Metamorphic Rocks Pages

Formed by Heat Pressure Hot fluids Caused by Plate tectonics Igneous intrusion Deeper burial

Change occurs by Recrystallization Often lose H 2 O or CO 2 Mechanical deformation No minerals are melted

Two types Two types we will mention Regional or Barrovian Contact

Regional Metamorphism Occurs over lg areas -state size Cause— plate tectonics

Contact Metamorphism Rocks that are in contact with hot magma or lava often become metamorphosed. magmalava

The metamorphic rock that develops depends upon the parent rock What is formed from limestone? What is formed from quartz sandstone?

Two Types Two Types of meta rx Foliated Non-foliated foliated

Foliated rocks Increasing grades of metamorphism with increasing heat and pressure Slate-Phyllite-Schist-Gneiss

Slate–Phyllite–Schist--Gneiss

Slate-Phyllite-Schist-Gneiss ?????????????????????????????? What rock would come before slate? shale What kind of rock is it? sedimentary What happens after gneiss? (more heat and pressure) melting What kind of rock is it? After cooling it is igneous

Slate Very flat--fissile Used for pool tables Roofing they can break along planes of weakness (cleavage) where soft, platy minerals like mica and chlorite grow during metamorphism

Phyllite Shiny, wavy surface Surface has more sheen than slate

Schist Flakes of mica visible on surface Often has larger mineral, like garnet schist

GneissGneiss— alternating layers of dark and light minerals Minerals align perpendicular to direction of force

Non-foliated formed around igneous intrusions where the temperatures are high but the pressures are relatively low and equal in all directions (confining pressure).

Marble Marble forms from metamorphosed limestone CaCO 3 so it fizzes

Uses of Marble Buildings like the Taj Mahal Countertops Tombstones Statues

The Pieta—Michelangelo

Many old tombstones are made of marble or limestone. Rocks made of calcium carbonate, such as these tombstones, are readily dissolved by rainwater.

Marble disintegrates Marble surfaces exposed to rain develop a rough "sugary" texture because the calcite grains are loosened as the edges dissolve in the rain water. Column capital volute, Jefferson Memorial, Washington, D.C.

Acid Rain Distilled water, which contains no carbon dioxide, has a neutral pH of 7. "Clean" or unpolluted rain has a slightly acidic pH of 5.6, because carbon dioxide and water in the air react together to form carbonic acid, a weak acid. Around Washington, D.C., however, the average rain pH is between 4.2 and 4.4. sulfur oxides and nitrogen oxides, react with water in the air to form strong acids (like sulfuric and nitric acid). The main sources of these pollutants are vehicles and industrial and power-generating plants. In Washington, the main local sources are cars, trucks, and buses.

Quartzite Forms from metamorphosed sandstone Often sugary looking Very hard, since it is made from quartz

The metamorphic rock depends on the parent rock

Metamorphic Rock Lab Separate rocks into foliated and non foliated Arrange foliated rocks by increasing grade of metamorphism I.e.. Slate, phyllite, schist, gneiss Test non-foliated rocks to discover which is marble which is quartzite Hint: marble is metamorphosed limestone (calcite)

For each rock test: >6 no Sugary looking quartzite

Study Guide Use your notes!!!!! Get on Moodle to reviewMoodle

Contact Metamorphism Rocks that are in contact with hot magma or lava often become metamorphosed. magmalava

The metamorphic rock that develops depends upon the parent rock

Sediment Metamorphic rock Heat and pressure Sedimentary rock Cementation & compaction Heat and pressure Weathering, erosion and deposition Melting Weathering, erosion and deposition WED igneous magma Cooling and crystallization