矿产勘查靶区优选:基本原则大纲
概述
选区 – 为何重要?
公司层面
基本战略选择
建立选区模式
应用选区模式
反馈
结论选区过程评述公司战略确定目标价值转为地质 /地理参数建立选区模型(技术和商业)
创建数据库确定靶区评价靶区选区:为何重要
Getting the area selection stage right is
critical
If we fail here it does not matter if:
– We have the best exploration technology
– We make the best deals
– We are the most efficient field explorers
Analysis indicates that the EMV of an exploration
project is most sensitive to target exploration
project is most sensitive to target quality
(Psuccess )
The opportunity cost of poor targeting is very high
Strategies that focus predominantly on turnover
rather than target quality are not viable
The Opportunity Cost of Poor Initial
Targeting is High!
Turnover alone is not enough
Gambler's Ruin Sensitivity Analysis
The Targeting Process,
公司层面公司战略确定目标价值转为地质 /地理参数建立选区模型(技术和商业)
创建数据库确定靶区评价靶区公司层面
公司战略应高水平投入到选区模型的建立方面
关键问题,
– 矿产品类型( Commodity type)
– 阀值大小( Threshold size)
– 资金强度(如加工工艺的复杂性)
– 不中意的元素(如 Pb)
– 地理因素( Geography)
上述因素强烈影响目标矿床类型的选择确定阀值大部分矿业财富是由巨型矿床贡献的
2/3的财富是由 10%的矿床贡献的基本战略决策 Decision
勘查经验揭示了两个根本点,
–,某地的最大矿床是在勘查史早期发现的,
–,发现新矿的最佳地是已发现有矿床之处,
看起来矛盾其实不是
反映了基本方面:矿是如何产出于自然界的,而自然界反过来对选区战略又极富重要意义。
任一地区规模( Size)与价值 (Value)几何分布关系
And the big ones tend to be found early - Kambalda Ni
example(Reserves + Cumulative Production)
Another example
发现费用随时间增加新概念与技术能改变时间进程成熟省 /矿区( Province / Camp)勘查战略管理模型基本战略决策
两个基本选区原则:
– 象园找象 ELEPHANT COUNTRY
– 首批进入 FIRST MOVER
选择决定于公司战略和风险的洞察力首批进入勘查战略
首先勘查前人没有勘查过的地区
尽管风险大,但发现大矿的潜力也大
成功的关键是准确评价前人勘查的盲点盲区象园选区战略
去已经发现有你的目标类型矿床的地方
可降低风险但是:
– 要求确定别人错失的机会(如新技术?)
– 不可能发现比已知矿床更大的矿床
– 若是太晚,就只剩下爆竹了( squibs )
选区过程:建模公司战略确定目标价值转为地质 /地理参数建立选区模型(技术和商业)
创建数据库确定靶区评价靶区建模
两大类:
– 新建( Process)
– 模拟(类比)
新建模型 Process Models
– 根据基本成矿作用的理解新建模型( Process Model)
根据矿床关键定位作用的解释 localising
不必对矿床成因的所有方面都能理解,只有空间关系最为重要
强项 Strengths
– 可以识别出有利的成矿区,而不必考虑与已知成矿环境是否相似
– 能够关注有限的关键参数
弱项 Weaknesses
– 对地质模型的质量极为敏感新建模型例子初始分熔的熔体从活动的上涌地幔中公离出来模拟模型 Analogue Models
根据经验模拟已知成矿环境
强项 Strengths:
– 不要求理解地质作用
弱项 Weaknesses:
– 可能错过主题的各个变种
– 不能从关键因素中区别出偶然因素,从而可能有高的假正率比例尺 Scale的重要性
建立选区模型时比例尺是相当重要的问题
从全球到矿床通常有依赖于比例尺的选区参数的层次
某一比例尺的关键因素对于其它比例尺来是不恰当的
各种选区参数的相对重要性的争论反映了比例尺的混乱
在某些比例尺,选区过程被直接检测所取代,
而不在那儿浪费努力基于比例尺的选区参数层次
At smaller scales,the Targeting Process
(Prediction)gives way to Direct Detection
Building the Targeting Model –
General Principles
Must reflect consequences of threshold size
decision
Must be expressed in terms of data readily
available during exploration
Must formalise in ranking templates to
ensure consistency and clarity of application
The Targeting Process:Application
公司战略确定目标价值转为地质 /地理参数建立选区模型(技术和商业)
创建数据库确定靶区评价靶区
Interacting with Data
Targeting first requires compilation of a
relevant database
Two end member ways of dealing with data:
– Venn Diagram Approach
– Hierarchical Approach
TWO APPROACHES TO DATA
Target Area
Venn Diagram Approach
– Classic,GIS-type” targeting
– Most Applicable to mature,data-rich rich
environments
Hierarchical Approach
– More efficient methodology in relatively data –
poor environments
– Effective way of rapidly reducing scale when
starting with very broad regions
Target Ranking
Formal Ranking system is required if more
than a few targets
Ranking systems can range from simple
checklist of key parameters to sophisticated
probability based models
– Choice depends on complexity of targeting
exercise
Target Ranking,Principles
Permissive principle
–,Absence of evidence is not evidence of absence”
– Do not penalise areas that are relatively poorly known
Multiplicative (not Additive) Scoring
– More realistic spread of scores
– Eliminates targets without key factors
Consistency across provinces
The Feedback Loop
All business activities require measurement
to ensure systematic improve performance
with time; Targeting is no exception!
The Exploration industry has been generally
poor at analysing performance and feedback
into continuous improvement
结论
选区是矿产勘查的关键,选区错误将付出高昂代价
地球科学选区过程需与公司发展战略高度一致
最重要的是去象园选区或作先行者,Elephant
Country” or,First Mover”
比例尺是设计、理解和应用选区模型的关键
执行分析需要持续改善模型
The Targeting Process in Mineral
Exploration:基本原理
Jon Hronsky
AIG Exploration Strategies Symposium
19 March 2003
WMC