Download Rocks and rock cycle

Rocks and rock cycle
By: Rashid And Andrew
Introduction
 Rock is the most and abundant
material on earth.
 When rocks are examined it consists
of smaller crystals or minerals.
 Minerals- are chemical compounds
with its own composition and physical
properties
 Texture- the size, shape, and
arrangement of its minerals.
Basic Rock Types
 Igneous Rocks
 Sedimentary Rocks
 Metamorphic Rocks
Igneous Rocks
 This rock forms when molten rock called magma cools
and solidifies. Magma is melted rock that can form at
various levels deep within the earths crust and upper
mantle.
 Igneous rocks are divided into two types :
 Intrusive rocks - Coarse grained igneous rocks that
form far below the surface are called intrusive rocks.
 Extrusive rocks – igneous rocks that form at earths
surface are described as extrusive rocks.
Sedimentary Rocks
 Sedimentary Rocks- accumulate in layers at earth’s
surface. They are materials derived from preexisting
rocks by the process of weathering.
 Weathering- Physically break rock into smaller pieces
with no change in composition. Other weathering
processes decompose rocks and that chemically
change minerals into new minerals and into
substances that readily dissolve in water.
 Beds- Are products of weathering which are usually
transported by water, wind, or glacial ice to sites of
deposition where they become flat layers.
 Sediments are commonly turned into rock or lithified.
 Compaction- takes place as the weight of overlying
materials squeezes sediments into denser masses.
……….
 Cementation- occurs as water
containing dissolved substances
percolates through open spaces
between sediment grains.
 Detrital Sediments- Sediments that
originate and are transported as solid
particles.
 Detrital sedimentary Rocks- Rocks
that are formed by Detrital
sediments.
Metamorphic rocks
 These rocks are produced from
preexisting igneous, sedimentary, or
even other metamorphic rocks. Every
metamorphic rock has a parent rock –
the rock from which it formed.
Metamorphic means to change form.
 During metamorphism, the rock must
remain essentially solid.
Three settings of metamorphic
rocks :
 Thermal – change is driven by a rise in temperature
within the host rock surrounding an igneous intrusion.
 Hydrothermal – it involves chemical alterations that
occur as hot, ion rich water circulating through
fractures in rocks.
 Regional – during mountain building, great quantity of
deeply buried rocks are subjected to the directed
pressures and high temperatures associated with large
scale deformation