Aerial photography

The taking of, or photos, acquired from aircraft used for surveying or other purposes.

 

AeromagneticSurvey

A survey made from the air for the purpose of recording magnetic characteristics of rocks.

 

Aircore Drilling

A type of drilling where compressed air is forced down between the inner & outer drill rod to operate a venturi vacuum system at the face of the drill bit. This then carries uncontaminated samples up through the inner tube to the cyclone which distributes cuttings at the bottom of the cyclone and releases the air into the atmosphere.

 

Alluvial

Transported and deposited by water.

 

Anomaly

Value higher or lower than the expected or norm.

 

Anomalous

Outlining a zone of potential exploration interest but not necessarily of commercial significance.

 

Anticline

Upward arching fold or rock strata (antonym = syncline).

 

Antrim Plateau Volcanics

Fine grained and vesicular tholeiitic basalts that are up to 800 metres in thickness.

 

Archaean

The oldest rocks of the Precambrian Era, prior to 2500 million years.

 

Argyle-style Lamproite Pipe

Argyle is to date the only resource showing economic quantities of diamonds to be hosted in a lamproite type of intrusion. Pipes were explored for showing similar geochemistry to the Argyle pipe.

 

Basalt

A hard, black volcanic rock with less than 52% silica. Consists of olivine, pyroxene and plagioclase. Typically it flows fast due to its low viscosity and also allows expulsion of gases.

 

Basement

Usually synonymous with Archaean and Proterozoic terrain.

 

Base metal

Generally a metal inferior in value to the precious metals, eg. copper, lead, zinc, nickel.

 

Basic rocksvolcanics

Igneous rocks containing between 45 and 52% silica, distinct from acid or intermediate rocks.

 

Basin

A low area of the earth's crust in which sediments accumulate.

 

Bed

Individual sedimentary layer

 

Bedding

A rock surface parallel to the surface of deposition.

 

Bedrock

Any solid rock underlying unconsolidated material.

 

Bottom of Hole Sample

A sample taken during drilling from the bottom of the hole/end of the hole. It is then usually sent for testing at a laboratory.

 

Breccia

Rock consisting of angular fragments in a finer grained matrix, distinct from conglomerate.

 

Bronzite

A mineral consisting of a iron-rich variety of enstatite.

 

Bulk Sample

A large representative sample that can be taken as an indication of potential grade of the resource were it to be mined. Otherwise known as a pre-feasibility study.

 

Bulk Sampling Operation

To test a representative larger sample of the material of interest to test for economic viability.

 

Cambrian

A time period from 600 to 510 million years ago.

 

Carat

The unit of weight for diamonds (1 carat = 0.2 gram).

 

Carbonatite

An intrusive igneous rock structure containing more than 50% carbonate and often rare earth minerals sometimes of economic significance.

 

Carr Boyd Group Sediments

Sediments belonging to the Carr Boyd Group of rocks which consist of arenites and lutites. These are up to 9,000 m thick in parts.

 

Carson Volcanics

A unit of 200 to 700 metres thick in sections which forms rounded hills and low rocky plains in the Kimberley Region. The dominant lithologies consist of mafic volcanics, amygdaloidal tholeiitic basalts and spilites, including flows of pillow lava, and volcaniclastic rocks with interspersions of quartz and feldspathic sandstones, siltstone and chert.

 

Certified Notice of Intent

A Notice of Intention for a small scale mining operation to proceed. Contains all details of the scope of the project to be undertaken and permitting requirements for the Department of Industry and Resources as well as the Department of Environment in order to proceed. Being a certified document, it has been signed off by an independent expert.

 

Chromite

An oxide of iron and chromium; an indicator mineral for kimberlite.

 

Clast

An individual constituent of sediment or sedimentary rock produced by the physical disintegration of a larger mass.

 

Clastic

A sedimentary rock composed of broken fragments of pre-existing rocks.

 

Complex

An assemblage of rocks or minerals intricately mixed or folded together.

 

Composite Samples

Samples from drilling which are grouped together over certain intervals within the hole as specified by a geologist. These are then usually tested by a laboratory.

 

Concentrate

An assembly of the best quality material/material of interest that has been extracted and grouped into a smaller portion.

 

Conglomerate

A sedimentary rock containing rounded rock clasts that are held together by a matrix or a cement.

 

Country-rock

A general term applied to rock surrounding or penetrated by mineral veins.

 

Craton

A relatively immobile part of the earth, generally of large size.

 

Diamond

A cubic variety of crystalline carbon which may be of gem quality.

 

Diamond-bearing

Containing diamond.

 

Diamondiferous

Containing diamond.

 

Diamond Stability Field

A region of pressure and temperature where diamonds may crystallize. Other high pressure minerals such as chromites and G10 garnets may be associated with such high pressure-temperature intrusions and can be used in exploration to track potential targets.

 

Diatreme

Breccia filled volcanic pipe formed by a gaseous explosion.

 

Digital Elevation Model

A dataset obtained during a geophysical survey which details spot height points at a specific interval. This can then be gridded and interpolated to form an image showing highs and lows. The dataset can also be merged with other remotely sensed data to produce a 3D model.

 

Dip

The angle at which a rock layer, fault of any other planar structure is inclined from the horizontal.

 

Dipolar Anomaly

A magnetic signature showing a high and low in one area/side by side. Can lead to something of prospective interest.

 

Drill testing

To sample a body of interest using drilling techniques whereby holes are drilled to a maximum or desired depth to find out what rock associations may occur.

 

Dyke

A tabular intrusive body of igneous rock that cuts across bedding at a high angle.

 

EM Survey

Electro-magnetic survey to measure physical properties of the earth.

 

Enstatite

An orthorhombic mineral, 2[MgSiO 3 ] ; pyroxene group; a common rock-forming mineral in basalt, gabbro, norite, pyroxenite, and peridotite.

 

Exploration

The process of searching with the intention of discovery.

 

Fault

A fracture in rocks on which there has been movement on one of the sides relative to the other, parallel to the fracture.

 

Feldspar

A group of abundant rock-forming aluminous silicate minerals containing potassium, sodium, calcium or barium.

 

Float

Pieces of rock, separated from their parent strata, scattered over the surface.

 

Facies

A rock or stratified body distinctive in appearance and composition.

 

Flowsort Machine

An X-Ray machine which can extract diamonds and create a super-concentrated material.

 

Gabbro

A dark, coarse grained intrusive igneous rock chemically equivalent to basalt.

 

Geochemistry

Study of variation of chemical elements in rocks or soils.

 

Geochemical survey

The systematic study of the variation of chemical elements in rocks and soil.

 

Geochemical Testing

Testing of a sample taken during exploration or drilling by a laboratory. Certain elements are required to be detected as specified by a geologist which are pathfinders to prospective sources.

 

Geological Mapping

A type of survey whereby rock types are observed and transposed to make a map.

 

Geological Sampling

To take samples of soil, loam, stream sediments or rock chips which can then be sent to a laboratory to determine specific indicator minerals that could lead to delineating a prospective area.

 

Geomorphology

Study of the form and origin of natural land surfaces.

 

Geophysical survey

A systematic study of the variation of physical properties in rocks and soils.

 

Geophysics

Study of the earth by quantitative physical methods.

 

Graben

A large downthrown block bounded by faults.

 

Grab sample

Sample of rock or sediment taken more or less indiscriminately at any place.

 

Grade

Average quality of ore, metal or an element in a specified quantity of rock.

 

Granitoid Body

Composed of an intrusive felsic igneous rock that forms at great depths and pressures under continents.

 

Grass-roots Exploration

Early stage exploration with little or no historical work to draw knowledge from.

 

Ground Gravity Techniques

A geophysical type of survey involving testing points for gravity values. Different rock types have different gravity readings and thus this can lead to areas that are possibly prospective.

 

Hart Dolerite

A type of dolerite occurring in the Phillips Range area of the Kimberley Region that consists of sills and intrusions that intrude rocks of the lower part of the Kimberley Group. The Hart Dolerite is comprised of tholeiitic dolerite sills and to a lesser extent, granophyric intrusions.

 

Hartzburgite

A variety of peridotite that consists essentially of olivine and enstatite or bronzite.

 

HMS Processing Plant

Heavy Media Separation type of processing plant that enables separation of heavier specific gravity material thus concentrating material likely to contain diamond (in this case).

 

Ilmenite

Oxide of iron and titanium.

 

Infill Drilling

Random drilling at particular intervals to approach an area of interest which may not fit directly into an assigned grid area for designated drill holes.

 

Intrusive

Having, while fluid, been injected into the earth's crust and solidifying before reaching the surface.

 

Key Indicator Minerals

Specific minerals associated with kimberlite or lamproite which are geochemically tested for their abundance in a sample. They are resistant to weathering and occur in greater abundance than diamond but can lead to potential areas of interest. The minerals include garnet, chromite, ilmenite, clinopyroxene, olivine, and zircon.

 

Kim berlite (-ic)

Volatile-rich, potassic, ultrabasic igneous rock which occurs as small volcanic pipes, dykes and sills, composed of olivine, phlogopite mica, calcite, pyroxene, apatite, spinel and indicator minerals. Often associated with diamond deposits.

 

Kimberlite Blow

A small offshoot from the root zone of pipe intrusions.

 

Kimberlite Dyke

A sheetlike type of kimberlite intrusion that cross cuts layering or contacts into which it intrudes.

 

Lamproite

Peralkaline (where sodium and potassium oxides combined are greater in abundance than aluminium oxide) volcanic rock. Diamonds may be hosted in the olivine lamproite pyroclastic variety of pipes and dykes.

 

Landsat

An unmanned satellite designed to provide multi-spectral imagery of the earth's surface.

 

Laterite

A red, residual soil, cemented in place, containing iron and aluminium oxides but leached of quartz.

 

Lava

Fluid rock such as that which issues from a volcano or a fissure in the earth's surface.

 

Lineament

A naturally occurring major linear feature in the earth's crust, often associated with mineral deposits.

 

Macrodiamond

A diamond larger than 0.4mm in diameter.

 

Mafic

A loosely used group-name for silicate minerals rich in iron and magnesium, and for rocks in which these minerals are abundant.

 

Magmatic/Molten Component

Pertaining to molten rock from beneath the surface of the Earth.

 

Magnetic Anomaly

A magnetic signature of particular interest that may lead to an area that is potentially prospective.

Magnetic Signature

A particular reading of magnetic values.

 

Magnetic Survey

Systematic collection of readings of the earth's magnetic field.

 

Magma

Naturally occurring mobile (generally fluid) rock material generated within the earth and capable of intrusion or extrusion.

 

Miocene

a division of geological time ranging between 23.8 million years and 5.3 million years ago.

 

Mica

A group of minerals consisting of phyllosilicates with sheet-like structures. (K, Na, Ca)(Mg, Fe, Li, Al) 2-3 (Al, Si)---- 4 O 10 (OH, F) 2 .

 

Microdiamond

A diamond that is smaller than 0.4 mm in diameter.

 

Microdiamond Analysis

Analysis by a laboratory for small diamonds less than 0.4mm in size. These are attributed to leading to an area of potential economic significance.

 

Microprobe

of a mineral using an electron microprobe analyser.

 

Mineral Resource

A tonnage or volume of rock or mineralisation of economic interest.

 

Mineralisation

In economic geology, the introduction of valuable elements into a rock body.

 

Mobile Belt

A portion of the earth's crust that is more mobile, as shown by folds, faults etc, than the adjacent stable blocks.

 

Non-Magnetic Pipe

An intrusion showing no geophysical magnetic signature compared to other areas tested with the technique.

 

Olivine

A rock forming silicate mineral series ranging from iron-rich to magnesium-rich. Important in mafic and ultramafic rocks.

 

Outcrop

The surface expression of a rock layer (verb: to crop out).

 

Palaeochannel

The remnants of a surface drainage system that was active in the geological past and may be buried now.

 

Palaeo

Relating to the past, ancient or fossil.

 

Palaeo-gravel Deposit

An alluvial deposit occurring in an old channel system that is no longer functioning.

 

Permian

A division of geological time from 280 to 225 million years ago.

 

Peridotite

A general term for a coarse-grained plutonic rock composed chiefly of olivine with or without other mafic minerals such as pyroxenes.

 

Petrographic Analysis

Analysis of rocks in thin section under a microscope to determine minerals present and thus to determine a definite rock type.

 

Petrological studies

The systematic description of rocks in hand specimen and thin section.

 

PGE

Platinum group elements i.e. Platinum, Palladium, Rhodium, Osmium, Iridium, Rhuthenium.

 

Photogeology

The geological interpretation of aerial photographs.

 

Picroilmenite

An oxide of iron and titanium; an indicator mineral for diamond exploration.

 

Pipe

A common term for a vertical cylindrical column-like mass of rock that cooled and solidified in the neck of a volcano.

 

Pipe Morphology

Shape of a pipe.

 

Prospective

An area showing favourable rock associations for potentially containing something of economic significance.

 

Province

Overlapping groups of rocks showing an association by deposition or emplacement, time and space and overprints caused by various metamorphic or deformation events.

 

Pyroclastic

A fragment of volcanic rock, resulting from explosive activity or eruption.

 

Pyrope garnet

The magnesium-aluminium end-member of the garnet group, characterised by a fiery-red colour. Associated with ultramafic rocks such as kimberlite.

 

Pyroxene

A group of chiefly magnesium-iron minerals.

 

RAB

Rotary Air Blast (as related to drilling)—A drilling technique in which the sample is returned to the surface outside the rod string by compressed air.

 

Radiometric Survey

A type of geophysical survey normally carried out in conjunction with magnetic surveys that detects element concentration of Potassium, Uranium and Thorium in rocks.

 

RC

Reverse Circulation (as relating to drilling)—A drilling technique in which the cuttings are recovered through the drill rods thus minimising sample losses and contamination.

 

Recent

Geological age from about 20,000 years ago to present (synonym: Holocene).

 

Reconnaissance

A general examination or survey of a region with reference to its main features, usually as a preliminary to a more detailed survey.

 

Rectification

The warping of a flat image to give it a spatial reference.

 

Regional Exploration

Exploring for a commodity over a large area to narrow particular areas of interest.

 

Rehabilitation

To help an area that has been degraded by mining techniques to return to its original composure as best as possible.

 

Remote Sensing Imagery

Geophysical data obtained by satellites processed and presented as photographic images in real or false colour combinations.

 

Resorbed

Formed and then melted again.

 

Resource

In-situ mineral occurrence from which valuable or useful minerals may be recovered, but from which only a broad knowledge of the geological character of the deposit is based on relatively few samples or measurements.

 

ROM Pad

The area where the ore is stored prior to being processed.

 

Sample Laydown

An area where the drilling recovery/ore can be laid down before being transported to the ROM pad prior to processing.

 

Sand

Unconsolidated sediment formed by fragments between 0.06 and 2.0mm in diameter.

 

Sandstone

A sedimentary rock composed predominantly of feldspar and quartz.

 

Sediment

Rocks formed by the deposition of solids from water.

 

Sedimentary Breccia

A sedimentary rock containing large, angular rock clasts or inclusions that are held together by a matrix or cement.

 

Sedimentary Cover

Underlying rocks which are overlain/blanketed by rocks of the sedimentary variety.

 

Shear (zone)

A zone in which shearing has occurred on a large scale so that the rock is crushed and brecciated.

 

Silica

Silicon dioxide, SiO 2 (cf . Quartz)

 

Silicified

Containing a high proportion of silicon dioxide.

 

Silt

A sediment in which most of the particles are between 0.0625mm and 0.0039mm diameter.

 

Slow Cooling Phase

Slower cooling time for a magmatic body. The rocks have time to take on the magnetic signature of the Earth occurring at that time.

 

Soil sampling

Systematic collection of soil samples at a series of different locations in order to study the distribution of soil geochemical values.

 

Stockwork

An interlocking system of small veins or lodes.

 

Stratigraphy

The succession of superimposition of rock strata. Composition, sequence and correlation of stratified rock in the earth's crust.

 

Strike

The direction or bearing of the outcrop of an inclined bed or structure on a level surface.

 

Structure

A linear or arcuate feature occurring over a long distance and visually recognizable on remotely sensed data. May be a fault, joint or other type of lineament.

 

Sulphide

A group of minerals in which one or more metals is found in combination with sulphur.

 

Surficial

Superficial. Characteristic of, pertaining to, formed on, situated at, or occurring on the earth's surface.

 

Syncline

Folded rocks that have an upward slope to either side. The oldest rocks are in the middle.

 

Tectonic

Relating to structural features.

 

Termite Mound Sampling

To take a dirt sample from a large anthill. Ants dig beneath the surface to depths and extract the material to the surface. This offers a representative study of geochemistry from beneath the surface without the laborious input.

 

Tertiary

A division of geological time ranging from 65 million years and 1.8 million years ago.

 

Triassic

A time period from approximately 248 to 212 million years.

 

Tuff (aceous)

A compacted pyroclastic rock of cemented volcanic ash.

 

Tuffaceous/Explosive Component

A part of a pipe which contains explosive pyroclastic material.

 

Ultramafic rocks

Igneous rocks with very high magnesium and iron content containing less than 45% silicon dioxide.

 

Unconformable

Descriptive of rocks on either side of an unconformity.

 

Unconformity

Lack of parallelism between rock strata in sequential contact, caused by a time break in sedimentation.

 

Upper Mantle

The mantle is a crystalline solid that is divided into the upper and lower mantle areas. These areas are distinguished from each other by a seismic discontinuity at 660 km depth.

 

Vein

A narrow intrusive mineral body.

 

Volcanic

Relating to the eruption of a volcano; Describes clastic fragments of volcanic origin.

 

Weathering

A process of change to rocks brought about by their exposure to oxygen and water.

 

Weakly Magnetic

Showing a weak magnetic survey signature relative to associated higher magnetic signature areas.

 

Wide Diameter Bauer Drilling

A specific type of drill rig developed by Bauer Maschinen technology that enables larger diameter holes to be drilled compared with other conventional drilling techniques. As a result, it can be used in a bulk sample operation. At Aries, 1.5 metre diameter holes were drilled.

 

Xenolith

A fragment of other rock or of an earlier solidified portion of the same mass enclosed in an igneous rock; an inclusion; an enclave.

 

Zircon

Zirconium silicate mineral.

 

Abbreviations

 

g gram

 

kg kilogram

 

km kilometre

 

km² square kilometre

 

m metre

 

m² square metre

 

m³ cubic metre

 

Ma One million years ago

 

mm millimetre

 

t metric tonne (1,000kg)

 

Ni Nickel

 

Cu Copper

 

Co Cobalt

 

Cr Chromium

 

Units of Concentration

 

ppb parts per billion

 

ppm parts per million

 

md/100kg number of microdiamonds per 100kg

 

cpht Carats of diamond per 100 tonnes