Lecture OverviewDefinition of Exploration GeochemistryOther fields of Applied GeochemistryTypes of SurveysReconnaissance SurveysDetailed SurveysProspecting Situations

What is Exploration Geochemistry?Any method of exploration based on the systematic measurement of one or more chemical properties of a naturally occurring material to find abnormal chemical patterns (anomalies) related to mineralization

Chemical PropertiesTrace concentration of the element of interestTrace concentration of a related element (pathfinder)Concentrations or ratios of groups of elementsisotope ratios

Types of MaterialsRock LithogeochemistrySoilGossanGlacial debrisVegetation Geobotany, BiogeochemistryStream sediments and/or waters DrainageVapor and aerosols

Applied GeochemistryAgricultural geochemistryEnvironmental GeochemistryPublic health geochemistryMarine geochemistryGeo-hazards prediction

ExplorationGeochemistryGeophysicsGeologyRemote Sensing

Scales of SurveysReconnaissanceDetailed

Reconnaissance SurveysDetect favorable indicators of ore provinces, districts, (ore bodies)Large area - X0 to X0,000 km2Sample density - 0.01- 1.0 /km2Cost $1 to $10 per square mileRapid, minimal samples, low cost

Reconnaissance MediaRocks Stream water and sediment aerosols (airborne dust)vegetation (especially photographic)geobotany and biogeochemistrySoils (rarely used because of cost)

Detailed SurveysOutline mineralized ground to pinpoint source Locate area for trenching, drilling, etc.Small area - X - X0 km2Area selected by other methodsSample density - 0.01 - 1/mCost $X00 to $X000 per square mile

Detailed MediaRocksSoils vegetation (biogeochemistry)Vapor surveys (soil gases)

Exposed OreOre

HaloGround WaterMass Transport

Leeched Ore

HaloGround WaterOreLeechedZone

Zoned Ore

HaloGround WaterMass TransportMnAgZnPbCu

Blind OreOre

HaloGround Water

Covered Ore BodyUnconformityOreGravelTillVolcanics