The Wisconsin Glacial Episode, also called the Wisconsin glaciation, was the most recent glacial period of the North American ice sheet complex. This advance included the Cordilleran Ice Sheet, which nucleated in the northern North American Cordillera; the Innuitian ice sheet, which extended across the Canadian Arctic Archipelago; the Greenland ice sheet; and the massive Laurentide Ice Sheet, which covered the high latitudes of central and eastern North America. This advance was synchronous with global glaciation during the last glacial period, including the North American alpine glacier advance, known as the Pinedale glaciation. The Wisconsin glaciation extended from approximately 75,000 to 11,000 years ago, between the Sangamonian Stage and the current interglacial, the Holocene. The maximum ice extent occurred approximately 25,000–21,000 years ago during the last glacial maximum, also known as the Late Wisconsin in North America.
The Last Glacial Period (LGP), also known colloquially as the last ice age or simply ice age, occurred from the end of the Eemian to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. The LGP is part of a larger sequence of glacial and interglacial periods known as the Quaternary glaciation which started around 2,588,000 years ago and is ongoing. The definition of the Quaternary as beginning 2.58 million years ago (Mya) is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Mya, in the mid-Cenozoic. The term Late Cenozoic Ice Age is used to include this early phase.
Lake Maumee was a proglacial lake and an ancestor of present-day Lake Erie. It formed about 14,000 Years Before Present (YBP) as the Huron-Erie Lobe of the Laurentide Ice Sheet retreated at the end of the Wisconsin glaciation. As water levels continued to rise the lake evolved into Lake Arkona and then Lake Whittlesey.
The Valparaiso Moraine is a recessional moraine that forms an immense U around the southern Lake Michigan basin in North America. It is a band of hilly terrain composed of glacial till and sand. The Valparaiso Moraine forms part of the Saint Lawrence River Divide, bounding the Great Lakes Basin. It begins near the border of Wisconsin and Illinois and extends south through Lake, McHenry, Cook, DuPage and Will counties in Illinois, and then turns southeast, entering Indiana. From this point, the moraine curves northeast through Lake, Porter, and LaPorte counties of Indiana into Michigan. It continues into Michigan as far as Montcalm County.
The Calumet Shoreline is an ancient shoreline of Lake Michigan located in the Lake Michigan Basin. It can be clearly seen as a sand ridge along Ridge Road south of Chicago. Closer to the lake from the Calumet Shoreline, there are the Tolleston shorelines and farther from the lake are the Glenwood Shoreline, the Tinley Moraine, and the Valparaiso Moraine. The shoreline is named after the Calumet Region of Northern Indiana.
The Glenwood Shoreline is an ancient shoreline of the precursor to Lake Michigan, Lake Chicago. It is named after the town of Glenwood, Illinois. The shoreline was formed when the lake was higher during the last ice age, while ice blocked the Straits of Mackinac. After the straits were freed, the lake receded and left behind a sand ridge at an elevation of about 640 feet (200 m) where the shore resided. This ridge can be seen clearly in Glenwood, Illinois, Dyer, Indiana, and Schererville, Indiana, all south of Chicago.
The Mississinawa Moraine begins in Ohio east of Lima in Hardin County, then running in a shallow arc to the south of Grand Lake St. Marys and St. Marys in Mercer County towards Fort Recovery, Ohio. Just west of Fort Recovery, the moraine again arches southward towards the Mississinewa River. The moraine follows the eastern bank of the river northwestward to where it enters the Wabash River at Wabash, Indiana. Angling towards the north and a little east, the Mississinawa moraine merges with the Packerton Moraine north of the Eel River in Whitley County near Columbia City. The moraine does not end here, but continues in a northeasterly direction through the three corners area of Michigan, Indiana, and Ohio until reaching Ann Arbor, Michigan where numerous moraines intermingle. Note: There are two common spellings of the name. Mississinawa is commonly used in the older reports. Mississinewa is the modern usage and the spelling used on modern maps and projects associated with the river. Both spellings are used interchangeably in this article, based on the source material.
The Union Moraine begins in Ohio, east of Bellefontaine and the highest point in that state, towards Greenville in Darke County. Traveling southwestward and arcing a little northward, the moraine reaches Union City, Ohio for which it is named. From here, it travels almost directly westward to Muncie, Indiana. From Muncie, the moraine runs northwest ending in the bluffs overlooking Pipe Creek at Bunker Hill, Indiana, just south of Peru on the Wabash River.
The Fort Wayne Moraine is considered contemporary to the last stages of the Valparaiso Moraine. Centered on Fort Wayne, Indiana, the northern leg of the moraine is mostly overlaid by the younger Wabash Moraine angling northeastward through Williams County, Ohio. It only becomes identifiable in Lenawee County, Michigan south and northeast of Adrian before ending in the intermingling of moraines around Ann Arbor. The south and eastern leg of the moraine follows the northern bank of the St. Marys River into the State of Ohio. At the north bend of the St. Marys River, the moraine arcs northeastward through Lima, continuing in a northward arc to reach north of U.S. 30 in Hancock County to pass through Upper Sandusky, again bending to the north to end 15 miles (24 km) to 20 miles (32 km) to the northeast.
Frank Leverett was an American geologist who specialised in glaciology.
Lake Kankakee formed 14,000 years before present (YBP) in the valley of the Kankakee River. It developed from the outwash of the Michigan Lobe, Saginaw Lobe, and the Huron-Erie Lobe of the Wisconsin glaciation. These three ice sheets formed a basin across Northwestern Indiana. It was a time when the glaciers were receding, but had stopped for a thousand years in these locations. The lake drained about 13,000 YBP, until reaching the level of the Momence Ledge. The outcropping of limestone created an artificial base level, holding water throughout the upper basin, creating the Grand Kankakee Marsh.
The Marseilles moraine is a terminal moraine that encircles the southern tip of Lake Michigan in North America. It begins near Elgin, Illinois, and extends south and west of Chicago metropolitan area, turning eastward 30 miles (48 km) to 40 miles (64 km) south of the lake in Kankakee and Iroqouis counties, entering Indiana. It formed during the Wisconsin glaciation. The glacier had been in retreat when it stopped for an extended period, depositing glacial till and sand creating the hills of the moraine.
Lake Saginaw occupied the basin of Saginaw Bay. There were two periods when it was an independent lake, not associated with a larger body of water in the Huron basin. The first Lake Saginaw was a contemporary of the last stages of Lake Maumee. When the ice border opened allowing these two lakes to become one, it entered the period of Lake Arkona. Then, the ice advanced, closing the link forming the second Lake Saginaw. This was during the time of Lake Whittlesey. When the ice margin retreated northward for the last time, it became the western bay of Lake Wayne and then of Lake Warren and Lake Lundy. During its periods as an independent lake, its outlet was west through Grand River channel.
Lake Whittlesey was a proglacial lake that was an ancestor of present-day Lake Erie. It formed about 14,000 years ago. As the Erie Lobe of the Wisconsin Glacier retreated at the end of the last ice age, it left melt-water in a previously-existing depression area that was the valley of an eastward-flowing river known as the Erigan River that probably emptied into the Atlantic Ocean following the route of today's Saint Lawrence River. The lake stood at 735 feet (224 m) to 740 feet (230 m) above sea level. The remanent beach is not horizontal as there is a ‘hinge line’ southwest of a line from Ashtabula, Ohio, through the middle part of Lake St. Clair. The hinge line is where the horizontal beaches of the lake have been warped upwards towards the north by the isostatic rebound as the weight of the ice sheet was removed from the land. The rise is 60 feet (18 m) north into Michigan and the Ubly outlet. The current altitude of the outlet is 800 feet (240 m) above sea level. Where the outlet entered the Second Lake Saginaw at Cass City the elevation is 740 feet (230 m) above sea level. The Lake Whittlesey beach called the Belmore Beach and is a gravel ridge 10 feet (3.0 m) to 15 feet (4.6 m) high and one-eighth mile wide. Lake Whittlesey was maintained at the level of the Ubly outlet only until the ice melted back on the "Thumb" far enough to open a lower outlet. This ice recession went far enough to allow the lake to drop about 20 feet (6.1 m) below the lowest of the Arkona beaches to Lake Warren levels.
Lake Arkona was a stage of the lake waters in the Huron-Erie-Ontario basin following the end of the Lake Maumee levels and before the Lake Whittlesey stages, named for Arkona, Ontario, about 50 miles (80 km) east of Sarnia.
The Lake Border Moraine is a complex group of moraines bordering the southern end of Lake Michigan. It can be traced north along the eastern shore of the lake basin and across the highlands between the northern Lake Michigan and Saginaw Bay. It continues around the Saginaw Basin into the " thumb " of Michigan, and south through southeastern Michigan on the eastern side of the "thumb." Along Lake Michigan, north to Holland the system is close to the shore. From Holland north to Oceana County it is 15 miles (24 km) to 25 miles (40 km) east of the shore. In Oceana County it forms the prominent "clay banks" along the shoreline of Lake Michigan. It again bears inland from Hart, where more recent moraines reside between it and Lake Michigan. It runs north of the great interlobate moraine that exists between the Lake Michigan and Saginaw lobes of the Laurentian ice sheet. A little north of Cadillac turns to the east. A short distance from Cadillac, it splits with the southern ridge or outer member heading to the Saginaw basin. The northern ridge heads towards Lake Huron, but turns south before reaching the shore. In Newaygo and Lake counties it rest on an earlier interlobate moraine. It separates in Wexford and Missaukee counties to continue south along the west side of the Saginaw basin.
Lake Warren was a proglacial lake that formed in the Lake Erie basin around 12,700 years before present (YBP) when Lake Whittlesey dropped in elevation. Lake Warren is divided into three stages: Warren I 690 feet (210 m), Warren II 680 feet (210 m), and Warren III 675 feet (206 m), each defined by the relative elevation above sea level.
Lake Wayne formed in the Lake Erie and Lake St. Clair basins around 12,500 years before present (YBP) when Lake Arkona dropped in elevation. About 20 feet (6.1 m) below the Lake Warren beaches it was early described as a lower Lake Warren level. Based on work in Wayne County, near the village of Wayne evidence was found that Lake Wayne succeeded Lake Whittlesey and preceded Lake Warren. From the Saginaw Basin the lake did not discharge water through Grand River but eastward along the edge of the ice sheet to Syracuse, New York, thence into the Mohawk valley. This shift in outlets warranted a separate from Lake Warren. The Wayne beach lies but a short distance inside the limits of the Warren beach. Its character is not greatly different when taken throughout its length in Michigan, Ohio, Pennsylvania and New York. At the type locality in Wayne County, Michigan, it is a sandy ridge, but farther north, and to the east through Ohio it is gravel. The results of the isostatic rebound area similar to the Lake Warren beaches.
Lake Chouteau was a glacial lake formed during the late Pleistocene along the Teton River. After the Laurentide Ice Sheet retreated, water melting off the glacier accumulated between the Rocky Mountains and the ice sheet. The lake drained along the front of the ice sheet, eastward towards the Judith River and the Missouri River.
