(pre-contact)Polynesian Stone Tools

Figures fromEncyclopédie de la Polynésie

Tracing StoneTools Across thePacific with Geochemistry(John Sinton, UH G&G)

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

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 Rocks1. Fine-grained, equigranular is ideal need to be able to fabricate and hold a fine edge without breaking2. Minimum vesicularity ‘a‘ā flow interiors, dikes, many massive alkalic lavas3. Not very porphyritic (crystals are defects in rock structure) most postshield alkalic rocks are aphyric, so are many 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.

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

The Role of Geochemistry and Petrology

Any rock can be described in terms of:

TextureMineralogyChemical 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

(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

Known Polynesian Adze Quarries(not including New Zealand)

Hawai‘i – 14Samoa (Tutuila) – 4Cook Is. – 4Austral Is. – 3Pitcairn – 2Rapa Nui – 5Marquesas – 4Society Is. – 5

By far the three biggest (export) quarries areMauna Kea (Hawai‘i)Tataga matau (Samoa)Eiao (N. Marquesas)

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

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

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 atollDon’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

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

Archeological Investigations at Hanamiai, TahuataB. 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 QuarryGlacially chilled hawaiite lava flow

Hawaiian Sources

Large squares denote documented quarries; small squares are other sources