Dokumentation und Bewertung ausgewählter Schnittzonen im Salinar des Standortes Hattorf/Wintershall (Werk Werra)
Research output: Thesis › Master's Thesis
Two profiles were examined at the site Hattorf and 159 samples were taken and analyzed with XRD to characterize mineral conversions in the surroundings of intrusions and gas occurrences. In addition, the Basalt in the center of the profile on the second level was examined using Raman and EDXS. At the profile in seam Hessen, mineral conversions in between the barren and the normal seam are visible in all fine-stratigraphic horizons and occur abruptly. Red Sylvinite mineralizations, which occur in the first associated seam and the Bändersalz vanish in the barren area. In the Flockensalz and the Wurmpartie white Kainite mineralizations occur in between the normal and the barren seam. On the whole, the barren part of the seam seems darker and otherwise invisible Anhydrite layers in the Flockensalz and the first associated seam get visible. At the profile in seam Thüringen conversions are primarily visible in the facies part, also geochemically they are most distinct in this horizon. The transition between Sylvinite- and barren-facies is accompanied by the disappearance of the Trümmercarnallitit-fabric and the occurrence of Langbeinit mineralizations. In both profiles there are indications that fluids ascended at different times and with different compositions. For the large-scale examination of the gas events in the Mine Werra, 12,580 gas occurrences were analyzed on the first level and 23,240 on the second level using ArcGIS software. On the first level most of the gas events occur in the Hartsalz-facies and in 75% of these the outburst mass is not relevant. In the case of bigger outbursts however, the development and gas impregnation of the first associated seam could play an important role. On the second level most of the outbursts take place in the Carnallite-, the Sylvinite- and the Sylvinite above Carnallite-facies. In the Carnallite-facies the outbursts are concentrated especially at the edges of the facies areas, which border on conversion facies such as Sylvinite above Carnallite, Sylvinite and barren areas. In particular, the Sylvinite- and the Sylvinite above Carnallite-facies reveal a high hazard potential because of the high density and size of the outbursts. Areas which are barren because of magmatic activity also show a higher hazard potential. On both levels mineral veins correlate well with gas events, especially in the Hartsalz-facies. The evaluation of more than 45,000 veins showed that most of them are N-S striking. A subordinate NW-SE striking also occurs. The gas events are mainly concentrated along the N-S striking veins, along the NW-SE striking veins they show poor correlation. The ArcGIS Hot Spot analysis shows that Hot Spots occur especially at the site Unterbreizbach and in the southern part of the site Hattorf. In some locations they accumulate level overarching. Maiden areas in the extensions of N-S striking magmatic dyke zones with related conversion facies (Sylvinite above Carnallite, Sylvinite, barren) bear an increased risk for gas events. Knowledge about the composition, the thickness and the proximity of the first associated seams could improve the risk assessment of big gas events.
|Translated title of the contribution||Documentation and validation of selected profiles in the salinar facies of the mine Hattorf/Wintershall (Werk Werra)|
|Publication status||Published - 2021|