Lithic RawMaterial Lithic Raw Material by yfr24536

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									Lithic Raw Material
                    Raw Material
• Best quality materials:
   – Micro- or crypto-crystalline – the minerals are not
                            eye,
     visible with the naked eye or amorphous – no
     mineral structure.
   – Fracture concoidally – the percussion force moves
                          evenly,
     through the material evenly in a cone shape that
     spreads out as the force moves down from the point
     of impact.
                                        inclusions.
   – Have a single mineralogy with few inclusions
• Identification of raw materials is important
  because it is linked to
   –   Acquisition spots
   –   Trade networks
   –                  gy
       Lithic technology
   –   Economics
                    Raw Material Types
•   Silicate Mi
    Sili t Mineralsl
    SiO2 tetrahedron that is negatively charged and must join with another
    element. They have extracrystalline water.
     – Massive quartz
           Precipitated mineral growth of SiO2
         • P i i      d i     l      h f SiO2.
     – Chert
         • 99% silica and less than 1% extracrystalline water.
         • Forms as a precipitate, replacement, or re-solution and deposition.
         • Generally opaque.
                     opaque
     – Jasper
         • Higher amount of other elements joined to the silicate mineral, which gives it a more
           colourful and banded look.
         • Type of chert.
       Chalcedony
     – Ch l d
         • Between 1 and 9% extracrystalline water.
         • Radiating or fibrous nature in thin section.
         • Higher translucency.
     – Opal
         • Greater than 10% extracrystalline water.
         • Amorphous silicate.
         • Replacement of organic material in the fossilization process.
     – Silicified woods
         • Replacement of wood by opal or chalcedony.
                    Raw Material Types
•   Igneous Rocks
    I         R k
    Intrusive and extrusive rock formed from volcanic magma or lava
    respectively. The faster the cooling process the finer the minerals.
     – Granite (slow cooling with large crystals. Intrusive)
     – Obsidian (rapid cooling. Extrusive. Crypto-crystalline)
     – Basalt (rich in ferromagnesian minerals. Extrusive. Fine grained crystals)
•   Sedimentary Rocks
                  y     pressure of overlying deposits.
     Rock formed by the p                y g p
     –   Siltstone (lithified silt particles)
     –   Mudstone (lithified clay particles)
     –   Sandstone (lithified sand particles).
     –        g            (
         Conglomerate (lithified g   gravels).)
     –   Limestone and dolomite (lithified carbonates)
•   Metamorphic Rocks
    Altered rock via pressure and heat.
     – Argillite (weakly metamorphosed shale, siltstone and mudstone)
     – Slate (moderately metamorphosed shale, siltstone and mudstone)
     – Silicified siltstone/mudstone (through metamorphous silica is deposited or
       replaces other elements)
                  (         p
     – Quartzite (metamorphosed sandstone via silica cementation)  )
     – Gneiss (banding produced due to differential pressures created when different
       textural minerals (granular vs prismatic) undergo the metamorphic process)
                                  Argillite
•   Definition
     – Weakly metamorphosed shale.
•   Material Colour
     – Dark red
     – Gray / green
•   Light green / gray (Kootenay)
•   Texture
     – Fine grained to very fine grained
•   Translucency
        p q
     – Opaque
•   Luster
     – Dull, Vitreous, Resinous
•   Sources
       Reddish     illit           l        in
     – R ddi h argillites commonly occur i gravel d       it throughout
                                                   l deposits th   h t
       southern Alberta and northern Montana. Large bedrock outcrops in the
       Rockies are likely the original source.
     – Green/gray argillites have been located in southeastern BC,
                                             Montana.
       southwestern Alberta and northern Montana
     – Kootenay Argillite comes from the Kootenay Lakes in southeastern BC.
                            Quartzite
•   Definition
    – Metamorphosed sandstone.
    – The individual sand grains of sandstone
                       cemented.
      rocks are firmly cemented
    – Generally homogeneous.
•   Material Colour
    –   Reds                             g       y
                          Quartzites are generally one colour
    –   Grays
    –   Greens
    –   Browns
•   Texture
    – Course to very course, medium to fine grained
•   Translucency
       p q
    – Opaque
•   Luster
    – Dull, Vitreous
•   Sources
    – Alluvial and glacial deposits throughout southern Alberta and northern
      Montana.
                                Basalt
•   Definition
    – Fine grained extrusive igneous rock.
•   Material Colour
    – Black to Dark gray
•   Texture
    – Course to fine grained
    – Similar to black chert but can be distinguished by the presence of small
      volcanic glass shards and vesicles.
•   Translucency
    – Opaque
•   Luster
    L t
    – Dull, Vitreous
•   Sources
                                                    Montana,
    – Tertiary basalts could have come from central Montana Washington or
      BC quarries. Coarser gray basalt comes from the Midvale Basalt Quarry
      in western Idaho.
                              Obsidian
•   Definition
    – Igneous, extrusive fast cooling rock.
•   Material Colour
    –   Black to Dark gray
    –   Orange
    –   Green
    –   Gray to white ash inclusions
•   Texture
    – Very fine grained (glass-like)
    – Translucency
    – Opaque to highly translucent
•   Luster
    – Vitreous
•   Sources
    – Volcanic deposits in BC, Washington, Oregon, and Yellowstone.
      Sourceable based on mineralogy.
                      Massive Quartz
•   Definition
    – Coarsely crystalline quartz silicate.
•   Material Colour
    – Clear
    – White
    – Occasional tinges of pink, yellow or black
•   Texture
    – Quartz minerals      Fractures unevenly
•   Translucency
    – Highly translucent
•   Luster
    – Vitreous
•   Sources
                                  Montana.
    – Quarries in southern BC and Montana
                  Brown Chalcedony
•   Definition
    – Chalcedony silicate – opaque to slightly translucent variety
      of silica that has replaced and replicated the modular and
                            peat.
      cellular structure of peat
•   Material Colour
    – Brown
    – May have white patina
•   Texture
    – Very fine grained
    – Knife River Flint can have pieces of peat (plant microfossils).
•   Translucency
    – Moderate to high
•   Luster
    – Vitreous
•   Sources
    – Knife River Flint quarries in North Dakota,
      which are secondary alluvial deposits.
    – Unknown other sources?
Knife River Flint Quarries, North Dakota
Knife River Flint Quarries, North Dakota
Knife River Flint Quarries, North Dakota
Knife River Flint Quarries, North Dakota
Knife River Flint Quarries, North Dakota
Knife River Flint Quarries, North Dakota
Knife River Flint Quarries, North Dakota
                           Avon Chert
•   Definition
    – Chert silicate – opaque. Silicified marl with diatoms.
•   Material Colour
    – White to light gray patinated surface
    – Brown
    – White to cream
•   Texture
    – Very fine grained
•   Translucency
    – Opaque
•   Luster
    – Dull
•   Sources
                  Missoula, Montana.
    – Quarry near Missoula Montana
                      Montana Cherts
•   Definition
    – Chert silicate – opaque variety.
•   Material Colour
    –   Yellow             Solid and mottled colours
    –   Brown              Dendrites
    –   Red                Inclusions
    –   Dark gray to black
    –   Can be patinated as well
•   Texture
    – Very fine grained
•   Translucency
    – Opaque
•   Luster
    – Vitreous
•   Sources
    – Montana.
                          Black Chert
•   Definition
    – Chert silicate – opaque variety.
•   Material Colour
    – Black
    – Dark gray
•   Texture
    – Fine grained
•   Translucency
    – Opaque
•   Luster
    – Dull to resinous
•   Sources
    – Alluvial deposits and from the Banff Formation of the Lower
      Mississippian.
      Mississippian
                   Etherington Chert
•   Definition
    – Chert silicate – opaque variety.
•   Material Colour
    – White to light gray patinated surface
    – Grays                – Browns
    – Blues                – Reds
•   Texture
    – Fine to medium grained
    – Distinct sugary texture
    – Flake scars can by milky fish scale-like
•   Translucency
    – Opaque to slightly translucent
•   Luster
    – Vitreous to dull
•   Sources
    – Modules in a limestone or dolomite matrix in the Livingston Range in the
      Rockies of southern Alberta.
    – Very similar to chert from the Bear Paw Mountains in northern Montana.
                         Petrified Wood
•   Definition
    – Silicate created by the replacement of the cellular structure of wood by
      opal or chalcedony.
•   Material Colour
    – Brown
    – Dark gray
•    e tu e
    Texture
    – Fine grained
    – Clear banding tending to platy layers of replacement silica
•   Translucency
      Opaque to slightly t
    – O                    l    t
             t li htl translucent
•   Luster
    – Dull to Vitreous
•   Sources
    – Relatively common in till and alluvial
      deposits throughout southern Alberta,
      Saskatchewan and northern Montana.
                   Swan River Chert
•   Definition
    – Chert silicate – opaque variety. Usually heat treated.
•   Material Colour
    – White
    – Light to medium gray
    – Brown
•   Texture
    – Fine to very fine grained
    – Vugs (small, irregularly shaped holes that may be filled with quartz
      crystals)
      Microfossil i l i
    – Mi f                    (feather-like    dl lik )
                il inclusions (f th lik or needle-like)
•   Translucency
    – Slightly to moderately translucent
•   Luster
    – Dull to vitreous
•   Sources
    – Swan River valley in Manitoba. Secondary deposits of cobbles in alluvial
        d l i l deposits th
      and glacial d              h t     th    Alberta, Saskatchewan and
                        it throughout southern Alb t S k t h             d
      possibly northern Montana and Iowa. It is also found in North and South
      Dakota and Minnesota. Bedrock source is west-central Manitoba.
              Top of the World Chert
•   Definition
    – Chert silicate – opaque variety.
•   Material Colour
    – White                – Banding
    – Light to dark gray   – Speckling
    – Bluish tinge         – Mottling
•   Texture
    – Very fine grained
    – Microfossils (some partly or completely replaced by slica)
•   Translucency
    – Opaque to moderately translucent
•   Luster
    – Vitreous to resinous
•   Sources
    – High plateau (2,134 m asl) in the Rocky Mountains of southeastern BC.
      Cores are small due to the highly bracciated nature of the source
      lenses.
                          Banff Chert
•   Definition
    – Chert silicate – opaque variety.
•   Material Colour
    – Dark gray
    – Black
    – Obvious laminate banding
•   Texture
    – Fine grained
    – Microfossils (some partly or completely replaced by silica)
•   Translucency
    – Opaque
•   Luster
    – Dull to resinous
•   Sources
    – Outcrops of the Lower Mississipian Banff Formation in the Rocky
      Mountains of southern Alberta and northern Montana.
                         Porcellainite
•   Definition
    – Fused silicate of chert and clay and carbonaceous matter that occurs in
      the roof and floor of burned coal seams.
•   Material Colour
    –   Medium to dark gray        – Banding in some specimens
    –   Yellow
    –   Black
    –   Red
•   Texture
    – Very fine grained
      Vesicles                i     l i l i
    – V i l are common as are irregular inclusions
•   Translucency
    – Opaque
•   Luster
    – Dull to Vitreous
•   Sources
    – Throughout southern Alberta in
               ith
      contact with coal seams or in
      secondary alluvial deposits.
                   Silicified Siltstone
•   Definition
    – Silt particles of various minerals which have hardened through
      metamorphosis. Silt particles have been impregnated with high amounts
                                 together.                homogeneous.
      of silica which hold them together Generally highly homogeneous
•   Material Colour
    – Medium to dark gray         – Banding in some specimens
    – Browns
•   Texture
    – Fine grained
    – Vesicles are common as are irregular inclusions
•   Translucency
    – Opaque
•   Luster
    – Dull
•   Sources
    – From the Banff Formation throughout the Rocky Mountains of southern
      Alberta and Montana. Also a quarry near Creston, BC. Elk River
      silicified siltstone? Siltstone cobbles are commonly found in alluvial
      deposits in the drainages of the Rockies.
 Archaeological Materials:
Laboratory Processing and
         Analysis

								
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