As part of the geothermal project GeneSys, the Federal Institute for Geosciences and Natural Resources, drilled the Groß Buchholz Gt1 geothermal well. At a depth of approx. 1,100 - 1,330m several sandstone layers of the Lower Cretaceous (predominantly Bückeberg Fm/Wealden) are present. Additionally to the borehole data, two seismic surveys covering the surrounding area (BGR 01-2001, 01-2006) were generated. For potential geothermal usage of these sandstone layers, their regional distribution within the larger Hanover area is one of the main questions. During the Early Cretaceaous the Lower Saxony Basin was bordered by the Pompeckj Swelll to the north, by the Rhenish Massif and Hildesheim Peninsula to the south, the Flechtingen High to the east and the East Netherlands Triassic Platform to the west. These large areas isolated the Lower Saxony Basin mainly from the sea at that time. The study area is located northeast of Hanover at the former basin margin, which is dominated by siliciclastic units (Bückeberg Fm, Wealden). Although there is some literature on the origin of these units, a detailed depositional model explaining their genesis is lacking. Therefore, we analyzed two 2D seismic sections in terms of seismic facies. First results pointing to a prograding deltaic - fluviatil system. These findings give new insights into the deposition of the so-called Wealden in the area of Hanover as well as in a regional context.