Freeze Shoe
The freeze shoe tool is a wireline drilling tool using CO2 cooling techniques to freeze the bottom ~10cm of a coring run in situ, to capture and retrieve soft sediment samples with pore waters intact and uncompromised by mixing or oxidation during recovery, for analysis of microbial communities, minerals, or other constituents that are easily altered during the recovery process.
Modified from the HPC and ALN soft sediment coring tools, the freeze shoe is a P-size tool that collects a 1 meter long, HQ3-size core (61.1mm diameter) in a polycarbonate tube, with the bottom ~15 cm frozen. After drilling the 1 meter run, the tool sits in place briefly while the freezing progresses. The tool is returned to the surface and the core is extracted.
Used For:
Specialized tools to freeze bottom 10 cm of core in situ, prior to recovery, for uncompromised sample for geomicrobiological analyses
Type:
Rotary Diamond Corer (ALN), Wireline Hyrdaulic Piston Corer (HPC)
Dimensions and Weight:
100s of kg, plus rig, rod, and associated equipment
Core Diameter/Profile (cm):
6.1
Lithologies:
Coarse-grained, Fine-grained, Hard Sediment, Soft Sediment, Soil/Regolith
Staff Requirements:
professional drillers
Maximum Formation Depth (m):
200
