Glossary: G

A wire cage containing rock which can be used to give protection against erosion or to counteract slope instability.

The material of no apparent value associated with minerals in lodes or veins.

The distance across the crusher feed opening between the fixed and moving members.

Any metal welding process in which a combination of gases are used to obtain a hot flame; the most commonly used process employs the oxy-acetylene combination.

abbr. General Development Order

The Town and Country Planning Development Order 1988.

The relationship between the amounts invested in a business by its owners as equity and by others as debt.

The making and interpretation of certain physical measurements to obtain information on the subsurface geological structures.

An exercise conducted on a tip or excavation to determine whether movement or collapse would present a significant hazard. If so, the tip is notifiable and a geotechnical assessment is required.

A synthetic fabric used as a filter in groundwork.

A prefix indicating multiplication by one thousand million.

abbr. G

Material transported and deposited by glaciers.

An open-pit method of excavation in which underground drives are put in below the area to be excavated and raises are then driven into the excavation site; the raises are used as passes for the broken ore or rock which is drawn off and transported as required.

A random sample taken from a stockpile or consignment when there is insufficient time or labour to take a representative sample. Taken by an experienced sampler, it can be used to obtain a good estimate of the quality of the material.

1. The percentage by weight of different sizes present in an aggregate, established by sieve analysis and expressed on a grading curve.
2. Shaping the ground surface, usually by means of a grader or bulldozer.

1. Degree of fineness or coarseness of texture.
2. Quarrying term, cleavage.
3. Direction along which igneous rocks can be split.

A jaw crusher with a high width/gape ratio, normally used for the reduction of oversize in gravel deposits at low capacity.

The set of cross-hairs fitted into the diaphragm of a surveying instrument telescope.

Also: reticule 

An instrument used in gravity surveying to measure changes in the value of gravity over an area.

Processes for sorting granular material by forces which depend on differences in the densities, shapes and sizes of the particles.

1. Sand or sandstone coloured with glauconite.
2. Lower and upper subdivision of Cretaceous rocks often containing glauconite.

A dark-coloured, poorly graded, argillaceous sandstone.

1. Term which, when applied to describe dispersions of small solid particles in air or other gas, refers to those particles which are larger than 76µm.
2. Small hard fragments of mineral aggregate for application to a road surface.

1. A machine or attachment to a lorry for applying chippings or small aggregate in a uniform layer to the surface of a road, as a surface dressing.
2. A machine for distributing small chippings, sand or salt over a road surface to counteract slipperiness caused by frost, snow etc.

Water which has penetrated from the surface and filled the pores and fissures of the strata up to the water table.

The wood or metal box in a concrete foundation, with a metal plate at its lower end through which the foundation bolt passes.

1. The pouring of grout into masonry joints and the space surrounding foundation bolts, also its injection into fissured ground.
2. Introduction of a liquid binder into the interstices of a material.

A low explosive composed of sodium or potassium nitrate, charcoal and sulphur.

Also: black powder