![](images/indent.JPG) |
|
|
|
| Heaton,
R. C., M. P. A. Jackson, M. Bamahmoud, and A. S. O. Nani, 1995, Superposed
Neogene extension, contraction, and salt canopy emplacement in the Yemeni
Red Sea, in M. P. A. Jackson, D. G. Roberts, and S. Snelson, eds.,
Salt tectonics: a global perspective: AAPG Memoir 65, p. 333-351. |
|
---|
![](images/indent.JPG) |
|
|
|
R. C. Heaton
BP Exploration
Uxbridge, Middlesex,
U.K.
Present address:
Cairn Energy PLC
Edinburgh, U.K.
|
| M. P. A.
Jackson
Bureau of Economic Geology
The University of Texas
at Austin
Austin, Texas, U.S.A.
M. Bamahmoud
A. S. O. Nani
Yemeni Ministry of Oil
and Mineral Resources
Sana'a, Yemen
|
|
|
---|
![](images/indent.JPG) |
|
Abstract
Although the
Neogene Red Sea basin has been intensively examined as the type example
of a young, narrow ocean, salt tectonics there has been neglected. The
Yemeni part of the Red Sea exhibits a wide array of salt tectonic features
within a small area. Above the rift section, a middle Miocene evaporite
layer, originally 1.5-2 km thick, is the source for autochthonous and allochthonous
salt structures. In the middle-late Miocene, evaporite-clastic overburden,
halite, and anhydrite layers 50-350 m thick assisted deformation by providing
several levels for décollement. Four southward-narrowing tectonic
zones trend subparallel to the basin axis. Areas of extension in the easternmost
Roller Zone, severe shortening in the central Canopy Zone, and mild shortening
in the western Anticline Zone all narrow then pinch out at roughly the
same latitude. This convergence suggests that extension and contraction
are linked by various salt layers and by transfer structures transecting
the tectonic zones. Extension, contraction, and coeval salt canopy emplacement
were superposed, mostly between 8 and 5 Ma. The presence of allochthonous
salt sheets casts doubt on previous estimates of salt 5 km thick in the
southern Red Sea. Fault scarp asperities in the basin floor may have acted
as buttresses against which contraction was initiated. The wide variety
of salt structures may be due to the weakness and anisotropy of the partially
evaporitic overburden and to high geothermal gradients (up to 77°C/km).
These factors enhanced the deformation driven by gravity spreading and
sedimentary differential loading. |
---|