Table of Contents
Why do we get exsolution textures?
Exsolution texture, a general term for the texture of mineral intergrowth formed by solid exsolution, is a common texture in minerals from both magmatic and metamorphic rocks. This texture is important for understanding variations of metamorphic conditions.
What is exsolution lamellae?
Exsolution is a process by which a solid solution phase unmixes into two separate phases in the solid state. These lamellae result from the exsolution of a separate pyroxene phase from a host grain due to subsolidus re-equilibration (that occurs while the mineral is in the solid state) during slow cooling.
How is Perthite formed?
The intergrowth forms by exsolution due to cooling of a grain of alkali feldspar with a composition intermediate between K-feldspar and albite.
What is solid solution in geology?
A solid solution series is the compositional range between end-member minerals that share the same basic chemical formula but experience substitution of elements in one or more atomic sites. For example, iron and magnesium can readily replace one another in a mineral.
Does potassium feldspar have lamellae?
Potassium feldspar (also orthoclase feldspar or K-spar) exhibits bands of different color on cleavage surfaces. These bands, or exsolution lamellae, are planar zones of slightly different composition.
What is Orthopyroxene made of?
In Earth’s crust, pyroxenes are found in a wide range of igneous and metamorphic rocks. They are most abundant in the dark-colored igneous rocks, such as basalt and gabbro, that comprise most of the oceanic crust….
| Physical Properties of Pyroxenes | |
|---|---|
| Chemical Classification | Silicate |
| Specific Gravity | 3 to 4 |
Which mineral has the exsolution lamellae structure?
pyroxene structure The lamellae are exsolved along specific crystallographic directions, producing oriented intergrowths with parallel and herringbone texture.
What is sub solidus exsolution?
A perthite is an intimate intergrowth of sodic and potassic feldspar resulting from subsolidus exsolution (unmixing of two minerals). An antiperthite is an intergrowth arising due to exsolution where potassic feldspar is present as blebs or lamellae within a sodic feldspar.
Does plagioclase have exsolution?
Plagioclase feldspars exhibit exsolution microtextures in three compositional ranges, the Peristerite, Bøggild and Huttenlocher ‘miscibility gaps’ shown in orange on Fig. 4 and in white in Fig. 8. These intergrowths are coherent and usually below the resolution of an optical microscope.
Which is a solid solution?
solid solution, mixture of two crystalline solids that coexist as a new crystalline solid, or crystal lattice. The substances may be soluble over a partial or even complete range of relative concentrations, producing a crystal whose properties vary continuously over the range.
What is binary solid solution?
Solid Solutions One of the simplest binary phase diagrams is one in which both components are completely miscible in each other in all proportions, forming a solid solution. Examples include metals which form alloys and many mineral systems.
What mineral has exsolution lamellae?
What is erosion in geology?
Erosion (geology) In earth science, erosion is the action of surface processes (such as water flow or wind) that remove soil, rock, or dissolved material from one location on the Earth’s crust, then transport it away to another location.
What is exploring geology?
Exploring Geology. Exploring Geology by Reynolds/Johnson/ Morin/Carter is an innovative textbook intended for an introductory college geology course, such as Physical Geology. This ground-breaking, visually spectacular book was designed from cognitive and educational research on how students think, learn, and study.
How is geology useful?
Geology is the study of the earth. Hydrogeology studies water, groundwater, and how permeable rock or ground is. The Hydrogeologist can help prove whether a factory polluted your well water. Geologists find oil and study how to more efficiently get it out of the earth.
What is quartz in geology?
Quartz is a chemical compound consisting of one part silicon and two parts oxygen. It is silicon dioxide (SiO2). It is the most abundant mineral found at Earth’s surface, and its unique properties make it one of the most useful natural substances. Rock crystal quartz: Transparent “rock crystal” quartz.