1 / 14

Metamorphic Rocks

Metamorphic Rocks. “If something is gneiss, don’t take it for granite.”. Metamorphic Agents. Pressure (>1,000 times atmospheric pressure) Temperature (>300 degrees C) Chemical Fluids (mineral saturated hot water). Metamorphic Environments. Contact (thermal) – intrusion by magma

edda
Télécharger la présentation

Metamorphic Rocks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Metamorphic Rocks “If something is gneiss, don’t take it for granite.”

  2. Metamorphic Agents • Pressure (>1,000 times atmospheric pressure) • Temperature (>300 degrees C) • Chemical Fluids (mineral saturated hot water)

  3. Metamorphic Environments • Contact (thermal) – intrusion by magma • Hydrothermal – ion-rich hot water circulates through cracks • Mountain Building – regional metamorphism

  4. Metamorphic Changes -Rocks adjust to new conditions by: • Changes in texture • Changes in mineralogy

  5. Changes in Texture • Compaction • Recrystallization - may cause • Foliation • Lineation

  6. Changes in Minerology • Recrystallization – small crystals reform into larger crystals of the same mineral • Formation of new minerals – elements recombine to form new minerals • Garnet, Chlorite and others found only (or mostly) in metamorphic rock

  7. Grades of Metamorphosis • Low Grade – Low temperature and pressure results in slate and phyllite • “Rock cleavage” in slate • Foliated • Fine grained • Slate looks dull, phyllite is shiny

  8. Grades of Metamorphosis (cont.) • Intermediate Grade – higher temperatures and pressures than Low Grade • Schist • Foliated • Mica, garnet

  9. Grades of Metamorphosis (cont.) • High temperatures and pressures • Gneiss and Migmatite • Dark & light banding of mica (dark), quartz & feldspar (light)

  10. Slate – parent rock is shale (sedimentary) Phyllite – parent rock is slate Schist – parent rock is phyllite Gneiss – parent rock is schist Migmatite – parent rock is gneiss Foliated Metamorphic Rock Sequence

  11. Non-Foliated Metamorphic Rocks & Their Parent Rocks • Marble – Parent rock is limestone or dolostone (calcite, reacts with acid) • Quartzite – Parent rock is sandstone • Anthacite – Parent rock is bituminous coal • Hornfels – Parent rock is any rock type

  12. Metamorphic Rock Dichotomous Key Proceed to Dichotomous Key Activity

  13. View in slide show, then click to view: Dichotomous Metamorphic Key

More Related