kimberlitic diamond exploration proposal

7/26/2019 Kimberlitic Diamond Exploration Proposal

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GEM 4106 FINALEXAM

Exploration Design for Kimberlitic Diamond Intrusion in Aricheng, Guyana

by Larissa Farnum Student SI! "##$#%&


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Area Selection Criteria

Geological Potential for target mineral primary diamonds

' Tectonic activity

' Lithological evidence

' Presence of alluvial diamonds

' Presence of indicator minerals garnet (red), ilmenite, chromite

Land Tenure

Available land in area of interest (partnerships can be wored on alater date)

Phase of !"ploration

#econnaissance


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$%G% &ulletin '*+ineral -eposit models('.)

-escriptive deposit

model by G/0 1rris and0/- &liss+ ''

Genetic model by #/2

itchell

3ene4uela5s Guaniamodeposit

&ra4il5s 6arolina7imberlite -eposit

-iamond 1ccurrences inGuyana

Previous 8ors

Why did I choosehere ?


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Descriptive Deposit Model

' Host rock imberlite diatremes, olivine lamproite and leucite lamproites

' Texture pipes9 porphyritic/ &reccias with inclusions of many rocs from mantle, basementand overlying se:uences/ Lapilli tu; >, .?> and '>>> a

' Depositional Environment- intrusion of pipes from mantle source under high pressurewith rapid cooling

' Tectonic environment cratonic areas, stable since early Protero4oic/ %ome intrude folded

cover rocs that overlie deformed cratonal margins/ Pipes occur in areas of epeirogenicwarping or doming and along ma@or basement fracture 4ones/ %ome pipes occur atintersections of regional 4ones of weanesses/

' Associated deposit type -iamond placers

' Mineralogy diamond, bort, carbonado, ballas and amorphous carbonado

'tructure

sparsley disseminated diamonds as phenocrysts or "enocrysts in breccia

' Alterations serpentini4ation which results in blue clayB 4ones/ %ilici


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Kimberlite lamprophyre


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Genetic Deposit Model

' 6li;ords #ule and %ubduction activity

' Lithospheric mantle is depleted in basalticcomponents and may contain spinel, garnetilher4olite, har4burgite and dunite

' %cattered throughout are eclogitic rocs

' Asthenospheric mantle consist of mantlematerial which can generate id+1ceanic#idge &asalts whose rocs are considered to

be fertileB

' 7imberlite intrusions occur in clusters or


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Genetic Model Contd

Lamproites occur along themargins of cratons or in cratoni4edaccreted mobile belts in regions ofthic crust (H>+?? m) and thiclithosphere ('?>+.?> m)

-istribution of imberlites and lamproites in

8est Australia showing their relationships to the7imberlyArchean craton and the ad@acentProtero4oic cratoni4ed mobile belts/


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!i"#erlite Localities on A"a$onian Craton

Allu(ial

diamonds

Guaniamo

Appro"/

location


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And G%&ana '' (%st all%vial dia"onds

Geologists such as 6onolly and %wain developed classi>=)

-uring TAT! cycle there would5ve possibly been the opening of deep seated

structures that would5ve allowed for later emplacement ofimberliteKlamproites/


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)e*ional Geolo*& Favora#le +or e"place"ent

' Trans+Ama4onian orogeny, nown as TAT!, is responsible for thecratoni4ation of the Paleoprotero4oic of the Guiana %hield

'The Granite greenstone belts are in the Dorth of the shield whilstthe Late Paleoprotero4oic to esoprotero4oic volcanic, intrusiveand sedimentary rocs lie in the southernmost part of the shield

and is separated by a 6entral Granitoid terrain/'The geological evolution of the Guiana %hield is divided into four

distinct changes9

' ormation of the Archean basement

' ain Trans+Ama4onian orogeny (./.+./> Ga)

' Late Trans+Ama4onian orogeny

' %ubse:uent Protero4oic and Paleo4oic anorogenic events


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,eca%se-..

6entral Ama4on + isindicative ofunderplating accumulation ofpartial melts duringsubduction ('/=+'/M

Ga)

whilst Tapa@os Parimaof is @uvenilemagmatic activitybetween ./'+'/=M Ga/


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)es%lted in t/e s/ear $ones red2ossi#le pat/3a&s +or "antlederived i"#erlitic "a*"aticintr%sions 2ost5AE


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District Geolo*& 7verlies "ostl& ,MS


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Land en%re ai" 3as to intercept t/e Avanavero

"&,)*# acres

"" ++S


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2revio%s 3ors #& Co*e"a and 2ro"et/e%s )eso%rces

8ell +ract%redrocs

locali$edpat/3a&s


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Lamprophyre

Aricheng

-orth.hefa(orableindication


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Episyenites

/lamprophyre0

a1reba Falls

%ince they occur as clusters, what would bethe odds JJ

2ed Garnetfound here3Isseneru


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E9ploration #& Golden Star )eso%rces

-o records of their

report and hencetheir explorationmethods


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E9ploration 2ro*ra"

1b@ectives

'To identify mantle derived indicator minerals in the area ofinterest

' 6orrelate local roc units to diamondiferous occurrences based

on


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E9ploration 2ro*ra"

Generally it will follow this Eow chart

ost important imberliteindicator minerals are9garnet, chromite, ilmenite,6r+-iopside and olivine

&ut the resistive ones aregarnet, ilmenite andchromite

antle+derived garnet, 6r+-iopside, ilmenite and

chromite have visualcharacteristics that permittheir distinguishing themfrom similar minerals ofcrustal origin


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Strea" Sedi"ent Sa"plin* all%vial "edi%"

#iver alluvial will /*+.mm

%ampling will tae place

at conEuence of streamsand along


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Data Anal&sis

Geochemical analysis of indicator minerals

Laboratory separation of the sample will be done to identify theindividual indicator minerals in the sample

3 Gravity */. %/G

3 agnetic (Para, Don and erro)

&inocular microscope identi


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Electron icroprobe data from indicator minerals of the E1ati mine disco(ery

4hether youha(ediamondssource or not

defines 5rrich field

+otenital forEclogitic garnets


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E* o+ indicator "inerals

G"#

G*

diopside

+eridote

garnet indiamond

Diamondiferouseclogite xenolith

Eclogiticgarnetinclusionindiamond


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Correlatin* )oc :nits Fro" )es%lts

' Essentially indicator minerals identified 6ould be plotted on a local map in an effort totrace upstream to the source area

' A tracer trail 6ould be follo6ed upstream by collecting additional stream sedimentsamples until samples are found that contain a notable increase in indicator minerals,follo6ed by samples 6ith no indicator minerals7

' 8nce this is achie(ed, the region bet6een the sets of samples 6ould be searched bothin drainage and along slopes abo(e drainage7

' After the region is identified then further follo63up 6or1 6ould be re9uired to identify the

source7


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Follo3 :p 5 So%rce +or t/e Indicator Minerals

' .he ob:ecti(e 6ould be to intercept the source in order to ha(e roc1 samples forpetrological testing

' .he body 6ould ha(e to be first delineated

' Li1ely source 6ould be buried and greater probability lies for it to be an intrusionand not a pipe gi(en the possible e(idence put for6ard by 5ogema

' Follo6ing in Snap La1e;s footsteps, seismic sur(ey 6ould better delineate a buried1imberlite dy1e

' Exploration drill to intercept source


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Snap Lae N8 i"#erlite d&e seen in seis"ic


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E9pendit%re +or one &ear o+ E9ploration

Ite" Mont/

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Mont/

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Mont/

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Mont/

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Mont/

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otal

Geolo*ists


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Anal&sis and Interpretation

Activities nit 5ost G? @

Separation o+ Sa"ple

Sa"ple 2reparationAbout S@$## per sample /&

kimberlitic diamond exploration proposal

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