Volume 48 1939 > Volume 48, No. 189 > Obsidian scrapers Bay of Plenty, New Zealand, by S. R. Mitchell, p 56-59
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DURING a brief visit to the Bay of Plenty in January, 1937, the writer found a type of stone artifact that has apparently not so far been recorded for New Zealand. Between Waihi beach and Bowentown, a distance of about five miles, many of the sand-dunes are capped by remnants of shell-middens, the former feeding-grounds of Maori people. Wind erosion has removed much of the dune-sand with the consequent exposure and concentration on the present surface of the less-perishable contents of the middens. The obvious artifacts have naturally been collected, and for several miles south from Waihi beach very little stone material is to be found. Toward Bowentown heads on the narrow isthmus separating the estuary of the Athenree creek and the coast, the character of the remains changes. Large numbers of flakes, lumps, and waterworn pebbles of obsidian, fragments of greywacke, jasper, and chalcedony, lie scattered about, among them being numerous drill-points and reamers of the two latter materials. Excavations on this site have revealed many stone and bone relics. On the low-lying hill across the estuary are to be seen old cultivation-trenches, indicating that this locality was the site of a fairly large coastal settlement.

The obsidian scrapers in question, numbering about 30 specimens, were collected over an area of about one acre, and no examples were found elsewhere. They are characterized by being more or less circular in form, ranging in size from 1.65 inches across to less than 1 inch, with the original thickness of the flakes varying from 0.7 inch to 0.25 inch. One perfect example 3LS and 3US in the illustration is 1.25 inch in diameter, with a plane upper surface, and opposite it a dome-like termination 0.7 inch high. In every case the working or flaking has been effected away from the plane surface, as is general with all scraper types.

Many stages are represented in the material collected, from flakes with comparatively little retouch, to others

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perfectly circular, with the chipping on the whole of the periphery. This would indicate that the circular form was not the ultimate objective, that the purpose of the user called for a scraper with a convex edge and through repeated re-chipping the result was a circular scraper. There was apparently a local need for deep grooving or scraping, hence the restricted occurrence of this interesting type.

Several of the specimens are semicircular in form with the chipping on the convex edge only, and have obviously been circular scrapers broken in two.

Numerous roughly-shaped implements of greywacke, (adze-and chisel-blanks and rejects) were found, together with quantities of chips and flakes from the fashioning of these tools, and some of the larger flakes show definite signs of use as scrapers or spokeshaves. In most cases, however, the working edges are rounded through weathering, to which this material seems very susceptible.

Many of the larger obsidian flakes also show signs of use as scrapers, but obsidian, being more brittle and not so hard as the other stone materials available, was little used for scraping. To an Australian student of stone tools the comparative scarcity of well-finished scrapers is remarkable, and can probably be attributed to the fact that in general Maori technique in working wood and bone was essentially carving and not scraping. However, like all primitive people, they could and did adapt their technique when the occasion arose.

The source of the obsidian is said to be Mayor island, about 18 miles off the coast. Shingle pebbles and boulders were used, being obviously the tougher, harder, and more resistant material.

Petrologically the obsidian is a glassy form of rhyolite quite black in colour, but occasionally a brown variety was observed. It is translucent in thin flakes, shows flow-structure, but crystallites are absent as far as can be ascertained without microscopic examination.

The extremely vesicular variety “pumice” is also plentiful and was apparently largely used for rubbing, rasping, and polishing, as shown by the number of pieces found that had evidently been used for these purposes.