2 Undergraduate Research – Environmental Geology, Hydrogeology, Quaternary Geology and Geomorphology (Posters)

Monday, 23 April 2001
8:00 AM - 12:00 PM

REMANENT MAGNETISM OF PRE-ILLINOIAN TILLS AND SEDIMENTS FROM NOTHERN MISSOURI

Paper number: 2-16
Program: Technical Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

We have studied the magnetic characteristics of a ten meter section of sediments and tills exposed in a clay pit (Musgrove Pit) in northern Missouri. The sequence includes a preglacial mass flow overlain by a proglacial silt which, in turn, is overlain by a till known informally as the Atlanta formation. Atkinson and Kean (2000) determined the magnetic mineralogy throughout the section is uniform in composition and grain size based on magnetic susceptibility, hysteresis properties and saturation isothermal remament magnetism (SIRM) studies. The remament magnetic directions throughout the sequence are predominantly reversed in polarity. Rovey and Kean (1996) suggest the till is older than 2.1 million years based on stratigraphic position and a date from an overlying tephra. The reversed magnetic directions and the stratigraphic information place this sediment sequence in the early part of the Matayama Reversed Chron. If this reversal sequence proves to be consistent among the other sites in Missouri, it can be used as a stratigraphic marker to correlate Pre-Illinoian tills.

Atkinson, L.R. and Kean, W.F., 2000, Magnetic Properties of Pre-Illinoian Tills from Northern Missouri, 37th Annual AIPG National Meeting, p.23, Milwaukee WI.

Rovey, C.W., II, Kean, W.F., 1996, Pre-Illinoian Glacial Stratigraphy in North-Central Missouri, Quaternary Research, 45, 17-29.