Understanding Isostasy's Role in Mountain Formation and Erosion, Slides of Geology

Download Understanding Isostasy's Role in Mountain Formation and Erosion and more Slides Geology in PDF only on Docsity! 1 GY 111: Physical Geology Lecture 30: Mountain Building 1: Isostacy and Thrusting Last time… A) Metamorphic Facies B) Shock Metamorphism C) Retrograde Metamorphism Last bit about Metamorphism Metamorphic facies The Problem: Parent rock High Grade Metamorphic rock Shale Rhyolite (granite) Gneiss Granite The Solution: Consider conditions of Pressure and Temperature rather than parent rock composition Temperature Pr es su re Low High High Pa rti al m el tin g Zeolite facies Hornfels facies G re en sc hi st A m ph ib ol ite G ra nu lit eBlue schist Eclogite facies slate phyllite schist gneiss Metamorphic facies Temperature Pr es su re Low High High Pa rti al m el tin g Burial curve (prograde metamorphism) Metamorphic facies Temperature Pr es su re Low High High Pa rti al m el tin g Metamorphic facies Retrograde metamorphism Docsity.com 2 Today’s Agenda Mountain Building 1 A) Distribution of mountain belts (the return of plate tectonics) B) Isostasy and the Rock Cycle (again) C) Thrust Faults in the Rockies (movie) Web notes: 30 Mountain Belts Mountain Belts Mountain Belts Mountain Belts Old Mountains New Mountains Mountain Belts Southern Transect Northern Transect Docsity.com 5 Isostasy (Isostacy) Isostasy will continue as long as continental roots still exist. Once isostasy stops, the mountains will get completely eroded away (it takes about 500 MA for this to occur). The Rock Cycle Mountain belts involve all types of rocks and minerals and all types of geological processes. For example, consider the Himalayan Mountains The Rock Cycle The Rock Cycle The Rock Cycle So in conclusion, mountain building (and mountain erosion) are excellent examples of the rock cycle in action. Incidentally, mountain building is itself, cyclic (see you in GY 112!) Thrust Faulting in the Rockies Movie time Docsity.com 6 Today’s Homework 1. Start Prepping for the Final Exam Next Time 1. Mountain building part 2: Appalachians Docsity.com