EOSC 116 notes
Module A
Lesson 1
Learning Goals
1. Describe the process of the 'Scientific Method'.
2. Distinguish between a hypothesis, a theory and a law.
3. Describe the concept of Earth System Science.
4. Identify the main layers and composition of the Earth and label schematic diagrams
of the Earth's interior.
5. Define the concept of a mineral and a rock as an aggregate of minerals.
6. List and differentiate between the three main types of rocks and divisions within
those main types where appropriate, and place them within a rock cycle framework.
7. Explain the concept of deep time.
Scientific method:
Compile observations, form a hypothesis, test the hypothesis (repeated testing =
hypothesis -> theory), theory -> law, constantly re-examine
Earth system Science = integrated study approach focusing on interaction of parts
Earth = atmosphere, biosphere (life), lithosphere (crust), hydrosphere (water), cryosphere
(ice)
System = anything that can be set apart from another and studied
,Layers of earths’ interior (from out to in):
- Lithosphere
o continental crust (rich in silica minerals), oceanic crust (rich in minerals with
iron) and uppermost mantle
o Fractured into plates
o Low metal content compared to the inner core
- Asthenosphere: upper mantle lubricates movement of lithospheric plates
- Mantle: continuous convection currents
- Outer core (liquid)
- Inner core (solid)
Rocks can essentially be thought of as aggregates (combinations) of minerals.
A mineral is a naturally occurring, crystalline, inorganic substance, with an ordered
arrangement of atoms.
Rock classification:
, 1. Igneous
o Crystals formed from a cooling “melt” (magma or lava)
o Intrusive / plutonic: formed below surface, eventually exposed via weathering
and erosion
▪ Generally forms large crystals
▪ Slow cooling forms larger crystals than faster cooling
o Extrusive / volcanic erupt onto surface eg lava & ash
▪ Generally microscopic crystals
2. Metamorphic
o Altercation of already existing rocks near surface by heat and pressure
(metamorphism)
o Commonly found in convergent margins and areas where magma comes up
and cools (contact metamorphism due to heat)
o Orientation of minerals: aligned linear shape, 90 degrees to force + new
minerals formed
3. Sedimentary
o Formed in a variety of sedimentary environments- oceans, deltas, lagoons,
lakes
o Formed by a number of processes
- Clastic
o Formed from erosion / breaking up of old rocks / transport / deposition of
existing rocks
o Composed of grains / clasts & not crystals, mostly quartz
o More weathering = more uniform and finer grain size
▪ Conglomerates, sandstones, siltstone, claystone
o Soft sediments -> rocks via diagenesis / lithification
▪ Pores between grains are reduced by compaction
▪ Precipitation between remaining grains = cement
- Chemical
o Formed from precipitation of mineral, not directly from biology
o Example:
▪ Evaporites – evaporation water & precipitation salt in the dead see
▪ Banded iron formations
- Biochemical
o Form from precipitation of material produced by organisms such as shells
o Example:
▪ Limestone from coral shells (mainly made of calcite)
▪ Chalk from shells of marine plankton (mainly made of calcite)
, ▪ Coal
▪ Chert from organisms with skeleton made of silica
At A, extrusive igneous rocks form from magma that cools as it reaches the surface of the
Earth. At B, Intrusive plutonic igneous rocks intrude from below the subsurface, cool,
crystallize, and eventually are exposed by erosion at Earth's surface. At C, metamorphic
rocks form as a result of the transformation of an existing rock. At D, sedimentary rock
forms from sediments such as chalk, limestone, dolomite, sandstone, conglomerate, and
shale, that are then compacted and converted to rock by the process of lithification.
Module A
Lesson 1
Learning Goals
1. Describe the process of the 'Scientific Method'.
2. Distinguish between a hypothesis, a theory and a law.
3. Describe the concept of Earth System Science.
4. Identify the main layers and composition of the Earth and label schematic diagrams
of the Earth's interior.
5. Define the concept of a mineral and a rock as an aggregate of minerals.
6. List and differentiate between the three main types of rocks and divisions within
those main types where appropriate, and place them within a rock cycle framework.
7. Explain the concept of deep time.
Scientific method:
Compile observations, form a hypothesis, test the hypothesis (repeated testing =
hypothesis -> theory), theory -> law, constantly re-examine
Earth system Science = integrated study approach focusing on interaction of parts
Earth = atmosphere, biosphere (life), lithosphere (crust), hydrosphere (water), cryosphere
(ice)
System = anything that can be set apart from another and studied
,Layers of earths’ interior (from out to in):
- Lithosphere
o continental crust (rich in silica minerals), oceanic crust (rich in minerals with
iron) and uppermost mantle
o Fractured into plates
o Low metal content compared to the inner core
- Asthenosphere: upper mantle lubricates movement of lithospheric plates
- Mantle: continuous convection currents
- Outer core (liquid)
- Inner core (solid)
Rocks can essentially be thought of as aggregates (combinations) of minerals.
A mineral is a naturally occurring, crystalline, inorganic substance, with an ordered
arrangement of atoms.
Rock classification:
, 1. Igneous
o Crystals formed from a cooling “melt” (magma or lava)
o Intrusive / plutonic: formed below surface, eventually exposed via weathering
and erosion
▪ Generally forms large crystals
▪ Slow cooling forms larger crystals than faster cooling
o Extrusive / volcanic erupt onto surface eg lava & ash
▪ Generally microscopic crystals
2. Metamorphic
o Altercation of already existing rocks near surface by heat and pressure
(metamorphism)
o Commonly found in convergent margins and areas where magma comes up
and cools (contact metamorphism due to heat)
o Orientation of minerals: aligned linear shape, 90 degrees to force + new
minerals formed
3. Sedimentary
o Formed in a variety of sedimentary environments- oceans, deltas, lagoons,
lakes
o Formed by a number of processes
- Clastic
o Formed from erosion / breaking up of old rocks / transport / deposition of
existing rocks
o Composed of grains / clasts & not crystals, mostly quartz
o More weathering = more uniform and finer grain size
▪ Conglomerates, sandstones, siltstone, claystone
o Soft sediments -> rocks via diagenesis / lithification
▪ Pores between grains are reduced by compaction
▪ Precipitation between remaining grains = cement
- Chemical
o Formed from precipitation of mineral, not directly from biology
o Example:
▪ Evaporites – evaporation water & precipitation salt in the dead see
▪ Banded iron formations
- Biochemical
o Form from precipitation of material produced by organisms such as shells
o Example:
▪ Limestone from coral shells (mainly made of calcite)
▪ Chalk from shells of marine plankton (mainly made of calcite)
, ▪ Coal
▪ Chert from organisms with skeleton made of silica
At A, extrusive igneous rocks form from magma that cools as it reaches the surface of the
Earth. At B, Intrusive plutonic igneous rocks intrude from below the subsurface, cool,
crystallize, and eventually are exposed by erosion at Earth's surface. At C, metamorphic
rocks form as a result of the transformation of an existing rock. At D, sedimentary rock
forms from sediments such as chalk, limestone, dolomite, sandstone, conglomerate, and
shale, that are then compacted and converted to rock by the process of lithification.
