The Cretaceous to Eocene succession in central and south Jordan is characterised by passive continental margin depositional sequences, which pass upward from alluvial/paralic to carbonate shelf and pelagic ramp settings. Detailed section logging and outcrop mapping have produced robust lithostratigraphic and lithofacies schemes that can be correlated throughout the region and in the subsurface. These schemes are set in a sequence-stratigraphic context in relation to the evolution sedimentation on the Arabian and Levant plates. Three major megasequences are described (Kurnub, Ajlun and Belqa), and these are further subdivided into large-scale depositional sequences separated by regional sequence boundaries that represent maximum flooding surfaces. There is close correspondence between maximum flooding surfaces recording major sea-level rise with those derived for the Arabian and Levant plates, although there are some discrepancies with the precise timing of global sea-level fluctuations. An upward change from braided to meandering stream fluvial environments in central and south Jordan during the Early Cretaceous, reflects a decreasing geomorphological gradient of the alluvial plain, declining siliciclastic sediment flux, and increased floodplain accommodation, associated with a regional Late Albian (second-order) rise in relative sea-level. The Late Albian to Early Cenomanian marine transgression across the coastal alluvial plain marks a major sequence boundary. During Cenomanian to Turonian times a rimmed carbonate-shelf was established, characterised by skeletal carbonates showing small-scale, upward-shallowing cycles (fourth- to fifth-order parasequences) ranging from subtidal to intertidal facies, arranged into parasequence sets. Rimmed carbonate shelf sequences pass laterally to coeval coastal/alluvial plain facies to the south and east. Eustatic (third-order) fluctuations in relative sea level during the Cenomanian and Early Turonian resulted in deposition of ammonite-rich wackestones and organic-rich marls, during high sea-level stands (maximum flooding surfaces). Progradational sabkha/salina facies passing landwards to fluvial siliciclastics were deposited during an Early Turonian sea-level low stand, marks a regional sequence boundary, above which a highstand carbonate platform was established. A second-order, regional rise in sea level and marine transgression during the Early Coniacian marks a Type 2 sequence boundary, and subsequent drowning of the rimmed carbonate shelf by Late Coniacian times. Sedimentation during the Santonian to Maastrichtian was characterised by a hemi-pelagic chalk-chert-phosphorite lithofacies association, deposited in shallow to moderate water depths on a homoclinal ramp setting, although thicker coeval sequences were deposited in extensional rifts. The marked change in sedimentation from rimmed carbonate shelf to pelagic ramp is attributed to Neo-Tethyan mid-oceanic rifting, tilting, intracratonic deformation and subsidence of the platform; this is reflected in changes in biogenic productivity and ocean currents. Oceanic upwelling and high organic productivity resulted in the deposition of phosphorite together with giant oyster banks, the latter developing within oxygenated wave-base on the inner ramp. Chalk hardgrounds, sub-marine erosion surfaces, and gravitational slump folds indicate depositional hiatus and tectonic instability on the ramp. In the Early Maastrichtian, deeper-water chalk-marl, locally organic-rich, was deposited in density-stratified, anoxic basins, that were partly fault controlled. Pulsatory marine onlap (highstand sequences) during the Eocene is manifested in pelagic chalk and chert with a paucity of benthic macro-fauna, indicating a highly stressed, possibly hypersaline, and density-stratified water column. Comparison with global and regional relative sea-level curves enable regionally induced tectonic factors (hinterland uplift and ocean spreading) to be deduced, against a background of global sea-level rise, changing oceanic chemistry/productivity and climatic change.

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.

The development of a rapid, non-parametric, and slightly conservative predictor for the estimation of probable weight loss in the standard Building Research Establishment sodium sulphate crystallisation test, and hence of estimated limestone durability class, based on [Porosity Saturation ] 0.5 is described. The time saving offered by application of the look-up tables provided here reduces the 3–4 weeks required for the Building Research Establishment crystallization weight loss test to a matter of hours and offers considerable practical advantage for rapid assessment of the suitability of limestone building stones quarried abroad (e.g. in Jordan) for use in the salt weathering conditions of the UK. However, there is a relatively large variance associated with this estimator (particularly when the microporosity coefficient exceeds 0.65) and in critical cases it should be followed up by confirmatory use of the standard crystallization weight loss test.

Hardgrounds and omission surfaces are rare in the predominantly pelagic and hemi-pelagic chalk, chert and phosphorite lithofacies association that forms the Upper Cretaceous (Coniacian to Maastrichtian) Belqa Group succession in central Jordan. However, newly-described hardgrounds of regional extent at the base of the Dhiban Chalk Member (Campanian) in central and south Jordan reveal a complex history of sedimentation and early diagenesis. Following drowning of the Turonian carbonate platform during the Coniacian, the chalk-chert-phosphorite association was deposited on a pelagic ramp in fluctuating water depths. The Mujib Chalk and Dhiban Chalk members represent highstand sea levels, separated by a regressive, lowstand chert-rich unit (Tafilah Member). Hardground successions can be traced over 100 km, and show an early diagenetic history of phosphatisation and biogenic silica lithification from opal-A to opal-CT and quartz that resulted in penecontemporaneous chert deformation, followed by submarine bioerosion and colonisation by corals and/or bivalves. Subsequent deposition of detrital, remanié phosphatic chalk passing up into pelagic coccolith-rich ooze reflects a transgressive third-order sea-level rise during the Early Campanian. These events provide a time-frame for early silica diagenesis and subsequent hardground development. Regional variations in the hardground successions and their early diagenesis are attributed to their precursor host sediment and relative palaeogeographic position on a homoclinal ramp at the southern margin of the Neo-Tethys Ocean.

No abstract