Arc Minerals Regulatory News (ARCM)

Arc Minerals Ltd

Nick von Schirnding (Chairman)

+44 (0) 20 7917 2942

SP Angel (Nominated Adviser & Broker)

Ewan Leggat / Adam Cowl

+44 (0) 20 3470 0470

"anomaly or anomalous"

something in mineral exploration that geologists interpret as deviating from what is standard, normal, or expected.

"assay"

The laboratory test conducted to determine the proportion of a mineral within a rock or other material. For copper, usually reported as percentage which is equivalent to percentage of the mineral (i.e. copper) per tonne of rock.

"azimuth"

the "compass direction" refers to a geographic bearing or azimuth as measured by a magnetic compass, in true or magnetic north.

"bornite"

Bornite, also known as peacock ore, is a copper sulphide mineral with the formula Cu5FeS4.

"breccia"

Breccia is a rock classification, comprises millimetre to metre-scale rock fragments cemented together in a matrix, there are many sub-classifications of breccias.

"chalcocite"

Chalcocite is a copper sulphide mineral with the formula Cu2S and is an important copper ore mineral. It is opaque and dark-gray to black with a metallic luster.

"chalcopyrite"

Chalcopyrite is a copper sulphide mineral with formula CuFeS2. It has a brassy to golden yellow colour.

"chargeability"

Chargeability is a physical property related to conductivity. Chargeability is used to characterise the formation and strength of the induced polarisation within a rock, under the influence of an electric field, suggesting sulphide mineralisation at depth.

"covellite"

Covellite is a copper sulphide mineral with the formula CuS. This indigo blue mineral is ubiquitous in some copper ores.

"diamond drilling"

A drilling method in which penetration is achieved through abrasive cutting by rotation of a diamond encrusted drill bit. This drilling method enables collection of tubes of intact rock (core) and when successful gives the best possible quality samples for description, sampling and analysis of an ore body or mineralised structure.

"dip"

A line directed down the steepest axis of a planar structure including a planar ore body or zone of mineralisation. The dip has a measurable direction and inclination from horizontal.

"grab sample"

are samples of rock material collected from a small area, often just a few pieces or even a single piece of rock "grabbed" from a face, dump or outcrop or roughly 2-5kg. These are common types of rock samples collected when conducting mineral exploration. The sample usually consists of material that is taken to be representative of a specific type of rock or mineralisation.

"grade"

The proportion of a mineral within a rock or other material. For copper mineralisation this is usually reported as % of copper per tonne of rock.

"g/t"

grams per tonne; equivalent to parts per million ('ppm')

"hematite"

Hematite is the mineral form of iron(III) oxide (Fe2O3), one of several iron oxides. Magnetite alteration is also typically associate with porphyry copper systems, at or close to the central core.

"Indicated Resource"

An "Indicated Mineral Resource" is that part of a Mineral Resource for which quantity, grade or quality, densities, shape and physical characteristics, can be estimated with a level of confidence sufficient to allow the appropriate application of technical and economic parameters, to support mine planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable exploration and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough for geological and grade continuity to be reasonably assumed.

"Inferred Resource"

An "Inferred Mineral Resource" is that part of a Mineral Resource for which quantity and grade or quality can be estimated on the basis of geological evidence and limited sampling and reasonably assumed, but not verified, geological and grade continuity. The estimate is based on limited information and sampling gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes.

"Induced Polarisation Geophysics"

Induced polarisation (IP) is a geophysical survey used to identify the electrical chargeability of subsurface materials, such as sulphides. The survey involves an electric current that is transmitted into the subsurface through two electrodes, and voltage is monitored through two other electrodes.

"intercept"

Refers to a sample or sequence of samples taken across the entire width or an ore body or mineralised zone. The intercept is described by the entire thickness and the average grade of mineralisation.

"JORC Code"

The Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves ('the JORC Code') is a professional code of practice that sets minimum standards for Public Reporting of minerals Exploration Results, Mineral Resources and Ore Reserves.

"K"

The element potassium, abundance on surface can be inferred from radiometric surveys

"Magnetics"

Rocks are made up of different minerals and the magnetic properties of a rock depends on the amount and type of iron rich minerals it contains. Earth's magnetic field interacts with these iron rich minerals to generate variations in the magnetic field. Measuring and mapping these variations allows remotely mapping of the distribution and patterns of magnetic rocks and, as a result, map the subsurface geology

"magnetite"

Magnetite is main iron ore mineral, with chemical formula Fe3O4. Magnetite is ferromagnetic, and it is attracted to a magnet and can be magnetized to become a permanent magnet itself.

"massive"

In a geological sense, refers to a zone of mineralisation that is dominated by sulphide minerals. The sulphide-mineral-rich material can occur in centimetre-scale, metre-scale or in tens of metres wide veins, lenses or sheet-like bodies containing sphalerite, galena, and / or chalcopyrite etc.

"Measured Resource"

A "Measured Mineral Resource" is that part of a Mineral Resource for which quantity, grade or quality, densities, shape, and physical characteristics are so well established that they can be estimated with confidence sufficient to allow the appropriate application of technical and economic parameters, to support production planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough to confirm both geological and grade continuity.

"ME-MS61L"

HNO₃-HClO₄-HF acid digestion, HCl leach, dissolves nearly all minerals in the majority of geological samples, paired with ICP-MS and ICP-AES analysis provide super-trace detection limits.

"Mineral Resource"

A "Mineral Resource" is a concentration or occurrence of diamonds, natural solid inorganic material, or natural solid fossilised organic material including base and precious metals, coal, and industrial minerals in or on the Earth's crust in such form and quantity and of such a grade or quality that it has reasonable prospects for economic extraction. The location, quantity, grade, geological characteristics and continuity of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge.

"mineralisation"

In geology, mineralisation is the deposition of economically important metals (copper, gold, lead, zin etc) that in some cases can be in sufficient quantity to form mineral ore bodies.

"open pit mining"

A method of extracting minerals from the earth by excavating downwards from the surface such that the ore is extracted in the open air (as opposed to underground mining).

"outcrop"

A section of a rock formation or mineral vein that appears at the surface of the earth. Geologists take direct observations and samples from outcrops, used in geologic analysis and creating geologic maps. In situ (in place) measurements are critical for proper analysis of the geology and mineralisation of the area under investigation.

"polymict"

A geology term, often applied to breccias or conglomerates, which identifies the composition as consisting of fragments of several different rock types.

"Preliminary Economic Assessment"

NI 43-101 defines a PEA as "a study, other than a pre-feasibility study or feasibility study, which includes an economic analysis of the potential viability of mineral resources".

"Pyrrhotite"

Pyrrhotite is an iron sulfide mineral with the formula Fe(1-x)S (x = 0 to 0.2). It is a nonstoichiometric variant of FeS, the mineral known as troilite. Pyrrhotite is also called magnetic pyrite

"Radiometrics"

The radiometric, or gamma-ray spectrometric method is a geophysical process used to estimate concentrations of the radioelements potassium, uranium and thorium by measuring the gamma-rays which the radioactive isotopes of these elements emit during radioactive decay

"sediments"

Sedimentary rocks formed by the accumulation of sediments. There are three types, Clastic, Chemical and Organic sedimentary rocks.

"sphalerite"

Sphalerite is a zinc sulphide in crystalline form but almost always contains variable iron, with formula (Zn,Fe)S. It can have a yellowish to honey brown or black colour.

"supergene"

Supergene ore processes occur near surface, and form deposits of secondary minerals, such as malachite, azurite, chalcocite, covellite, digenite, etc.

"surface rock chip samples"

Rock chip samples approximately 2kg in size that are typically collected from surface outcrops exposed along rivers and mountain ridgelines.

"Th"

The element thorium, abundance on surface can be inferred from radiometric surveys

"U"

The element uranium, abundance on surface can be inferred from radiometric surveys

"veins"

A vein is a sheet-like or anastomosing fracture that has been infilled with mineral ore (chalcopyrite, covellite etc) or mineral gangue (quartz, calcite etc) material, within a rock. Veins form when minerals carried by an aqueous solution within the rock mass are deposited through precipitation and infill or coat the fracture faces.

"volcanics"

Volcanic rock such as andesite or basalt that is formed from magma erupted from a volcano, or hot clastic material that erupts from a volcano and is deposited as volcaniclastic or pyroclastics.