MAPPING THE MIGHTY MISSOURI RIVER: DEVELOPING AN INTEGRATED MAP DATA SET FROM SURFICIAL ALLOSTRATIGRAPHIC MAPS OF A REACH OF THE MISSOURI RIVER VALLEY FLOOR FROM YANKTON, SD TO MONDAMIN, IA

Surficial mapping of the Missouri River Valley has revealed valuable insights into the evolution and development of the Missouri River since the last glacial maximum with the recession of the Laurentide Ice Sheet. Despite being in our own backyard, there is very limited geological research available on the Missouri River. Using existing aerial, topographic and digital elevation maps along with field research, students funded by the USGS EDMAP and NSF REU programs mapped the allostratigraphy of a reach of the Missouri River Valley from Yankton, SD to Mondamin, IA. The purpose was to provide a visual representation of the morphological changes the Missouri River has undergone and present it in a fashion similar to the Saucier (1994) maps of the Lower Mississippi Valley.

With the existing maps and field research data in hand; a total of 30 NSF REU and 10 USGS EDMAP students built the surficial maps using ArcGIS, drawing the allostratigraphic units overlaying USGS topographic maps and aerial imagery. The maps underwent numerous edits during initial preparation to assure quality to confirm consistency with established geologic knowledge (e.g. a cutoff meander loop should be cut off by another channel type or otherwise terminated, etc.). These initial maps still, however, were independent products and were not fully consistent in format and were unintegrated.

This project defines an effort to re-master the full set of maps into a consistent and integrated map set to be published in entirety by the South Dakota University Press. Efforts to integrate the map set include: adding surficial features missed in initial mapping, refining shape, edge mapping, adding latter-obtained data (e.g., OSL dates), and edge mapping. Final maps will hopefully be available as interactive PDF’s where a user will be able to select dig site data from borehole locations.