Arc 1 focuses on learning about rocks and minerals and their properties. 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. Lecture notes mechanical properties of rocks earth. Metamorphic rocks types and properties of metamorphic rocks.
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 an overview sciencedirect topics. Two groups of metamorphic rocks can be identified based upon the presence or absence of a specific texture foliation in the rocks. The preexisting rocks may be igneous, sedimentary, or other metamorphic rocks. As a rock is buried in the crust, it is subjected to heat and pressure, which makes it harder and changes. Bedrock aquifers much of the bedrock is also covered with tens to hundreds of metres of unconsolidated sediments a. Foliated metamorphic rocks will split along cleavage lines that are parallel to the minerals that make up the. 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.
These rocks are identified by the presence of certain mineral types and specific textures. During a rock wall scavenger hunt, students begin to explore rocks in an. We classify these compositegenesis rocks according to descriptive properties that reflect the multiple processes that make the rock composite. What are the properties of sedimentary rocks answers. 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. C thermal properties thermal expansion, conductivity, and c in situ stresses. Igneous rocks are classified by where they are formed. Changes in physical and mechanical properties in metamorphic rocks lead to corresponding variations in failure pattern singh et al. Read this sciencestruck article to gain extensive information about the main features of these rocks. Metamorphic rocks can form in different conditions, in different temperatures up to 200 c and pressures up to 1500 bars. 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. Most metamorphic rocks are comprised of the relatively insoluble silicate minerals.
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. Almost invariably this leads to the development of interlocking textures with low porosities. 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. Metamorphic rocks are former igneous, sedimentary or metamorphic rocks that have changed their texture and composition. A new approach for estimation of properties of metamorphic rocks. Rock, in geology, naturally occurring and coherent aggregate of one or more minerals.
Chapters 6 and 7 give examples of microtextures for igneous and metamorphic rocks, respectively. When sedimentary rocks or igneous rocks go through the physical process such as pressure exposure, heat changes, and tectonic plate movement at plate edges. 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. The three major classes of rock are igneous, sedimentary, and metamorphic rock. An investigation of the properties of rocks and minerals will use samples of multiple different rocks and minerals. Although most bedrock aquifers are within sedimentary rock, in some areas igneous or metamorphic rock can be important as aquifers. Physical and mechanical properties of metamorphic rocks. The mechanical properties of rocks change with density, porosity, ucs, specific gravity, grain size, texture and effective pressures acting on them. As strain increases, the foliation becomes more intense, and the minerals may sort themselves into thicker layers. Names that are not linked are ones for which picturesdescriptions are not yet available. Temperature during metamorphism minerals remain stable at a finite temp range, if that range is exceeded new minerals will result.
It is anticipated that values of these thermal properties of rocks and minerals will be useful for. Find materials for this course in the pages linked along the left. Characteristics of sedimentary, igneous and metamorphic rocks. The student will create a story using facts about igneous rocks. Characteristics of metamorphic rocks science struck. The mechanical properties of rocks change with density, porosity, variation of mineral assemblage, grain size, texture and effective pressures acting on them. There is also an exploration of the properties of contact metamorphism, a process of baking the rock from nearby intrusions that.
We are able to do this because the properties do not overlap completely. Formed by hardening or crystallization of hightemperature, molten material magma. Specific heats for rocks can be obtained from data on rockforming minerals. Students will conduct online research, as well as participate in handson activities. Many precious materials, such as marble and many types of gemstones, including diamonds, are formed by the metamorphic process. What are some properties of metamorphic rocks answers. The two characteristics used to classify metamorphic rocks are foliation and lineation. 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. Changes in physicomechanical properties in metamorphic rocks lead to corresponding variations in failure pattern.
Eighth grade lesson metamorphic rocks i betterlesson. 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. Igneous rocks are one form of rocks commonly found on the earth. 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 are formed when rock changes over a period of time due to a lot of physical changes like pressure, heat and different chemical activity. Metamorphic they are formed through the change metamorphosis of igneous and sedimentary rocks. 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. Pdf physical and mechanical properties of metamorphic rocks. This requires the ability to observe and recognize these properties.
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. Physical geology metamorphic rocks flashcards quizlet. This rock changes occur when these rocks are exposed to an environment. 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. 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. Change is a result of pressure directed stress and heat solid state reaction no net change in chemistry ideally role of groundwater recrystallization of. Metamorphic rocks are the third major type of rock, the other two being igneous and sedimentary.
Formed by modification of previously existing rocks by the application of heat. Under greater heat and pressure, as metamorphic minerals such as mica and feldspar begin to form, strain orients them in layers. Parent rock composition usually no new material added, resulting rock will have similar comp to parent rock. 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. 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.
Values are the lowest in pure sandstone and carbonate rocks which are primarily quartz, feldspars, and carbonates. Two examples are magnetite and hematite metamorphic rocks formed from igneous, sedimentary, or other metamorphic rocks which contain minerals that have been changed. 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. Metamorphic rocks rocks ks3 chemistry revision bbc. The protolith is subjected to heat greater than 150 degrees celsius andor extreme pressure causing profound physical andor chemical change. Microtextures of igneous and metamorphic rocks pdf free. The student will describe how an igneous rock is formed. Such aggregates constitute the basic unit of which the solid earth is composed and typically form recognizable and mappable volumes. Foliates are composed of large amounts of micas and chlorites. Below is an alphabetical list of metamorphic rocks. A new approach for estimation of properties of metamorphic. Those that are formed under the earths surface are. Because of how they are formed, metamorphic rocks constitute a great deal of the bedrock in earths crust.
The key to common metamorphic rocks allows someone to identify a rock based on its properties. 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. They are not made from molten rock rocks that do melt form igneous rocks instead. Start studying characteristics of sedimentary, igneous and metamorphic rocks learn vocabulary, terms, and more with flashcards, games, and other study tools. Physical properties of rocks, volume 8 1st edition. Metamorphic rocks form when existing sedimentary or igneous rocks get heated to the extent that the existing minerals start to recrystallize into new minerals. These are the rocks that form by the effects of heat, pressure, and shear upon igneous and sedimentary rocks. Burial changes is the first step in transforming sedimentary rocks into metamorphic rocks. The magma can cool below the earths crust, or erupt as lava and cool on the earths surface.
Atlas of metamorphic minerals university of oxford. The student will create a model of how metamorphic rocks are formed. Formed by solidification of material deposited by wind, water, glaciers, or direct chemical precipitation. These rocks remain essentially solid during metamorphism, but they can flow in a plasticlike manner due to differential pressure. The presence of mineral layers, called foliation, is an important feature for classifying metamorphic rocks. This lesson focuses on the properties of metamorphic rocks that help in its identification, most notably characteristics such as banding and foliation. They are created when hot magma from deep within the earth cools and hardens. Metamorphic rocks are an important topic in geology. Sedimentary rocks are formed when pieces of sand, dirt, and other types of sediment are cemented together in layers. 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.
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