Rock coring collects bedrock cores for engineering and geological data. 

A diamond bit attached to a core barrel is lowered into the hole on the end of drill rods.  Rock core samples are obtained by removing the inner barrel assembly from the core barrel of the drill rod using an overshot retriever.  Rock cuttings are removed from the bore hole in a similar manner as mud rotary by drilling fluids. The NSF approved fluid circulates in the bore-hole as it pumps down through the rod string, where it picks up drill cuttings and carries them to the surface.

Holocene operates a variety of large and small truck mounted and track mounted auger rigs to meet both on road and off-road site conditions.  Holocene operates Diedrich D-50 track rigs, D-90 and 120 truck mounted rigs, CME 850 track rig, Mobile B-58 truck rig that perform auger, mud rotary and rock coring. Drilling mud is circulated with deck mounted mud pumps.

Applications:  Best used in studies for foundation investigations, material sources, rock cut investigations and general rock coring of native bedrock substrates to obtain geotechnical data and samples. Not effective in sediments, cobbles or gravels where mud circulation is difficult.

Rig Type	Length	Width	Height*	Weight
D-70 Track Rig	16.5′	8′	Tower up: 25′	25,000 No tooling
D-50 Track Rig	14.5′	8′	Tower up: 25′ Short tower: 14′	26,000 No tooling
CME 850 Track Rig	18.5″‘	8′	Tower up: 25′	28,000 No tooling
D-90 Truck Rig	30′	8′	Tower up: 30′	28,000 No tooling
D-120 Truck Rig	30′	8′	Tower up: 30′	35,000 No tooling
B-58 Truck Rig	30′	8′	Tower up: 30′	38,000 No tooling

* specifications are nominal and depths will vary depending on sub-surface conditions