ADVANCES IN SURFICIAL KARST FEATURE MAPPING IN THE HIAWATHA NATIONAL FOREST, MICHIGAN

Surficial karst feature mapping has been ongoing for decades on the Hiawatha National Forest (HNF), Michigan. These karst features are found on and in the Niagara Escarpment which runs from eastern New York, through Ontario, Canada, across the Upper Peninsula in Michigan, and back south through the Door Peninsula in Wisconsin. The bedrock group that makes up the largest area of the Niagara Escarpment in the HNF is the Engadine group, which is primarily a dolostone unit. The HNF contains some of the last undeveloped land within the Niagara Escarpment.

Karst features have been mapped in this area for the last few years, including: alvar, boulder fields, caves, cliffs, fissures, ledges, outcrops and sinkholes. With the completion of this summers (2010) mapping there are a sufficient number of identified features to allow for interpretation of the features spatial locations.

Analysis inside of ArcGIS has allowed for statistical study of feature location in relation to elevation. Statistically sound observations (p = 0.685) were made that demonstrate that the karst features occur at similar elevations (i.e. 250m). It has been proposed that the expression of surficial karst features can be caused by wave action of paleo lakes (Futyma, 1981). The Main Stage of the late post glacial Lake Algonquin was also at this elevation (250m). This abstract suggests that the reason this specific elevation exhibits the strongest expression of surface karst features is wave action from Lake Algonquin and supports Futyma’s hypothesis.

With this observation future surfical karst inventory work can be focused around 250m of elevation. This will reduce the number of labor hours required for the surveying of the area, and result in more efficient and thorough surveying methods. Anticipated future work will to add more factors to the model including, wetlands and swamps, depth to bedrock, and land surface steepness.