® Ontario ontario institute of pedology - Agriculture and Agri-Food ...

The Precambrian bedrock resisted the scouring action of ice, and the upland areas are bareto thinly covered by till material.The distribution of surficial geological materials is shown in Figure 4 . The glacial till, sand,gravel and clay that make up these surficial deposits, are the parent materials in which the presentdaymineral soils developed .At the end of the glacial period, depressional areas became vegetated with mosses, sedges,and/or trees, and under wet conditions, accumulated deep deposits of organic material in whichorganic soils developed .The soil materials derived from Precambrian rock, and those derived from organic materials,are acid in reaction ; while those derived from lacustrine or lacustrine-modified till are neutral toalkaline. This has contributed to important differences in the resultant soils which have developedsince deposition of the parent material .ClimateTable 4 shows some climatic data for the Timiskaming District (6), that is applicable to theVille-Marie map sheet .The factors controlling the temperature of this area are latitude, altitude, relief, andproximity to the Great Lakes, and to a lesser degree to Hudson Bay. Thus, those land areasadjacent to Lake Huron and Lake Superior have the mildest climates .The more rugged area of the north, with deep valleys and high uplands, have wide variationsin climate . Weather stations are generally located in the valleys in these areas, so the data will belargely applicable to the valleys . The data for the Clay Belt, and other level areas of low relief, willbe applicable to most areas within such a physiographic region .According to climatic data, the New Liskeard-Englehart region has a longer, warmer growingseason than the northern Clay Belt, but a cooler and shorter growing season than those regions thatare closer to the moderating effects of Lakes Huron and Superior, such as the Sault Ste. Marie-Sudbury area, or the Rainy River-Thunder Bay area.Table 4. Climatic data from the Timiskaming District (6)Climatic ParameterTimiskamingMean date of lastfrost in spring June 10Mean date of firstfrost in fall Sept . 13Mean annual frostfreeperiod-days 96Mean annual lengthof growing season 172Mean annualprecipitation - mm 813Mean May to Septemberprecipitation - mm 406