kuliah geokimia 3 4

Faculty of Agro Industry and Natural Resources

Geochemical Exploration

Click to edit Master title styleFACULTY OF AGRO INDUSTRY AND NATURAL RESOURCES DEPARTEMENT GEOSCIENCE

FACULTY OF AGRO INDUSTRY AND NATURAL RESOURCES DEPARTEMENT GEOSCIENCE


Geochemical exploration or geochemical prospecting or exploration geochemistry

the search for economic deposits (of minerals or petroleum) by detection of abnormal concentrations of chemical elements or hydrocarbons in surficial materials such as soils, waters, and plants. usually divided into two areas of specialization: • the search for metallic and non metalic minerals deposits, and• the search for accumulations of crude oil and natural gas.

the discovery of some dispersion of chemical elements or hydrocarbon compounds at levels sufficiently above normal to be called a geochemical anomaly.It is hoped that the anomaly might indicate the presence of mineralization or hydrocarbon accumulations at depth.


In the past prospector and geologist base on visual observation ( on the existing Outcrop) .

In mexico 90 % mines found by spaniardA parts of europe were known to the Romans.

Modern EG involves ; sensitive, sophisticated instrumentationRemote sensing and GISSample Collection and analysisElectronic data processingMethode of interpretation

25 ys ago copper were not economic unless > 1,5 % in sufficient tonage, today 0,4% is economic EG is ideally suite for low grade deposits, imposible to recognise visually


The use of EG since 16th century from Agricola’s book “ De Re Metallica”, the quotes paragraph


Modern Method first used in 1930 in USSR were concerned with the search for tin – emission spectographic analytical method.Modern methods of geochemical prospecting :

The recognition of the nature of primary and secondary halosThe analytical method using emission spectographThe development of polyethylene laboratory equipmentThe development of atomic absorption spectrometryThe development of gas cromatographyThe digital statistic methods


Survey GE according to the type of material being sampled and analyzed;

SoilRockStream SedimentWaterVegetationAirOther : Heavy Minerals, Bog material, Fish and other Fauna, Isotopic surveys, Overburden survey

Survey GE according to the scopeReconnaisanceDetail


Study of current trend :The continued search for methode effective in finding burried ore bodiesAirborne detection methodesDevelopment in instrumentation for chemical analysisElectronic data processingBiogeochemistryGeochemicall methods

kuliah geokimia 3 4

Education

geochemical anomaly

andthe search

continued search

economic deposits of

metalic minerals deposits

heavy minerals

hydrocarbon accumulations

natural gas