3. geology of ore deposit
Post on 24-Feb-2018
239 Views
Preview:
TRANSCRIPT
-
7/24/2019 3. Geology of Ore Deposit
1/29
Metallogenic ProvincesMetallogenic Provinces
Geology of Ore Deposits:Geology of Ore Deposits:An OverviewAn Overview
ByBy
DR. ARIFUDIN IDRUSDR. ARIFUDIN IDRUS
Laboratory of Mineral ResourcesLaboratory of Mineral ResourcesDepartment of Geological EngineeringDepartment of Geological Engineering
Gadjah Mada UniversityGadjah Mada University
Jl. Grafika No. 2Jl. Grafika No. 2 BulaksumurBulaksumurYogyakarta 55281 IndonesiYogyakarta 55281 Indonesiaa
-
7/24/2019 3. Geology of Ore Deposit
2/29
Major tectonic plates
Lempeng Pasifik
Lempeng AfrikaLempeng Hindia-Australia
Lempeng Antartik
Lempeng Eurasia
Lempeng Amerika Utara
LempengAmerika Selatan
Lempeng Nazca
-
7/24/2019 3. Geology of Ore Deposit
3/29
Tectonic setting vs Ore depositsTectonic setting vs Ore deposits
-
7/24/2019 3. Geology of Ore Deposit
4/29
SSouthwest Pacific Rimouthwest Pacific Rim
-
7/24/2019 3. Geology of Ore Deposit
5/29
Tertiary island arcs in IndonesiaTertiary island arcs in Indonesia
-
7/24/2019 3. Geology of Ore Deposit
6/29
CommodityCommodity--type classification of ore deposittype classification of ore deposit(Evans, 1993):(Evans, 1993):
Precious metals (logam mulia)Precious metals (logam mulia): emas (Au), perak (Ag), platina (Pt): emas (Au), perak (Ag), platina (Pt)
NonNon--ferrous metals (logam nonferrous metals (logam non--ferrous)ferrous): tembaga (Cu), timbal: tembaga (Cu), timbal(Pb/lead), seng (Zn/zinc), timah (Sn/tin), dan aluminium (Al). E(Pb/lead), seng (Zn/zinc), timah (Sn/tin), dan aluminium (Al). Empatmpatpertama dikenal sebagai logam dasar (base metals).pertama dikenal sebagai logam dasar (base metals).
Iron and ferroalloy metals (logam ferroalloy dan besi)Iron and ferroalloy metals (logam ferroalloy dan besi): besi (Fe),: besi (Fe),Mangan (Mn), nikel (Ni), krom (Cr), molibdenum (Mo), wolframMangan (Mn), nikel (Ni), krom (Cr), molibdenum (Mo), wolfram
(W/tungsten), vanadium (V), kobal (Co).(W/tungsten), vanadium (V), kobal (Co). Minor metals and related nonMinor metals and related non--metalsmetals : antimon (Sb/antimony),: antimon (Sb/antimony),
arsen (As), berilium (Be/beryllium), bismut (Bi), kadmium (Cd),arsen (As), berilium (Be/beryllium), bismut (Bi), kadmium (Cd),magnesium (Mg), air raksa (Hg/mercury), REE, selenium (Se),magnesium (Mg), air raksa (Hg/mercury), REE, selenium (Se),
tantalium (Ta), telurium (Te), titanium (Ti), Zirkonium (Zr), dstantalium (Ta), telurium (Te), titanium (Ti), Zirkonium (Zr), dsb.b.
Fissionable metalsFissionable metals : uranium (U), torium (Th), radium (Ra).: uranium (U), torium (Th), radium (Ra).
-
7/24/2019 3. Geology of Ore Deposit
7/29
Genetic classification of Ore depositsGenetic classification of Ore deposits
MMagmatiagmaticc--hhydrothermalydrothermal--related depositsrelated deposits Magmatic lMagmatic l iquidiquid deposits: Cr, Ni, PGMdeposits: Cr, Ni, PGM
PegmatitPegmatitee (Sn, Nb/Ta, Li, Be, etc).(Sn, Nb/Ta, Li, Be, etc).
HyHydrotdrothhermal:ermal: CyprusCyprus--typetype (VMS); skarn (W, Sn, Cu, etc), por(VMS); skarn (W, Sn, Cu, etc), porphyryphyry (Cu,(Cu,Mo, Sn, etc);Mo, Sn, etc); Vein/lodeVein/lode (Sn, W, U);(Sn, W, U); EEpitpithhermalermal ((AuAu--AgAg))..
HyHydrotdrothhermalermal--diagenetidiagenetic related depositsc related deposits KupferschieferKupferschieferttypesypes (Cu, Pb, Zn)(Cu, Pb, Zn) SEDEXSEDEX
MississippiMississippi--Valley TypeValley Type (MVT): Pb(MVT): Pb--ZnZn--BaBa--FF in marine carbonatesin marine carbonates
HyHydrotdrothhermalermal--metamormetamorphic related depositsphic related deposits QuartzQuartz--lode gold (orogenic gold deposits)lode gold (orogenic gold deposits)
Chemical weathering related depositsChemical weathering related deposits Bauxite,Bauxite, FeFe--lateritlaterite,e, NiNickel andckel andAu lateritAu lateriteses
Mechanical weathering related depositsMechanical weathering related deposits Placer deposits (alluvial, marine): Au, Sn, Fe/Ti, REE)Placer deposits (alluvial, marine): Au, Sn, Fe/Ti, REE)
-
7/24/2019 3. Geology of Ore Deposit
8/29
Geology of Bushveld complex, RSAGeology of Bushveld complex, RSA
-
7/24/2019 3. Geology of Ore Deposit
9/29
Chromite layers of Bushveld complexChromite layers of Bushveld complex
-
7/24/2019 3. Geology of Ore Deposit
10/29
Model ofModel of AuAu--AgAg low sulphidationlow sulphidation epitermalepitermal depositdeposit
Epithermal refers to mineral deposits that form in association with hot waters.
The deposits form within 1 km of the surface and water temperatures are about
50-200 degrees C.
-
7/24/2019 3. Geology of Ore Deposit
11/29
CLASSIC MODEL OF PORPHYRY DEPOSITSCLASSIC MODEL OF PORPHYRY DEPOSITS
PERIPHERAL
Ccp-Gn-Sp-Au-Ag PERIPHERAL
Ccp-Gn-Sp-Au-Ag
LOW PYRITE
SHELL
Py ~2%
Mag>Py
PYRITESHELLPy~10%Ccp0.1-3%Morare
Mag>Py& Ccp
ORE SHELLPy 1%Ccp 1-3%Mo 0.03%
LOW GRADE
CORE
low totalCcp-Py-Mo
?
?
SAN MANUEL FAULT
KALAMAZOOSEGMENT
SAN MANUELSEGMENT
Propylitic(Chl-Ep-Carb)
Adul-Ab
Argi ll icQtz-Kln-Chl
PhyllicQtz-Ser-Py
PotassicQtz-Kfs-Bt-+Ser+Anh
Qtz-Ser-Chl-Kfs
Chl-Ser-Ep-Mag
?
?
?
??
A
-
7/24/2019 3. Geology of Ore Deposit
12/29
Three major models:
1. Quartz-monzonite
2. Diorite
3. Breccia
QuartzQuartz--MonzoniteMonzonite
modelmodel
-
7/24/2019 3. Geology of Ore Deposit
13/29
Quartz lode goldQuartz lode gold
-
7/24/2019 3. Geology of Ore Deposit
14/29
Schematic illustrations showing the principal features of Archean erogenic gold deposits -
many of which also apply to Proterozoic and Phanerozoic examples. The main features at amegascale are that the deposits are associated with a convergent plate margin where
metamorphism results in the production of fluids that are focused along major structural
discontinuities. At a mesoscale major shear zones within or along the margins of greenstone
belts represent district-scale hosts to mineralization that are accompanied by broad zones of
intense alteration. Individual deposits occur along second- and third-order structures. Oredeposition is a function of fluid rock reaction and/or H2O-CO2 phase separation (after
Hagemann and Cassidy, 2000).
-
7/24/2019 3. Geology of Ore Deposit
15/29
Quartz lode goldQuartz lode gold
-
7/24/2019 3. Geology of Ore Deposit
16/29
Volcanogenic Massive SulphideVolcanogenic Massive Sulphide
VMS d i d l (K k )VMS d i d l (K k )
-
7/24/2019 3. Geology of Ore Deposit
17/29
VMS deposit model (Kuroko type)VMS deposit model (Kuroko type)
Maj or sour ce of BMaj or sour ce of Base met al s, e.g. Cu, Zn dan Pbase met al s, e.g. Cu, Zn dan Pb
-
7/24/2019 3. Geology of Ore Deposit
18/29
-
7/24/2019 3. Geology of Ore Deposit
19/29
Diagram illustrating the setting for the formation of SEDEX-type Pb-Zn ores and a scenario
which incorporates both exhalative and replacement concepts for the formation of theseores (after compilations by Goodfellow et al., 1993; Misra, 2000).
-
7/24/2019 3. Geology of Ore Deposit
20/29
SEDEX (e.g. Sullivan, Canada)
-
7/24/2019 3. Geology of Ore Deposit
21/29
SEDEX Deposits
Sulphide mineral layers are enclosed by and parallel to thesedimentary strata.
-
7/24/2019 3. Geology of Ore Deposit
22/29
Placer DepositsPlacer Deposits
Placer deposit : formed by the mechanical concentrationPlacer deposit : formed by the mechanical concentrationof resistant mineralsof resistant minerals, which, which are released by weatheringare released by weathering
from source rocksfrom source rocks
Main Commodities:Main Commodities:Tin, Gold, Platinum, Niobium, Tantalum, Titanium, Zircon,Tin, Gold, Platinum, Niobium, Tantalum, Titanium, Zircon,
DiamondDiamond
PaleoPaleo--placers:placers:The lithified equivalents of placer depositThe lithified equivalents of placer deposit
Economic deposits are limited geographical distributionEconomic deposits are limited geographical distribution
(Archean(ArcheanProterozoic)Proterozoic) Uranium, CanadaUranium, Canada
Gold & Uranium, South AfricaGold & Uranium, South Africa
TinTinbearing paleobearing paleo--placer: Nigeria, Brazil, Malaysiaplacer: Nigeria, Brazil, Malaysia
Gold placer depositGold placer deposit
-
7/24/2019 3. Geology of Ore Deposit
23/29
Gold placer depositGold placer deposit
Ni k l l t it d it: P f i l
-
7/24/2019 3. Geology of Ore Deposit
24/29
Nickel laterite deposit: Prof i le
Nickel laterite deposit: Soroako
-
7/24/2019 3. Geology of Ore Deposit
25/29
Nickel laterite deposit: Soroako
Nickel laterite deposit: Hand Auger drilling
-
7/24/2019 3. Geology of Ore Deposit
26/29
Nickel laterite deposit: Hand Auger drilling
Nickel laterite deposit: Cor e loggi ng
-
7/24/2019 3. Geology of Ore Deposit
27/29
Nickel laterite deposit: Cor e loggi ng
Nickel laterite deposit: Deposi t model l i ng
-
7/24/2019 3. Geology of Ore Deposit
28/29
Nickel laterite deposit: Deposi t model l i ng
Nickel laterite deposit: Min ing /exp lo i ta t ion
-
7/24/2019 3. Geology of Ore Deposit
29/29
p g p
top related