326
K. Leyrer· C. Strohmenger . K. Rockenbauch . T. Bechstaedt
PSI are not reworked along the slope of the platform and high-relief off-platform highs in East Germany. The main reasons for this are higher subsidence
rates in slope positions and differences in water energy regimes (reefal buildup
facies, moderate water energy), resulting in greater segmentation of the slope
surface.
Parasequence 2 (PS2; Figs. 14, 22)
An initial transgression of fifth-order magnitude characterizes the first stage of
the second parasequence of Zechstein sequence ZS3. Simulations of the south
Oldenburg area show that this transgression reworks the last remaining PSI
shallow-marine carbonates in slope position, but creates new high-energy carbonates in slope position somewhat above the highest sea-level point of PSI.
Due to the slow sea-level rise, which follows the initial sea-level rise of PS2, these
carbonates also are reworked and resedimented. As a consequence, the progradation in Northwest Germany caused by sediments of the second parasequence
is very small. The simulation of the eastern German high-relief off-platform
high (and the platform) setting shows a continuation of the PSI development.
Somewhat above the PSI sea level, the shallow-marine carbonates of PS2 are deposited (upper part of Ca2 cycle Ia), and, together with the PSI carbonates, build
a stacked pattern of shallow-marine carbonates (reefal buildups) in upper-slope
position. The high tectonic subsidence rates, which mainly influence sedimentation in slope realms of the high-relief off-platform highs, lead to a rapid
"downward movement" of those shallow-marine carbonates. Consequently,
these carbonates are not exposed to high erosional energy for a long time and
are not reworked. The water energy in general seems to be lower in easterb Germany, and therefore the early consolidated shallow-marine carbonates resist
erosional processes of the subtidal environment. Because erosion mainly affects
unconsolidated sediments in upper and middle parts of the slope, the rate of
progradation is similiar to that in Northwest Germany.
Parasequence 3 (PS3; Figs. 15,23)
Parasequence 3 builds up Ca2 cycle I (Ca2-cycle Ib) and its top (PSB3) was
picked, for convenience, at the maximum flooding surface (mfs). This gives PS3
a duration of about 200 ka, which is about 30-50 ka longer than an average
parasequence duration in Ca2 time. In eastern Germany, sea level during PS3 is
characterized by a gradual, short-term rise and a smooth, long-term sea-level
fall, which results, due to the estimated subsidence rates, in an overall relative
sea-level fall of several meters. Facies patterns show no aggradational or progradational trends and produced sediments are completely reworked during the
following transgression, which includes the mfs of Zechstein sequence ZS3. Simultaneously, the preserved high-energy carbonates of PSI and PS2 are sealed
(drowned) by upper-slope sediments deposited in the final stages of PS3. Reaching the mfs, the first carbonate sediments are deposited on top of the high-relief
off-platform high built by the Werra-Anhydrite (AI). Simulation results show
that these sediments belong completely to intertidal and shallow-subtidal facies
K. Leyrer· C. Strohmenger . K. Rockenbauch . T. Bechstaedt
PSI are not reworked along the slope of the platform and high-relief off-platform highs in East Germany. The main reasons for this are higher subsidence
rates in slope positions and differences in water energy regimes (reefal buildup
facies, moderate water energy), resulting in greater segmentation of the slope
surface.
Parasequence 2 (PS2; Figs. 14, 22)
An initial transgression of fifth-order magnitude characterizes the first stage of
the second parasequence of Zechstein sequence ZS3. Simulations of the south
Oldenburg area show that this transgression reworks the last remaining PSI
shallow-marine carbonates in slope position, but creates new high-energy carbonates in slope position somewhat above the highest sea-level point of PSI.
Due to the slow sea-level rise, which follows the initial sea-level rise of PS2, these
carbonates also are reworked and resedimented. As a consequence, the progradation in Northwest Germany caused by sediments of the second parasequence
is very small. The simulation of the eastern German high-relief off-platform
high (and the platform) setting shows a continuation of the PSI development.
Somewhat above the PSI sea level, the shallow-marine carbonates of PS2 are deposited (upper part of Ca2 cycle Ia), and, together with the PSI carbonates, build
a stacked pattern of shallow-marine carbonates (reefal buildups) in upper-slope
position. The high tectonic subsidence rates, which mainly influence sedimentation in slope realms of the high-relief off-platform highs, lead to a rapid
"downward movement" of those shallow-marine carbonates. Consequently,
these carbonates are not exposed to high erosional energy for a long time and
are not reworked. The water energy in general seems to be lower in easterb Germany, and therefore the early consolidated shallow-marine carbonates resist
erosional processes of the subtidal environment. Because erosion mainly affects
unconsolidated sediments in upper and middle parts of the slope, the rate of
progradation is similiar to that in Northwest Germany.
Parasequence 3 (PS3; Figs. 15,23)
Parasequence 3 builds up Ca2 cycle I (Ca2-cycle Ib) and its top (PSB3) was
picked, for convenience, at the maximum flooding surface (mfs). This gives PS3
a duration of about 200 ka, which is about 30-50 ka longer than an average
parasequence duration in Ca2 time. In eastern Germany, sea level during PS3 is
characterized by a gradual, short-term rise and a smooth, long-term sea-level
fall, which results, due to the estimated subsidence rates, in an overall relative
sea-level fall of several meters. Facies patterns show no aggradational or progradational trends and produced sediments are completely reworked during the
following transgression, which includes the mfs of Zechstein sequence ZS3. Simultaneously, the preserved high-energy carbonates of PSI and PS2 are sealed
(drowned) by upper-slope sediments deposited in the final stages of PS3. Reaching the mfs, the first carbonate sediments are deposited on top of the high-relief
off-platform high built by the Werra-Anhydrite (AI). Simulation results show
that these sediments belong completely to intertidal and shallow-subtidal facies