Temperature during metamorphism minerals remain stable at a finite temp range, if that range is exceeded new minerals will result. Their study provides us with important data regarding formation of the earth and the past geological environment. Formed by solidification of material deposited by wind, water, glaciers, or direct chemical precipitation. Rock, in geology, naturally occurring and coherent aggregate of one or more minerals. They are created when hot magma from deep within the earth cools and hardens. Many precious materials, such as marble and many types of gemstones, including diamonds, are formed by the metamorphic process. They are crystalline and often have a squashed foliated or banded texture. The next three deal with the criteria for establishing the order of crystallization in igneous and metamorphic rocks, a topic which is rather underplayed in other texts on mineral textures.
These rocks remain essentially solid during metamorphism, but they can flow in a plasticlike manner due to differential pressure. This lesson focuses on the properties of metamorphic rocks that help in its identification, most notably characteristics such as banding and foliation. This second set of lecture notes focuses on physical properties such as weathering potential, slaking potential, swelling potential, hardness, abrasiveness, and other properties such as porosity, density, water content, etc. The preexisting rocks may be igneous, sedimentary, or other metamorphic rocks. Metamorphic rocks are the third major type of rock, the other two being igneous and sedimentary. Parent rock composition usually no new material added, resulting rock will have similar comp to parent rock. These can range from textures similar to the original protolith at low grades of metamorphism, to textures that are purely produced during metamorphism and leave the rock with little resemblance to the original protolith. Below is an alphabetical list of metamorphic rocks. Because of how they are formed, metamorphic rocks constitute a great deal of the bedrock in earths crust. The presence of mineral layers, called foliation, is an important feature for classifying metamorphic rocks.
Metamorphic rocks form when existing sedimentary or igneous rocks get heated to the extent that the existing minerals start to recrystallize into new minerals. Rocks on the surface of the earth are continually broken down into smaller pieces by wind, water, plant roots, etc. Slate is made of finegrained interlocking crystals which lie flat in the same direction, known. Metamorphic rocks are those formed by other types of rocks that have been exposed to heat, pressure and time, which change them into a different type of rock. Formed by hardening or crystallization of hightemperature, molten material magma. Igneous rocks are one form of rocks commonly found on the earth. C thermal properties thermal expansion, conductivity, and c in situ stresses. Metamorphic rocks can form in different conditions, in different temperatures up to 200 c and pressures up to 1500 bars.
Change is a result of pressure directed stress and heat solid state reaction no net change in chemistry ideally role of groundwater recrystallization of. For this purpose a companion web site contains a selection of model based equations in excel worksheets for practical application and. By being b uried deep enough for a long enough time, a rock will. Metamorphic rocks are formed when rock changes over a period of time due to a lot of physical changes like pressure, heat and different chemical activity. Under greater heat and pressure, as metamorphic minerals such as mica and feldspar begin to form, strain orients them in layers. Specific heats for rocks can be obtained from data on rockforming minerals. Two groups of metamorphic rocks can be identified based upon the presence or absence of a specific texture foliation in the rocks.
Metamorphic rocks do not usually have pores or openings. There is also an exploration of the properties of contact metamorphism, a process of baking the rock from nearby intrusions that. Metamorphic rocks rocks ks3 chemistry revision bbc. They are not made from molten rock rocks that do melt form igneous rocks instead. Find materials for this course in the pages linked along the left. Most metamorphic rocks are comprised of the relatively insoluble silicate minerals.
Metamorphic they are formed through the change metamorphosis of igneous and sedimentary rocks. Physical and mechanical properties of metamorphic rocks. Start studying characteristics of sedimentary, igneous and metamorphic rocks learn vocabulary, terms, and more with flashcards, games, and other study tools. The domain of this classification system includes not only metamorphic rocks as commonly understood, but also a variety of hydrothermally altered, myloniteseries, cataclastic, and impactmetamorphic rocks. Arc 1 focuses on learning about rocks and minerals and their properties.
The mechanical properties of rocks change with density, porosity, variation of mineral assemblage, grain size, texture and effective pressures acting on them. Changes in physical and mechanical properties in metamorphic rocks lead to corresponding variations in failure pattern singh et al. A workbook is a symbiosis of a brief description of physical fundamentals of rock properties based on typical experimental results and relevant theories and models with a guide for practical use of different theoretical concepts. An investigation of the properties of rocks and minerals will use samples of multiple different rocks and minerals. Two examples are magnetite and hematite metamorphic rocks formed from igneous, sedimentary, or other metamorphic rocks which contain minerals that have been changed. This webpage provides a compilation of online instructional resources and teaching activities related to optical mineralogy and petrography. Bedrock aquifers much of the bedrock is also covered with tens to hundreds of metres of unconsolidated sediments a.
Microtextures of igneous and metamorphic rocks pdf free. A new approach for estimation of properties of metamorphic. Foliated metamorphic rocks will split along cleavage lines that are parallel to the minerals that make up the. This rock changes occur when these rocks are exposed to an environment. Metamorphic rocks undergo changes in texture, mineralogy, and chemical composition through partial or complete recrystallization of their minerals, either solidstate or solutionmediated 2527. Metamorphic rocks were once igneous or sedimentary rocks, but have been changed metamorphosed as a result of intense heat andor pressure within the earths crust.
Although most bedrock aquifers are within sedimentary rock, in some areas igneous or metamorphic rock can be important as aquifers. The two characteristics used to classify metamorphic rocks are foliation and lineation. Rocks are identified by making a series of decisions about their properties, such as texture, composition, hardness, etc. Characteristics of metamorphic rocks science struck. When sedimentary rocks or igneous rocks go through the physical process such as pressure exposure, heat changes, and tectonic plate movement at plate edges. Formed by modification of previously existing rocks by the application of heat.
Metamorphic rocks types and properties of metamorphic rocks. Metamorphic rocks and processes metamorphism comes from the greek words meta change morphe form metamorphic rocks form by solidstate no melting transformation of preexisting rock by processes that take place beneath earths surface. Igneous rocks are classified by where they are formed. A new approach for estimation of properties of metamorphic rocks. If you know the name of a rock and want to learn more about it, clicking on the name will take you to a picture and a description.
What are some properties of metamorphic rocks answers. Classification of rocks and description of physical properties of rock introduction uniformity of definitions, descriptors, and identification of rock units is important to maintain continuity in geologic logs, drawings, and reports from a project with multiple drilling sessions, different loggers and. Metamorphic rocks form when changes in the composition andor texture of a rock occur as a result of increasing pressure or temperature but stop short of melting minerals. Characteristics of sedimentary, igneous and metamorphic rocks.
Sedimentary rocks are formed when pieces of sand, dirt, and other types of sediment are cemented together in layers. These are the rocks that form by the effects of heat, pressure, and shear upon igneous and sedimentary rocks. One of the oldest types of rocks on our planet, metamorphic rocks are mainly formed due to changes in the parameters of temperature and pressure, which act on the parent material. Metamorphic rocks metamorphic rocks are formed when rock changes over a period of time due to a lot of physical changes like pressure, heat and different chemical activity.
We classify these compositegenesis rocks according to descriptive properties that reflect the multiple processes that make the rock composite. The mechanical properties of rocks change with density, porosity, ucs, specific gravity, grain size, texture and effective pressures acting on them. Names that are not linked are ones for which picturesdescriptions are not yet available. The key to common metamorphic rocks allows someone to identify a rock based on its properties. The student will create a model of how metamorphic rocks are formed. Chapters 6 and 7 give examples of microtextures for igneous and metamorphic rocks, respectively.
Lecture notes mechanical properties of rocks earth. Pdf on jun 1, 2018, zozk abdaqadir and others published physical and mechanical properties of metamorphic rocks find, read and cite all the research you need on researchgate. Students will conduct online research, as well as participate in handson activities. Igneous rocks formed from minerals that have melted deep within the earth luster the way a mineral reflects light magnetic minerals minerals which show magnetic properties. The student will identify properties of minerals and be able to identify certain minerals using specific tests. It is anticipated that values of these thermal properties of rocks and minerals will be useful for. Changes in physicomechanical properties in metamorphic rocks lead to corresponding variations in failure pattern. Pdf physical and mechanical properties of metamorphic rocks. Almost invariably this leads to the development of interlocking textures with low porosities. We are able to do this because the properties do not overlap completely. Such aggregates constitute the basic unit of which the solid earth is composed and typically form recognizable and mappable volumes.
As a rock is buried in the crust, it is subjected to heat and pressure, which makes it harder and changes. Physical properties of rocks, volume 8 1st edition. The student will create a story using facts about igneous rocks. Some form during mountainbuilding by forces of others from the heat of igneous intrusions in regional metamorphism others from the heat of igneous intrusions in contact metamorphism. What are the properties of sedimentary rocks answers. Values are the lowest in pure sandstone and carbonate rocks which are primarily quartz, feldspars, and carbonates. Foliates are composed of large amounts of micas and chlorites. The student will describe how an igneous rock is formed.
A new approach for estimation of properties of metamorphic rocks 115 table 1 rock properties and range of aweighted equivalent sound level values obtained during drilling of metamorphic rocks. Burial changes is the first step in transforming sedimentary rocks into metamorphic rocks. The three major classes of rock are igneous, sedimentary, and metamorphic rock. Eighth grade lesson metamorphic rocks i betterlesson. These rocks are identified by the presence of certain mineral types and specific textures. Atlas of metamorphic minerals university of oxford. Read this sciencestruck article to gain extensive information about the main features of these rocks. Stable mineral assemblages in metamorphic rocks equilibrium mineral assemblages at equilibrium, the mineralogy and the composition of each mineral is determined by t, p, and x mineral paragenesisrefers to such an equilibrium mineral assemblage relict minerals or later alteration. Physical geology metamorphic rocks flashcards quizlet. During a rock wall scavenger hunt, students begin to explore rocks in an. Metamorphic rocks are an important topic in geology. Those that are formed under the earths surface are.
As strain increases, the foliation becomes more intense, and the minerals may sort themselves into thicker layers. Metamorphic rocks are former igneous, sedimentary or metamorphic rocks that have changed their texture and composition. Metamorphic rocks metamorphic rocks are the result of the transformation of a preexisting rock type, the protolith, in a process called metamorphism, which means change in form. Metamorphic rock, any rock that results from the alteration of preexisting rocks in response to changing conditions, such as variations in temperature, pressure, and mechanical stress, and the addition or subtraction of chemical components. This requires the ability to observe and recognize these properties. Metamorphic rocks an overview sciencedirect topics. The magma can cool below the earths crust, or erupt as lava and cool on the earths surface. The protolith is subjected to heat greater than 150 degrees celsius andor extreme pressure causing profound physical andor chemical change.
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