and lowlands in the southwest are filled with groundwater close to the surface. These gley soils are natural locations for grasslands. Peaks and ridges are rising from the lowlands consisting of dune sands und meltwater sands, which are sediments and sedimentary rock of the quaternary. These sands have decomposed to nutrient-poor, acidic heather soils (Podsols), partly with hardpan in the subsoil. On the south-western slope of the Teutoburg Forest, for example near Künsebeck, they occupy large areas. As a consequence of historic tillage techniques and long-term agricultural usage these soils are partly composed of deeply rooting humus, in scattered areas with a sod coat. Some isolated dells are located in south-westerly direction of the main ridge of the Teutoburg Forest, for example the Hesseln mountains. Slim clay-loam soils (Rendzina) have developed here from limestone and marlstone of the Cretaceous. These basic soils are typical locations for precious hardwood. The main ridge, for example represented by the Große Egge (=Big Harrow), is composed of sandstone of the Cretaceous. On this stone thick, acidic and rocky heather soils have built up. Halle is fairly to well, in areas on or near the ridge very well suited to use geothermal power sources by means of geothermal probes and heat production using a heat pump (see also adjoining map). Dimensions and usage of urban area The town covers an area of . The major part consists of agricultural area () and forests (), in total approx. 83%, followed by developed area () and circulation area (), in total approx. 15%. The maximum stretch both in northern – southern direction and in western – eastern direction is approx. 10 km. The northernmost point is north of Eggeberg at approx. 52° 5´ 4´´ northern latitude, the southernmost point is south of Kölkebeck at approx. 51° 59´ 38´´. Neighbouring communities Halle borders the town of Borgholzhausen in the northwest, the town of Werther in the northeast, the community of Steinhagen in the southeast and south, the town of Harsewinkel in the southwest and the town of Versmold in the west, all belonging to the district of Gütersloh. Major neighbouring cities are Bielefeld and Gütersloh, both in approx. 15 km distance. Subdivisions of the town Halle (Westf.) is divided into ten urban districts, of which (besides Halle itself) only the industrial-suburban Künsebeck as well as the rural-agrarian villages Bokel, Hesseln, Hörste and Kölkebeck are built-up areas. While the