To locate economic deposits, geologists must be able to identify zones where minerals are most likely to have accumulated. The size and quality of the deposit can then be determined.
Logs are especially useful in economic evaluation.
Case Study ODP Hole 856H penetrated a mound of massive metallic sulfide in Middle Valley, northern Juan de Fuca Ridge. The caliper log shows that hole diameter is fairly constant down to 50 mbsf, indicating that log-data quality should be high over the featured interval. The geochemical logs from this site show high relative levels of iron and sulfur but very low levels of silica. These geochemical data require further processing in order to refine the relative concentrations to absolute values and thereby provide a continuous depth record of sulfide composition.