Zusammenfassung
This work presents the first palaeostress results obtained from fault-slip
data along the eastern margins of the Dead Sea Rift (also named Dead
Sea Transform) in South-western Jordan. Stress inversion of the fault-slip
data was performed using an improved Right-Dieder method, followed
by rotational optimisation. Fault-slip data (totalling 2773) include
fault planes, striations and sense of movements, obtained from outcrops
ranging in age from Neoproterozoic crystalline basement to Holocene
sediments. The data were inverted to determine 88 different palaeostress
tensors. Eight palaeostress tensor groups (stages) have been identified,
ranging from the Late Neoproterozoic to the Holocene period, and
have been correlated with the tectonic evolution of the Dead Sea
Rift. The new palaeostress data evidence a general clockwise rotation
with time of the SHmax axis from an E-W trend in the Cretaceous to
a N-S trend in the Pleistocene. Two stages can be distinguished in
this rotation. The older one marks the change of the SHmax axis from
E-W to NW- SE (about 50 deg rotation), and took place in the Miocene.
The second one illustrates the changes of the SHmax axis from NW-SE
to NNW-SSE to N-S (38 deg rotation), taking place during the Pleistocene
(the last 6 Ma). The data also show the appearance of E-W extension
in the Late Pleistocene, superimposed on the Dead Sea Stress Field.
We therefore suggest that the Dead Sea Rift system formed in a combination
of strike-slip and dip-slip movements.
Nutzer