A Lugeon is a unit devised to quantify the water permeability of

bedrock In geology, bedrock is solid Rock (geology), rock that lies under loose material (regolith) within the crust (geology), crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface mater ...

and the

hydraulic conductivity Hydraulic conductivity, symbolically represented as (unit: m/s), is a property of porous materials, soils and rocks, that describes the ease with which a fluid (usually water) can move through the pore space, or fractures network. It depends on th ...

resulting from fractures; it is named after

Maurice Lugeon Maurice Lugeon FRS(For) HFRSE FGS (10 July 1870 – 23 October 1953) was a Swiss geologist, and the pioneer of nappe tectonics. He was a pupil of Eugène Renevier. Named for Maurice Lugeon, the lugeon is a measure of transmissivity in rocks ...

, a Swiss geologist who first formulated the method in 1933. More specifically, the Lugeon test is used to measure the amount of water injected into a segment of the bored hole under a steady pressure; the value (Lugeon value) is defined as the loss of water in litres per minute and per metre

borehole A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water ( drilled water well and tube well), other liquids (such as petro ...

at an over-pressure of 1

MPa MPA or mPa may refer to: Academia Academic degrees * Master of Performing Arts * Master of Professional Accountancy * Master of Public Administration * Master of Public Affairs Schools * Mesa Preparatory Academy * Morgan Park Academy * Mound ...

. Although the Lugeon test may serve other purposes, its main object is to determine the ''Lugeon coefficient'' which by definition is water absorption measured in litres per metre of test-stage per minute at a pressure of 10 kg/cm² (1 MN/m²).Lancaster-Jones, P. F. F. 1975. The interpretation of the Lugeon water-test. Quarterly Journal of Engineering Geology and Hydrogeology; 8(2):151-154.
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References

Hydrology {{Hydrology-stub