Geology

Compare and contrast elastic deformation and plastic deformation

During Elastic Deformation strain is proportional to stress, and the deformation/strain is recoverable. However, during Plastic Deformation strain is not proportional to stress, and the deformation/strain is not recoverable.

. Water, which contains an abundance of Carbonic Acid and is still capable of dissolving more Limestone, is referred to as

"aggressive".

What are 3 major sources for carbon dioxide?

(1) Atmosphere (2) Respiration by organisms (3) Plant decomposition and bacterial decay of organisms in soil.

What are the 4 factors that determine how a rock deforms?

(1) Pressure-Temperature environment in which the rock resides, which is mostly a function of depth; (2) the physical strength of the rock type, which is a function of its mineral composition and atomic structure. Rocks such as shale, rock salt, and rock gypsum tend to flow plastically at very shallow depths whereas rocks, such as granite, gneiss, quartzite, and massive sandstones tend to fracture or behave brittlely at shallow depths; (3) time, or how long a rock has been subjected to stress; and (4) the rate at which it has been subjected to stress.

List 9 general features associated with Tower Karst.

(1) Steep-sided cylindrical hills or cone-shaped hills (2) Closed depressions lacking surface drainage features or Dry Valleys (3) Swallow or Sink Holes (4) Disappearing Streams (5) Relict Caves or Remnant Caves (6) Foot Caves (7) Natural Bridges (8) Broad Alluvial Plains (9) Terra Rosa

For each of the 3 types of directional stress, define it, and describe what types of brittle deformation result from it.

(A) Compressional Stress - Stress that pushes together on a rock, which tends to shorten it and may also reduce its volume. Both Folding (Plastic Deformation) and Reverse and Thrust Faults (Brittle Deformation) result from Compressional Stress. (B) Tensional Stress - Stress that pulls a rock apart or extends it, which tends to increase its length and may also increase its volume. Normal Faults (Brittle Deformation) result from Tensional Stress. (C) Shear Stress - Stress that causes a rock to break along an infinite number of parallel planes and slide along those planes. Strike Slip Faults (Brittle Deformation) result from Shear Stress.

. What is a Cave?

A cave is a natural cavity in rock large enough to be entered by man or woman.

Compare and contrast a Fault and a Joint.

A fault is a fracture along which there has been significant displacement whereas a Joint is a fracture along which there has been little or no displacement.

What percentage of the Earth's surface is covered with Carbonate Karst?

About 7 to 10% of the Earth's land surface is covered by Carbonate Karst.

A cave containing a stream and active speleothems is called a/an ______/____ cave whereas a Cave without a stream and active drip formation of speleothems is called a/an ___/____ cave.

Active/live, Dry/dead

What is an orogeny?

An Orogeny is a period of deformation, regional metamorphism, igneous activity, and mountain building.

What are the factors that control the dissolution of limestone below the ground surface?

Availability of Carbonic Acid (Water in the Unsaturated Zone and Groundwater in the upper part of the Saturated Zone is rich in Carbonic Acid because carbon dioxide productivity is high in soils Fractures, Bedding Planes, and other Zones of Weakness providing Secondary Porosity. Climate - Availability of "aggressive" water, which contains an abundance of Carbonic Acid and is still capable of dissolving more limestone.

A valley that is closed abruptly at its lower end by a cliff or slope facing up the valley is called a/an

Blind Valley

What is brittle deformation, and what P-T conditions favor it?

Brittle Deformation is a type of permanent deformation in which rocks fracture or break and in some cases experience faulting or relative movement along the zones of breakage/fracture. Relative low P-T conditions at relatively shallow depths favor Brittle Deformation.

List the rock types that most often express karst topography

Carbonate Rocks (Limestone and Dolostone) - Karst Features are more prominent in Limestone because it is more soluble than Dolostone. Marble - (Metamorphic equivalent of Limestone and/or Dolostone) Evaporite Rocks - Gypsum and Halite (These rock types are more soluble than Carbonate Rocks but less widely distributed than Limestone.

What acid is produced when carbon dioxide is dissolved in water?

Carbonic Acid (H2CO3)

Four examples or types of Speleogens are

Cave Notches, Roof Pendants, Cave Pillars, and Cave Potholes

____________ are the below surface expression of Karst.

Caves

The largest order of cavity in a cave, with considerable width and length but necessarily great Height is called a

Chamber, Room, or Brothel.

What are the 2 major types of stress?

Confining Stress and Directed Stress

List the principal type of directional stress that is associated with each of the 3 types of plate tectonic boundaries.

Convergent Plate Boundaries - Compressional Stress Divergent Plate Boundaries - Tensional Stress Transform Plate Boundaries - Shear Stress

A surface stream that disappears underground into a cave system is called a

Disappearing Stream.

Groundwater erodes soluble rocks by what Chemical Weathering Process?

Dissolution

Write the reversible equation that represents the dissolution of limestone to form caves and caverns and the precipitation of dripstone (calcite) within caves. With arrows indicate the direction in which dissolution and precipitation occur.

Dissolution of Limestone to Form Caves H2O + CO2 + CaCO3 Ca++ + 2HCO3- water carbon calcite in calcium bicarbonate dioxide limestone ion ion Development of Dripstone and Formation of Various Types of Speleothems by Precipitation after CO2 Degasses into the Cave Atmosphere

Cave deposits, composed of a type of limestone formed from drops falling from cave roofs and walls, are called

Dripstone

A valley without a surface stream channel is called a/an

Dry Valley.

What types of evidence in the field suggest that faulting has occurred at some time in the past?

Field evidence that suggests that faulting has occurred at some time in the past includes: (1) offset, repeating, and/or missing beds (2) fault gouge, shear zones, and fault breccias (3) slickensides

A moderately-sized Room in a cave that is well decorated with Speleothems is called a

Grotto.

Briefly list and describe the processes which can produce Joints.

Joints can form as a result of Tensional/Extensional Stresses, Shear Stresses, Contraction related to cooling (produces Columnar Joints, and Stress Release (e.g., produces sub-horizontal Exfoliation Joints).

Features that form both above and below the ground surface due to groundwater dissolution are called

Karst

The ground surface expression of Landforms that results from of ground-water and surface water dissolution of soluble rocks is called

Karst Topography

. List and briefly define the 3 types of Caves

Lava Tube Caves - Most lava tube caves form when fluid Basaltic lava flows down the sides of volcanoes. The upper layer begins to cool, and the lava beneath continues to flow in tubular conduits beneath the surface. Rock preference is Basalt. Erosional Caves - Erosional caves are those formed by the action of water or wind, carrying abrasive particles capable of carving rock, similar to how canyons are formed. However, in order to form a cave instead of just a canyon, something must create a zone of weakness in the host rock that allows an influx of water. Rock preference is Granitoid Rocks Solution Caves - These caves are dissolved out of Soluble Rocks by aggressive, acidic groundwater. Rock preference is Limestone.

What rock type produces the most prominent expressions of karst?

Limestone

The longest cave system in the World is ________ ____. In what country is this cave system located?

Mammoth Cave, USA

A bridge of rock spanning a ravine or valley is called a/an

Natural Bridge.

What is the typical concentration of Carbon Dioxide in the Open Atmosphere versus the Atmosphere of a Cave?

Open Air Atmosphere - 0.03% Cave Atmosphere - 0.05 to 2%

. List the 3 areas we discussed in class, all in SE Asia or East Asia, that have classic and beautiful Tower Karst.

Phang Nga Bay, Krabi, and Phi Phi Islands, THAILAND Halong Bay, VIETNAM City of Guilin in Guangxi Province, CHINa

What is Pinnacle Karst, and where is it referred to as a "Stone Forest?"

Pinnacle Karst refers to Tropical Karst characterized by up to 50 meter high, vertical rock blades fretted with sharp-edged Karren that form due to very high rates of surface or subsurface (under soil) dissolution in tropical climates.

For an East-West striking bed of quartz sandstone, what are the 3 possible dip directions?

Possibility #1 - Dips in a North direction Possibility #2 - Dips in a South direction Possibility #3 - Has a vertical dip (90o)

For an North-South striking bed of quartz sandstone, what are the 3 possible dip directions?

Possibility #1 - Dips in an East direction Possibility #2 - Dips in a West direction Possibility #3 - Has a vertical dip (90o)

The largest cave room or chamber in the World is called or the Good Luck Cave. In what country is this cave chamber located?

Sarawak Chamber, malaysia

. What does the term, karst, mean?

Short Version - Bleak, waterless place. Long Version - "A terrain with distinctive drainage, hydrology (surface and groundwater movement), and landforms arising from a combination of high rock solubility and well-developed secondary porosity."

. List 5 karst landforms or features that would be typically found in Temperate Climate zone regions.

Sinkhole or Doline - Basin or funnel-shaped depression in limestone formed due to dissolution or collapse. Disappearing Stream - A surface Stream that disappears underground into cave systems. Dry Valley - A valley without a surface stream channel. Blind Valley - A valley that is closed abruptly at its lower end by a cliff or slope facing up the valley. It may have a perennial or intermittent stream, which sinks at its lower end or it may be a Dry Valley. Natural Bridge - A bridge of rock spanning a ravine or valley and formed by erosive agents

A basin or funnel-shaped depression in limestone formed due to dissolution or collapse is called a/an

Sinkhole or Doline.

Karst terrains in Temperate Climate Zones are generally referred to as

Sinkhole/Doline Karst.

All cave features formed by erosion are referred to as

Speleogens

The scientific study of caves, cave features, and cave processes

Speleology.

All cave deposits are generally referred to as

Speleothems

List and briefly define following types of Speleothems (Cave Deposits). You should also be able to visually recognize the ones of these that are emphasized in class discussion.

Stalactite is a conical or cylindrical Speleothem usually with a central hollow tube that hangs down from the roof or wall of a cave. Stalagmite is a Speleothem projecting vertically upward from a cave floor and formed by Precipitation from drips. Column is a Speleothem formed by the union of a stalagmite and a stalactite. Flowstone is a Speleothem formed from thin films or trickles of water over cave floors or walls. Cave Draperies are Speleothems deposited from calcite-rich solutions flowing along an overhung surface. Caves Pearls - A Speleothem, formed from concentric concretions found in shallow cave pools into which water drips. Rimstone Dam is a ridge like deposit, often curved convexly downstream, formed by precipitation from water flowing over the rim of a pool.

Compare and contrast stress and strain.

Stress is an applied force per unit area whereas strain is a change in shape in response to stress. Hence, stress causes strain.

. Reddish-brown residual soil mantling Limestone bedrock derived from clay impurities in the Limestone is called

Terra Rosa.

List 5 countries that exhibit tropical karst landforms.

Thailand, China, Vietnam, Cambodia, Laos, Cuba

Define Elastic Limit

The Elastic Limit is the maximum stress that a substance can withstand and still show Elastic Behavior.

What type of fault is the San Andreas Fault, and where is it located?

The San Andreas Fault is a Transform Fault with a Right Lateral Strike Slip sense of displacement. The San Andreas Fault is located in California.

What are the 3 main Cave Colours, and what is their origin?

The main colours in caves are white, reddish-brown, and gray. Without impurities the mineral calcite is white, the reddish-brown colour is from iron oxide, and the gray is from magnesium.

Karst Topography that is characterized by steep-sided cylindrical- or conical-shaped limestone hills and is characteristic of the Tropical Climate Zone is called

Tower Karst.

Karst terrains in Tropical Climate Zones are referred to as

Tower Karst.

The part of a cave to which daylight penetrates is called the

Twilight Zone

What is the typical concentration of Carbon Dioxide in a Temperate Climate Zone Soil versus a Tropical Climate Zone Soil?

Typical Temperate Zone Soils - 2% Tropical Zone Soils - 3 to 8%

Cave formation probably begins just below the ______ _____ in the upper part of the Zone of Saturation where carbon dioxide-rich water is available.

water table