ava-~pp~ \" made of rock-- contains mlnerol-
butle limestone calcite
Look for Surface Forms These are evident in
the physical forms seen on the surface-hills， valleys， cliffs，
and basins. Some forms and structures are associated with
a particular type of rock and can be recognized at a dis-
tance， Knowing forms and structures does more than help
you find rocks and minerals. It aids you in interpreting lhe
landscape， so that you can read dramatic chapters of
the history of the earth， Rock structures are dealt with
under rocks (pp. 121-145). Physical geology treats them
in greater detail.
Lank for Rocks These are the materials of which
the crust of the earth is made. They form the mountains
and underlie the valleys. You see them when they have
been pushed or folded upward or when they jut through
soll to form an outcrop. All minerals occur within rocks，
and often are components of rocks. Rocks include the solid
bedrock and also the unconsolidated debris above it，
called the mantle.
Look for Minerals These are the bricks of which
the earth itself is made. They are inorganic chemical
elements or compounds (some quite complex) found nat-
urally in the earth. Because each is a chemical or a mix-
ture of closely related chemicals， a mineral has fairly
definite and stable properties.
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