330
K. Leyrer· C. Strohmenger . K. Rockenbauch . T. Bechstaedt
areas commonly takes place from mostly intertidal Ca2 carbonates to pure anhydrites, indicating a salina environment.
5
Results and Conclusions
The high-resolution forward stratigraphic modeling of the Ca2 platform in the
northwest German south Oldenburg area and the Ca2 high-relief off-platform
highs in the eastern German southeast Brandenburg area gives insights on factors ruling sedimentation during Ca2 time.
As shown by the results of detailed core description and supported by the
simulation results, the general facies distribution and, more importantly, the
reservoir facies distribution within the Ca2 are mainly driven by the topography
of the underlying anhydrite (Werra-Anhydrite, or AI). In addition, the modeling
shows that differential subsidence rates (Sect. 3.2) contribute to the shaping of
the different depositional systems during Ca2 time. The assumed carbonate production curves (Sect. 3.4; Fig. 3) show substantial differences between Northwest Germany and eastern Germany during Ca2 deposition. northwest German
Ca2 carbonate production rates are assumed to be considerably higher than
those in eastern Germany, and show a substantial decrease at the end of the HST
of Zechstein sequence ZS3 (after about 900 ka of Ca2 sedimentation). Since this
decrease cannot be recognized in the investigated eastern German area, it is
thought to be linked to the different paleogeographic positions of each study area. In the case of the eastern German southeast Brandenburg area, the subsidence rates also contribute to the preservation of a highly dissected morphology
characterized by the existence of a platform and two types of off-platform highs.
Interacting with sea level, different subsidence rates in this region also influence
the deposition and preservation of primary reservoir sediments at the upper
slope area during the first two parasequences (PSI and PS2, Sect. 4.I).
The drop in sea level which marks the end of Zechstein sequence ZS3 is slower
and of minor impact in areas directly connected to the Tethys, which acts like an
open marine system. Even minor sea-level rises add a certain amount of normal
marine water to the restricted water body near the connection site and the impact of evaporation on the water chemistry is weakened considerably in these
places. However, the impacts of such processes depend on the direction and
power of water flow, and generally vanish with increasing distance from the
open marine system. This idea is supported by comparing Ca2 sediments in the
two study areas since the southeast Brandenburg area is situated considerably
nearer to the South Polish opening to the Tethys than the northwest German
South Oldenburg area. The higher water currents in this southeastern-most part
of the Southern Permian Basin contribute to the buildup of isolated carbonate
bodies (off-platform highs) and widely prevent the accumulation of sediments
in slope and basin areas of these islands.
The late LST, TST and HST of Zechstein sequence ZS3 are built up of seven shallowing upward cycles (parasequences), which mark minor flooding events and
K. Leyrer· C. Strohmenger . K. Rockenbauch . T. Bechstaedt
areas commonly takes place from mostly intertidal Ca2 carbonates to pure anhydrites, indicating a salina environment.
5
Results and Conclusions
The high-resolution forward stratigraphic modeling of the Ca2 platform in the
northwest German south Oldenburg area and the Ca2 high-relief off-platform
highs in the eastern German southeast Brandenburg area gives insights on factors ruling sedimentation during Ca2 time.
As shown by the results of detailed core description and supported by the
simulation results, the general facies distribution and, more importantly, the
reservoir facies distribution within the Ca2 are mainly driven by the topography
of the underlying anhydrite (Werra-Anhydrite, or AI). In addition, the modeling
shows that differential subsidence rates (Sect. 3.2) contribute to the shaping of
the different depositional systems during Ca2 time. The assumed carbonate production curves (Sect. 3.4; Fig. 3) show substantial differences between Northwest Germany and eastern Germany during Ca2 deposition. northwest German
Ca2 carbonate production rates are assumed to be considerably higher than
those in eastern Germany, and show a substantial decrease at the end of the HST
of Zechstein sequence ZS3 (after about 900 ka of Ca2 sedimentation). Since this
decrease cannot be recognized in the investigated eastern German area, it is
thought to be linked to the different paleogeographic positions of each study area. In the case of the eastern German southeast Brandenburg area, the subsidence rates also contribute to the preservation of a highly dissected morphology
characterized by the existence of a platform and two types of off-platform highs.
Interacting with sea level, different subsidence rates in this region also influence
the deposition and preservation of primary reservoir sediments at the upper
slope area during the first two parasequences (PSI and PS2, Sect. 4.I).
The drop in sea level which marks the end of Zechstein sequence ZS3 is slower
and of minor impact in areas directly connected to the Tethys, which acts like an
open marine system. Even minor sea-level rises add a certain amount of normal
marine water to the restricted water body near the connection site and the impact of evaporation on the water chemistry is weakened considerably in these
places. However, the impacts of such processes depend on the direction and
power of water flow, and generally vanish with increasing distance from the
open marine system. This idea is supported by comparing Ca2 sediments in the
two study areas since the southeast Brandenburg area is situated considerably
nearer to the South Polish opening to the Tethys than the northwest German
South Oldenburg area. The higher water currents in this southeastern-most part
of the Southern Permian Basin contribute to the buildup of isolated carbonate
bodies (off-platform highs) and widely prevent the accumulation of sediments
in slope and basin areas of these islands.
The late LST, TST and HST of Zechstein sequence ZS3 are built up of seven shallowing upward cycles (parasequences), which mark minor flooding events and