Abstract:
Industry seismic reflection profiles shot in the 60's and early 70's in the central
Persian (Arabian) Gulf are used to map two late Tertiary unconformities, and velocity data
from a centrally located well is used to convert travel time to depth to the unconformities.
The deeper horizon correlates with a regional unconformity at the end of the Eocene in most
wells and dips monotonically to the northeast, whereas the shallower horizon is flatter and
correlates with the mid-upper Miocene section in one well. Isopach maps based on wells
indicate that sedimentation was relatively uniform across the region until the middle to late
Miocene. Sediments deposited since the late Miocene thicken from 100-200 m on the
Arabian side of the Gulf to >1000 m near Iran reflecting deposition of sediments eroded
from the rapidly uplifting Zagros fold-belt. As a result of the rapid deposition, the velocity
gradient in the upper 1 km decreases from ~4 km/sec per km near Arabia to about 2 km/sec
per km on the Iranian side of the Gulf.
