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I I I I I 1 I 1 I I 1 III. ENVIRONMENTAL SETTING OF PHYSICAL ENVIRONMENT A. TOPO- GRAPHY B. SOILS 1 I I I 1 :1 I I The topography of the site may be described as irregular with distinct upland and lowland areas. The site presently (November, 1975) contains two areas of ponded water and one small pond bed devoid of water. Surface elevations on the site range from 956 feet Mean Sea Level in the extreme north- west corner of the site to approximately 938 at the pond surfaces. The standing water depth ranges from 0.5 feet to 3.5 feet. Land to the north of the site (across County Road E) is approximately 8 to 14 feet higher than the site. Most of the soil conditions throughout Minnesota have resulted from geologically recent glaciation. The Twin Cities area has been overridden by two major advances of glacial ice. One moved from the Lake Superior Basin down the Minneapolis lowland and terminated at the St. Croix Moraine. The mate- rials carried by this movement of ice are charac- terized by a red color and sandy texture (unified soils classification for the till is generally SM- silty-sand). The second advance of the Grantsburg sublobe of the Des Moines lobe transported gray till of a much finer grained texture (clay) mixed with stones. The western New Brighton area, including the Windsor Center site, is situated in the contact or mixing zone of these till deposits. This mixing zone is characterized by brownish and reddish-brown soils which are basically clays and sandy clays with a comparatively low plasticity and permeability. Preliminary soil borings of the Windsor Center site, by Geotechnical Engineering, (Appendix A) 111-1 I -- ~