In this article, the authors sought to examine the sediments of 3 lakes to better understand the dynamics of forest succession as the glaciers moved northward after the Pleistocene period.  Two of the lakes were in Indiana: Winona Lake and Tippecanoe Lake, while TSL was the third lake.  Winona and Tippecanoe occur near the border of the interlobate moraine between the Huron-Erie and Saginaw lobes of the Wisconsin ice sheet.  Only 10 miles separates the two lakes. 

Samples of sediments were collected down to the parent material (unwashed gravel) in 1 foot increments.  Pollen grains were separated from the sediments and 200 grains were counted for each foot-level of sediment.  Grains were identified to genus taxa level. 

In Winona Lake, depth of sediment reached 33 feet, with sediment being mostly black with gray streaks which the authors attribute to oxidation of organic matter.  Exposure to air turned the black sediments brown and then gray.  Sediments here decreased in water content with depth.  Tippecanoe Lake had a much deeper layer of sediment, to 59 feet.  Sediment was similar to Winona lake, but with more oxidized layers.  The last 15 feet also had much higher proportions of sand.  Sediments here also contained much more water than at Winona.  TSL had 33 feet of sediment.  As Eggleton (1931) and others have noted, this consisted of alternating layers of allocthonous clay and autocthonous organic deposition for 4 feet, followed by peat for 18 feet, then alternating layers of peat and marl for eight feet, fine sand for seven feet and finally a foot of sandy marl.  TSL had substantially less carbonates in its sediments than the other two lakes and quite a bit more organic material and R2O3 in its surface and 25 foot level sediments.  Winona Lake had much aquatic macrophytes, especially Potamogeton along its shore while Winona Lake had very little shoreline vegetation.  TSL was dominated by water lilies extending approximately 30 feet into the lake. 

The three lakes exhibited similar successional trends in their surrounding forest ecosystems.  Earliest forest assemblages were from fir or fir/spruce to spruce/pine to pine/oak to oak/maple.  TSL started with pine in its assemblage in addition to fir/spruce.  Pines were less dominant at Winona than the other two lakes and lasted longest in TSL.  At Tippecanoe Lake, the oak/maple end succession continued to oak/mixed lowland species.  Oaks dominated (often with other species) half to 2/3 of the total time that sediment was deposited.  Conifers were the climax longer in Michigan than in the Indiana lakes (and persisted 3x longer).  Maple only achieved high abundances in recent sedimentary history and the authors do not have confidence over what species of maples were present.  Picea and Abies also persisted longer at TSL. Larix was often part of the forests, but never dominant.  Winona and TSL were more similar in the deeper sediments than Tippecanoe.  The authors suggest that the high rates of deposition at Tippecanoe are due to its sandy shores and accelerated shoreline erosion.   Overall, diversity of taxa increased with the change to a broad-leaved forest.  Climate changed on a gradient from cool-moist to cool-dry, warm-dry and finally warm-moist. 

Significance to TSL:  TSL is on the northern extension of the Fort Wayne moraine of the Huron-Erie lobe of the Wisconsin ice sheet.  The authors state that 54.87% of the original basin is filled in with sediment averaging 17 feet in depth.  Hammer may have found that sedimentation is occurring more rapidly now.  It would be interesting to determine how much of the original basin is now filled in and at what point will the lakeí¢â‚¬â„¢s eutrophication turn it into more of a wetland.

Overall Literature Significance: Cited by 6, most recently in 1997 by: Hammer, B.K., and E.F. Stoemer. 1997. "Diatom-based interpretation of sediment banding in an urbanized lake." Journal of Paleolimnology 17 (4): 437-449.