A time‐space model for the distribution of shoreline archaeological sites in the lake superior basin

Abstract

Archaeological site interpretation can be enhanced by consideration of related geological and geomorphological processes. Lake Superior has a history of glaciation, isostatic recovery, and water-level change. Two examples are given of shoreline sites at which interpretation is enhanced by an understanding of local geologic factors. The archaeologic history of the Lake Superior basin is reviewed, and three cultural traditions are recognized; (1) Paleoindian, (2) Archaic, and (3) Woodland. Three significant factors ofgeologic history are then discussed: (1) ice margin oscillation, (2) differential isostatic uplift, and (3) lake-level fluctuations. The factors reducing o r improving shoreline archaeological site preservation are examined, and a summary model of shoreline site distribution for the Lake Superior basin is offered. It is concluded that the north shore provides the best potential for a complete archaeological record. 8 1993 John Wiley & Sons, Inc. PROLOGUEIt is of concern to many geologists and geomorphologists who approach archaeology in their work, that incomplete or erroneous interpretation of archaeological sites sometimes comes about through insufficient attention to the "geologic filter," that is, the set of geological processes acting on the site and the context in which they took place. The object of pointing out the potential for misinterpretation is not to criticize the existing skills of the archaeologist, but to demonstrate that archaeological interpretation, both at local and regional scales, can be enhanced by more adequate consideration of geologic and geomorphic processes.Lake shorelines are biologically productive zones, particularly where sheltered embayments, marshes, and river mouths occur, and it is in these locations that prehistoric peoples have tended to concentrate their activities. The shoreline of Lake Superior, 82,103 km2 in area, is for the greater part comprised of rugged rock shores, such that bayhead beaches, marshlands, and river mouths are particularly important as potential habitation sites. Because of glaciation and isostatic uplift, Lake Superior is rimmed by the remains of strandlines of former post-glacial lakes occupying the basin, and it is on these that much of the evidence for prehistoric occupation has been found. SHORELINE SITE MODEL, LAKE SUPERIOR 50. 90 85 I I NORMERN ON 90 85 Figure 1. The Lake Superior basin-location map.-50 of these shoreline related sites has been closely linked to the succession of strandlines, which in places descend to present lake level in a staircase of lakeshore terraces . Larsen (1985), in a study of Lakes Michigan and Huron, warns that past approaches t o geological and archaeological studies of those lakes has shown that archaeological interpretation has been too closely tied to the current interpretation of post-glacial chronology, and that the interpretation of coastal landforms has relied more on surficial studies than on subsurface stratigraphical relationships (p. 96). The glacial and post-glacial history of the Superior ba...

Geoarchaeology and late glacial landscapes in the western lake superior region, Central North America

“…Three less developed shorelines, designated Highbridge, Moquah, and Washburn, are between the sub-Duluth level and the well-developed Beaver Bay shoreline. Several other lake margins have also been recognized between the Beaver Bay and Minong levels (Phillips andHill, 1993, 1994a). By about 9500 yr B.P., Lake Minong shorelines formed around the entire margin of the Superior basin.…”

“…Proglacial lake sediments were likely deposited Figure 12 in Hill, 1995b). during the melting of the St. Croix phase ice sheet (Figure 3) because they were incorporated into the younger Automba phase deposits (Figure 4). High abandoned lake shorelines may indicate separate glacial lakes or a single extensive lake along the north and southwest shores of the Superior basin prior to and during the Marquette phase (Phillips andHill, 2001, 2004; Figure 7). Shorelines thought to be associated with isolated high lakes along the Superior basin, such as Lake Nemadji and Ontonagon, may have been present sometime after 11,220 yr B.P.…”

“…Melting of the Marquette phase ice enlarged the area of the lake in the Superior basin and began to lower water to the Minong level again (Phillips andHill, 2001, 2004). The earliest of these recessional shoreline features is at about 307 masl in the Duluth area.…”

“…Lake levels continued to drop from 9500 to 8000 yr B.P. The extreme low around 8000 yr B.P is designated the Houghton level (Phillips andHill, 2001, 2004).…”

“…Some examples of the use of a geoarchaeological perspective in the Agassiz basin include Pettipas and Buchner (1983), Buchner and Pettipas (1990), and Ross (1997). Studies by Farrand (1977), Storck (1988), Julig (1991), Phillips (1993), Cleland et al (1998), Kuehn (1998), Anderton (1999), Jackson et al (2000), and Julig and McAndrews (1993) logical and vertebrate settings by integrating geomorphic and ecological dynamics, which are partly based on interpretations of the regional glacial geology. In fact, early in his career, Rip Rapp served as a field assistant for H. E. Wright, Jr., conducting research on the history of various glacial lobes and their regional direction of advances using pebble counts and till fabric studies.…”