Alteration
Vectors

Geochemical Exploration Tools

From raw data to discovery
— faster
Transform multi-element drill data into powerful vectors toward ore. See the invisible. Vector with confidence.
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The Aim

The goal of Alteration Vectors is to share my knowledge and experience of over 40 years working with altered and mineralised rocks related to various ore types.
The website is aimed at geologists, both exploration and research, who are keen to get the most from multielement drill hole data in order to understand hydrothermal alteration and vectors to ore.
This is my way of giving back to an industry in which I have had a great career as a mineral explorer, ore deposit researcher and economic geology teacher.

The Problem

Why exploration programs miss targets and waste capital

Hidden Alteration

Hydrothermal halos invisible during core logging and chip drilling

Missed Targets

Drilling programs miss buried mineral systems, wasting time and budget

Poor Vectors

No clear directional guidance in complex overprinting scenarios

The Solution

Simple but powerful geochemical workflows using data you already collect

Transform raw geochemical data into actionable exploration intelligence. Map the footprint of buried mineral systems and vector toward ore with confidence.

What you get

  • Proven graphical plots (AI-CCPI, PCD Alteration Diagram)
  • Clear alteration type identification from whole-rock chemistry
  • Zonation patterns pointing toward high-grade mineralization
  • Methods for VHMS and porphyry copper systems

Why It Works

  • Uses data you already collect (multi-element assays)
  • Detects alteration invisible to the naked eye
  • Reveals patterns across entire drill programs quickly
  • Guides drilling decisions with spatial context

Fundamentals

Click below to learn more about
Ore deposit systems

select an alteration system to learn more

Volcanic-Hosted Massive Sulfide
Progressive mineralogy changes toward massive sulfide orebodies
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Porphyry Copper Systems
Reveals exactly where Cu-Au grades concentrate
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Sediment-Hosted Cu
Short Description here  xxxx  xxxx xxxx xxxx xxxx xxxx xxxx xx
Sediment-hosted Zn-Pb-Ag
Short Description here xxxx xxxx xxxx xxxx xxxx xxxx xxxx xx
Orogenic Gold
Short Description here xxxx xxxx xxxx xxxx xxxx xxxx xxxx xx
research & publications

Published Work

Ross has published over 150 papers on ore deposits and mineral exploration. He is rated by Scopus as number three in the world based on his publications in the field of economic geology. A few of his papers that relate directly to alteration vectors are given below.
Porphyry
2025

Simple graphical tools to understand the relationship between porphyry composition, hydrothermal alteration, mineralogy and copper-gold grades in porphyry copper deposits

Ross R. Large
Read Paper
Porphyry
2001

The Alteration Box Plot: A Simple Approach to Understanding the Relationship between Alteration Mineralogy and Lithogeochemistry Associated with Volcanic-Hosted Massive Sulfide Deposits

ROSS R. L ARGE ,† J. B RUCE GEMMELL , HOLGER PAULICK
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Porphyry
2001

Hydrothermal Alteration and Volatile Element Halos for theRosebery K Lens Volcanic-Hosted Massive Sulfide Deposit, Western Tasmania

ROSS R. L ARGE ,† RODNEY L. ALLEN,* MICHAEL D. BLAKE, AND WALTER HERRMANN
Read Paper
Read more papers here

Case Studies

Review some of our latest case studies
Porphyry
2025

Perschanka, Russia

Ross Large

Workflow for PCD Alteration: WF1: Peschanka PCD Interpretation in ioGAS.

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Porphyry
2025

Khamagtai porphyry Cu-Au Mongolia

Ross Large

Ross to provide details.

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Porphyry
2025

Onto porphyry Au-Cu Indonesia

Ross Large

Ross to provide details

Read Case Study
Porphyry
2025

Bellas Gate Jamaica

R.Large

Workflow # 4. for PCD Alteration: Dataset CS4 Bellas Gate Jamaica. Interpretation in ioGAS.

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Read more case studies here
authority & experience

Dr. Ross Large

Ross Large
55 years in mineral exploration and academia. Founded and led CODES for 25 years. Published extensively on VHMS, porphyry copper, and hydrothermal alteration systems.
full biography
Alteration
Vectors
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