Uplift and denudation history of the eastern Dead Sea rift flank, SW Jordan: Evidence from apatite fission track thermochronometry

Abstract

The Dead Sea rift (DSR), developed along the Dead Sea transform plate boundary, is characterized by salient flanks and morphotectonic asymmetry. Apatite fission track thermochronology (AFT) along ~1200 m high vertical profiles in Neoproterozoic basement and overlying Cambrian sandstone in southwestern Jordan is used to reconstruct timing, magnitude, and rate of uplift and denudation of the eastern DSR flank and examine its relationship to rift development and its flank landscape. Time‐temperature models based on AFT data suggest three major Phanerozoic heating and cooling episodes, Late Paleozoic, Early Cretaceous, and Oligocene. The latest episode, on which this study focuses, indicates uplift of ~3.8±0.3 km under a moderate paleogeothermal gradient. About 40% of the uplift was tectonically driven with the remainder attributed to isostatic rebound in response to denudation and erosion. Models suggest that uplift commenced in the Oligocene with a considerable part occurring prior to development of the DSR, despite being ~200 km from the Red Sea‐Gulf of Suez rift margin. Uplift is probably part of a regional rearrangement along the western Arabian platform margin occurring at the time of Red Sea rift initiation. Transition from primarily sedimentary layer stripping, most likely by scarp retreat, to one of dominantly incision of the underlying crystalline basement occurred in Late Miocene‐Pliocene time following enhanced subsidence and development of a low base level in the DSR. Consequently, the magnitude of uplift by isostatic rebound due to incision exceeded lowering by surface truncation and increased summit elevation and riftward flexing of the flank.

Oligocene regional denudation of the northern Afar dome: Pre- and syn-breakup stages of the Afro-Arabian plate

“…Our study demonstrates that the separation between Africa and Arabia had two phases: its initiation began in the Eocene-Oligo cene, and intensifi ed since the late Oligocene-early Miocene. This two-phase scenario is in agreement with fi ssion-track analyses (e.g., Omar and Steckler, 1995;Feinstein et al, 2000Feinstein et al, , 2004Feinstein et al, , 2010.…”

“…This two-stage morphotectonic evolution model for the Afar-southern Levant region is clearly demonstrated by fi ssion-track analysis presented by Omar and Steckler (1995) from the Red Sea region and by Feinstein et al (2000Feinstein et al ( , 2004Feinstein et al ( , 2010 from the northern tip of the Gulf of Aqaba. Both studies indicated that, besides the well-known rifting and rock uplift phase centered in the early Miocene, an initial early Oligocene stage was clearly identifi ed.…”

Cenozoic epeirogeny of the Arabian Peninsula from drainage modeling

“…The temporal variation of uplift within this 30 Ma period can be constrained in different ways. First, thermochronometric measurements are used to determine rates of denudation at spot locations [Kohn and Eyal, 1981;Bohannon et al, 1989;Menzies et al, 1997;Feinstein et al, 2013]. At present, these spot measurements are sparse and dominated by localities in Yemen.…”

The formation of graben morphology in the Dead Sea Fault, and its implications

“…Our thermomechanical modeling demonstrates that narrow asymmetric half‐graben, bounded by a planar active normal eastern fault and a slightly curved less active western fault (Figures c and b), observed also in the field [ ten Brink et al ., ; Wdowinski and Zilberman , ; Feinstein et al ., ], originated in the early stages of the rift evolution. During the entire rifting period (circa 5 Ma), deformations concentrated at these normal faults.…”

“…The topography at the southern segment of the DSF shows a distinct asymmetry [ Ben‐Avraham and Zoback , ; Wdowinski and Zilberman , , ]. The larger subsidence and higher uplift are observed at the eastern border fault [ ten Brink et al ., ; Feinstein et al ., ]. East from the rift axis, the elevation rises sharply to 1400–1700 m above sea level (asl) at the peaks of Transjordan Mountain Belt (TJMB), located 20–30 km away (Figure a).…”