Initial Core Description (ICD)
Initial core description (ICD) is the portion of core processing that precedes subsampling and analysis. Data collected during ICD, especially lithological and compositional information (i.e., core description and smear slides) form the basis and context for all further analyses, and often provide most of the interpretation of depositional environments and changes.
Specific methods include:
Whole core (preferred) or split core logs with Geotek MSCL-S for:
- Magnetic susceptibility (loop)
- Gamma density
- P-wave velocity and amplitude
- Natural gamma radiation
- Electrical resistivity
Split core logs with Geotek MSCL-XYZ for:
- Magnetic susceptibility (high-resolution point sensor)
- Color reflectance spectrophotometry
Digital linescan core imaging, with cross-polarized filters for elimination of glare on core face;
Macroscopic description of lithologic features, sedimentary textures, and coring/drilling artifacts;
Microscopic description of sediment composition, mineralogy, clastic grain size, floral and faunal remains, diagenetic features, etc., using petrographic smear slides;
Correlation between overlapping cores from the same site (and development of a composite depth scale) or between cores from different sites.