Class 3 xid-15234938_1

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Published on March 8, 2014

Author: jasondloxton

Source: slideshare.net

GEL 304: Early History of Resource Use

Modern resource use complicated* & intensive *Foreshadowing to Friday assignment

1.66 Ma China Stone earliest resource use predates human species (>2.5 Ma)

1.1 Ma—India 250 Ka—France By 1.75 Ma hand axes emerge—Stay till 400-250 Ka

Conchoidal fracture 1.1 Ma—India 250 Ka—France Requires selection of rock with particular characteristics, e.g., chert, obsidian, etc.

5,500-2,000 BC, Northwest Africa Last big steps: Compound tools, e.g., arrows, spear, axes World Museum of Man

2,700 BC, Switzerland Neolithic ground stone tools Michael Greenhalgh & Sandstien

2,700 BC, Switzerland Neolithic ground stone tools Michael Greenhalgh & Sandstien

Next step?

Next step? (Detour)

Early use of Decorations

Early use of Red ochre Pinnacle Point, SA: 165 Ka

South Africa 100 Ka

Natural pigments: clays stained by various oxides, e.g., iron oxide = red

(Iron oxide) Yellow ochre (goethite) Umber (Iron and manganese oxide) Limonite

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

Minnesota Not totally true… Copper widely used in many societies, but not ideal

Malachite Azurite Real problem: Most copper occurs bound up in minerals

Malachite Azurite Must be isolated before use = smelting

Malachite Azurite The process of melting ore minerals to separate desired metals from other components ( = reducing reaction)

Which involved this

Granite

Mica Feldspar Quartz Granite

Mica Aluminosilicate minerals Granite Feldspar

Mica Aluminosilicates Feldspar Weather to form clays

What happened after it dried?

Unless heated, fragile & easy to rehydrate

Kaolinite Porcelain

Kaolinite Porcelain 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 Wet clay Slightly better dinosaur 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 Wet clay 3 Al2Si2O5(OH)4

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.

Kitchen oven = ~500F Proper firing required inventing means of moving temps above fires

Hottest part of camp fire Firing temp. for many clays Proper firing required inventing means of moving temps above fires

Earliest firing method Beehive kiln What happens when you put malachite in one of these?

~750C/1400F needed for reduction = no problem for basic kilns!

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