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We investigated a 10 x 20 km area approx. 40 km north of Hannover using 3D reflection seismics. The Top Rotliegend surface in this area lies between –4600 m and –4150 m elevation (see Fig.). Rotliegend sandstones are gas plays, but low permabilibities (< 0,6 mD) hinder extraction. We differenciated the following types of faults from seismic analysis: 1) N-S striking normal faults, 2) a NW-SE striking strike-slip fault, and 3) late NE-SW striking faults with along-strike throws of 0-90 m, 0-150 m and 0-50 m, respectively. In the decimetre sandstone/shale units of the Upper Rotliegend these throws tend to increase across-fault connectivity. We suggest type 1 and 2 faults developed in a synsedimentary, dextral transtensive regime. Only faults with more than 50 m throw extend down to the Carboniferous and offer shortcuts for hydrocarbon flow. A compilation of paleostresses from published data (cf. Ziegler 1990), shows all the faults were under dilation during the Triassic and Jurassic, but sealing from Barremian to Eocene times. This is substantiated by the exclusive Jurassic ages of chlorite and illite diagenesis. Top Rotliegend surface of the ‘Tight Gas’ area. Faults are black. Reference: Ziegler, P.A. (1990) Geological Atlas of Western and Central Europe