The ice's frame, in the survey's own names

WHAT THE GEOLOGICAL SURVEY ATTACHES TO THIS GROUND — AND WHAT IT REFUSES TO

This ground's glacial frame is stated by the Indiana Geological Survey, and this section prints the survey's names and no others: Henry H. Gray's Physiographic Divisions of Indiana (Special Report 61, 2000) divides the township's two-part ground between two of his sections. The riverfront is the St. Joseph Drainageways, in Gray's words "an extensive alluvial plain that lies along the northern border of the state and that is bounded on the south by the Plymouth Morainal Complex," whose rivers "collected meltwater from the Lake Michigan, Saginaw, and Huron–Erie Lobes of the Late Wisconsin glacier and for a time directed that drainage down the Kankakee Drainageways. When the ice began to clear the Lake Michigan basin, drainage was diverted into the present lower course of the St. Joseph River, hence the bend at South Bend." South of the plain stands the Plymouth Morainal Complex itself, "built by ice of three lobes — the Lake Michigan Lobe on the northwest, the Saginaw Lobe on the northeast, and the Huron–Erie Lobe on the southeast" — and here the survey's sentence governs this section's discipline: "These did not create a so-called interlobate moraine, but rather competed for space intermittently," leaving "a jumble of discontinuous ridges and unorganized hummocky topography of moderate relief." No interlobate framing and no moraine name from any other city's ground is imported into this township, because no source attaches one to Township 37 North, Range 4 East. The drift beneath is glacial outwash, till and lacustrine sediment at thicknesses "from about 15 to more than 70 meters" (roughly 50 to more than 230 feet) in the Geological Survey's northeastern-county study (Water-Resources Investigations Report 95-4041, 1995), whose Penn-specific sentence is the one that matches the township's two-part surface: south of the St. Joseph River the thickness of sand and gravel diminishes and clay-rich deposits dominate. The Department of Natural Resources' county ranges — unconsolidated thickness from 150 feet in the county's northeast and west to over 300 feet in its northwest — are county ranges and are printed as such; no Penn Township-specific drift thickness is published in what was reached. The bedrock under the drift is shale: the state maps exactly one bedrock aquifer system for the county, "the Devonian and Mississippian age Coldwater, Ellsworth, and Antrim Shales," about 300 feet thick, and states that in St. Joseph County only the Ellsworth and Antrim are present; the federal study identifies the conductive bedrock beneath this ground's drift as the Ellsworth Shale. The shale yields bedrock wells commonly less than 5 gallons per minute — an aquitard-grade unit, which is why the county drinks from the drift. Which of the two shales subcrops under Penn Township specifically was not established; the published text reached goes no finer than the county, and the township split is a map question, named at this section's edge.