Pertaining to an igneous rock containing more than 66 per cent silica.
Change in the mineralogical composition of a rock, commonly brought about by reactions with hydrothermal solutions.
anomaly / anomalous
An occurrence of geochemical or geophysical values distinct from background levels which may be caused by the presence of mineralization.
Metal associated with certain types of gold deposit, chemical symbol Sb.
Metal associated with certain types of gold deposit, chemical symbol As.
An iron-arsenic sulphide, chemical composition FeAsS.
A chemical test performed on a sample of ores or minerals to determine the amount of valuable metals contained.
bankable feasibility study
An extensive technical and financial study to assess the commercial viability of a project, of sufficient detail and integrity that it can be used to arrange project financing.
Generally non-ferrous, non-precious metal, mainly copper, lead, zinc, nickel and aluminium.
The use of bacteria to oxidise sulphide minerals.
A rock fragmented into angular components.
Converted into, characterised by, or resembling a breccia.
A sedimentary rock, comprised largely of mineral containing CO3.
The process of dissolving carbonate rock.
Period in geological time ranging from 345 to 280 million years ago.
Refers to a type of gold deposit first recognised in the Carlin area of Nevada, USA, and characterised by gold-bearing disseminated pyrite, carbonate dissolution, alteration and silicification of carbonate-rich sedimentary rocks.
A method of extracting exposed gold or silver grains from crushed or ground ore by dissolving it in a weak solution of sodium- or calcium-cyanide. Also known as leaching. May be carried out in agitated tanks or by irrigating ore stacked in large heaps or dumps.
Drilling method which obtains a cylindrical core of rock by drilling with an annular bit impregnated with diamonds.
environmental impact study
Survey conducted to ascertain the conditions of a site prior to the realisation of a project, to analyse its possible impacts and compensative measures.
A permit granted in Spain with a maximum size of 280 square kilometres, on which regional sampling programmes are allowed.
Descriptive of a light-coloured igneous rock with an abundance of one or all of feldspar, quartz and feldspathoids.
A milling process by which some mineral particles are induced to become attached to bubbles and float and others to sink. In this way the valuable minerals are concentrated and separated from the worthless gangue.
The mass of rock below a fault, vein, bed or mineralization.
geochemistry / geochemical
Relating to the chemistry of rock, sediment or soil.
Grams per tonne.
The concentration of a particular element in a mass of rock, sediment or soil.
A coarse-grained granular acid intrusive rock.
A body of rock serving as a host for other rocks or for mineral deposits.
Of or relating to the action of water under conditions of high temperature, especially in forming rocks and minerals.
iberian pyrite belt
A prominent geological terrain extending from southwest Spain into southern Portugal, which is one of the world’s largest massive sulphide provinces.
A rock formed by congealing rapidly or slowly from a molten state.
indicated mineral resource
That part of a Mineral Resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a reasonable level of confidence. It is based on exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are too widely or inappropriately spaced to confirm geological and/or grade continuity but are spaced closely enough for continuity to be assumed.
inferred mineral resource
That part of a Mineral Resource for which tonnage, grade and mineral content can be estimated with a low level of confidence. It is inferred from geological evidence and assumed but not verified geological and/or grade continuity. It is based on information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes which may be limited or of uncertain quality and reliability.
Drilling designed to fill or close gaps between existing drill holes.
intrusion / intrusive
Igneous rock body that has forced its way in a molten state into older surrounding country rock.
Refers to a type of gold mineralization hosted and/or related to intrusive rocks, often granite.
A permit granted in Spain with a maximum size of 84 square kilometres, on which detailed investigation activities are allowed including drilling and trenching.
A tabular, relatively narrow mineral deposit.
A sulphide body containing over 50 per cent of sulphide minerals.
measured mineral resource
That part of a Mineral Resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a high level of confidence. It 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. The locations are spaced closely enough to confirm geological and grade continuity.
Metal associated with certain types of gold deposit, chemical symbol Hg.
Scientific tests on the extraction, refining, alloying and fabrication of metals and of their structure and properties.
The dry and wet crushing and grinding of ore or other mineral bearing products for the purpose of raising concentrate grade, removal of waste and unwanted or deleterious substances from an otherwise useful product, separation into distinct species of mixed minerals or chemical attack and dissolution of selected values.
A concentration or occurrence of material of intrinsic economic interest in or on the Earth’s crust in such form, quality and quantity that there are reasonable prospects for eventual 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. Mineral Resources are sub-divided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories.
The concentration of metals and their chemical compounds in a body of rock.
The study of minerals.
A permit granted in Spain which allows mining activities.
A mine working or excavation open to the surface.
Material which can be extracted and/or treated at a profit.
ounce / oz
Troy ounce (31.1035 grams).
A chemical reaction caused by exposure to oxygen that results in a change in the chemical composition of a mineral.
Parts per million, equivalent to g/t.
An iron-bearing sulphide mineral, chemical composition FeS2.
reverse circulation (rc) drilling
A percussion drilling technique where air is pumped down the outer part of the drill rods and used to return drill chips to surface.
The heating of an ore or concentrate to effect some chemical change which will facilitate metal extraction.
Images of the Earth’s surface captured by satellite by means of photography and/or spectroscopy.
A preliminary order-of-magnitude technical and economic study conducted to investigate the approximate economics and viability of various development options for the mining and treatment of a mineral deposit.
A tabular zone in the Earth’s crust along which movement has occurred and in which the rocks have been crushed, stretched or flattened.
Rock unit occurring at the La Zarza deposit comprising silicate minerals, dominantly quartz, and sulphide, with significant concentrations of gold, copper and silver.
Addition of silica to a rock.
A network of veinlets, usually containing quartz.
The orientation of the long horizontal dimension of a planar or tabular geological feature such as a bed, vein or fault.
The length of a geological feature along the direction of its strike.
A compound of sulphur with a metallic element.
The removal of cover to allow mapping and sampling of the underlying rock.
Secondary grinding of ore to very fine grain sizes, usually in the 10 to 20 micron range, in special small grinding mills.
Igneous rocks formed from magma that has flowed out or has been violently ejected from a volcano.
Rock formation containing alternations volcanic and sedimentary rock types.