Turning Rocks into Money™ requires an understanding of the geological characteristics of a mineral system and a reasonable sense of what it will cost to get the metal out of the rock. Because the odds of success—finding an economic ore deposit—are so heavily stacked against the explorationist, it is just as imperative to know when a project is failing as when it is succeeding. Knowing more than the crowd is key.

Since we are usually dealing with early-stage exploration projects at Exploration Insights, we are as often as not dealing with limited data and projecting that into the third dimension—Earth. Exploration geology is not an exact science, it is an art supplemented by experience and imagination that evolves as mapping, sampling, drilling, etc., adds to the picture. Over the years we have discussed hundreds of companies and mineral properties. These discussions often involve examining and interpreting the exploration data.

Our goal is to help subscribers better evaluate their own investments in the junior mining and exploration sector, as well as stocks in the EI portfolio; therefore, we have compiled this document titled EI Geo-Insights, a compendium of excerpts from Exploration Insights newsletters up to 2012 that we hope will be of help and value in your own research.

If interested in receiving a copy, email us at contactus@explorationinsights.com and we will send you one. Once ready to take the leap, consider subscribing to the newsletter.

Table of Contents

GENERAL GEOLOGY

RECUMBENT SYNCLINE AS SITE FOR MINERALIZATION: SERRA PELADA

GEOLOGY OF PATAGONIA; CONTINENTAL DRIFT

LAYERED IGNEOUS COMPLEX: RING OF FIRE

GREENSTONES BELTS

CARLIN-STYLE GOLD MINERALIZATION AT LONG CANYON

GEOLOGIC HISTORY OF THE CARLIN TREND

ALKALIC ROCKS

EPITHERMAL DEPOSITS: IN A NUTSHELL

EPITHERMAL SYSTEMS: Low-Sulfidation Deposits, High-sulfidation Deposits

THE GEOLOGY OF COLOMBIA

GOLD PORPHYRY

VOLCANICLASTIC

GEOLOGY OF INDONESIA

BRECCIATION

RHYOLITE VOLCANIC ROCK

MINERALIZATION

“GOOD” AND “BAD” GRADES--INTERPRETING DRILL RESULTS AND GRADES

Ivanhoe Mine’s Bakrychik contrasted with Goldcorp’s Marigold mine

COMPARING THE ECONOMICS OF A HIGH GRADE AND LOW GRADE DEPOSIT

Comparing Newmont/Fresnillo Herradura and Great Basin Gold’s Hollister deposit

GOLD COMPANY VALUATIONS AND ECONOMIC STUDIES

Gammon Gold

ALTERATION

Feldspar and Pyrite

CALCRETE URANIUM DEPOSITS

GOLD MINING: EXPLORATION AND PRODUCTION ISSUES

MINING IN THE YUKON

CARLIN-TYPE MINERALIZATION

SKARN TYPE MINERALIZATION

GEOLOGY AND MINERALIZATION: IXTACA EPITHERMAL PROPERTY

MINERALIZATION IN VOLCANIC LAYERS

RESOURCE ESTIMATES

RESOURCE ESTIMATES DEFINED

DRILL HOLE INTERVAL CALCULATOR

ASSAYS AND RESOURCE ESTIMATES

How a drill interval is converted to an assay

BIMODAL GRADE POPULATIONS: MINERALIZATION, FAULTING AND ERUPTION, GRADE DISTRIBUTION PLOT

Examples of mineralization

CAPPING OR TOP CUTTING ASSAYS

COEFFICIENT OF VARIATION FOR AN ASSAY

GRADE DISTRIBUTION GEOLOGICAL BIAS: A “FEEL” FOR ROCKS

EXPLORATION AND MINING TOOLS

RADIOMETRIC READINGS

ORE BODY AND OPEN PIT: WHITTLE PIT OF LYDIAN INTERNATIONAL

SOIL SAMPLES

CSAMT

STREAM SEDIMENT SAMPLES

GRAB SAMPLES, CHIP SAMPLES

LIFE EXPECTANCY OF A MINE

BLOCK CAVING

METALLURGY

OXIDE AND SULFIDE MINERALIZATION AT CAMINO ROJO

AQUILINE (NAVIDAD): VOLCANOGENIC SULFIDES AND METALLURGY

VAT AND HEAP LEACH

METALLURGY: LONG CANYON, AMULSAR AND MIWAH

Example: Fronteer Gold

HE 80-20 RULE OF METALLURGY