Elements, Rocks, Minerals and
The Structure of the Earth
The Lithosphere is made up of elements, minerals, and
rocks.
Elements – cannot be broken apart by chemical or
physical means. Of the 92 elements found in nature only
8 of them form most of the Earth’s crust (i.e. carbon,
Silicon)
Minerals – inorganic compounds of one or more elements
found naturally in the lithosphere. Minerals are formed
as a result of naturally occurring geologic processes.
 Minerals are usually 2 or more elements combined:
(Si Silicon) and (O Oxygen) combined make Silicon
Dioxide or Quartz in the crust
Rocks – several minerals combined together. Granite =
Quartz + Mica + Feldspar.
Rock Types
1) Igneous Rock – created from molten rock. Magma is
beneath the surface and lava flows on top of the surface.
 Extrusive Igneous Rocks –
formed from volcanic
eruptions. Obsidian
resembles black glass
and is formed when
lava cools very fast so
that no crystals form.
 Intrusive Igneous Rocks –
Molten rock that cools and
solidifies deep within the
lithosphere. They are called
plutonic rocks and they reach
the surface through millions
of years of erosion.
***Igneous Rocks can be classified by how quickly they
are formed:
 Rapid Cooling – Fine Texture
 Slow Cooling – Coarse Texture
2) Sedimentary Rocks – Rocks that form in layers from
eroded material. There are 3 types of sedimentary
rocks.
 (1) Clastic Sedimentary – Formed when
accumulations of stones and smaller
pieces of weathered rock are cemented, through
pressure, together (eg. Sandstone)
 (2) Chemical Sedimentary – The formation of
rock through natural chemical reactions and
cementing. (eg. Gypsum – Water evaporates
leaving behind salt to combine with other rock)
 (3) Biogenetic Sedimentary – Formed from living
organisms and sea creatures cementing as rock.
eg. Limestone CaCO3 (Former Sea Shells), Coal (C)
(Accumulation of dead plant matter)
3) Metamorphic Rocks – Rocks that have undergone
change in the form of composition, structure, and
texture as a result of extreme heat and pressure in
crust. (eg. Limestone becomes marble, shale to slate)