Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ore deposits > Lec 4 - Controls On Ore Deposition > Flashcards

Lec 4 - Controls On Ore Deposition Flashcards

1
Q

4 controls on Ore Deposition

A
  1. Chemical
  2. Lithological
  3. Stratgraphic
  4. Structural
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Factors under chemical

A
  • temperature change
  • pressure change
  • reaction between solution and wall rocks
  • chemical changes due to solution mixing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  • It affects mineral solubilities,
  • influences ion-pairing hydrolysis constants of ions such as Cl and HS
  • affects oxyfen fugacit
A

Temperature change (cooling)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Loss of volatiles disabling metal transport

A

Boiling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Change in pressure regime from lithostatic to hydrostatic across an obstruction

A

Throttling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Loss of volatiles without change in temperature but only in pressure

A

Retrograde Boiling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  • Addition of anions or cause of disolution

- disolution can cause precipitation by causing dissociation of some metal complexes and recombination

A

Solution mixing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

T and P drop will result in precipitation from aqueous solution

A

Solubility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Separation of one mineral from another in a natural solution (unmixing)

A

Exsolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Certain microbes are agents of mineral precipitation

A

Bacterial precipitation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Simultaneous capillary solution and deposition by which new minerals are substituted for earlier mineral or rocks

A

Replacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Loss and gaiin of electrons to specific ions

A

Oxidation and reduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In openspace without outright replacement

A

Direct Deposition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Precipitation from solution without themselves entering into solution

A

Catalytic action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Taking up of one substance at the surface of another

A

Adsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Occurs between solids and liquids whereby cations are exchanged, producing changed characteristics of both

A

Base exchange

17
Q

Rate of pore volume to the total volume of rock

A

Porosity

18
Q

Necessary for passage of solutions through host rock to depositional sites
-main factor of localization in absence of fracture

A

Premeability

19
Q

Brittle rocks crackle readily

A

High permeability

20
Q

Ductile rocks do not crackle

A

Less permeable

21
Q

Thick accumulation of sediments in orogenic environments

A

Geosynclines

22
Q

Regional loci of ore deposition, deposition cluster within or about stocks or batholiths

A

Igneous Intrusions

23
Q

Weathered zones beneath unconformities are more porous, control location of syngenetic sedimentary deposits

A

Unconformities

24
Q

Permeable pathways, replacement or metasomatic deposits extend or deposit along these_____

A

Bedding

*cross bedding are more favorable

25
Q

Serves as barriers for mineralizing solutions; concentrate mineral deposition in strata below or above

A

Impervious Layer

26
Q

Supergene Sulfides deposits at

A

Above Impervious layers

27
Q
  • The most important loci of ore
  • Provides zone of porosity and permeability
  • provides channelways for hydrothermal fluid to pass
A

Structural

28
Q

Broader localization of ore belts/mineral districts

A

Regiona

29
Q

Immediate localization of ore

A

Detailed

30
Q

Cupolas, deposits can be located if fluid is lighter than magma

A

Structural Highs

31
Q

Cut of a stock dome

A

Cupolas

32
Q

Lopoliths, sulfide melt is heavier than silicate melt so located at bottomof intrusives

A

Structural Lows

33
Q

Fold axes with increased fracturing provided channel ways for pre-ore deposition

A

Folds

34
Q
  • Control deposition of ore deposits

- Can result from regional stresses

A

Fractures / Lineament

35
Q

When your ore deposits in a structural intersection

A

Ore shoot

36
Q
  • favorable for deposition
  • increased permeability
  • loci for interaction of different fluids
A

Structural intersection

37
Q

Faults that occur before deposition if ore minerals, Controlling structure

A

Syngenetic Faults

38
Q

The deposition of ore minerals happened first before faulting, it cut and displaces ore bodies

A

Epigenetic Faults

39
Q

High veolocity explosion vent

A

Diatremes

Ore deposits (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions