Mineral and petroleum exploration is a crucial aspect of the geoscience industry, as it helps in discovering new resources and exploring untapped areas. To achieve this, Petrologists and Geologists use various techniques and tools to obtain information about rock and reservoir properties. One of the essential tools used in mineral and petroleum exploration is thin section preparation, which provides valuable information about the properties and characteristics of rocks and minerals. In this article, we will discuss the process of thin section preparation, its importance in mineral and petroleum exploration, and the recommended equipment for preparing thin sections.
Thin section preparation involves cutting a thin sample of the rock using a diamond saw and grinding it optically flat. The sample is then mounted onto a glass slide and ground smooth using progressively finer abrasive grit until the sample is only 30 μm thick. The thin section is then placed between two polarising filters set at right angles to each other. The optical properties of the minerals in the thin section alter the colour and intensity of the light as seen by the viewer. The interference patterns produced by the thin sections on the Michel-Lévy Interference Colour Chart are assigned a specific colour based on the wavelength of light that is being amplified or cancelled out. Mineralogists can then use these patterns to identify the mineral and determine its optical properties.
Thin section preparation is crucial in mineral and petroleum exploration, as it provides valuable information about the properties and characteristics of rocks and minerals. Geologists can use thin sections to study the pore structures, grain size, and orientation of the rocks, which can provide information about the permeability and porosity of the reservoir rocks. This information is essential in determining the potential for oil and gas accumulation. Mineralogists can also use thin sections to understand the composition, texture, and formation of rocks and minerals. This information is used to make informed decisions about mineral exploration and extraction.
Recommended Equipment for Thin Section Preparation:
To produce top quality thin sections, specialised equipment is essential. The 'KemTech Geo' stands out as a precision machine designed for both cutting and grinding stages in a single unit. In the cutting module, the specimen, mounted on a slide, is securely fixed onto a holder using a vacuum and sliced to a thickness of up to 0.5mm. Water cooling is employed during cutting to prevent deformation and heat-induced degradation of the samples. In the grinding module, the grinding position can be finely adjusted in microns, with an encoder displaying the position on the HMI with a resolution of 0.001mm, ensuring the utmost precision.
The 'KemTech III Thin Section Lapping Machine' excels in precisely lapping and polishing thin sections affixed to glass slides, achieving a thickness as fine as 30 microns. Controlled dispensing of diamond and/or traditional abrasives onto the lapping plate is achieved through the integrated peristaltic dispenser. The 'Lift Off Disc' system facilitates swift transitions between the lapping and polishing stages.
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