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Sediments and stratigraphy at the Tower Buried Forest site provide a glimpse into the immediate post-glacial environment of northern Lower Michigan, USA. At this site, sandy glacial outwash is overlain by (1) ≈37 cm of peat associated with a wetland, above which are (2) flat-lying spruce and larch logs and branches that date between ≈10 910 and 10 340 cal years BP. Above the woody materials are ≈55-75 cm of sand, interbedded with organic muck laminae, which we interpret as local alluvium. This stratigraphic sequence is overlain by muck soil materials associated with the modern wetland. Pollen and plant macrofossil analysis of the lower peat indicate that a tundra-boreal parkland had been established here, shortly after final deglaciation. Later, Picea glauca (white spruce) , Picea mariana (black spruce), Larix laricina (larch), and Abies balsamea (balsam fir) became abundant in an open boreal forest - Spaghnum peatland. Subsequent increases in Pinus (pine) and Typha (cattail) indicate drying and possibly warming conditions. At ca. 10 340 cal years BP (or a few centuries prior), nearly two millennia after final deglaciation, water flowed across the site, possibly knocking over the trees.. Interbedded sand and muck deposits above the flat-lying logs are interpreted as alluvial deposits from this event, after which the wetland became quiescent again. [ABSTRACT FROM AUTHOR]

Glacial Lake Algonquin, the most widespread proglacial lake in the Great Lakes basin, attained a high (Main) stage at about 11,000 b.p., at which time it developed a conspicuous shoreline. Several lower, less obvious Algonquin shorelines also exist. Previous research on this lake has involved three drawbacks: (1) imprecise methods of establishing the location and elevation of shoreline features, (2) misidentification of some offshore coastal landforms as beach ridges, and (3) tenuous and difficult correlation of named shorelines across wide distances. We believe that more than one name is used for some lake phases, making correlation difficult. Our study focused on these problems by surveying and mapping 160 Algonquin wave–cut bluffs throughout northern Michigan. We utilized global positioning system (GPS) technology to precisely record the three–dimensional positions of the bases of these bluffs and statistically fit trend surfaces to these positions. Classification of bluff data indicates that four strong Algonquin shorelines exist in the region, for which we recommend these names: Main, Ardtrea, Wyebridge, and Payette. Weak evidence for a possible fifth, lower shoreline was observed at five locations. Maps of the landscape during each lake phase were created, revealing islands not previously recognized. Rebound curves and maps of the lake during each phase, using the positional data set, indicate that isostatic rebound in the study area appears to be greatest in the northeast sector. [ABSTRACT FROM AUTHOR]

Describes and explains the geographic distribution of Spodosol soils (Podzols) on a regional scale. Because they employed a spatially-based, functional-factorial model of soil formation and, held four factors constant, they were able to examine the effects of climate on soil genesis and distribution. Patterns in southern Michigan; Methods; Results and discussion; Conclusions.