Although the technique is itself not extremely useful in geothermal exploration, it is an important characteristic of rocks that allows other useful exploration techniques (e.g.
gravity surveys, to be applied and quality checked.
Various rock lab analyses are commonly used in geothermal exploration to understand the geologic and thermal history of an area, study hydrothermal alteration produced by past (or present) interactions between host rocks and thermal fluids, define and evaluate the characteristics of a geothermal reservoir, and ultimately “prove” the quality of a geothermal resource.
Select samples are then sent to labs for a more detailed investigation.
They typically involve measuring the physical and chemical properties of the rock.
For most Ar-Ar work, a fist-sized specimen is a good amount, allowing you the chance to make a thin section, do some geochemistry, get the minerals you need (including apatite and zircon), and still leave you with a small hand specimen.
We strongly prefer to carry out final sample preparation and loading for irradiation here at Lehigh, and will either do this ourselves or guide you in these final steps.
Any costs you have been quoted for analyses do not include the cost of mineral-separation supplies or technician time, and in general we will do this work for you only under special circumstances.
Analysis of radioactive and stable isotopes in rock samples can be used to investigate the thermal history of a reservoir, to determine the degree of water-rock interaction that has occurred in a system, and to date hydrothermal alteration minerals.
Petrographic analysis of thin sections prepared from rock samples is critical when trying to learn about a rock, reservoir, or formation of interest, and can be used to obtain information regarding rock textures, alteration mineralogy, and thermal history of a sample.