ABSTRACT

In geophysical and geological exploration, the identification of lithological units is a crucial tool, and in engineering, borehole logging is a common instrument and method for gathering data on the underlying formations. This study aims to precisely define lithological units using data obtained from borehole logging. To classify and characterise the lithological units, the study collects, processes, and interprets borehole logging data obtained from several drilling operations. The comprehension of the underlying geological formations and decision-making for a variety of geophysical, geological, and engineering applications will be aided by this research outcome.

The Benin Metropolis boreholes were used to collect soil samples at different depths. The samples were subjected to a series of tests, including sieve analysis, which determined the grain size distribution, specific gravity, and soil moisture content (SMC).

The lithological units from the several sites were categorised as laterites, clay, sand, sandy clay, clayey, clayey sand, and sand stone, located at different depths inside the subsurface, based on the findings of the numerous tests that were conducted. The invasive technique of borehole logging provides us with the true depth at which the lithologies are located. The order of the lithologies within the Benin formation is laterite, clay, sandy clay, clayey, and sandstone, based on the moisture content tables obtained from the various locations.