Chapter 3 Metamorphic Rocks PDF

PETROLOGY https://geologyistheway.com/it/metamorphic/phyllite/ Origin of Metamorphic Rocks Metamorphic rocks form from pre-existing igneous, sedimentary...

PETROLOGY https://geologyistheway.com/it/metamorphic/phyllite/ Origin of Metamorphic Rocks Metamorphic rocks form from pre-existing igneous, sedimentary and metamorphic rocks under the conditions of high temperature and pressure (higher than conditions of formation of starting material), or through the action of chemical alteration induced by very hot and chemically aggressive pore water. The original texture, composition and mineralogy of the Agents in the Process of parent rocks get changed in the new physico-chemical and/or tectonic conditions. The process responsible for Metamorphism this change is known as metamorphism and the resultant rock is called metamorphic rock. The parent rock (original rock) that has undergone metamorphism is called the protolith. Product of metamorphism is metamorphosed rock. https://www.learner.org/wp-content/interactive/rockcycle/rockdiagram/ Agents in the Process of Metamorphism Agents in the Process of Metamorphism AGENT EFFECTS AGENT EFFECTS TEMPERATURE (HEAT) Typically exceeding 150-200°C, elevated temperatures TEMPERATURE (HEAT) Typically exceeding 150-200°C, elevated temperatures activate chemical reactions that alter the mineral composition activate chemical reactions that alter the mineral composition of the parent rock. of the parent rock. PRESSURE Often greater than 100 megapascals, pressure compacts the It provides the energy to drive chemical reactions that result in the rock, promoting recrystallization and the formation of new recrystallization of existing minerals and/or the formation of new minerals. structures. FLUIDS (CHEMICALS) Hot fluids carrying dissolved minerals can introduce new chemical components or remove existing ones, further modifying the rock's composition. TIME These transformative processes occur over vast timescales, spanning millions of years, allowing for gradual and profound changes. https://www.learner.org/wp-content/interactive/rockcycle/rockdiagram/ https://www.learner.org/wp-content/interactive/rockcycle/rockdiagram/ Agents in the Process of Metamorphism AGENT EFFECTS Confining pressure has equal pressure PRESSURE Often greater than 100 megapascals, pressure compacts the on all sides and is responsible for rock, promoting recrystallization and the formation of new causing chemical reactions to occur structures. Types of Pressure in Metamorphism Confining Pressure (Lithostatic Pressure) It is the pressure exerted by the weight of overlying sediments, including the weight of the contained fluids. https://www.sciencedirect.com/topics/engineering/lithostatic-pressure Directed Pressure (Differential or Tectonic Stress) Plate tectonics provide the underlying mechanical control for all forms of directed Direct pressure is an unequal pressure. balance of forces on a rock in one or more directions. https://www.learner.org/wp-content/interactive/rockcycle/rockdiagram/ Agents in the Process of Metamorphism Agents in the Process of Metamorphism AGENT EFFECTS AGENT EFFECTS FLUIDS (CHEMICALS) Hot fluids carrying dissolved minerals can introduce new TIME These transformative processes occur over vast timescales, chemical components or remove existing ones, further spanning millions of years, allowing for gradual and profound modifying the rock's composition. changes. Chemically reactive fluids are expelled by crystallizing magma and Most metamorphic reactions take place at very slow rates. For example, created by metamorphic reactions. the growth of new minerals within a rock during metamorphism has been estimated to be about 1 mm per million years. These reactive fluids are made of mostly water (H2O) and carbon dioxide https://www.geologyin.com/2018/01/the-factors-that-control-metamorphic.html (CO2), and smaller amounts of potassium (K), sodium (Na), iron (Fe), magnesium (Mg), calcium (Ca), and aluminum (Al). https://www.learner.org/wp-content/interactive/rockcycle/rockdiagram/ Classifications of Metamorphism CLASSIFICATION PROCESS BURIAL Sediments are buried deeply enough that the heat and pressure METAMORPHISM cause minerals to begin to recrystallize and new minerals to grow, but does not leave the rock with a foliated appearance. Classifications of Metamorphism https://www.learner.org/wp-content/interactive/rockcycle/rockdiagram/ https://slideplayer.com/slide/13780147/ Classifications of Metamorphism Classifications of Metamorphism CLASSIFICATION PROCESS CLASSIFICATION PROCESS CONTACT Contact metamorphism occurs adjacent to intrusive igneous rocks REGIONAL Regional metamorphism refers to large-scale metamorphism, METAMORPHISM due to temperature increases resulting from hot magma intrusion METAMORPHISM such as what happens to continental crust along convergent into the rock. The metamorphosed zone is known as the tectonic margins (where plates collide). The collisions result in the metamorphic aureole around an igneous rock. formation of long mountain range. Regional metamorphism of oceanic crust at a subduction zone occurs at high pressure but relatively low temperatures. https://www.learner.org/wp-content/interactive/rockcycle/rockdiagram/ Regional metamorphism beneath a mountain range resulting from continent-continent collision. https://www.learner.org/wp-content/interactive/rockcycle/rockdiagram/ https://www.geologyin.com/2014/03/contact-metamorphism.html https://openpress.usask.ca/physicalgeology/chapter/10-3-types-of-metamorphism-and-where-they-occur-2/ Classifications of Metamorphism Classifications of Metamorphism CLASSIFICATION PROCESS (a) regional metamorphism related to mountain building at a continent-continent convergent boundary, HYDROTHERMAL Hydrothermal metamorphism alters rocks at high temperatures (b) seafloor (hydrothermal) metamorphism of oceanic crust in the area on either side of a spreading ridge, (SEAFLOOR) and moderate pressures by hydrothermal fluids. (c) regional metamorphism of oceanic crustal rocks within a subduction zone, METAMORPHISM (d) contact metamorphism adjacent to a magma body at a high level in the crust, and (e) regional metamorphism related to mountain building at a convergent boundary. https://www.learner.org/wp-content/interactive/rockcycle/rockdiagram/ https://geologybase.com/hydrothermal-metamorphism/ https://www.learner.org/wp-https://opentextbc.ca/geology/chapter/7-3-plate-tectonics-and-metamorphism/ Classifications of Metamorphism Effects of Metamorphism on Different Protoliths CLASSIFICATION PROCESS Metamorphic Grade PLUTONIC Plutonic metamorphism takes place at great depths underneath Very Low Grade Low Grade Medium Grade High Grade METAMORPHISM PROTOLITH the Earth’s surface. Since at high static pressure there will be a 150 - 300C 300 - 450C 450 - 550C Above 500C reduction in volume, there is a change in mineral composition and Mudrock Slate Phyllite Schist Gneiss denser minerals are formed during recrystallization. Granite Granite gneiss CLASSIFICATION PROCESS Basalt Chlorite schist Amphibolite (amphibole gneiss) RETROGRADE Also known as regressive metamorphism, this occurs when high- Sandstone No change Little change Quartzite METAMORPHISM temperature metamorphic mineral assemblages change to low Limestone Little change Marble temperature ones. Temperature ranges are approximate https://www.learner.org/wp-content/interactive/rockcycle/rockdiagram/ https://opentextbc.ca/physicalgeologyh5p/chapter/classification-of-metamorphic-rocks/  Textures of Metamorphic Rocks TEXTURE BASED ON FOLIATION FOLIATED (Layered or Banded) Foliated textures are characterized Textures of Metamorphic Rocks by the parallel alignment of mineral grains. This alignment gives the rock a banded or layered appearance. Foliated textures are common in metamorphic rocks that have been subjected to high pressure and/or directed stress. Platy and elongated Mineral grains that are mineral grains having aligned roughly random orientation https://www.geologyin.com/2014/11/metamorphic-rock-textures.html Examples of Foliated Rocks Examples of Foliated Rocks Protolith Metamorphosed Rock Protolith Metamorphosed Rock Shale Slate Siltstone Phyllite SLATY foliation PHYLLITIC foliation https://www.thoughtco.com/shale-rock-4165848 https://geologyscience.com/rocks/metamorphic-rocks/slate/ https://www.thoughtco.com/shale-rock-4165848 https://geologyscience.com/rocks/phyllite/ Examples of Foliated Rocks Examples of Foliated Rocks Protolith Metamorphosed Rock Protolith Metamorphosed Rock Siltstone Schist Granite Gneiss SCHISTOSE foliation GNEISSIC foliation https://www.thoughtco.com/shale-rock-4165848 https://geologyscience.com/rocks/phyllite/ https://opengeology.org/textbook/wp-content/uploads/2017/04/06.1-03-Granite-vs-Gneiss.jpg Textures of Metamorphic Rocks Examples of Non-Foliated Rocks TEXTURE BASED ON FOLIATION NON-FOLIATED Protolith Metamorphosed Rock (Non-Layered) Non-foliated textures are characterized by the absence of Sandstone Quartzite parallel alignment of mineral grains. These rocks are typically more massive and blocky than foliated rocks. GRANOBLASTIC https://www.geologyin.com/2014/11/metamorphic-rock-textures.html https://geologylearn.blogspot.com/2015/03/sandstone.html https://opengeology.org/textbook/wp-content/uploads/2017/04/06.1-03-Granite-vs-Gneiss.jpg Examples of Non-Foliated Rocks Examples of Non-Foliated Rocks Protolith Metamorphosed Rock Protolith Metamorphosed Rock Siltstone Hornsfel Limestone Marble HORNFELSIC https://dinotracksdiscovery.org/supporting/fastfact/siltstone/ https://geologyscience.com/rocks/metamorphic-rocks/hornfels/#jp-carousel-1708 https://dinotracksdiscovery.org/supporting/fastfact/siltstone/ https://www.zmescience.com/feature-post/natural-sciences/geology-and-paleontology/rocks-and-minerals/marble/ Garnet Schist https://opengeology.org/textbook/wp-content/uploads/2016/07/MetaRx3.png  https://opengeology.org/textbook/wp-content/uploads/2016/07/MetaRx3.png Amphibolite Quartzite Soapstone Hornfels Serpentine Anthracite Coal Metaconglomerate Slate Rock Formation Examples of Metamorphic Rocks Formation https://www.flickr.com/photos/jsjgeology/23507935285  Hornfels Rock Formation Schist Rock Formation https://www.thoughtco.com/hornfels-definition-and-formation-4165525 https://geologyistheway.com/metamorphic/schist/ Marble Rock Formation Examples of Metamorphic Rocks and Their Uses https://geologyistheway.com/metamorphic/schist/ Uses of Slate Tiles Uses of Quartzite 1. Flooring Material: 1. For Making Countertops: Slate tiles can be used as a flooring material because of their durability and water resistance. Quartzite is an excellent material for countertops because it is very strong and durable. It is also Slate flooring is a good choice for high-traffic areas and areas that are susceptible to spills heat resistant, making it ideal for use in kitchens. Quartzite countertops can add a beautiful and because the slate can resist staining and is easy to clean. unique look to any kitchen. 2. Roofing Material: 2. Flooring: Slate tiles make for an excellent roofing material because of their durability and water resistance. Quartzite is a popular choice for flooring because it is extremely durable and resistant to scratches Slate tiles can last for over a hundred years, making them a wise investment for any home. Slate and other types of damage. It is also easy to clean and maintain, making it a low-maintenance tiles are also fire-resistant, which is an important consideration for any roofing material. option for busy households. Quartzite flooring can also be very beautiful, with a wide variety of https://civiltoday.com/geotechnical-engineering/geology/405-metamorphic-rock-uses https://civiltoday.com/geotechnical-engineering/geology/405-metamorphic-rock-uses 3. For Making Countertops: colors and patterns to choose from. Slate tiles can make excellent countertops because they are very strong and durable. They are 3. Tiles: also heat resistant, so they can withstand hot pans and dishes being placed on them. Slate Quartzite can be used as a tile in many different ways. It can be used as a floor tile, a backsplash countertops can last for many years with proper care. tile, or even an accent tile in a design. Quartzite is a durable option for a tile and can withstand 4. For Making Tabletops: heavy foot traffic. It is also resistant to staining and fading, making it a good choice for areas that Slate tiles make great tabletops because they are durable and heat-resistant. Slate is a natural might see a lot of use. stone that is easy to clean and maintain. Slate tabletops can add a touch of elegance to any room.  Uses of Quartzite Uses of Marble 4. Roofing Shingles: 1. As a Countertop Or Tabletop: Quartzite can be used as a roofing material because it is weather-resistant and durable. It is also Marble is a popular choice for countertops and tabletops. Marble is heat-resistant and durable, a fire-resistant material, which makes it ideal for use in areas where wildfires are a concern. making it a good choice for areas that see a lot of use. Marble is also easy to clean, which is Quartzite roofing shingles can last for many years with proper maintenance. another plus for areas that see a lot of activity. 5. As a Construction Stone: 2. In Flooring: Quartzite is a popular choice for construction stone due to its durability and weather resistance. Many people choose to use marble as flooring because it is very durable and looks amazing. Not The stone is also easy to cut and shape, making it ideal for a variety of construction projects. only does it look great, but it is also very easy to care for. Simply sweep or vacuum it regularly and 6. In Railroad Ballast: it will be just like new. https://civiltoday.com/geotechnical-engineering/geology/405-metamorphic-rock-uses https://civiltoday.com/geotechnical-engineering/geology/405-metamorphic-rock-uses Quartzite is used in railroad ballast because it is a durable and strong material that can withstand 3. In Sculpture: the wear and tear of train traffic. The quartzite material helps to keep the track in place and One use of marble in sculpture is as a material for statues. Marble is a very durable material, so provides a good foundation for the train wheels to roll on. statues made from it can last for a long time. 7. In Aquariums: The Statue of Liberty was made from marble. While quartzite can be used in aquariums, it is not a common material to use. Quartzite is 4. In Pools and Showers: generally not as smooth as other materials that are used in aquariums, such as glass or acrylic. One use for marble in pools and showers is for its aesthetic value. It can add an extra level of Quartzite can also be more expensive than other materials. beauty and luxury to a space. Additionally, marble is a very durable material, which means it can handle a lot of water and rough treatment. https://www.britannica.com/science/marble-rock