Hyperspectral CL Imaging of Sandstone
Panchromatic CL image of sandstone
Sandstone is a type of sedimentary rock which has strong relevance to the petroleum industry, as it presents one of the main rock types in which fossil fuels can be found. In addition to a high quartz content, sandstone often contains cement which affects the porosity and permeability of the rock material.
Using an integrated SPARC cathodoluminescence system, CL imaging provides valuable information to characterize the structure and material properties of geological samples. Hyperspectral CL techniques reveal microscopic textures and phases of materials like sandstone, as illustrated below. This example details the sequence used to determine material in a healed crack from SEM imaging, first using large area CL imaging and then applying hyperspectral imaging in specific areas of interest at higher resolution.
SEM (a) and CL (b) images over an area of sandstone. Hyperspectral CL data in (c-e) from area selected in white box from (b). False RGB CL image (e) shows contrast between granular material (1) and cement in healed crack (2) with corresponding CL spectrum (f) normalized to grain (1). Standard thermal oxide spectrum is shown for comparison.