class 3 xid-15234938_1
TRANSCRIPT
GEL 304: Early History of Resource Use
Modern resource use complicated* & intensive
*Foreshadowing to Friday assignment
1.66 MaChina
Stone earliest resource usepredates human species (>2.5 Ma)
By 1.75 Ma hand axes emerge—Stay till 400-250 Ka
250 Ka—France 1.1 Ma—India
Requires selection of rock with particular characteristics, e.g., chert, obsidian, etc.
250 Ka—France 1.1 Ma—India
Conchoidalfracture
Last big steps: Compound tools, e.g., arrows, spear, axes
5,500-2,000 BC, Northwest Africa
World Museum of Man
2,700 BC, Switzerland
Neolithic ground stone toolsMichael Greenhalgh & Sandstien
2,700 BC, Switzerland
Neolithic ground stone toolsMichael Greenhalgh & Sandstien
Next step?
Next step?(Detour)
Early use of
Decorations
Early use of
Pinnacle Point, SA: 165 Ka
Red ochre
South Africa100 Ka
Natural pigments: clays stained by various oxides, e.g., iron oxide = red
(Iron oxide)Umber
(Iron and manganese
oxide)
LimoniteYellow ochre(goethite)
France: ~32,000 years
Metals
Gold & copper earliest used metals (~15,000 ago)
Metals most likely to occur in native state
Bulgaria (~4,500 BC)
Earliest uses likely decorative
Bulgaria (~4,500 BC)
Why?
Both gold and copper ductile and malleable
Too soft to be much good
Not totally true… Copper widely used in many societies, but not ideal
Not totally true… Copper widely used in many societies, but not ideal
Minnesota
AzuriteMalachite
Real problem: Most copper occurs bound up in minerals
AzuriteMalachite
Must be isolated before use
= smelting
AzuriteMalachite
The process of melting ore minerals to separate desired metals from other components ( = reducing reaction)
Which involved this
Granite
Granite
Mica
Quartz
Feldspar
Granite
Mica
FeldsparAluminosilicateminerals
Weather to form clays
Mica
FeldsparAluminosilicates
What happened after it dried?
Unless heated, fragile & easy to rehydrate
Kaolinite Porcelain
Kaolinite Porcelain
3 Al2Si2O5(OH)4
Wet clay
3 Al2Si2O5(OH)4
Let dry
Wet clay
3 Al2Si2O5(OH)4
Let dry
Wet clay
3 Al2Si2O5(OH)4
Heat
Wet clay
3 Al2Si2O5(OH)4
Heat
Slightly better dinosaur
Wet clay
3 Al2Si2O5(OH)4
Cook the crap
Wet clay
3 Al2Si2O5(OH)4
Cook the crap
Wet clay
3 Al2Si2O5(OH)4
Cook the crap
Al6Si2O13
+ 4 SiO2
+ 6 H2O
Cook the crap
3 kaolinite --> mullite + 4 silica + 6 water
What does this have to do with copper?
Early firing 9,000 BC
First fabricated new materials.Use = housing, water, storage, etc.
Proper firing required inventing means of moving temps above fires
Kitchen oven = ~500F
Proper firing required inventing means of moving temps above fires
Hottest part of camp fireFiring temp. for many clays
Beehive kiln
What happens when you put malachite in one of these?
Earliest firing method
~750C/1400F needed for reduction
= no problem for basic kilns!
