ACCA, MBA, Tax Agent ជាអ្នកនិពន្ធហើយអាចប្រលងជាប់៖ ACCA រហូត ៤ មុខវិជ្ជាក្នុងពេលតែម្តង, Tax Agent ពិន្ទុខ្ពស់, MBA & BBA ជាប់ជាសិស្សពូកែ និងមានបទពិសោធការងារជាង ១៥ ឆ្នាំ ព្រមទាំងអ្នកនិពន្ធផ្សេងៗ ?ទិញឯកសារហើយ អានមិនយល់អាចសួរបាន
Table Mountain Group : A group of rock formations within the Cape Supergroup sequence of rocks.
Tektite : Natural glass formed from terrestrial ejecta during a meteorite impact.
syntaxis : An abrupt change in the orientation of a mountain belt or individual fold/thrust structure
Syncline : A geological fold with strata dipping inwards towards the fold axis. Contrast anticline.
Syenite : A coarse-grained igneous rock of intermediate composition, composed essentially of alkali-feldspar to the extent of at least two thirds of the total, with a variable content of mafic materials, of which common hornblende is characteristic.
Surficial : Of or pertaining to the surface.
Stylolite : An irregular discontinuity or non-structural fracture in limestone and other sedimentary rocks. Stylolites result from compaction and pressure solution during diagenesis.
Strain : A change in the volume or shape of a rock mass in response to stress.
Storm ridge : A beach ridge usually located further or higher inland caused by wave action from storms.
Staurolite : A red brown to black, mostly opaque, nesosilicate mineral with a white streak.
Sphene :
A calcium titanium nesosilicate mineral.
Sorting : Sorting describes the distribution of grain size of sediments, either in unconsolidated deposits or in sedimentary rocks. Very poorly sorted indicates that the sediment sizes are mixed (large variance); whereas well sorted indicates that the sediment sizes are similar (low variance).
Soil liquefaction : The process describing the behavior of soils that, when loaded, suddenly suffer a transition from a solid state to a liquefied state, or which have the consistency of a heavy liquid.
Slump : A form of mass wasting that occurs when a coherent mass of loosely consolidated materials or rock layers moves a short distance down a slope.
Slickenside : A smoothly polished surface caused by frictional movement between rocks along the two sides of a fault. This surface is normally striated in the direction of movement.
Slaty cleavage : The property of splitting easily along regular, closely spaced planes of fissility, produced by pressure in fine-grained rocks, with the cleavage planes lying in the directions of maximum elongation of the mass.
Slate : Very fine-grained sedimentary rock of the clay or silt grade which as a consequence of regional metamorphism has developed a slaty cleavage.
Silt : Granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment (also known as suspended load) in a surface water body. It may also exist as soil deposited at the bottom of a water body.
Silcrete : An indurated soil duricrust formed when surface sand and gravel are cemented by dissolved silica.
Shingle beach : A beach which is armoured with pebbles or small- to medium-sized cobbles (as opposed to fine sand), typically ranging from 2 to 200 millimetres (0.1 to 7.9 in) diameter.
Shield : A large area of exposed Precambrian crystalline igneous and high-grade metamorphic rocks that form tectonically stable areas.
Shear zone : A tabular to sheet-like, planar or curviplanar zone composed of rocks that are more highly strained than rocks adjacent to the zone. See also fault.
Shale : A fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite.
Sericite : A white potash-mica, similar to muscovite in chemical composition and general character but occurring as a secondary mineral, often as a decomposition product of orthoclase.
Sequence : A sequence of geological events, processes, or rocks arranged in chronological order.
Sediment trap: A depression in which sediments substantially accumulate over time.
Scree : See talus.
Schist : A group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. In French, schist is understood as shale.
Sanidine : A form of potash feldspar identical in composition with orthoclase but physically different, formed under different conditions and occurring in different rock types. It is the high temperature form of orthoclase, into which it inverts at 900 °C (1,650 °F). Occurs in lavas and dyke rocks.
Sandstone : Sand (with grains up to 2 mm in diameter) in which the grains are cemented together by secondary silica or calcite. Maybe loosely cemented and soft or well cemented and hard. Buff to brownish; sometimes reddish, due to presence of iron oxides, or greenish, due to presence of glauconite.
Saccharoidal : Having a texture similar to that of granulated sugar.
Rudite : Any of a set of sedimentary rocks composed of rounded or angular detrital grains, i.e. granules, pebbles, cobbles, and boulders, which are coarser than sand in size.
Rudaceous : Having the composition and characteristics of clastic rocks, i.e. coarse-grained sedimentary rocks, conglomerates, and breccias, with a particle size of less than 2 mm.
Roche moutonnée : An elongated post-glacial rock formation with a smoothed surface on the uphill side and a “plucked” surface on the downhill side.
Rhyolite: An aphanitic, buff to greyish flow-banded rock, often containing spherulites or phenocrysts of quartz and feldspar.
Reverse fault :
Dip-slip faults can be sub-classified into the types “reverse” and “normal”. A reverse fault occurs when the crust is compressed such that the hanging wall moves upward relative to the footwall. Contrast normal fault.
Retrograde metamorphism : The reconstitution of a rock via revolatisation under decreasing temperatures (and usually pressures), allowing the mineral assemblages formed in prograde metamorphism to revert to those more stable at less extreme conditions.
Reticulite : A basaltic pumice in which the walls of the vesicles have collapsed, leaving a network of fine, interconnecting glass threads. It is the lightest rock known.
Regional metamorphism : Over wide areas resulting from deep burial with consequent rise in temperature and static pressure, usually with the help of folding movements that accompany the formation of mountain ranges.
Quartzite : A compact, hard, very fine-grained white to creamy white rock which breaks into sharp angular fragments. Quartzite is always associated with other metamorphic rocks, while cemented sandstone is always associated with other sedimentary rocks.
Quaternary : The most recent of the three periods of the Cenozoic Era in the standard geologic time scale. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present.
Guartzite : A compact, hard, very fine-grained white to creamy white rock which breaks into sharp angular fragments. Quartzite is always associated with other metamorphic rocks, while cemented sandstone is always associated with other sedimentary rocks.
Pyroxenite : A coarse-grained, holocrystalline igneous rock consisting mainly of pyroxenes. It may contain biotite, hornblende, or olivine as accessories.
Pyroxene : Any of a set of mineral species which, although falling into different systems (orthorhombic, monoclinic, and triclinic), are closely related in form and structure. They are metasilicates of calcium, magnesium, and iron with manganese, and less often with sodium, potassium, zirconium, and fluorine.
Pyroclastic : A volcanic fragment, such as a volcanic bomb, breadcrust bomb, or achnelith.
Pyroclastic flow : A fast-moving current of hot gas and rock (collectively known as tephra), which normally hugs the ground and travels downhill or spreads laterally under gravity.
Pumice : A light-coloured, highly vesicular volcanic rock of very low density.
Pseudomatrix : A weaker material (mainly lithic fragments) that becomes crushed and matrix-like in a rock.
Psammite : A general term for a sandstone, most often used to describe a metamorphosed rock unit with a dominantly sandstone protolith.
Protolith : The source rock from which a metamorphic, or in some rare cases a sedimentary, rock was formed. In most cases the appropriate sedimentary term is “provenance” rather than “protolith”, since the material has been transported.
Prograde metamorphism : Mineral changes in rocks under increasing pressure and/or temperature conditions.
Precipitate: A rock or mineral precipitated into solid form from an aqueous solution.
Precambrian : A non-standard geologic time period immediately preceding the Phanerozoic Eon, divided into several eons of the geologic time scale. It spans from the formation of Earth about 4540 Ma (million years ago) to the beginning of the Cambrian Period, about 541.0 ± 1.0 Ma, when macroscopic hard-shelled animals first appeared in abundance.
Porphyry: 1. A rock that is porphyritic, containing large and small crystals.2. In mining, a specific deposit containing widely disseminated metals, typically copper.
Porphyroblast : A large mineral crystal in a metamorphic rock which has grown within the finer-grained groundmass.
Pneumatolysis : The destructive after-action of the concentrated volatile constituents of a magma, effected after the consolidation of the main body of the magma.
Plumose structure : A ladder or grid pattern that occurs during jointing that resembles plumes, oriented perpendicular to the stress, hence which usually form parallel to the upper and lower surfaces of the constituent rock unit.
Plutonic : Having crystallised at depth within the Earth’s crust, used of a rock. Plutonic rocks are slow-cooling and coarse-grained and have relatively low temperatures of final consolidation.
Pliocene : The geologic period that extends from 5.332 million to 2.588[2] million years Before Present. It is the second-youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene and is followed by the Pleistocene.
Pleistocene : The geologic epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the world’s recent period of repeated glaciations. The Pleistocene is the first epoch of the Quaternary Period and the sixth epoch of the Cenozoic Era.
Plate tectonics : The set of natural processes and phenomena which result in large-scale movements of portions of the Earth’s lithosphere.