EES 119/219
Lecture 1
Goals of the course: Formation and availability of resources; geologic processes leading to the formation of mineral resources; consequences of the use of mineral and energy resources.
Materials used by humans fall into three categories:
à Building materials and Fertilizers
à Metals
à Fuels
Example fur the annual use of materials (Fig. 3.1 in the textbook)
• Some population numbers:
•
World
6.4x109 = 6,400,000,000
–
–
–
•
•
–
»
UR-UG
4.5x103 = 4500
Transition from qualitative
to quantitative statement
•
‘Lots’
of people use a ‘lot’ of stuff
à a qualitative observation
•
How can
we convert a qualitative statement into a quantitative
statement?
•
Example: annual consumption of iron in the
•
Approach:
–
Combine information on population and annual
use
–
Compare to familiar entity
–
Example annual Fe consumption in USA
Units
•
We will
use Metric (SI) units in this course
•
Length:
1 km = 1000 m
–
1 mile = 1.609 km
–
1ft = 0.3048 m
•
Area: 1
km2 = 106 m2
–
1 acre = 4047 m2
•
Volume:
1 m3 = 1000 L
–
1 gal = 3.8 L
•
Mass: 1
ton = 1000 kg
–
1 lbm = 0.45 kg
•
Temperature:
Degree C
–
Range:
0 oC freezing point; 100 oC boiling point of water
oF = oCx1.8
+ 32
Absolute
T: Degree Kelvin oK = oC - 273
Range of materials used;
Almost all elements find use, most of them come from the crust (Fig. 1.10 in the text)
Quick overview of make-up and history of solid earth
• Earth as part of solar system
• Distribution of elements in
– Solar system
– Whole Earth
– Crust
• Make-up of the crust
– Minerals
– Rocks
• The dynamic Earth
– The geologic cycle
– Plate Tectonics
– History of the Earth
The earth: two scales - microscopic - macroscopic:
Earth is a planet in solar system
specific
characteristics: Fig. 1
size: two groups:
Earth is largest of terrestrial planets, relatively high density (5,500 kg/m3)
Distance to sun:
third closest to sun; elliptical orbit around sun with small differences in the
two axes of ellipse; rotation of earth around axis which is slightly tilted
with respect to plane of rotation around sun - important for energy balance at
surface of earth; causes for change in day and night; seasons; difference in
climatic zones.
Important features of earth: energy flux from sun allows presence of atmosphere, hydrosphere; surface temperature around 10oC (variations between -40oC and 50oC, i.e., between freezing and evaporation of water - water is predominantly in liquid state at surface of earth; relatively small variations in surface temperature (day and night; seasons) - tempered by presence of atmosphere (and hydrosphere) - feed back mechanism
Microscopic scale: Element distribution
Universe (solar system): Observations: Fig. 3
Predominance of hydrogen and helium; decrease in abundance from light to
heavy elements; local maxima and minima; even-numbered elements preferred over
odd-numbered
Potential reasons: building block system: larger nuclei are formed by fusion of
smaller nuclei - probability for forming nuclei decreases with increasing size
stability rules: symmetry prefers even numbered nuclei; 'magic' numbers
(2,8,10,...82,126...): local maximum at 4He; Fe; Pb; local minimum
at Li, Be, B
Earth: Observations: absence of H, He; eight elements make up more than 99%;
dominance of Fe; O; Si
Crust: same elements, but in different proportions, make up 99% of
crust Fig. 4
Explanations: Absence of light elements due to size of earth - too small to
hold on to light elements
differentiation in the earth: different subsections of the earth: core - mantle
- crust
processes active in differentiation:
gravity - heavy elements are dominant in core and compatibility: classification
of elements into siderophile, chalcophile, lithosphile and atmosphile elements
Siderophile: compatible with metallic iron (e.g. Fe; Ni, Au)
Chalcophile: compatible with S (e.g. Cu; Ag; Fe)
Lithophile: compatible with O (e.g. Na; Si; Fe)
Atmophile: gaseous (e.g. noble gases; N)
inner core: siderophile
outer core: chalcophile
mantle and crust: lithophile
atmosphere: atmophile
Makeup
of solid Earth
Elements à Minerals à Rocks
Mineral: A naturally occurring, solid compound with a precise chemical formula and distinct crystal structure
Rock: A solid, cohesive aggregate of one or more minerals.
• Igneous Rocks: formed by solidification of magma
– Volcanicà formed at surface (Basalt)
– Plutonicà formed at depth (Granite)
• Sedimentary Rocks: Rocks formed by weathering, transport and cementation
– Sandstone
– Limestone
• Metamorphic Rocks: Rock changed by temperature and/or pressure
– Granite à Gneiss
– Shale à Schist
à Geologic Cycle Fig. 5
