EAR 110 1st Edition Lecture 15Outline of Previous Lecture:I. Force and stressII. Strength of rockIII. How rocks respond to force and stressIV. Types of fracturesV. Stresses that form jointsVI. Describing faultsVII. FoldsOutline of Current Lecture:I. ReviewII. Rock CleavageIII. Rock FabricsIV. Metamorphism of Sedimentary RocksV. Metamorphism of Igneous RocksVI. Causes of MetamorphismVII. Types of MetamorphismVIII. Processes During MetamorphismChapter 8: Metamorphic Rocks ContI. Reviewa. In brittle, upper portion of crust (highest temp 300C) types of metamorphism:i. Reverse fault (from compression)ii. Normal fault (from tension)iii. Strike-slip fault (from shear stress)iv. Anticline, syncline (folding)II. Rock Cleavagea. NOT mineral cleavageb. Is the physical and chemical change in rock due to stresses; splittingi. Example: pencil cleavage – low P/T environment in shaleii. Example: crenulation cleavage – higher P/T - more mass transportIII. Rock Fabricsa. Rocks have textures; different metamorphic featuresi. Foliation – layering you see in rocks; fine scaled layering of metamorphic minerals1. Example: schisosity, gneissic (alternating quartz rich and iron rich bands), flattened pebblesii. Lineation – lines; linearly arranged minerals1. Example: stretched crystals, shearing marks, oriented mineralsiii. Other – preserved features (ripples), shear zone, folded pebblesIV. Metamorphism of sedimentary rocksThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.a. Order of increasing metamorphism of shale: slate schistgneissb. Sandstone becomes quartzitec. Limestone becomes marbleV. Metamorphism of igneous rocksa. Basalt or andesite become green schistb. Granite becomes gneissVI. Causes of metamorphisma. Pressureb. Temperaturec. Tectonic Stressd. FluidsVII. Types of Metamorphisma. Two Main typesi. Contact – magma body intrudes into rock and at edges of the body, it changes the host rockii. Regional – more extensive; causes: burial, subduction, heat, and hot fluidsb. Metamorphic Gradei. Contact: low pressure, high temperatureii. Regional: continental conditionsiii. Subduction zone: high pressure, low temperatureVIII. Processes during metamorphisma. Chemicali. Recrystallizationii. Pressure solution – interlocking crystals formiii. Remobilization (rigid body rotation)b. Physicali. Deformation (smashing)ii. Rotationiii.