Tectono-stratigraphic analysis of Early Syn-Rift Siliciclastic Deposits of
Nakheil and Ranga Formations, based on outcrop data from Hamadat  Half Graben basin, south Quseir indicates that the evolution of normal faulting was
an important role on syn rift depositional patterns and sequence stratigraphic
development. The Nakheil Formation was deposited in depocentres formed
during the low subsidence rift initiation phase. The Nakheil and the Lower
Ranga Formations are composed of fluvial-deltaic lacustrine deposits that
arranged in several stacked aggradational-progradational cycles having a wegeshaped
geometry near the the fault–bounded areas, reflecting the continuo
creation of accommodation. In the hangingwall dip-slope margins where low
accommodation, the deposits are dominated by progradational cycles with local
incised channels. The overlying Ranga Formation was deposited during the high
subsidence, rift-climax phase, and is composed of stacking aggradational and
progradational Gilbert-type fan deltas.
Three major paleogeographical evolutionary stages can be established:
During the earliest rift-initiation stage (stage 1), propagation of isolated fault
segments of the basin-bounding fault zone led to formation of a series of
hangingwall synclines acted as depocentres in which Nakheil and Abu Ghusun
formations were deposited. Withtime intrafault block with a relatively small
displacement were developed. This resulted in the formation of hangingwall
depocenters in which Nakheil Formation was accumulated. During the latest
syn-rift-initiation stage (stage 2), lateral propagation and linked between the
 enlargement and coalescence of early intrafault block depocenters, resulting in
one large depocenter has a more typical half graben geometry filled by
sediments of Lower Ranga Formation. In stage 3, during the early rift-climax
event and formation of tilt fault-block rotation, the southeastward decrease of
displacement of the Hamadat and Zug El Bohar faults led to open the half
graben basins southwards and acted as pathway for clastic sediments of Upper
Ranga Formation, derived from the uplifted rift margins to the west and
northwest.basin-bounding fault segments caused breaching of the folding and led to the