if you want to cut down a tree… or build a canoe… or wage war…. or scrape meat out of a...
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If you want to cut down a tree… Or build a canoe… Or wage war…. Or scrape meat out of a coconut… Or cut meat from a pig… You need to make tools. Lacking metal, (pre-contact) Polynesians made tools out of stone. Figures from Encyclop é die de la Polyn é sie. - PowerPoint PPT PresentationTRANSCRIPT
If you want to cut down a tree…
Or build a canoe…
Or wage war….
Or scrape meat out of a coconut…
Or cut meat from a pig…
You need to make tools
Lacking metal, (pre-contact)Polynesians made tools out of stone
Figures fromEncyclopédie de la Polynésie
Is one stone as good as another?
• Vesicular pāhoehoe lava makes a lousy adze, but an excellent grinding or
polishing stone
• Coarse-grained rocks make crumbly adzes, but excellent sinkers and lures
• Glass is best for cutters and scrapers (but hard to find in large pieces)
What makes a good source rock for making an adze?
1. Fine-grained, with even sized grains is best - need to be able to fabricate and hold a fine edge without breaking2. Not many vesicles (bubbles are structural defects) ‘a‘ā flow interiors, dikes, some massive alkalic lavas3. Not many large crystals (crystals are defects too) most postshield alkalic rocks; some shield lavas4. Fractures previously fractured outcrops save labor columnar jointed lavas and dikes were widely exploited sources unusual cooling of Mauna Kea lava that ponded against ice
Making tools from raw stone
The stone must withstand fabrication
And not break when being used
The Role of Geochemistry and Petrology
Any rock can be described in terms of:
• Texture• Mineralogy• Chemical Composition
Although Polynesians largely selected rocks based on physical properties (texture and fracture characteristics), the best method for “sourcing” artifacts is through the use of quantitative geochemical data.
Matches of artifacts to source
Does an artifact have the same texture, mineralogy and chemical composition within uncertainties to a known source (outcrop, volcano, island)
Chemical data are fully quantitative, allowing for realistic uncertainty estimates to be determined.
Sources of Uncertainty
Analytical Uncertainty Quarry Variability
Different analytical methods have different inherent “errors”
Two critical analytical issues are precision (reproducibility) and accuracy (correctness)
How variable is the actual source area? This can only be determined from dedicated investigations of specific quarries
(17) 1 SiO2 46.98 0.11 TiO2 3.79 0.03 Al2O3 15.24 0.06 Fe2O3 13.58 0.05 MnO 0.19 0.01 MgO 6.45 0.09 CaO 9.31 0.03 Na2O 3.15 0.06 K2O 1.00 0.03 P2O5 0.53 0.00
Sc 21 2 V 311 5 Cr 84 7 Ni 111 22 Cu 44 4 Zn 138 7 Rb 20 3 Sr 592 5 Y 36 1 Zr 302 1 Nb 30 1 Ba 187 18 Th 3 1
Chemical Data for Eiao Adze QuarryAverage of 17 analyses ± 1 standard deviation
wt % ppm
Archeologists use artifacts to make interpretations about “spheres of influence”
This map shows some known and suspected interactions based on ethnohistoric sources and documented transfers of artifacts (mainly lithic)
These interpretations are largely based on macroscopic appearance or stylistic similarities
Weisler, 1998
Adze from 100 ft depth, Honolulu Harbor, near Sand Island
1986-602adze
Kaua‘iadze
C-159
SiO2 46.24 46.12 45.91
TiO2 3.11 3.33 3.02
Al2O3 16.72 16.67 16.63
FeO* 11.72 11.93 12.23
MnO 0.23 0.22 0.23
MgO 4.70 4.76 4.14
CaO 8.11 8.39 8.10
Na2O 4.95 5.01 5.44
K2O 1.60 1.64 1.84
P2O5 2.50 2.49 2.43
Sum 99.89 100.57 99.97
LOI 2.23 1.88 1.10 * total Fe as FeOLOI = loss on ignition at 900°C
Rock sections viewed through the microscope
1986-602 adze(large adze found in Honolulu Harbor)
C-159(sample collected by G. A. Macdonald from Pu‘u Pāpa‘i, Moloka‘i)
apatite crystals
Chemical analyses of rocks
Pu‘u Pāpa‘i, E. Moloka‘i
Known Polynesian Adze Quarries(not including New Zealand)
Hawai‘i – 15Samoa (Tutuila) – 4Cook Is. – 4Austral Is. – 3Pitcairn – 2Rapa Nui – 5Marquesas – 4Society Is. – 5
By far the three largest (export) quarries are
Mauna Kea (Hawai‘i)Tataga matau (Samoa)Eiao (N. Marquesas)
Geochemical Evidence of Interaction
1. Tataga-matau adzes in N. Cook Is.
2. Tataga-matau maybe in Line Is.
3. Eiao throughout Marquesas
4. Eiao on Moorea5. Eiao on Mangareva
(Gambier)6. Pu‘u Wa‘awa‘a
obsidian in Halawa (O‘ahu)
7. Pu‘u Mō‘iwi (Kaho‘olawe) adze on Kaua‘i; Lāna‘i adze on Kohala
8. Mauna Kea adze on O‘ahu
9. Moloka‘i adze on O‘ahu and Kaua‘I
10. Possible Hawaiian adze in Tuamotus
11. Pitcairn obsidian on Henderson atoll
Don’t know:- Process of transfer (commercial enterprise, bartar, exchange)- Organizational system for quarries (ownership if any, division of labor)
Major interaction within archipelagos; limited interaction between archipelagos
Quarry Types (from a geological perspective)
Outcrops:1. Columnar lavas (Tahiti)2. Dikes (Tahiti and elsewhere - see also residual dike rock)3. Massive lava flows (W. Moloka‘i, Kailua, Kaho‘olawe, Haleakalā, Rurutu)4. Massive flow chilled against ice (Mauna Kea)
Residual Deposits1. Dike boulders in streams on Ra‘iatea2. Major quarry of dike rocks in alluvial (stream) deposit on Eiao, N. Marquesas
Columnar jointed lava, East Maui
Dike Quarry – Papeenoo Valley, Tahiti
Eiao, N. MarquesasSelective mining of dike rocks in stream deposit
The Tuamotu example
-all atolls – no local volcanic sources
-Geochemical evidence suggests some adzes from Society Is., Pitcairn, N. Marqueseas (Eiao) and possibly Hawai‘i
Collerson and Weisler, 2007
Eiao – An important adze quarry in the Northern Marquesas
Evidence for major breakdown in the system of interaction ~1450 A.D.
Archeological Investigations at Hanamiai, Tahuata, MarquesasB. Rolett, Univ. Hawai‘i, Dept. Anthropology
Adze Quarries of West Moloka‘i
Ka Lua Ko‘i“The adze pit”
14 separate adze sources known
Most quarries on postshield lavas, but not all
One dike quarry
Pu‘u Mō‘iwi adze quarry – Kaho‘olawe
At least one Mō‘iwi adze found in an archeological site on Kaua‘i
Recently discovered adze quarry on Maui
The Nu‘u quarry, Maui
Mauna Kea Adze QuarryGlacially chilled hawaiite lava flow
Hawaiian Sources
Large squares denote documented quarries; small squares are other sources
Note – at least one significant quarry on each inhabited island