ORE DEP (MAGMATIC HYDRO ORE PROCESSES)

Question 1

Notable properties of Water

Answer 1

High Heat Capacity
High Surface Tenstion
Max density just above freezing temp
High Dielectric constant

Question 2

Clustering of water molecules around a dissolved ion

Answer 2

Hydration

Question 3

Measure of a fluid’s ability to separate ions or other dipoles and is a function of the number of dipoles per unit vol

Answer 3

Dielectric Constant

Question 4

Implication of high dielectic constant of water?

Answer 4

enhancing dissolution and increasing solubility

Question 5

Lines of equal density

Answer 5

Isochores

Question 6

Crystalline structure of Ice

Answer 6

Hexagonal

Question 7

The phase boundary at which liquid and vapor are in equilibrium

Answer 7

Saturation vapor pressure
Boling Point Curve

Question 8

Boiling point of water _______ as pressure increases

Answer 8

Increases

Question 9

The point where it is no longer possible to increase the boiling pt by increase of pressure and where there is no longer a physical distinction between liquid and vapor

Answer 9

critical point

Question 10

T and P of Critical Pt

Answer 10

374 deg cel and 221bar

Question 11

The triple pt of water coexist at

Answer 11

0.008 deg cel
0.06 bar

Question 12

Critical density of water at critical pt

Answer 12

0.3g/cc

Question 13

a homogenous single phase (of water) that exist at pressures and temperatures above the critical point

Answer 13

Supercritical Fluid

Question 14

Ideal Gas Law

Answer 14

PV=nRT

Question 15

Early water derived from the degassing of volcanic magmas as they extruded onto the early crust

Answer 15

Juvenile Water

Question 16

Substantial bodies of water first appeared on

Answer 16

Early Archean (Eoarchean) 3800 Ma

Question 17

what is responsible for the water content of granitic magma?

Answer 17

Ponding of hyrdous basaltic melt at the base of the crust and diffusive transfer of elements and volatiles across conrod

Question 18

Melting occurs without the presence of free water in the rock and is regarded as a realistic model for the generation of Granitic Magma in the Crust

Answer 18

Dehydration Melting

Question 19

Arrange (Musc, Biot, Hnbld) in terms of water content (Hydrous)

Answer 19

(8-10%)Musc
(3-5%)Biot
(2-3%)Hbld

Question 20

When meta-sed rocks compose of musc or musc+Biot-bearing rocks is melted it will produce

Answer 20

S-type Granites
Peraluminous
Relatively wet due to intila high H2O content

Question 21

Ores related to wet Sgranite

Answer 21

Sn-W-U

Question 22

What corresponds to the S granite in ishihara classification

Answer 22

Relatively reduced
Ilmenite series with low fO2

Question 23

When meta-ign composed of Biot or Biot+Hbld Bearing rocks are melted it will yield

Answer 23

I-type Granite
Metaluminous
Relatively Dry

Question 24

Ore deposits related to Itype Granites

Answer 24

Porphyry Cu-Mo

Question 25

Why does magmatic hyrdothermal fluid boil at relatively shallow depth?

Answer 25

Because of low pressure and since the equilibrium vapor pressure equals that f the load pressure on the magmatic system and bubble of gas vesiculate

Question 26

Process by which VAPORSATURATION Is achieved by VIRTUE OF DECREASING Pressure after only about 10% crystallization and the water content of resdiual magma is at 3.3%

Answer 26

first boiling

Question 27

Where does first boiling usually occur?

Answer 27

high level systems (2km depth)

Question 28

Vapor saturation achieved by progressive crystallization of dominantly anhydrous minerals under isobaric conditionsan occurs more in deep-seated magmatic systems and only after relatuvely advanced stage of crystallization

Answer 28

Second Boiling

Question 29

Results in the overpressuring of the chamber interior and can cause brittle failure of the surroundung rocks

Answer 29

Hydrofracturing

Question 30

The products of precipiration of silica from hot aqueous solutions precolating thru farctures in the Crust

Answer 30

Qtz veins

Question 31

form of Qtz when dissolved

Answer 31

H4SiO4

Question 32

Composition of solute in High Tand P conditions

Answer 32

High Si, Na and K

Question 33

At lower P and T

Answer 33

Alkali decreases relative to silica

Question 34

Anionic substances contained in the magmatic aqueous soln

Answer 34

Ligands

Question 35

Typical solute content of magmatic fluis

Answer 35

Alkali, Alkali Earth metal Cations Cl as dominant ligan

Question 36

Amount of sulfur in magmatic fluids reflects

Answer 36

Crustal levels

Question 37

At high crustal levels SO2 partitions into

Answer 37

Vaport Phase on Boiling

Question 38

What Form of sulfur is related to I-type magmatic fluids?

Answer 38

Oxidized and ftationates in the liquid phase

Question 39

Porphyry Cu and MO are asociated with abundant sulfides like

Answer 39

Pyrite and Chalcopyrite

Question 40

Reduced sulfur content promotes stability of sulfide minerals to lower temp and leads to the formation of

Answer 40

Scheelite and Wolframite

Question 41

Earlier generated fluids in primary fluid inclustions is characterized by

Answer 41

high T, High Salinity Liqui-Vapor Phase Separation or boliing

Question 42

What confirms the high salinites in ore forming fluids trapped in fluid inclusions

Answer 42

Daughter Crystals - Tiny minreals precipitated from fluid on coling after it was trapped w/in the incusion

Question 43

Samples of daughter crystals

Answer 43

Halite and Sylvite

Question 44

A technique qwhich accuratrely and completely assess PCD related ore fluid composition from the quantitative analysis of individual fluid inclusions. This allows analysis of a cationic species in tiny volume of inclusion fluid up to 1ppm

Answer 44

Laser Ablation (LA) Inductively Couples Plasma (ICP) Mass Spectrometry

Question 45

In such boiling of magmatic fluid, where do metals or elements preferentially partition?

Answer 45

The liquid phase (Na, K, Fe, Mn, Cu, Pb and Zn)

Question 46

where does Cu partition?

Answer 46

Into the vapor phase

Question 47

In this kind of magma CO2 exist as carbonate ionic complex

Answer 47

Alkaline

Question 48

CO2 solubility in magma is a function of

Answer 48

Presure and Alkalinity

Question 49

Where does CO2 preferetntially partition in early crystallizaton?

Answer 49

Vapor hase

Question 50

At higher crust describe CO2 abd H2O volatile levels

Answer 50

H2O is enriched while CO2 has already bubbled awat

Question 51

High CO2 magmatic fluids will promote

Answer 51

Immiscibility between Vapor and Saline Liquid Phase

Question 52

Whats the effects of Effervescene or removal of CO2 in the reminaing fluid

Answer 52

High Ph or salnity

Question 53

Effects of increasing pressure in phase partitioning of magmatic fluid

Answer 53

decreasig salineinity Brine slowly increasing Saline fluid

Question 54

The tendency for brine solutions a low pressure, or in the presence of CO2 at higher pressure to segragate into two phases

Answer 54

Immiscibility

Question 55

what are the two phases to which a magmatic brine segragate

Answer 55

1) Dense more saline Brine 2) Less dense low salinity aqueous soln