Travertine deposits in Deir Alla, Suwayma, and Az Zara areas were investigated. Mineralogy, geochemistry, stable isotopes and age dating indicate the presence of low-Mg calcite, with minor quartz components. The variable isotope (δ13C and δ18O) signatures indicate dependence on water temperature and water/rock isotopic exchange. In contrast, the high δ13C values in some travertine samples reflect 12CO2 degassing processes, increased input of 13C-enriched groundwater, and the presence of surface and groundwater hydrological systems. The high δ18O values may be attributed to evaporation effects and low water temperature during the formation of localized travertine. The age of travertine is the Late Pleistocene.

δ18O

Isotope Geochemistry

10.3390/min7050082

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Citations (11)

Late Triassic-early Jurassic Neotethyan evolution at Northern Gondwana (Jordan and Libya, Mediterranean region)

Geologica Acta (2006)

Issa M. Makhlouf

The Early Mesozoic record of northern Gondwana was strongly influenced by sea level fluctuations during the opening of the Neotethys Sea. Detailed facies analysis of the Late Triassic / Early Jurassic Abu Shaybah Fm (Libya, western Mediterranean), and the Triassic Mukheiris Fm (Jordan, eastern Mediterranean) documents the transgressions and regressions that took place during the Neotethys opening. Both formations present similar facies and depositional environments, and are made up mainly by continental siliciclastic sequences and minor carbonate deposits. The facies arrangement in both zones indicates deposition in a tide-dominated environment as a part of a transgressive sequence, succeeded by a high-energy sandy fluvial deposition. In both regions the braided fluvial systems drained basinwards and impinged into the Neotethys Sea located to the north. The fluvial deposition of both formations ended abruptly due to renewed Neotethyan marine floodings that resulted in the development of carbonate shelf environments.

Marine transgression

Siliciclastic

Palaeogeography

Transgressive

Carbonate platform

Deposition

10.1344/105.000000350

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Citations (7)

MICROFACIES OF LATE PLEISTOCENE TRAVERTINE DEPOSITS IN JORDAN

Malaysian Journal of Science (2022)

Issa M. Makhlouf Khalil Ibrahim Ali R. El Naqah Sana’ M. Al-Thawabteh

The Late Pleistocene travertine outcrops from Deir Alla, Suwayma, and Az Zara were investigated, and their microfacies were identified. The microfacies of the Deir Alla travertines include micrite and spar groundmass, shrubs, crystalline crusts, a stromatolite-like structure, peloids, and cements. Shrub travertine includes spar calcite-coated stems with probably microbial micritic clumps. The crystalline crust travertine displays an alternation of micrite and sparite laminae. The micritic laminae are dark-coloured. Bundles of radial spar crystals are associated locally with micritic groundmass. The crystalline crust developed where biogenic activity is limited. Peloidal microfacies are less than 0.25 mm in diameter, cryptocrystalline, pale-dark green in colour, elliptical to spherical in shape, and usually associated with microorganisms. The microfacies of the Suwayma and Az Zara travertines include crystalline calcite rhombs and other composite scalenohedral crystals. They occur as small anhedral-subhedral crystals, monocrystalline to some polycrystalline, corroded, subrounded, and mainly coated with iron oxide and/or clay minerals. Peloids, ooids, and oncoids are common. They are dark-green coloured, cryptocrystalline to microcrystalline carbonates of spherical and ellipsoidal shape with less than 1 mm in diameter. Rich flora travertines include reed and paper-thin rafts with leaf impressions encrusted on moss cushions. The flora observed in the upper part of the Suwayma section was identified as charophyte oospores (gyrogonites). A few grains of quartz are present as small subhedral-euhedral crystals, monocrystalline, corroded, rounded, and mainly coated with iron oxide. The iron is irregularly distributed among the laminae and voids and is occasionally replaced by carbonates. The described macrophyte encrustation structures probably represent algae, cyanobacteria, or bryophytes. All samples of micrite and spar calcite appear as groundmass.

Micrite

Chalcedony

10.22452/mjs.vol41no2.8

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Citations (1)

Hirnantian glaciation: a high latitude Palaeo-Tethys perspective

EGS - AGU - EUG Joint Assembly (2003)

H. A. Armstrong B. R. Turner Issa M. Makhlouf

High latitude

Source

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Citations (0)

Recent colluvial sedimentation in Jordan: fans evolving into sand ramps

Sedimentology (2002)

Brian R. Turner Issa M. Makhlouf

Abstract High‐angle accumulations of sand and escarpment‐derived gravel along the outcrop walls of Plio‐Pleistocene sandstones, eastern Jordan, form small, coalesced colluvial fans, built by rockfalls, rockfall‐derived debris flows, dry sandfalls and sandy grainflows. These deposits are sourced through wind erosion of fault‐controlled outcrops of weakly cemented sandstone and a hard, gypsum‐cemented sandstone and fine conglomerate caprock exposed in sandpits. Eroded sediment is supplied to the fans directly as rockfalls and sandfalls, and indirectly as gully‐confined sandy grainflows. The preserved colluvium fans comprise sandy, matrix‐rich rockfall, rockfall‐derived, dry debris‐flow lenticular gravel deposits and minor lenticular sandy grainflow deposits. The fans develop initially against the footwall escarpment and, as erosion continues, the outcrop and the fans become covered by stable sand sheet ramps in a self‐regulatory geomorphic system. Preserved fan–sand ramp systems in eastern Jordan are characterized by a threefold hierarchy of genetically related bounding surfaces, which develop over short time scales. Rapid fault‐controlled uplift and/or rapid stream incision may produce non‐equilibrium scarp faces, identical to those in the sandpits, associated with the colluvial fan–sand ramp systems. Thus, such systems have the potential to identify fault‐related unconformities, rapid uplift events and episodes of rapid downcutting in the rock record. Colluvium deposits have good preservation potential, but are often associated with complex, coarse, basin‐margin facies, and are thus difficult to identify in the stratigraphic record; a problem exacerbated by the lack of adequate colluvium facies models and diagnostic sedimentary criteria.

Colluvium

Rockfall

Outcrop

Escarpment

Debris flow

Alluvial fan

Conglomerate

Caprock

10.1046/j.1365-3091.2002.00497.x

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Citations (18)

Recognition of quartz geodes in the Upper Cretaceous Wadi Umm Ghudran Formation, Ras En Naqab, South Jordan