Mylonite is a fine-grained, compact metamorphic rock produced by dynamic recrystallization of the constituent minerals resulting in a reduction of the grain size of the rock. Mylonites can have many different mineralogical compositions; it is a classification based on the textural appearance of the rock.
Anatexis is the partial melting of rocks. Traditionally, anatexis is used specifically to discuss the partial melting of crustal rocks, while the generic term "partial melting" refers to the partial melting of all rocks, in both the crust and mantle.
In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation. The hydraulic flow involved is usually due to hydrothermal circulation.
Exfoliation joints or sheet joints are surface-parallel fracture systems in rock, and often leading to erosion of concentric slabs. (See Joint ).
A monocline is a step-like fold in rock strata consisting of a zone of steeper dip within an otherwise horizontal or gently-dipping sequence.
The Moab Fault, near Moab, Utah, United States, is an extensional fault that runs approximately NW-SE, passing to the west of the Arches National Park. It is about 45 km (28 mi) long and has a maximum displacement of about 960 m (3,150 ft). The fault connects with the Tenmile Graben in the north and extends through the Moab-Spanish Valley to the south. The fault outcrop has a well-defined fault zone bordered by a damage zone of minor faults and fractures.
In geology, transpression is a type of strike-slip deformation that deviates from simple shear because of a simultaneous component of shortening perpendicular to the fault plane. This movement ends up resulting in oblique shear. It is generally very unlikely that a deforming body will experience "pure" shortening or "pure" strike-slip. The relative amounts of shortening and strike-slip can be expressed in the convergence angle alpha which ranges from zero to 90 degrees. During shortening, unless material is lost, transpression produces vertical thickening in the crust. Transpression that occurs on a regional scale along plate boundaries is characterized by oblique convergence. More locally, transpression occurs within restraining bends in strike-slip fault zones.
In structural geology section restoration or palinspastic restoration is a technique used to progressively undeform a geological section in an attempt to validate the interpretation used to build the section. It is also used to provide insights into the geometry of earlier stages of the geological development of an area. A section that can be successfully undeformed to a geologically reasonable geometry, without change in area, is known as a balanced section.
Quartz is the most abundant single mineral in the earth's crust, and as such is present in a very large proportion of rocks both as primary crystals and as detrital grains in sedimentary and metamorphic rocks. Dynamic recrystallization is a process of crystal regrowth under conditions of stress and elevated temperature, commonly applied in the fields of metallurgy and materials science. Dynamic quartz recrystallization happens in a relatively predictable way with relation to temperature, and given its abundance quartz recrystallization can be used to easily determine relative temperature profiles, for example in orogenic belts or near intrusions.
Concordia is a town in Namakwa District Municipality in the Northern Cape province of South Africa. The distance from Concordia to Cape Town is approximately 600 km (370 mi).
Setlagole(Se tlaa gola) is a historical Setswana village next to the N18 in Ngaka Modiri Molema District Municipality in the North West province of South Africa.
The Karakoram fault is an oblique-slip fault system in the Himalayan region across India and Asia. The slip along the fault accommodates radial expansion of the Himalayan arc, northward indentation of the Pamir Mountains, and eastward lateral extrusion of the Tibetan plateau. Current plate motions suggest that the convergence between the Indian Plate and the Eurasian Plate is around 44±5 mm per year in the western Himalaya-Pamir region and approximately 50±2 mm per year in the eastern Himalayan region.
Zoe Kai Shipton is a British geologist. She is a professor of Geological Engineering at Strathclyde University.
Strain partitioning is commonly referred to as a deformation process in which the total strain experienced on a rock, area, or region, is heterogeneously distributed in terms of the strain intensity and strain type. This process is observed on a range of scales spanning from the grain – crystal scale to the plate – lithospheric scale, and occurs in both the brittle and plastic deformation regimes. The manner and intensity by which strain is distributed are controlled by a number of factors listed below.
Robert J. Twiss is an American geologist emeritus of University of California, Davis. He made his Ph.D. 1971 at Princeton University.
Soche is a 3,955-metre-high (12,976 ft) dacitic volcano in Ecuador and is located on the northern end of a secondary volcanic chain. Constructed on a Paleozoic substratum, it contains an eastwards-opening caldera in the summit region. A large eruption in 6650 BCE generated ashfall into Colombia and two lava domes in the caldera. The ash- and lapilli-fall is about a metre thick in the Interandean valley and the neighbouring cordilleras and most likely represented a long-lasting obstacle for human population. Earlier eruptive events involving a lava flow that was subsequently offset by a fault zone named the Cayambe-Chingual fault by 110m occurred 9.67 ka BP, and another involving a pyroclastic flow was dated at 37.22 ± 0.63 ka BP.
The Colangüil Batholith is a group of plutons in western Argentina between the latitudes of 29 and 31° S. The plutons of the batholith were emplaced and cooled in the Late Paleozoic and the Triassic. Runs in a north-south direction. The plutons of the batholith are intruded into volcanic rocks produced by the same plutons plus some earlier deformed basement. The most common rocks in the batholith are granodiorite, granite and leucogranite. The batholith contains also a dyke swarm of north-south trending dykes. Compared to other subduction-related batholiths around the Pacific Ocean Colangüil Batholith is more felsic.
This is a compilation of the properties of different analog materials used to simulate deformational processes in structural geology. Such experiments are often called analog or analogue models. The organization of this page follows the review of rock analog materials in structural geology and tectonics of Reber et al. 2020.
Microcracks in rock, also known as microfractures and cracks, are spaces in rock with the longest length of 1000 μm and the other two dimensions of 10 μm. In general, the ratio of width to length of microcracks is between 10−3 to 10−5.
Jan Tullis is a geologist known for her research on the deformation of crustal rocks and an educator known for educating and mentoring young scientists.
