The early to middle Holocene was marked by considerable variability in lake levels in the Lake Superior Basin due to a combination of meltwater runoff, isostatic adjustment, shifting glacial margins, and climate change. These processes likely had a large impact on the preservation and visibility of coastal archaeological sites dating from the Early Period (Paleoindian) to the Middle Period (Shield Archaic). Of particular interest is the brief interval after 9300 cal. B.P. when ancestral Lake Superior dropped to its lowest level (Houghton) and human populations may have made incursions deeper into the basin. Elsewhere in the Upper Great Lakes, this period is associated with offshore archaeological sites submerged by rising water levels later in the Holocene. New geological data from the Thunder Bay, ON, region yield exceptional insight into the paleohydrology of the Houghton phase and, hence, the underwater archaeological prospects of this low water phase in the northern Lake Superior Basin. These data indicate that the lake reached its lowest level by at least ~9100 cal. B.P. but was highly unstable, at least initially, due to a combination of climate and meltwater runoff. Early underwater sites may be confined to two short, hydrologically closed, lowstands between ~9100 and 8700 cal. B.P. and would have been impacted by at least one lake transgression. Such sites, however, may still hold better potential for organic preservation and the visibility of large cultural features compared to their terrestrial counterparts. Coastal sites occupied when the lake was hydrologically closed may be especially well-preserved due to rapid inundation before the gradual, and generally erosional, Nipissing transgression occurred.

中文翻译：

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苏必利尔湖北部盆地沿海考古遗址能见度问题和水下前景


全新世早期到中期，由于融水径流、均衡调整、冰川边缘移动和气候变化的综合作用，苏必利尔湖盆地的湖泊水位发生了相当大的变化。这些过程可能对从早期（古印度）到中期（盾古）沿海考古遗址的保存和可见性产生了巨大影响。特别令人感兴趣的是 9300cal 之后的短暂间隔。 B.P.当祖先苏必利尔湖下降到最低水位（霍顿）时，人类可能已经侵入该盆地的更深处。在五大湖上游的其他地方，这一时期与全新世后期被水位上升淹没的近海考古遗址有关。来自安大略省桑德贝地区的新地质数据为霍顿期的古水文学提供了独特的见解，因此也为苏必利尔湖盆地北部这一低水期的水下考古前景提供了独特的见解。这些数据表明，该湖的水位至少达到了 9100 卡的最低水平。 B.P.但由于气候和融水径流的共同作用，它非常不稳定，至少在最初是这样。早期的水下地点可能仅限于两个较短的、水文封闭的、介于 ~9100 和 8700cal 之间的低位。 B.P.并且会受到至少一次湖泊侵扰的影响。然而，与陆地上的同类遗址相比，这些遗址在有机保护和大型文化特征的可见性方面仍然具有更好的潜力。由于在尼皮辛海侵发生之前，尼皮辛湖水文逐渐被侵蚀，湖水被迅速淹没，因此在水文关闭时占据的沿海地区可能保存得特别完好。