, and other
minor minerals such as mica. Feldspar and biotite are chemical unstable and are susceptible to
hydrolysis, therefore, although rock is resistant to mechanical weathering due to its physical strength, it
is prone to chemical weathering and will be weathered easily in humid climate. When feldspar reacts
with water, KOH and alumino-silica acid is produced. The former is carbonated and removed in solution
while the latter is broken down into clay minerals (kaolinite) and silicic acid (removed in solution).
Therefore, granular disintegration will occur when feldspar is reduced to kaolinite clay while unaltered
quartz remains as sand particles, forming a mass of gruss. At a more advanced stage of weathering, the
regolith will crumble in residual debris. Embedded within the residual debris are unweathered and
rounded corestones due to selective weathering along joints to produce blocks and their subsequent
weathering by spheroidal weathering.
Gruss - Correct Answer: A loose accumulation of fragmental products formed from the weathering of
granite.
Residual Debris - Correct Answer: when regolith crumble into a structureless mass of clay and sand.
Rock texture of granite - Correct Answer: Granite is characterised by large crystals that make it
phaneritic, which is due to the slow solidification of granitic magma that takes place deep within the
crust due the high temperature and pressure that that causes it to cool slowly. Therefore, there is ample
time for crystallisation to take place and the large crystals that form leads to the development of large
minerals.
Landforms Exam
Questions with Correct
Answers
Denning [Date] [Course title]
, Granite - Correct Answer: one of the most common rocks found on earth and is associated with
landforms vastly different from those found in karsts regions and different climatic zones tend to
produce different granite landforms due to their distinct climate regimes.
Formation of Granite - Correct Answer: intrusive igneous rock formed from the solidification of granitic
magma. When granitic magma is viscous and moves slowly, it seldom travels far enough to reach the
surface but solidifies underground to form granitic plutonic structures such as batholiths (that form core
of mountains). Since the rock is usually relatively more resistant to weathering and erosion than the
surrounding rocks, it will be exposed after denudation (erosion). As it is formed underground under high
pressure and heat, it is prone to the weathering process of pressure release.
Characteristics and Weathering of Granite - Correct Answer: Includes how chemical composition, rock
texture and rock structure affect how it is broken down.
Chemical composition of granite - Correct Answer: made up of 25-35% quartz, >50% feldspar, and other
minor minerals such as mica. Feldspar and biotite are chemical unstable and are susceptible to
hydrolysis, therefore, although rock is resistant to mechanical weathering due to its physical strength, it
is prone to chemical weathering and will be weathered easily in humid climate. When feldspar reacts
with water, KOH and alumino-silica acid is produced. The former is carbonated and removed in solution
while the latter is broken down into clay minerals (kaolinite) and silicic acid (removed in solution).
Therefore, granular disintegration will occur when feldspar is reduced to kaolinite clay while unaltered
quartz remains as sand particles, forming a mass of gruss. At a more advanced stage of weathering, the
regolith will crumble in residual debris. Embedded within the residual debris are unweathered and
rounded corestones due to selective weathering along joints to produce blocks and their subsequent
weathering by spheroidal weathering.
Gruss - Correct Answer: A loose accumulation of fragmental products formed from the weathering of
granite.
Residual Debris - Correct Answer: when regolith crumble into a structureless mass of clay and sand.
Rock texture of granite - Correct Answer: Granite is characterised by large crystals that make it
phaneritic, which is due to the slow solidification of granitic magma that takes place deep within the
crust due the high temperature and pressure that that causes it to cool slowly. Therefore, there is ample
time for crystallisation to take place and the large crystals that form leads to the development of large
minerals.
