GEL341 Exam 01 Review

Question 1

Uniformitarianism/law or principle of uniformity

Answer 1

Stratigraphic law that states:
​”Present is the key to the past.”

Assumption that earth processes have probably worked pretty much the same way they do now throughout geologic time.

Question 2

Law of original horizontality

Answer 2

Stratigraphic law that states:
​Sedimentary layers are initially deposited in horizontal layers

Question 3

Law of superposition

Answer 3

Stratigraphic law that states:
​Oldest layer is on the bottom, younger ones are on top

Question 4

Law of cross-cutting [relationships/relations]

Answer 4

Stratigraphic law that states:
​Material that is cut is older than what did the cutting

Question 5

Law of lateral continuity

Answer 5

Stratigraphic law that states:
Sedimentary rocks are laterally continuous over large areas

Question 6

Law of inclusions

Answer 6

Stratigraphic law that states:
​Rock fragments within another rock must be older than the rock containing the fragments

Question 7

Principle of faunal succession

Answer 7

Stratigraphic law that states:
​Fossils and groups of fossiles exist for limited amounts of time, thus they appear in the rock record in a definitive pattern

Question 8

Geomorphology

Answer 8

Investigates landforms and the processes that fashion them

Form, process, and the interrelationaships between them are central to understanding the origin and development of landforms

Question 9

Form (or morphology)

Answer 9

Has three facets (form variables):

1. Constitution
2. Configuration
3. Mass flow

Question 10

Constitution

Answer 10

Chemical and physical properties described by material property variables

Question 11

Configuration

Answer 11

Size and form described by geometry variables

Question 12

Mass flow

Answer 12

Rates of flow described by such mass-flow variables as discharge, precipitation rate, and evaporation rate.

Question 13

Form variables

Answer 13

Constitution, configuration, and mass flow.

Form variables contract with dynamic variables.

Question 14

Dynamic variables

Answer 14

Chemical and mechanical properties representating the expenditure of energy and the doing of work.

e.g. power, energy flux, force, stress, momentum

Question 15

Endogenic processes

Answer 15

Tectonic and volcanic processes driven by geological forces.

Forces orginating from inside the Earth.

Question 16

Exogenic processes

Answer 16

Geomorphic processes driven by climatic forces.

Forces originating at or near the Earth’s surface and in the atmosphere.

Question 17

Extraterrestrial processes

Answer 17

Forces coming from outside the Earth.

e.g. asteroid impacts

Question 18

Four approaches used by geomorphologists

Answer 18

1. Process-response (process-form or functional) approach
2. Landform evolution approach
3. Geographical spatial science approach
4. Environmentally sensitive approach

Question 19

Surface process geomorphology (or process geomorphology)

Answer 19

Process-response (process-form) or funcational approach to geomorphology.

Question 20

Historical geomorphology

Answer 20

Landform evolution approach to geomorphology, which has roots in historical geology.

Broken into two groups:
(1) Quaternary geomorphology
Phanerozoic > Cenozoic > Quaternary
Quaternary = Holocene & Pleistocene
(2) Long-term geomorphology

Question 21

Geographical cycle (4)

Answer 21

Expounded by William Morris Davis.

1. Uplift takes place quickly.
2. Geomorphic processes gradually wear down raw topography. (With no further complications from tectonics.)
3. Slopes within landscapes decline through time – maximum slope angles slowly lessen.
4. Topography reduced to an extensive, flat region close to baselevel.

*Stages = youth, maturity, old age. (Borrowed from biology.)

Question 22

Peneplain

Answer 22

An extensive flat region close to baselevel.

Question 23

Monadnocks

Answer 23

Occasional hills (within a peneplain) that are local erosional remnants, standing conspicuously above the general level.

Question 24

Denudation chronology

Answer 24

Denudation = to strip bare;
a general name for processes of weathering, transport, and erosion.

Question 25

Relative v. absolute chronologies

Answer 25

Relative = events placed in order of occurence but without accurately fixed dates Absolute = derived from sequences dated using historical records, radiocarbon analysis, dendrochronology, luminescence, palaeomagnetism, etc.

Question 26

Long-term geomorphology

Answer 26

Studies of landforms and landscapes older than the Quaternary, or even late Quaternary. Includes Cenozoic, Mesozoic, and even Palaeozoic landforms (eras within Phanerozoic eon).

Question 27

Threshold

Answer 27

Can be either intrinsic (from within) or extrinsic (from outside). The point at which a landform becomes unstable. _Instrinsic:_ Changes within the system e.g. surging glacier) _Extrinsic:_ Changes outside of system that affect the system e.g. formation of gullies because of progressive vegetation removal

Question 28

[Dynamically] metastable states

Answer 28

Incremental change (trigger mechanism) pushes a system across a threshold from a stable equilibrium to a new equlibrium

Question 29

Sediment budgets

Answer 29

The balance between sediment added to and removed from the coastal system Surplus of sediment vs deficit of sediment

Question 30

Biogeoscience

Answer 30

Investigates the interactions between the biological, chemical, and physical processes in life (the biosphere) with the atmosphere, hydrosphere, pedosphere, and geosphere.

Question 31

Principle of simplicity (or uniformity of process)

Answer 31

States that no extra, fanciful, or unknown causes should be invoked if available processes will do the job. In line with actualism (what is often confused with uniformitarianism).

Question 32

Actualism v. non-actualism

Answer 32

Actualism = the same processes and natural laws that operated in the past are those we can actually observe or infer from observations as operating at prsent **Non-actualism = Circumstances under which processes acted in the past were very different from those experienced today**, and that those differences greatly influence the interpretation of past processes.

Question 33

Gradualism v. catastrophism

Answer 33

Gradual processes v. abrupt, major events

Question 34

Steady-statism

Answer 34

More or less a constant state, or at least cyclical changes about a comparatively invariant mean state. Challenges gradualism and catastrophism.

Question 35

Directionalism

Answer 35

Directional changes Challenges gradualism and catastrophism, as well as steady-statism.

Question 36

Uniformitarianism (specific to geomorphology)

Answer 36

Set of beliefs about Earth surface processes and states, using actualism (uniformity of process), gradualism (uniformity of rate), and steady-statism (uniformity of state). Opposing set of beliefs: non-conformity of process, rate, and state (non-actualism, catastrophism, and directionalism)

Question 37

Systems approach

Answer 37

Examining system variables and how they interact to form a regular and connected whole.

Question 38

System variables

Answer 38

Variables that affect a geomorphic system, both internally and externally e.g. internal & external variables of drainage basin internal = soil wetness, streamflow external = precipitation, solar radiation, tectonic uplift Change in variables = readjustment of form and process

Question 39

Isolated v. closed v. open v. dissipative systems

Answer 39

**Isolated** = *completely* cut off from its surroundings \*No import/export of **neither** **matter nor energy** **Closed** = has boundaries \*Open to passage of **energy, but *not* matter** Open = has boundaries \*Both energy & matter are free to move * *Dissipative** = irreversible processes resulting in dissipation of energy * *\*Energy moves one way** (e. g. solar energy, tectonic uplift, precipitation)

Question 40

Kinds of geomorphic systems (4)

Answer 40

1. **Form** (AKA: **Morphological**) system 2. **Process** (AKA: **Cascading**, **Flow**) system 3. **Form and process** (AKA: **Process-form**, **Process-response**) system 4. **Control** system

Question 41

Form (morphological) systems

Answer 41

Sets (or systems) of form variables (or elements) deemed to interrelate in a meaningful way in terms of system origin or system function. e.g. measures of anything on a hillslope that has size, shape, or physical properties

Question 42

Process (cascading, or flow) systems

Answer 42

Interconnected pathways of transport of energy or matter or both, together with such storages of energy and matter as may be required. e.g. hillslope represented as a store of materials (weathering of bedfrom and wind deposition add to the store; erosion by wind and fluvial erosion removes from the store)

Question 43

Form and process (process-form, or process-response) systems

Answer 43

Comprise an energy-flow system linked to a form system in such a way that system processes that may alter the system form and, in turn, the changed system form alters the system processes. e.g. rock falling off the cliff builds up the talus store; as store increases, so it begins to bury cliff face, reducing area that supplies debris --\> rate of talus growth diminishes, system changes at an ever-decreasing rate (negative feedback)

Question 44

Control systems

Answer 44

Process-form systems that interact with humans Includes managed rivers, coasts with sea defences, some caves.

Question 45

Simple systems