Pahoehoe – Basaltic lava flow with a glassy, smooth, and undulating, or ropy, surface.
Pahoehoe Lava – The two main types of lava, pahoehoe and `a`a, differ in various properties, such as crystal and gas bubble content, as well as having slight differences in temperature. Once cooled, pahoehoe and `a`a are easily identifiable by their characteristic textures. Pahoehoe has a smooth, billowy, ropy surface and has at times been likened to the surface texture of a pan of chocolate brownies. On the other hand, `a`a has a rough, and jagged surface. it is difficult to imagine traversing `a`a in anything less than sturdy footwear. In an eruption with a high effusion rate – where a lot of lava is being discharged at once – `a`a flows tend to form. If the rate of effusion is low, a pahoehoe flow is more likely to develop.
Paleocene, Palaeocene Epoch – Epoch from 65.5 to 54.8 million years ago with three Ages: the 1) Danian, 2) Selandian, and 3) Thanetian ages.
Paleoclimate – Average state or typical conditions of climate during some past geologic period.
Paleocurrent Map – Map of depositional currents that have been inferred from cross-bedding, ripples, or other sedimentary structures.
Paleogene – Period from 65.5 to 23.03 million years ago. This is the new name given to the first portion of the Tertiary Period.
Paleogeographic Map – Displays the surface landforms and coastline of an area at some time in the geologic past.
Paleomagnetism – Science of the reconstruction of the earth’s ancient magnetic field and the positions of the continents from the evidence of remnant magnetization in ancient rocks.
Paleoproterozoic – Era from 2500 to 1600 mya with four periods: the 1) Siderian, 2) Rhyacian, 3) Orosirian, and the 4) Statherian periods.
Paleosol – Soil horizon from the geologic past.
Paleontology – Science of fossils and ancient life-forms, as well as their evolution.
Paleowind – Prevailing wind direction in an area, inferred from dune structure or the distribution of volcanic ash for one particular time in geologic history.
Paleozoic or Palaeozoic – Era of geologic time lasting from 542 to 248 mya.
Pangaea – Great proto-continent from which all present continents have broken off by the mechanism of sea-floor spreading and continental drift.
Panthalassa – Hypothetical primeval ocean covering two-thirds of the world except for the continent of Pangaea.
Parent Element – Element that is transformed by radioactive decay to a different daughter-element.
PEA – Preliminary Economic Assessment Study is a more preliminary study than a prefeasibility or feasibility study that also includes an economic analysis of the potential viability of mineral resources.
Peat – Marsh or swamp deposit of water-soaked plant remains which contains more than 50 percent carbon.
Pedalfer – Common soil type in humid regions characterized by an abundance of iron oxides and clay minerals deposited in the B-horizon by leaching.
Pediment – Planar, sloping rock surface forming a ramp up to the front of a mountain range in an arid region and sometimes covered locally by thin alluvium.
Pedocal – Common soil type of arid regions, characterized by accumulation of calcium carbonate in the A-horizon.
Pegmatite – Igneous rock with extremely large grains more than a centimeter in diameter usually found as dykes or veins, and commonly composed of quartz, feldspar and mica.
Pelagic Sediment – Deep-sea sediments composed of fine-grained detritus that slowly settles from surface waters. Common components are clay, radiolarian ooze, and foraminiferal ooze.
Peneplain – Extensive area of low elevation and relief produced by a long period of erosion and representing the end product of the ideal geomorphic cycle.
Pentlandite – Common ore mineral of nickel composed of nickel, iron and sulfur.
Peralkaline – Igneous rocks which have a deficiency of aluminum such that sodium and potassium are in excess of that needed for feldspar.
Percentage Frequency Effect – PFE is percent difference in resistivity measured at two frequencies, one high and one low. It is the basic polarization parameter measured in frequency domain resistivity surveys. Its equivalent to chargeability in time domain surveys.
Perched – Sandstone-hosted uranium mineralization isolated from and found in discrete zones above mineralization occurring at the unconformity.
Perched Boulder – Large block of rock that has been left by melting ice in a prominent and relatively precarious position.
Perched Groundwater – Isolated body of ground-water that is perched above and separated from the main water table by an aquiclude.
Percussion Drilling – Drilling technique that utilizes a hammer bit to produces rock chips.
Period – Division of geologic time lasting tens of millions of years which shorter than an era and longer than an epoch.
Peridot – Gem-quality form of olivine, (Mg, Fe)2SiO4, with Mg in greater quantities than Fe.
Peridotite – Coarse-grained mafic igneous rock composed of olivine and pyroxene but also with amounts of pyroxene and amphibole, but little or no feldspar.
Permafrost – Perennially frozen ground in areas where the temperature remains at or below 0o C for two or more years in a row.
Permittivity – Property which enables a three-dimensional material to store electrical ge.
Perovskite – Calcium titanium oxide mineral composed of calcium titanate, with the chemical formula CaTiO3.
PFS – Preliminary Feasibility (Pre-Feasibility) Study is a comprehensive study of a range of options for the technical and economic viability of a mineral project that has advanced to a stage where a preferred mining method, in the case of underground mining, or a pit configuration, in the case of an open pit, has been established and an effective method of mineral processing has been determined. The Study includes a financial analysis based on reasonable assumptions regarding mining, processing, metallurgical, economic, marketing, legal, environmental, social and governmental factors and the evaluation of any other relevant factors which are sufficient for a Qualified Person, acting reasonably, to determine if all or part of the Mineral Resource may be classified as a Mineral Reserve. The Canadian Institute of Mining Definition Standards requires the completion of a Preliminary Feasibility Study as the minimum prerequisite for the conversion of Mineral Resources to Mineral Reserves.
PGEs – Platinum group elements, specifically platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir), ruthenium (Ru) and osmium (Os). Also often referred to as PGMs.
PGMs – See PGEs above.
Phaneritic – Igneous rock in which the matrix grains are large enough to be distinguished with the unaided eye.
Phanerozoic – Most recent eon of geologic time beginning 542 million years ago and continuing to the present. It comprises the Paleozoic, Mesozoic, and Cenozoic eras.
Phase II Study – Common nomenclature for the part of an environmental investigation that first involves on-site activities such as geophysics, soil gas surveys and drilling.
Phase Shift – Measure of the offset between two periodic signals of the same frequency and measured in degrees or radians/milliradians.
Phreatic Zone – Zone of saturation in the area of an aquifer that is below the water table, in which relatively all pores and fractures are saturated with water.
Phyllosilicate – Mineral with parallel sheets of silicate tetrahedra such as mica.
Physical Properties – Physical characteristics of the ground being investigated, such as density, electrical conductivity, and other physical traits.
Pillow Lava – Rounded masses of volcanic rock, usually basalt, that have been formed by rapid cooling of lava under water.
Pitting – Procedure of digging a pit.
Plagioclase – Type of feldspar containing various proportions of anorthite and albite.
Plate – Rigid parts of the earth’s crust and part of the earth’s upper mantle that move and adjoin each other along zones of seismic activity.
Plate Tectonics – Theory that the crust and part of the mantle are divided into a number of individual plates that move and interact with each other causing seismic and tectonic activity. Plate tectonics explains how continents drift and oceans open and close.
Pliocene Epoch – Epoch from 5.3 to 2.58 million years ago with two Ages: the 1) Zanclean and 2) Piacenzian ages.
Pluton – Body of igneous rock that solidified below the earth’s surface.
Plutonic – Igneous rocks formed beneath the surface of the earth usually comprised of large crystals due to the slowness of cooling.
Plutonic Rock – Igneous rock formed deep beneath the earth’s surface that have cooled slowly and thus their crystals are large and coarse-grained.
Polarize/Polarization/Polarizable – Separation of ge, as in induced polarization also known as IP.
Poly-Deformed – Multiple phases of deformation
Porosity – Ratio, expressed as a percentage, of the void volume of a porous rock to the total volume.
Porphyritic – Texture in igneous rocks in which some crystals are distinctly larger than others.
Porphyroblast – Large grains or crystals, commonly perfectly shaped, developed in schists during metamorphism.
Porphyry – Igneous rock which has porphyritic texture.
Potable Water – Water that is agreeable to the taste and not dangerous to the health.
Potential Field – A field that obeys Laplace’s equation, such as gravity, magnetic, or electrical fields.
Pothole – Semispherical hole in the bedrock of a stream bed formed by abrasion of small pebbles and cobbles in a strong current.
ppm – parts per million.
Pratt Isostatic Compensation – Mechanism in which variations in crustal density act to counterbalance the varying weight of topographic features. The crust is here assumed to be of approximately uniform thickness, thus a mountain range would be underlain by lighter rocks.
Precambrian – Geologic time 4567 to 542 mya from the beginning of the Earth to the beginning of the Cambrian Period of the Paleozoic Era.
Precision – Reproducibility of a measurement; the closeness of each of a set of similar measurements to the arithmetic mean of that set.
Pre-Collar – Upper portion of a hole during core drilling for which no core is yet recovered.
Predicted Data – Synthetic data produced when forward modeling is applied to predict the values of what measurements would be if a geophysical survey was carried out over a given model.
Preferred Orientation – Deviation from randomness in the distribution of the crystallographic or grain shape axes of minerals of a rock, including flow cleavage and foliation, produced by deformation and non-uniform stress during crystallization in metamorphic rocks or by depositional currents in sediments.
Preliminary Economic Assessment Study – PEA is a more preliminary study than a prefeasibility or feasibility study that also includes an economic analysis of the potential viability of mineral resources.
Preliminary Feasibility (Pre-Feasibility) Study – PFS is a comprehensive study of a range of options for the technical and economic viability of a mineral project that has advanced to a stage where a preferred mining method, in the case of underground mining, or a pit configuration, in the case of an open pit, has been established and an effective method of mineral processing has been determined. The Study includes a financial analysis based on reasonable assumptions regarding mining, processing, metallurgical, economic, marketing, legal, environmental, social and governmental factors and the evaluation of any other relevant factors which are sufficient for a Qualified Person, acting reasonably, to determine if all or part of the Mineral Resource may be classified as a Mineral Reserve. The Canadian Institute of Mining Definition Standards requires the completion of a Preliminary Feasibility Study as the minimum prerequisite for the conversion of Mineral Resources to Mineral Reserves.
Primary Magnetic Field – Magnetic field generated by an EM transmitter which may induce a secondary magnetic field.
Primary Sulphide – Sulphide mineral that forms first.
Probable Mineral Reserve – Economically mineable part of an Indicated and, in some circumstances, a Measured Mineral Resource demonstrated by at least a Preliminary Feasibility Study (PFS). This study must include adequate information on mining, processing, metallurgical, economic, and other relevant factors that demonstrate, at the time of reporting, that economic extraction can be justified.
Probable Reserves – Economically mineable part of an Indicated Resource, and in some cases Measured Resource, which has a lower level of confidence than proved reserves but is of sufficient quality to serve as the basis for a decision on the development of the deposit.
Probe – Downhole logging instrument.
Processing – Geophysically, to change data so as to emphasize certain aspects or correct for known influences, thereby facilitating interpretation.
Profiling – Geophysical survey method whereby an array of sensors is moved along the earth’s surface without change in its configuration in order to detect lateral changes in the properties of the subsurface such as faults, buried channels, and so on.
Prospect – Area in which potential is suggested for economic mineralization.
Proterozoic – Second oldest geological period, it is a geologic eon between the Archean and Phanerozoic eons, beginning about 2500 and ending 542 million years ago. It is typical of the age of the copper deposits in Southern Africa
Proton – Nucleus of a hydrogen atom; a positively charged nuclear particle with a mass of one.
Proto-Sun – Large cloud of dust and gas gradually coalescing into a star under the force of gravity.
Proven Mineral Reserves – Economically mineable part of a Measured Mineral Resource demonstrated by at least a Preliminary Feasibility Study (PFS). This Study must include adequate information on mining, processing, metallurgical, economic, and other relevant factors that demonstrate, at the time of reporting, that economic extraction is justified.
Proven Resources – Economically minable part of a Measured Resource which represents the highest confidence category of reserve estimate. The geochemistry of some deposits of mineralisation or other factors could mean that proved reserves are not achievable in some deposits.
Pseudosection – Cross section showing the distribution of a geophysical property, such as seismic travel time, from which the distribution of the geological property of interest such as depth to bedrock for example can be interpreted.
Pumice – Solidified frothy lava created when super-heated, highly pressurized rock is violently ejected from a volcano. Pumice has a low density and floats on water.
P-Wave – Primary or fastest elastic body-wave traveling away from a seismic event through the solid rock and consisting of a train of compressions and dilations of the material along the path of the wave. Sometimes referred to as the push-pull wave, it is the wave assumed in most seismic surveys.
Pyrite – Metallic, pale yellow cubic mineral composed of iron and sulphur, often referred to as fool’s gold.
Pyroclastic – Fragmental material formed by volcanic explosions.
Pyroclastic Rock – Rock formed by the accumulation of fragments of volcanic rock scattered by volcanic explosions.
Pyroclastic Texture – Unsorted, angular and un-rounded texture of the fragments in a pyroclastic rock.
Pyroxene – Common, dark-coloured, silicate mineral which contains iron and magnesium and is a common constituent of gabbro, anorthosite and some ultramafic rocks.
Pyroxene Silicate Compounds – Frequently found in volcanic lava with the general formula XYT2O6.Minerals in the pyroxene group are abundant in both igneous and metamorphic rocks and here are twenty accepted pyroxene mineral names.
Pyroxene Granulite – Coarse-grained contact metamorphic rock containing pyroxene, formed at high temperatures and low pressures.