Buffalo Head Hills kimberlite field grained, and well bedded, with high bedding angles. The reworked kimberlite is well sorted, distinctly bedded, and contains abraded olivine grains. Multiple layers of pyroclastic and reworked kimberlite separated by layers of marine mudstone are present at some pipes. These represent a series of discrete kimberlite eruption events separated by quiescent periods during which the muds were deposited. The majority of the BHH kimberlites are diamondiferous, in contrast to those of the Birch Mountains kimberlite field to the northeast which are mostly barren of diamonds. Based on petrography and whole-rock geochemistry, the BHH pipes are classed as Group 1A kimberlites.
Elliott County Kimberlite Elliott County Kimberlite The Elliott County Kimberlite (Sometimes called the Ison Creek Kimberlite) was discovered in Elliott County, Kentucky, by Albert R. Crandall in 1884 over two years before Carvill Lewis named a similar porphyritic peridotite occurring near Kimberley, South Africa, a kimberlite. It occurs as three separate elongate intrusive bodies 1/4 to 1/2 mi in length and a few hundred feet in width, within an area of about a square mile. The rock is a dark-green peridotite (kimberlite) composed of serpentinized olivine and a number of accessory minerals, including phlogopite, pyrope, calcite, enstatite, magnesian ilmenite, and others. Xenoliths, mainly