Metamorphic RocksPPT

14 4 0
  • Loading ...
1/14 trang

Thông tin tài liệu

Ngày đăng: 30/11/2016, 16:08

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 • Hydrothermal – ion-rich hot water circulates through cracks • Mountain Building – regional metamorphism Metamorphic Changes Rocks adjust to new conditions by: • Changes in texture • Changes in mineralogy Changes in Texture • Compaction • Recrystallization - may cause – Foliation – Lineation 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 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 Grades of Metamorphosis (cont.) • Intermediate Grade – higher temperatures and pressures than Low Grade – Schist • Foliated • Mica, garnet Grades of Metamorphosis (cont.) • High temperatures and pressures – Gneiss and Migmatite • Dark & light banding of mica (dark), quartz & feldspar (light) Foliated Metamorphic Rock Sequence • • • • • 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 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 Metamorphic Rock Dichotomous Key Proceed to Dichotomous Key Activity View in slide show, then click to view: Dichotomous Metamorphic Key [...]...Foliated Metamorphic Rock Sequence • • • • • 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 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 Metamorphic Rock Dichotomous Key Proceed to Dichotomous Key Activity View in slide show, then click to view: Dichotomous Metamorphic Key
- Xem thêm -

Xem thêm: Metamorphic RocksPPT , Metamorphic RocksPPT , Metamorphic RocksPPT

Gợi ý tài liệu liên quan cho bạn

Nạp tiền Tải lên
Đăng ký
Đăng nhập