the mystery of the guangala obsidian: a functional examination through experimental archaeology
DESCRIPTION
… Thousands of years later …TRANSCRIPT
The Mystery of The Mystery of the Guangala the Guangala
Obsidian:Obsidian:
A Functional Examination A Functional Examination Through Experimental Through Experimental
ArchaeologyArchaeology
……Thousands Thousands of years of years later…later…
Nature of ExperimentNature of Experiment Choose artifactsChoose artifacts Create replicas using experimental Create replicas using experimental
methodsmethods Use replicas on various contact materialsUse replicas on various contact materials Use microscopy to examine damage on Use microscopy to examine damage on
artifacts and replicasartifacts and replicas Compare replicas to artifactsCompare replicas to artifacts Draw conclusions about function of the Draw conclusions about function of the
obsidian bladesobsidian blades
History of the GuangalaHistory of the Guangala● Culture flourished from 100 BC-800 AD• Lived in Southern Coastal Ecuador• Artifacts and descendant cultures provide clues• Many questions unanswered
Culture and SocietyCulture and Society
Religion: animisticReligion: animistic Beauty: tattooing, Beauty: tattooing,
body painting, body painting, piercingpiercing
Clothing: cottonClothing: cotton
Lifestyle Revealed Lifestyle Revealed Through ArtifactsThrough Artifacts
GrindstoneGrindstone Agriculture AgricultureFish hooks Fish hooks Fishing FishingForeign resources Foreign resources Trade TradeObsidian Obsidian ??? ???
FlintknappingFlintknapping Process of manufacturing stone Process of manufacturing stone
toolstools– Works because brittle stone Works because brittle stone
fractures with pressurefractures with pressure Obsidian—natural glass material Obsidian—natural glass material
that forms sharp edgesthat forms sharp edges
MaterialsMaterials
SoftSoft MediumMedium HardHardSkinSkinGrassGrass
WoodWoodCartilageCartilage
BoneBoneShellShell
SEM and Light SEM and Light MicroscopesMicroscopes
Light microscope—reflects Light microscope—reflects and refracts lightand refracts light
-shows greater amount of objectshows greater amount of object
SEM—shoots electron SEM—shoots electron beamsbeams
-higher resolution and magnificationhigher resolution and magnification-Preparation may inhibit analysisPreparation may inhibit analysis
The ArchaeologyThe Archaeology
What Makes a Good Match?What Makes a Good Match?
Flake scarsFlake scars Edges: peaks, crevices, Edges: peaks, crevices, etc.etc.
Other: Striations, Pitting, etc. Other: Striations, Pitting, etc.
Meet the Meet the Artifacts!Artifacts!
Artifact 1Artifact 1
SEM x100SEM x100
Flake Scarring: 1 large Flake Scarring: 1 large flake scar and smaller flake scar and smaller irregular flake scars, irregular flake scars, shallow scarsshallow scars
Edges: deep crevices with Edges: deep crevices with rounded/dull fracture rounded/dull fracture peaks, shallow ridgespeaks, shallow ridges
Other: striationsOther: striations22
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11
Artifact 2Artifact 2
SEM x1000
Flake Scarring: shallow but Flake Scarring: shallow but well-defined flake scarswell-defined flake scars
Edges: jagged edges, Edges: jagged edges, rounded peaks between rounded peaks between flake scarsflake scars
Other: deep striations Other: deep striations radiating from flake scars, radiating from flake scars, some crumblingsome crumbling 33
11
22
Artifact 3Artifact 3
SEM x500
Flake Scarring: shallow micro-Flake Scarring: shallow micro-scars (when magnified), scars (when magnified), extremely small, irregular extremely small, irregular distributiondistribution
Edge: irregular, jagged Edge: irregular, jagged damage, edges worn down damage, edges worn down with no distinct peakswith no distinct peaks
Other: percussion ripples, Other: percussion ripples, striationsstriations
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11
22
Meet the Meet the Replicas!Replicas!
Replica 1: WoodReplica 1: Wood
SEM x500SEM x500
Flake Scarring: micro-Flake Scarring: micro-scars visible only under scars visible only under SEMSEM
Edge: minor, irregular Edge: minor, irregular shallow chipping with shallow chipping with small, rounded peakssmall, rounded peaks
Other: frequent, irregular Other: frequent, irregular surface pittingsurface pitting
11
22 33
Replica 2: Grass on Replica 2: Grass on GrindstoneGrindstone
SEM x2000
Flake Scarring: micro-Flake Scarring: micro-scars visible only under scars visible only under SEM SEM
Edges: rounded off dull Edges: rounded off dull edges without peaks edges without peaks
Other: noneOther: none33
11
22
Replica 3: CartilageReplica 3: Cartilage
SEM x2000
SEM x360
Flake Scarring: well-defined Flake Scarring: well-defined flake scars, vary from wide flake scars, vary from wide and smooth to deep and and smooth to deep and narrownarrow
Edges: very deep crevices Edges: very deep crevices with steep fracture peaks, with steep fracture peaks, shallow jagged edge shallow jagged edge fractures with sharp peaksfractures with sharp peaks
Other: damage striationsOther: damage striations 33 44
11
22
Replica 4: SkinReplica 4: Skin Flake Scarring: small, Flake Scarring: small,
shallow irregular flake shallow irregular flake scarsscars
Edges: jagged edges Edges: jagged edges sections with flattened sections with flattened peakspeaks
Other: surface pitting, Other: surface pitting, small striations, edge small striations, edge crumblingcrumbling
SEM x45
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22
Replica 5: BoneReplica 5: Bone
SEM x45
Flake Scarring: irregular, Flake Scarring: irregular, shallow flake scarsshallow flake scars
Edges: low jagged edges Edges: low jagged edges with rounded peakswith rounded peaks
Other: deep striationsOther: deep striations
33
11
22
Replica 6: ShellReplica 6: Shell
SEM x2000
Flake Scarring: regular Flake Scarring: regular shallow flake scarsshallow flake scars
Edges: jagged peaks with Edges: jagged peaks with very deep ridges, rounded very deep ridges, rounded edges, irregular wearedges, irregular wear
Other: crumblingOther: crumbling33
11
22
SEM SEM x100x100
Flake ScarsFlake ScarsComparisons IComparisons I
Replica 4 Replica 4 (Skin)(Skin)Artifact Artifact
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SEM SEM x45x45
Comparisons IIComparisons IIArtifact 2Artifact 2
Replica 3 Replica 3 (cartilage)(cartilage)
SEM x2000SEM x2000 SEM x2000SEM x2000
PeaksPeaks
Comparisons IIIComparisons III
Replica 5 Replica 5 (bone)(bone)Artifact 3Artifact 3
StriationsStriations
Thanks Thanks for for
Playing!Playing!
Experimental VariablesExperimental Variables-TechniqueTechnique-SuppliesSupplies-EnvironmeEnvironmentnt
Conclusions IConclusions IEvidenceEvidence ConclusionConclusion-Wood Wood pitting pitting-Cartilage Cartilage deep deep crevicescrevices-Etc.Etc.
-Different contact Different contact materials create materials create characteristic wear characteristic wear patterns on obsidianpatterns on obsidian
-Artifacts lack Artifacts lack intentional serrationintentional serration-Replicas did not Replicas did not require retouchingrequire retouching
-Retouching not Retouching not required to maintain required to maintain sharp edge on obsidian sharp edge on obsidian bladeblade
Conclusions IIConclusions IIEvidenceEvidence ConclusionConclusion-Comparisons of Comparisons of artifacts and replicasartifacts and replicas
-Nonmatches: grass, Nonmatches: grass, wood, shellwood, shell-Closest matches: skin, Closest matches: skin, cartilage, bonecartilage, bone
-Closest matches to Closest matches to skin, cartilage, and skin, cartilage, and bonebone
-Artifacts most likely Artifacts most likely used in some type of used in some type of butchering (range of butchering (range of animal material)animal material)
Conclusions IIIConclusions IIIEvidenceEvidence ConclusionConclusionObsidian blades are…Obsidian blades are…-RareRare-Acquired through Acquired through tradetrade-Not used intensivelyNot used intensively-Sacred material in Sacred material in other pre-Columbian other pre-Columbian culturescultures
-Blades not used for Blades not used for everyday butchering everyday butchering ritualistic functionritualistic function
Final ConclusionFinal Conclusion
RITUAL RITUAL SACRIFICESACRIFICE
Further experimentation requiredFurther experimentation required