1000 water wells logs located in the map area and compiled by the Michigan Department ... moraine of the Port Huron advance (map unit Qph). This end ...
Map Description for Quaternary Geologic Map of the Muskegon West and Muskegon East, Michigan 7.5 Minute Quadrangles. Patrick M. Colgan and Jonathan M. Stark (2005) The field data gathered for this geologic map were collected during the summer of 2004 by Jonathan Stark under the supervision of Patrick Colgan of Grand Valley State University. Field observations consisted of descriptions and laboratory analyses of sediment samples collected from shallow hand augering, stream exposures, exposures in foundations, drainage ditches, and sand pits. Approximately 140 sediment samples were analyzed for grain size distribution in the laboratory (see attached grain size data). Additional information on sediment thickness and variability was gathered from over 1000 water wells logs located in the map area and compiled by the Michigan Department of Environmental Quality (http://www.deq.state.mi.us/well-logs/default.asp). Vertical aerial photos (black and white, USDA 1968, and NAPP 98-Michigan infrared digital orthophotos) were used to delineate dune sand and to map stream terraces. These observations were then checked in the field. Geotechnical boring logs and sample laboratory data were also collected from environmental and geotechnical site investigations. Most of the wells were shallow drinking water wells that did not go deeper than 50 feet. A few well logs indicate that the thickness of Quaternary sediment is as much as 260 feet thick in the map area. The bedrock underlying the area is the Mississippian Marshall Sandstone. The elevation of the bedrock surface varies from 350 to 430 feet above sea level. Overlying bedrock is glacial till (Saugatuck Till) and outwash mainly associated with the Lake Border end moraines which are at the surface just to the east of the mapping area. The geologic map covers the areas contained by the Muskegon East and Muskegon West, Michigan 7.5 Minute Quadrangles. The area is dominated by a very low relief surface underlain primarily by lacustrine sediments. This surface gently slopes to the west (the slope varies from 5 to 15 feet per mile). The sediments underlying this surface (map unit Qld) were deposited in glacial outwash streams, shallow-water lake deltas that flowed westward into Glacial Lake Chicago when it was at the Glenwood Level (about 90 feet above current lake level), and more distal lake silt and clay deposited in deeper water. Glacial Lake Chicago first formed after the Lake Michigan lobe retreated from the Lake Border end moraines at about 14,500 14C yr BP. Most of the area was probably covered by Glacial Lake Chicago during the Glenwood Stage except for the end moraine of the Port Huron advance (map unit Qph). This end moraine was deposited by a glacial readvance that occurred at about 13,000 14C yr BP. As ice advanced into Glacial Lake Chicago sediment both from the ice margin and from streams draining land to the east were deposited into the lake. The moraine is buried by lacustrine sediment both to the north and to the south of where it rises above lake sediment in the City of Muskegon. The red dashed line on the map shows the extent of a reddish-brown, silty diamicton (interpreted to be basal till of Shorewood Till) in the subsurface beneath lake sediments. Glacial Lake Chicago dropped to a lower level during the Calumet stage after about 11,800 14C yr BP. This lake level was about 40 feet above the current lake level. Evidence for this lake level includes a wave cut scarp in the City of Muskegon south of Muskegon Lake. This scarp is also cut into the Port Huron end moraine in Muskegon
showing that this lake level occurred after 13,000 14C yr BP. Older lacustrine sediments were reworked during this lake level and are mapped as lacustrine sediment (Ql). Stream terraces formed along the Muskegon River and Black Creek as Glacial Lake Chicago dropped from the Glenwood level to the Calumet level. Along Black Creek two higher stream terraces made up of pebbly sand are present at elevations of 640 to 650 feet (Qt3), and 620 to 635 feet (Qt2). An exposure in the highest terrace (Qt3) shows evidence of braided stream deposition at the time sediment in the terrace was being deposited. The lowest stream terrace (Qt1) along Black Creek is slightly higher than the present floodplain and probably was formed during the Holocene by a meandering Black Creek. Two lake terraces are also present on Muskegon Lake and Mona Lake. The terraces have elevations of 590 to 600 feet (Qlt1) and 600 to 610 feet (Qlt2). These lake terraces probably formed during the Holocene during the Nipissing high lake levels. Large parabolic dunes began forming along Lake Michigan after lake level dropped from the Nipissing high water level about 5,500 years ago. Low parabolic dunes up to a mile inland stabilized first (Qld) because they are buried by the high parabolic dunes. The larger high parabolic dunes have probably been active on and off for the last 5,000 years. Many of these dunes are currently active. Three radiocarbon ages were obtained on charcoal found in buried paleosols at three locations in the dunes. This paleosol has been described in detail by others and called the Holland Geosol. The Holland Geosol is a well developed inceptisol with a brightly colored Bs horizon. The three radiocarbon dates obtained from this paleosol in three separate locations provide ages of 1,860 ± 40 14C yr BP (Beta-196928, Hoffmaster Dunes State Park), 1,280 ± 40 14 C yr BP (Beta-202483, Lake Harbor Park), and 1,350 ± 40 14C yr BP (Beta-202482, Muskegon State Park). This paleosol probably represents a period of widespread dune stabilization that occurred from 2000 to 500 years ago. Numerous small inland dunes (Qd) cover the lacustrine surface. Very little is known about the age of these dunes, except that they are younger than the lacustrine surface they lie upon. Inceptisols are formed on the dunes indicating that they have been stable for some time. Some of these dunes have active blowouts in them where poor landuse has caused the soil cover to be eroded. These soils and dune landscapes are very sensitive to development. Beach sand, lake sediment, and alluvium are currently being deposited in stream valleys, and along lake shorelines. Most of this sediment is derived from the widespread Pleistocene lacustrine deposits. Organic marsh deposits are found in a few wetland locations. Most marsh deposits in alluvial valleys were too small or to patchy to map as a separate unit (most are included in Qa, not Qm).
