First 540 words of the document:
Introduction Work Metamorphic rocks form when a parent chamber, Mircogranite in the vent and
rock is altered by heat and/or pressure. Rhyolite on the surface.
What Are Rocks and Minerals: *NO MELTING IS INVOLVED!!*
A rock is an aggregate of minerals .e.g. Regional Metamorphism occurs with high Faulting:
granite is composed of the three mineral temperatures and high pressures. A fault occurs when rocks are broken and
mica, quartz and feldspar. Commonly found at Destructive displacement happens.
A mineral has a definite chemical boundaries. Normal (Graity) faults: these types of
composition and regular atomic structure. Contact/Thermal Metamorphism occurs faults are caused by tensional forces
E.g. rock salt (Halite NaCl) with low pressures and high which result in crustal extension. The
temperatures. Commonly found near the tensional forces are usuall found at
Igneous rocks: surface of Constructive boundaries. constructive boundaries.
Igneous rocks form from magma cooling. Reverse faults: these types of faults are
Magma becomes lava on the surface of Volcanic Activity: caused by compressional forces which
the Earth or on the sea floor. Rocks that Basic: these types of volcanoes are results in crustal shortening. The
form on the surface are called extrusive known as shield volcanoes, and are very compressional forces are usually found
while rocks that form underground are low and very wide. The lava is low at destructive boundaries.
called intrusive. viscosity, so it is very runny and has a Wrench/Tear faults: these types of faults
low Si%. E.g. Mauna Loa and Kilauea in are caused by vertical movement. There
Sedimentary rocks: Hawaii. Forms rocks such as Gabbro in is no crustal extension/shortening
Sedimentary rocks are classed into three the magma chamber, Dolerite in the vent involved.
groups. Detrital a parent rock is and Basalt upon the surface.
weathered and/or eroded, transported Cone Volcano: these types of volcanoes
and deposited elsewhere. E.g. Brechia. are known as cone volcanoes, and are
Carbonates all carbonates are very high and very narrow. The lava is
chemical precipitates. E.g. limestone. high viscosity, so it is very sticky, and has
Organic sediments are substances such a high V.E.I. (volcanic explosion index).
as oil, coal and gas. Oil is the remains of Very explosive. Mount Pelee on
marine animals; coal is the remains of Martinique (an island in the Caribbean)
land plants and animals while the gas Composite volcanoes: these types of
methane is formed from the decay of volcanoes are the most deadly of volcano
these remains. types. They are made of alternate layers
Sandstones can form on land as well as of ash and lava and have steep sides
in the sea. built up by eruptions of intermediate
viscosity andesitic lava and explosive
Sand: tephra. Often the lava cools creating a
Sand can acculmate in rivers, beaches plug which blocks the vent resulting in a
and dunes. huge explosion blowing out the plug. E.g.
Mount Saint Helens, Alaska. Forms
Metamorphic Rocks: rocks such as Granite in the magma