280 likes | 572 Views
(pre-contact) Polynesian Stone Tools. Tracing Stone Tools Across the Pacific with Geochemistry (John Sinton, UH G&G). Figures from Encyclop é die de la Polyn é sie. Adze from 100 ft depth, Honolulu Harbor, near Sand Island. Rock sections viewed through the microscope.
E N D
(pre-contact) Polynesian Stone Tools Tracing Stone Tools Across the Pacific with Geochemistry (John Sinton, UH G&G) Figures from Encyclopédie de la Polynésie
Rock sections viewed through the microscope Chemical analyses of rocks 1986-602 adze (large adze found in Honolulu Harbor) apatite crystals C-159 (sample collected by G. A. Macdonald from Pu‘u Pāpa‘i, Moloka‘i) * total Fe as FeO LOI = loss on ignition at 900°C Pu‘u Pāpa‘i, E. Moloka‘i
Different stones for different uses • Vesicular pāhoehoe lava makes a lousy adze, but an excellent grinding or • polishing stone • Coarse-grained rocks make lousy adzes, but excellent sinkers and lures • Glass is best for cutters and scrapers (but hard to find in large pieces) Good Adze Source Rocks 1. Fine-grained, equigranular is ideal need to be able to fabricate and hold a fine edge without breaking 2. Minimum vesicularity ‘a‘ā flow interiors, dikes, many massive alkalic lavas 3. Not very porphyritic (crystals are defects in rock structure) most postshield alkalic rocks are aphyric, so are many shield lavas 4. 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.
Archeologists use artifacts to make interpretations about “spheres of influence” Weisler, 1998 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
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. Ideal matches of artifacts to sources The artifact has the same texture, mineralogy and chemical composition within uncertainties to a known source (outcrop, volcano, island) Chemical data can be 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 Chemical Data for Eiao Adze Quarry Average of 17 analyses ± 1 standard deviation
Known Polynesian Adze Quarries (not including New Zealand) Hawai‘i – 14 Samoa (Tutuila) – 4 Cook Is. – 4 Austral Is. – 3 Pitcairn – 2 Rapa Nui – 5 Marquesas – 4 Society Is. – 5 By far the three biggest (export) quarries are Mauna Kea (Hawai‘i) Tataga matau (Samoa) Eiao (N. Marquesas)
Quarry Types (from a geological perspective) • Outcrops: • Columnar lavas (Tahiti) • Dikes (Tahiti and elsewhere - see also residual dike rock) • Massive lava flows (W. Moloka‘i, Kailua, Kaho‘olawe, Haleakalā, Rurutu) • Massive flow chilled against ice (Mauna Kea) • Residual Deposits • Dike boulders in streams on Ra‘iatea • Major quarry of dike rocks in alluvial (stream) deposit on Eiao, N. Marquesas Columnar jointed lava, East Maui
Eiao, N. Marquesas Selective mining of dike rocks in stream deposit
Evidence of Interaction Major interaction within archipelagos; limited interaction between archipelagos • Tataga-matau adzes in N. Cook Is. • Tataga-matau maybe in Line Is. • Eiao throughout Marquesas • Eiao on Moorea • Eiao on Mangareva (Gambier) • Pu‘u Wa‘awa‘a obsidian in Halawa (O‘ahu) • Pu‘u Mō‘iwi (Kaho‘olawe) adze on Kaua‘i • Mauna Kea adze on O‘ahu • Moloka‘i adze on O‘ahu and Kaua‘I • Possible Hawaiian adze in Tuamotus • 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)
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
Archeological Investigations at Hanamiai, Tahuata B. Rolett, Univ. Hawai‘i, Dept. Anthropology
Evidence for major breakdown in the system of interaction ~1450 A.D.
Adze Quarries of West Moloka‘i Ka Lua Ko‘i “The adze pit” 14 separate adze quarries 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
Mauna Kea Adze Quarry Glacially chilled hawaiite lava flow
Hawaiian Sources Large squares denote documented quarries; small squares are other sources