Abstract
A detailed three-dimensional (3-D) gravity model of upper crustal
structures was created for the Dead Sea Transform in the Araba/Arava
Valley, located some 80 km south of the Dead Sea Basin. The density
model covers an area of \~30x30 km and incorporates results from
several recent geophysical experiments performed in this region.
The model presented is a local density model that focuses on the
uppermost crustal layers to a depth of \~5 km. Therefore, in order
to separate the effect of regional structures (such as the crust-mantle
boundary) from that of local structures within the crust, a residual
anomaly was computed from a newly compiled Bouguer gravity anomaly
database. In contrast to the Bouguer anomaly, which is negative across
the entire study area, the residual gravity field contains both positive
and negative values. The 3-D structural image of the upper crust
reveals that the basement east and west of the Dead Sea Transform
is vertically offset by 1.5 to 2.8 km. Considering the 105 km of
sinistral displacement of the Dead Sea Transform, this result confirms
the findings of other geophysical measurements that show an abrupt
change in the physical parameters and geometry of the two lithological
blocks that are juxtaposed along the Dead Sea Transform. Additionally,
analysis of the calculated gravity gradients suggests that the Dead
Sea Transform and the neighboring Zofar fault could be offset at
depth with respect to the present-day traces at the surface.
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