Hydrogeological overview map of Lower Saxony 1: 500 000 — Aquifer types of near-surface rocks (WMS service)

The map shows the aquifer types of near-surface rocks in a scale of 1:500 000. The rock units of the Geological Survey Map have been divided into three classes describing the essential conductor characteristics: Pore aquifers, cleft aquifers and aquifers. — Pore aquifers These non-solidified sedimentary rocks consist predominantly of the coarser grain components gravel and sand and have a coherent cavity volume, which, depending on the specific composition, is between 10 and 35 % of the rock volume. The groundwater can move well in these rocks, is distributed relatively evenly and forms a clearly pronounced groundwater surface, which can be easily accessed by drilling. — Groundwater low-water ladder Rocks with very low effective cavity proportions and dense rock masses can only store or pass on groundwater to a small extent. As such, the fine-grained loose rocks and solid rocks (tony, fluffy), but also the barely-capped dense volcanoites and magmatites act as such aquifers. The clay rocks have a high primary porosity of more than 30 %, but this is not available for groundwater movement because of the capillary forces acting in them. — Submersible aquifers These solidified compact rocks, which were mainly formed by diagenesis of sediments, have subsequently been cracked and disturbed to varying degrees by tectonic stress. This secondary cavity volume occupies only a small part (few %) of the total rock volume, but can facilitate a relatively rapid movement of groundwater. The primary cavity volume in these rocks has been significantly reduced by the diagenesis processes. The map presented here was created by reattributing the contents of the "Geological Overview Map of Lower Saxony 1: 500 000" and thus, as a rule, only takes into account a depth range of about 2 m below the top of the terrain. Information about the properties of lower-lying rock layers can not be found from this map.