Core logs from three shallow holes drilled in summer 2000 into the flanks of Mauna Loa volcano, Island of Hawai‘i, Hawaii

This data release includes documentation of rock core recovered from three shallow holes drilled during the summer of 2000 into the flanks of Mauna Loa volcano, on the Island of Hawai‘i, Hawaii. Holes were drilled to accommodate installation of U.S. Geological Survey Hawaiian Volcano Observatory volcano-monitoring instruments in the year 2000. Rock core recovered from the holes, which extend 112–119 m (367–392 ft) below the ground surface, were logged to characterize the sub-surface local geology. Core are described by depth below the ground surface, lithologic unit type and class, phenocryst type and abundance, groundmass type, vesicle abundance, morphology, and distribution, alteration, fracturing, and unit contacts. This data release includes a PDF that describes the general geology of the three drilled locations and the core-logging procedure, ML_core_project_description. A separate PDF file—ML_core_log_sheets—contains representations of the drill core logs, with photographs, for each of the three drilled locations. Logged core information is alternatively provided in tabular format as a CSV file—ML_core_log_data.