Flake Cores Research Articles

A Review of Lynch's Descriptions of South American Pleistocene Sites

The description of major South American Pleistocene sites by Lynch (1990) contains significant errors and omissions. The artifact assemblage at the Colombian site of Tibitó, dated at 11,740 ± 140 B.P., is much larger than indicated by Lynch and well represents the Abriense industry, which features small unifacially retouched flake tools and core tools, with no stone projectile points. Lynch did not describe the 1976 stratigraphic profile at the Venezuelan site of Taima-Taima, and he failed to refer to the evidence for butchering of the juvenile mastodon with which an El Jobo projectile point fragment and a utilized flake were associated directly. The descriptions of Brazilian sites also feature serious mistakes. For the site of Alice Boër, Lynch overlooked a thick sterile stratigraphic unit (Bed IV) that intervenes between Bed III, with its thermoluminescence dates as early as 10,970 ± 1020 B.P. and radiocarbon dates as early as 14,200 ± 1150 B.P., and the artifact-bearing surface of Bed V. For Lapa Vermelha, Lynch failed to indicate that several artifacts were recovered from an older cemented cave fill that yielded radiocarbon dates of 22,410 B.P. and > 25,000 B.P. Lynch’s description of the site of Toca do Boqueirào da Pedra Furada does not correspond to eyewitness reports, and his description of the nearby Toca do Sitio do Meio was incomplete and confused. Finally, in his description of the stratigraphy of the Patagonian site of Los Toldos, Cueva 3 Lynch misquoted and misconstrued the original reports, which indicate clearly the stratigraphic priority and integrity of the Level 11 industry. For accurate descriptions of early South American archaeological sites, readers are urged to examine the original sources.

4 Chipped Stone Tools

The chipped stone artifacts comprise a full tool kit. Ranging in size from the largest of the choppers to the tiniest of the flake scrapers, they conform to a characterization of generalized implements shaped with a minimum of modification. The broad and shallow flaking, unifacial percussion technique, use of flawed lithic material, re-working of artifacts from one kind to another, and the great number of tools retaining cortex and bulb of percussion are typical of the basic simplicity of all classes. Something of a paradox exists between the wide variety of shapes and sizes of the tools, which do tend to fall into groups, and the elementary technology of their manufacture. The major classifications include projectile points and blades, flake knives, drills, gravers, choppers, hammerstones, scrapers, picks, crescents, cores, and flakes.

Sendust Flake- A New Magnetic Material for Low-Frequency Application

A high permeability, low-loss core was prepared by compacting Sendust flakes, which were produced by warm rolling Sendust powder. Sendust, a brittle magnetic alloy of iron, silicon, and aluminum, was discovered by the Japanese in 1936 and is used extensively by them in cast and powder form. The low permeability values (70-80) of Sendust powder cores precluded their acceptance in this country to any extent. The improved magnetic properties of the new flake cores, called Flakenol I, make them an attractive nonstrategic substitute for applications which now require powdered high nickel alloys. The permeability values as measured on compacts of this newflake core ranged from 150-280, with electrical losses as low as present powder cores. The very low eddy-current loss coefficient value measured on Sendust flake cores indicates their usefulness at higher frequencies than possible for present high permeability powder cores. The flake cores, which have a negative temperature coefficient of permeability, were stabilized by the addition of Alfenol flake material. The comparatively simple techniques for processing Sendust flake cores from the cast alloy are described, along with the factors which most influence their ultimate magnetic characteristics.