Ison Creek Kimberlite (Elliott County Peridotite, Late Cretaceous, 75 Ma; west of Stephens, Elliott County, Kentucky, USA) 1
Ison Creek Kimberlite from the Cretaceous of Kentucky, USA (cut surface; field of view 4.5 centimeters across).
This rock is from the Ison Creek Kimberlite (a.k.a. Ison Creek Pipe) of northeastern Kentucky. Petrographic studies report that Ison Creek rocks contain serpentinized olivine, perovskite, ilmenite, vermiculitized phlogopite, pyrope garnet, bronzite pyroxene, Cr-diopside, calcite, and xenoliths. Documented xenoliths include Pennsylvanian Breathitt Formation black shale, limestone, basement granite fragments, and upper mantle eclogite fragments. The Ison Creek Kimberlite is part of the Elliott County Peridotite and formed about 75 million years ago (Late Cretaceous). Diamonds have not yet been reported from this unit.
Locality: Ison Creek valley area (vicinity of Rt. 409 & Hamilton Creek Road), just west of Stephens, east of Newfoundland, eastern Elliott County, northeastern Kentucky, USA (vicinity of 38° 07’ 41.95” North latitude, 82° 59’ 42.21" West longitude)
Info. mostly synthesized from:
Schulze (1984), in Kimberlites II: the Mantle and Crust-Mantle Relationships.