Quaternary Geology of the Indiana Portion of the Eastern Extent of the South Bend 30- x 60-Minute Quadrangle

The Quaternary Geology of the eastern South Bend 30- x 60-Minute Quadrangle in Indiana represents landforms and near-surface sediments deposited during Wisconsin Episode, Late Pleistocene. Sediments reflect interplay between Saginaw Michigan Lobes Laurentide Ice Sheet. A relatively shallow, buried pre-Wisconsin mid-Wisconsin morphology has been overridden by advances leading to Last Glacial Maximum (LGM), ca. 24 ka. Between 17 ka, retreating ice fronts from Lobe left a succession ice-contact sediment ramps associated pitted collapsed fan-moraine complexes throughout south west map area. sequence stacked diamicton sand gravel fan heads appears at hinged interlobate area north northeast Bend. margin positions are marked distinct features like fans, kames ice-walled lake plains, which well developed on margins. thicker glaciofluvial packages appear mostly interbedded with beds along heads, minor deposits valley train units. Lowlands occupied post-LGM (ca. 18 ka) valley-train outwash deposits, interpreted flow toward west, derived an first north, near Mishawaka, then southeast northwest across Kankakee valley. Sand colluvial alluvial fans short span after retreated, incision ice-sculpted morphology. Late-glacial aeolian dunes sealed landscape. Relatively modification landscape Holocene is indicated palustrine deposits.