The distribution of raw materials in this part of the state has not been adequately studied. If it were possible to survey this large area in detail, specific bedrock sources could no doubt be located and described; the geological literature contains some detailed information of this kind (e.g., Sims and Morey 1972). Theoretically, petrographic and trace element analysis would make it possible to assign specimens (i.e., individual lithic artifacts) to specific sources. But the fact that glaciers spread materials from the same sources over large areas means that such intensive analysis is not likely to provide archaeologically useful information. The analyses would not address the question of whether a piece of raw material was obtained from the signified bedrock source or from a secondary context where it was redeposited.

Detailed knowledge of raw material sources in the vicinity of an Eastern Resource Region site is still useful. In addition to a review of geological literature, a first hand, on the ground survey of raw material sources could prove valuable. An adequate raw material analysis may still be conducted without detailed source information, however, by placing the analysis within the context of regional raw material resources.

Siltstone is especially abundant in the Eastern Resource Region, both as a raw material and at archaeological sites (Romano 1991). Because it is usually a marginal quality material, its utilization may have been based more on availability than desirable characteristics. However, some consideration should be given to the theory that, at least in Paleoindian technological traditions, siltstone was a desirable material for chipped stone adzes and similar implements. This desirability could be based on its relative resiliency; for such intensive uses, it would be better suited than high quality, more brittle cherts (George Christianson, personal communication 1992).

The term "Knife Lake Siltstone" is commonly applied to any siltstone in the region. This name originates from siltstone quarries found along outcrops at Knife Lake and other locations along the Minnesota and Ontario border. These quarries produce material of apparently better quality than is generally found in the glacial drift (Jon Nelson, personal communication 1992; see also Romano 1991). The drift material probably originates from multiple geological sources, not just to those represented in the Knife Lake vicinity. With some reluctance I suggest that it is better to reserve the term "Knife Lake Siltstone" for siltstone that can be demonstrated to originate from the Knife Lake sources, at least until more is known about the material.

The situation is further complicated by the use of the term "Lake of the Wood Chert." Lake of the Woods Chert in fact appears to be a finer grade, green to black siltstone available around Lake of the Woods (Jon Nelson, personal communication 1992). The material does have a cherty appearance and good flaking qualities, and application of the name "Lake of the Woods Chert" to other siltstones does not seem appropriate. To make matters worse, the name "argillite" (or even argillite-quartzite) has also been applied to siltstone. I recommend that "siltstone" is preferable to "argillite," because it is more widely used, more descriptive and more obviously pronounceable. The relatively subtle petrographic distinction between siltstone and argillite is not important in this context. Perhaps the primary concern in this situation is realizing that these terms all apply to different phases of the same raw material, and realizing also that at least some of this material is widely available in glacial drift.

As mentioned above, quartz appears to be available in glacial drift throughout the state, including the Eastern Resource Region. The extent of its utilization at sites in this region, however, has not been adequately evaluated. It seems to have been extensively utilized in parts of the region during certain periods. Quartz is difficult to reduce using standard reduction techniques. Based on initial studies, it appears that specialized bipolar reduction techniques were used with this material, possibly with the goal of producing expedient flake tools. Quartz is easily identified by the presence of flat fracture plains which follow its crystalline structure.

Jasper Taconite (JT), Gunflint Silica (GFS) and Kakabeka Chert are related materials (Romano 1991). Their common characteristics include a transparent chalcedonic matrix and the presence of distinctive inclusions within the matrix. Occasionally pieces may be seen which incorporate characteristics of more than one of these materials, or resemble these materials but cannot be specifically identified as one or the other material. These ambiguities probably relate to the long and complex geological history of the region and the rocks it contains. I propose the use of a generic, blanket term for these materials, at least when a specific identification cannot be made. Any material which exhibits a clear matrix with an "icy" texture; contains various granular, acicular or other inclusions; and is believed to originate in the early strata of northeastern Minnesota and surrounding areas, may be referred to as an "Animikie Silicate." These silicates appear to come from Middle Precambrian sedimentary strata that form the Animikie Group (see Morey 1972).

Jasper Taconite is available in drift in the Eastern Resource Region. (As discussed above and below, JT of inferior quality is also available from drift in the Western and Southern Resource Regions.) Bedrock quarries are known from northwestern Ontario (Julig et al. 1989; Steinbring 1976) and may also exist in Minnesota. This good quality material appears to have been favored for tool production throughout prehistory. It is easily recognized by its normal, distinctive deep red color and the presence of small, round inclusions which superficially resemble ooliths. The inclusions dominate the material; the transparent matrix forms only a small part of the material between the inclusions. The color will vary to dark green, dark blue or almost black, but these colors are rare.

In Gunflint Silica, the translucent to transparent matrix is dominant. The matrix is usually translucent and grey to bluish grey, but can vary to colorless and nearly transparent. Working quality is not as good as Jasper Taconite. Inclusions consist of scattered small black granules resembling pepper grains. Romano (1991, 1994) reports finding samples of GFS on Gunflint Lake, one of the Ontario border lakes in northeastern Minnesota, as well as in deep iron mines within Minnesota. The extent of its availability in glacial drift has not been evaluated, although it is present.

Inclusions also dominate matrix in Kakabeka Chert. The inclusions are acicular (needle shaped) and too small to see individually with the naked eye. They give the material a distinctive fine, wood grain appearance. Color is generally a mixture of grey and brown. The availability of Kakabeka Chert in the state has not been evaluated, although small amounts occur in drift (Tony Romano, personal communication 1994).

Lake Superior Agate (Ojakangas and Matsch 1982:54) is not uncommon is glacial drift in the Eastern Resource Region. It is distinctive and easily identified. The color is light to dark "salmon" or "coral" red, alternating with bands of white. Texture is waxy. The center of the agate is often filled with a mass of colorless quartz crystals. Although LSA usually occurs as relatively small pebbles, it is not uncommon at archaeological site. In many cases, it seems to have been reduced by the same specialized bipolar technique used with quartz. Again, the goal of this technique may have been to produce expedient flake tools.

Hudson Bay Lowland Chert (HBLC) (Julig et al. 1989:297; Romano 1991) remains something of an enigma in regional archaeological studies. Its sources and characteristics are not well documented. Apparently it occurs only as cobbles in secondary deposits. Some authorities speculate that it is actually more than one material, and in fact a "catch all" category. However, comparative samples available to me, as well as occurrences of what appears to be HBLC at archaeological sites in Minnesota, suggest that the category is valid and useful. Until better information is available, it will be considered here as one material. The color of HBLC is variable. Distinguishing characteristics would seem to be an extremely fine texture which preserves remarkably minute details of flake morphology; a thin, buff colored cortex; and a strong red color of transmitted light. Its natural availability in Minnesota is unevaluated. It is conceivable that some pieces might be found in glacial drift, especially in the extreme northern part of the Eastern Resource Region, although this has not been demonstrated. HBLC appears to be a very high quality material. Flakes very often show signs of retouch or utilization, a characteristic HBLC shares with KRF.

The archaeological literature contains certain references to "gold chalcedony" or "light brown chalcedony." Steinbring discusses the occurrence of "a very homogeneous light brown chalcedony" at a number of Old Copper Complex sites, and speculates that it may have a source in Ontario on the north side of Lake Superior (Steinbring 1974:68; cf. Griffin 1961:98). He specifically notes that this material "is not Knife River flint. It is much lighter, more translucent, and completely lacks the common inclusions and impurities of Knife River" (Steinbring 1974:70). In addition, an unattributed, undated note in the site files for Cook County at the Wilford Archaeology Lab, University of Minnesota, reads: "A quarry of amber colored flint said to be on the north side of Gunflint Lake. A point on the Canadian side. Some implements, and in places the chip material is said to be several inches in depth." Examination of some of the artifacts discussed by Steinbring (at the archaeology laboratory, University of Minnesota, Minneapolis) suggests that this material is Hudson Bay Lowland Chert. The description of this "light brown chalcedony" is within the range of characteristics for HBLC, and no further information has come to light regarding sources or quarries for such a "light brown chalcedony" or "amber colored flint."

Jasper (not Jasper Taconite) occurs in the Eastern Resource Region. The original association is probably with the iron deposits found in parts of the region. For example, the tailing from the open pit iron mine in Virginia, Minnesota contain ocher colored and apparently flakable material which might be called jasper and which resembles pieces occasionally found at regional archaeological sites. The occurrence of this and other "jasper" in the region requires further evaluation.

A form of "rhyolite" is also available in the Eastern Resource Region (see Romano 1991). It is not similar to the material of the same name found in the Western Resource Region. The Eastern Resource Region rhyolite is opaque, and available samples indicate that it is brown or reddish brown in color. Phenocrysts of a sort are present, but they are not transparent and colorless as in the western material. This brown rhyolite is reported to occur occasionally at archaeological sites (Tony Romano, personal communication 1994). It is coarse, and flaking quality is generally poor.

Some variety or varieties of quartzite should also be available in this region, based on a reading of the geological literature. Present raw material samples from the region, however, are inadequate to give more specific information.

Nonlocal raw materials occurring at sites in the Eastern Resource Region include many of the materials available in other parts of the state, plus Hixton Quartzite, Knife River Flint and small amounts of obsidian. The quantity of any of these materials can vary considerably from site to site.

There are a number of quarry sites relating to the lithic material resources of this region, although most of them are located in nearby parts of Ontario. Fox (1980:136) reports that outcrops of siltstone along Knife Lake (in this case on the Ontario side of the lake) show evidence of prehistoric quarrying. He suggests that this activity began in the Late Paleoindian period and probably continued into later periods. The Cummins Quarry site (DcJi-1), near the city of Thunder Bay, Ontario, covers "miles of exposed jasper [Jasper Taconite] deposits" (Steinbring 1976:21). The types of artifacts recovered from the quarry indicate that it was also in use as early as the Paleoindian period.

An example of a known procurement site within the state is Bradbury Brook (21ML42), located a few miles south of Mille Lacs Lake in east central Minnesota. Here Late Paleoindian inhabitants gathered cobbles of siltstone from a streambed or directly from glacial drift. A partially intact stone workshop at this site was dated to 9220 +/- 75 BP. The siltstone was used to produce a variety of tools, including a stemmed point, other bifaces, keeled scrapers, blades and chipped stone adzes. The workshop also contained several fragmented anvilstones and an abundant sample of hammerstones of various sizes (Malik and Bakken 1991, 1993).

The views and opinions expressed in this page are strictly those of the page author.
The contents of this page have not been reviewed or approved by the University of Minnesota.