Search

Biochar production from organic waste offers an important alternative for waste management, also improves soil properties (bio-physico-chemical) and reduces heavy metal pollution risk caused by the...

Iron (Fe) in the soil is a very important element for agricultural applications and the development of plants, which have different forms. The presence of Fe in the rhizosphere is controlled by the activity of Fe forms in the soil and the microorganisms and surrounding root-soil interaction of plants and roots. The objectives of this study were to identify, and to examine their interaction with soil properties in vertisols. The results showed that; FeT contents ranged from 1.17 and 47.71 g kg-1, mean 13.81 g kg-1 › FeD contents 0.18 to 17.85 g kg-1 and mean 7.23 g kg-1 › FeO contents 0.01–0.31 g kg-1 mean 0.18 g kg-1 › FeDTPA contents 0.00–0.17 g kg-1 mean 0.04 g kg-1 › FeP contents 0.00–0.02 g kg-1 mean 0.01 g kg-1. Clay-silt fractions and organic matter had a very powerful impression on Fe forms distribution. FeD, FeDTPA, FeO ve FeP had low quantities. This is thought to be due to insufficient rainfall and some soil characteristics (including high pH, low organic matter, clay texture, and high lime content), as iron is not easily dissolved in the soil. There was a very important relation between clay content, organic matter, silt fractions, and Fe forms in the studied area. There was a positive correlation between soil organic carbon and DTPA-extractable Fe. There was a negative correlation between DTPA-extractable Fe and soil pH, also calcium carbonate content. When total Fe was rised, clay-silt content and cation exchange capacity (CEC) increased in the soil profiles. Especially in Zone 3 has more Fe and Fe contents, the results showed that; There was a very good balance between the different Fe fractions and soil properties. Zone 3 had more total iron contents than the other zones, because of their soil properties. Fe bound by organic sites, water-soluble plus exchangeable Fe and Fe were adsorbed onto oxides (amorphous surfaces) and were positively correlated with the DTPA-extractable Fe.

It is widely recognized that the optimal development of river terraces globally has been in the temperate latitudes, with NW and Central Europe being areas of particular importance for the preservation of such archives of Quaternary environmental change. There is also a growing consensus that the principal drivers of terrace formation have been climatic fluctuation against a background of progressive (but variable) uplift. Nonetheless river terraces are widely preserved in the Mediterranean region, where they have often been attributed to the effects of neotectonic activity, with a continuing debate about the relative significance of fluctuating temperature (glacials–interglacials) and precipitation (pluvials–interpluvials). Research in Syria and southern–central Turkey (specifically in the valleys of the Tigris and Ceyhan in Turkey, the Kebir in Syria and the trans-border rivers Orontes and Euphrates) has underlined the importance of uplift rates in dictating the preservation pattern of fluvial archives and has revealed different patterns that can be related to crustal type. The NE Mediterranean coastal region has experienced unusually rapid uplift in the Late Quaternary. The relation between the Kebir terraces and the staircase of interglacial raised beaches preserved along the Mediterranean coastline of NW Syria reinforces previous conclusions that the emplacement of the fluvial terrace deposits in the Mediterranean has occurred during colder climatic episodes.

We suggest a working hypothesis for the geometry of the strike-slip faults that formed the boundaries between the Turkish, African and Arabian plates in the latest Miocene to Mid-Pliocene (LMMP), between 7-6 Ma and 3.5 Ma. This geometry differed significantly from the modern geometry; the northern Dead Sea Fault Zone (DSFZ) was located east of its present line and the TR-AR boundary was formed by the Malatya-Ovacik Fault Zone (MOFZ), located well north of the modern East Anatolian Fault Zone (EAFZ). The MOFZ is potentially the most problematic aspect of such a scheme, given the dramatically different interpretations of it that have been proposed. However, the presently-available evidence, albeit limited, is consistent with our proposed interpretation. Significant differences between the proposed LMMP fault geometry and the modern geometry include, first, the transtensional geometry of the MOFZ, the modern EAFZ being typically a left-lateral transform fault zone but with localized transpression. Second, the MOFZ slip rate was much lower than the 9-10 mm a 1 EAFZ slip rate; it is estimated as 2-3 mm a 1 , having produced no more than 8 km of slip during its approximately three million year long activity. The Euler vector is tentatively inferred to have involved relative rotation between the Turkish and Arabian Plates at 0.85±0.15 Ma 1 about a pole at 37.75±0.15 N, 38.8±0.3 E. Third, unlike at present, there was no throughgoing linkage of left-lateral faulting between the LMMP DSFZ and the MOFZ; instead, the DSFZ terminated northward, and the MOFZ terminated southward, in a zone of localised crustal shortening adjoining the suture of the former Neotethys Ocean in the Kahramanmaras ¸-Pazarcik region of SE Turkey. The different motion of the Turkish plate relative to Arabia, and, thus, relative to Eurasia, means that senses and rates of crustal deformation can be expected to have been different during the LMMP phase from at present, throughout the eastern Mediterranean region.

Incision by the River Euphrates has created a dramatic erosional landscape in the northern Arabian Platform in SE Turkey. We obtain accurate heights of its terrace deposits in the Birecik area using differential GPS, and summarise evidence regarding heights of Late Miocene basalt flows and low-altitude wetland sediments. We thus estimate ∼600 m of uplift since the early Late Miocene (∼9 Ma), represented by ∼270 m of fluvial incision, the difference reflecting downstream channel-lengthening as the coastline has retreated to the Persian Gulf, ∼1400 km away. The oldest recognised sediments, inset below this level, form a thick aggradation between ∼100 and ∼130 m above the present level of the Euphrates. We estimate that this accumulated during ∼5–3 Ma when uplift rates were low, such that aggradation was necessary to maintain a downstream channel gradient in response to the coastal retreat. Palaeolithic artefacts have been reported locally in Euphrates deposits up to ∼80 m above present river level, which we tentatively date to ∼1.8 Ma. The Euphrates subsequently incised to within ∼10 m of its present level before aggrading ∼45 m higher in the late Early Pleistocene. The final ∼55 m of incision reflects the increase in uplift rates observed worldwide in the early Middle Pleistocene, following the Mid-Pleistocene Revolution.

We present the first overall synthesis of the terrace deposits of the River Euphrates in SE Turkey, northern Syria, and western Iraq, combining new observations with summaries of data sets from different reaches that had previously been independently studied on a piecemeal basis. The largest number of terraces observed in any reach of the Euphrates is 11, in western Iraq, where this river leaves the uplands of the Arabian Platform. In many other localities not more than 5 or 6 terraces have previously been identified, although we infer that some of these are resolvable into multiple terraces. These terraces are typically formed of gravel, principally consisting of Neotethyan ophiolite and metamorphic lithologies transported from Anatolia. Although older gravels are also evident, most of the Euphrates terrace deposits appear, given the chronologies that have been established for different parts of the study region, to date from the late Early Pleistocene onwards, the cold stages most often represented being interpreted as marine Oxygen Isotope Stages 22, 16, 12, 8, 6 and/or 4, and 2. The formation of this terrace staircase reflects regional uplift of the Arabian Platform. Estimated amounts of uplift since the Middle Pliocene decrease southeastward from almost 300 m in SE Turkey to ∼150 m in western Iraq. Uplift rates increased in the late Early Pleistocene, the uplift estimated since then decreasing from ∼110 m in SE Turkey to a minimum of ∼50 m in the Syria–Iraq border region, then increasing further downstream across western Iraq to ∼70 m. Numerical modelling of this uplift indicates a relatively thin mobile lower-crustal layer, consistent with the low surface heat flow in the Arabian Platform.

In the Arabian Platform of SE Turkey abundant evidence exists of fluvial incision by c . 110 ± 10 m since the late Early Pleistocene, starting in or around marine oxygen isotope stage 22 at 870 ka. This incision, which has accompanied regional surface uplift as the isostatic response to regional erosion, has progressively ‘locked’ rivers into their gorges in landscape that formerly had much lower relief. We use this effect to estimate 4.44 ± 0.06 km of left-lateral slip on this time scale on the Golbasi–Turkoglu Fault, a segment of the East Anatolian Fault Zone, from offset river gorges, giving a slip rate of 5.10 ± 0.07 mm a −1 . Piercing points indicate that this fault has slipped a total of 19 km, making its age 3.73 ± 0.05 Ma. A total of 33 km of relative motion between the Turkish and Arabian plates is documented on this time scale in the vicinity of Golbasi, at an overall time-averaged rate of 8.85 ± 0.12 mm a −1 , the estimated Euler vector for relative motion between these plates being 0.89 ± 0.01° Ma −1 about 33.4°N, 42.3°E. This method can be readily applied to determine slip rates, time-averaged since the late Early Pleistocene, on other strike-slip fault zones worldwide.

International audience; Central-southern Turkey, NW Syria, and adjacent offshore areas in the NE Mediterranean region form the bound-ary zone between the Turkish, African and Arabian plates. A great deal of new information has emerged in recent years regarding senses and rates of active crustal deformation in this region, but this material has not hitherto been well integrated, so the interpretations of key localities by different teams remain contradictory. We have reviewed and synthesised this evidence, combining it with new investigations targeted at key areas of uncertain-ty. This work has led to the inference of previously unrecognised active faults and has clarified the roles of other structures within the framework of plate motions provided by GPS studies. Roughly one third of the relative mo-tion between the Turkish and Arabian plates is accommodated on the Misis–Kyrenia Fault Zone, which links to the study region from the Kyrenia mountain range of northern Cyprus. Much of this motion passes NNE then eastward around the northern limit of the Amanos Mountains, as previously thought, but some of it splays north-eastward to link into newly-recognised normal faulting within the Amanos Mountains. The remaining two thirds of the relative motion is accommodated along the Karasu Valley; some of this component steps leftward across the Amik Basin before passing southward onto the northern Dead Sea Fault Zone (DSFZ) but much of it continues southwestward, past the city of Antakya, then into offshore structures, ultimately linking to the subduction zone bounding the Turkish and African plates to the southwest of Cyprus. However, some of this offshore motion con-tinues southward, west of the Syrian coast, before linking onshore into the southern DSFZ; this component of the relative motion is indeed the main reason why the slip rate on the northern DSFZ, measured geodetically, is so much lower than that on its southern counterpart. In some parts of this region, notably in the Karasu Valley, it is now clear how the expected relative plate motion has been accommodated on active faults during much of the Quaternary: rather than constant slip rates on individual faults, quite complex changes in the partitioning of this motion on timescales of hundreds of thousands of years are indicated. However, in other parts of the re-gion it remains unclear whether additional major active faults remain unrecognised or whether significant rela-tive motions are accommodated by distributed deformation or on the many smaller-scale structures present.

Refers to: Ali Seyrek, Tuncer Demir, Rob Westaway, Hervé Guillou, Stéphane Scaillet, Tom S. White, David R. Bridgland The kinematics of central-southern Turkey and northwest Syria revisitedTectonophysics, Volume 618, 31 March 2014, Pages 35-66, https://doi.org/10.1016/j.tecto.2014.01.008; International audience; The authors regret to inform that there is a need to make correction to the published article and the corrected text is provided here. We would like to apologise for any inconvenience caused.The Seyrek et al. (2014) synthesis of active crustal deformation in the northeast Mediterranean region combines offshore data with onshore evidence from central-southern Turkey and northwest Syria. The part of this synthesis integrating data from within and offshore of northwest Syria made extensive reference to Hardenberg and Robertson, 2007 and Hardenberg and Robertson, 2013. Part of this critique involved the presumption that the offshore seismic line located in Fig. 2 and depicted in Fig. 5 of Hardenberg and Robertson (2013) was in fact seismic line 5 of Vidal et al., 2000a and Vidal et al., 2000b, which Hardenberg and Robertson (2013) had plotted in the wrong place. However, subsequent discussions with Mat Hardenberg and Alastair Robertson have established, on the contrary, that they depicted a different seismic line. Thus, although there is no error in the Seyrek et al. (2014) interpretation of the geology or sense of active crustal deformation in the study region, a mistake was evidently made in the preparation of our paper, which this present note seeks to clarify.Given the current political situation, which makes additional substantive work in Syria unlikely for the foreseeable future, it is helpful to clarify the source of the above-mentioned confusion so mistakes arising from it do not propagate farther when research in Syria eventually resumes. We thus note, first, that Mat and Alastair have explained that the reference to ‘offshore seismic evidence’ on p. 234 of Hardenberg and Robertson (2007) is not to Vidal et al. (2000a), even though the latter is the only publication on seismic reflection data from the region immediately offshore of Syria that they cited, it is to an unpublished offshore dataset collected in 1975 by Spectrum Energy. Likewise, the acknowledgement on p. 468 of Hardenberg and Robertson (2013) that ‘We are grateful to Shell Syria for helping to sponsor the fieldwork and Spectrum Energy for providing access to 2D seismic data.’ is also referring to this 1975 seismic dataset, even though it does not say so and the wording in relation to fieldwork creates the impression that it relates to seismic data from somewhere onshore in Syria. Neither of the Hardenberg and Robertson (2013) figures that report seismic data makes any mention of Spectrum Energy and one of their captions refers to the Vidal et al., 2000a and Vidal et al., 2000b publications, seemingly confirming the impression of a connection with the latter when in reality no such link exists. The nature (indeed, the existence) of this 1975 seismic dataset only becomes evident on pp. 172–174 of Hardenberg (2003), although neither of the subsequent publications suggests that anyone might wish to read any part of this thesis for this information. In particular, the map in Fig. 4.3 on p. 173 of Hardenberg (2003) makes it clear that the seismic line discussed by Hardenberg and Robertson (2013) is Spectrum Energy line 24 S and the southern part of their line 24 N. Rather than showing the mis-plotting of any seismic line, Fig. 4 of Seyrek et al. (2014) can therefore now be regarded as an attempt to depict the relative positions, which no-one had previously illustrated, of this Spectrum Energy seismic line (in grey) and seismic line 5 of Vidal et al., 2000a and Vidal et al., 2000b (in purple), the mid-point of the latter being plotted ~ 8 km west of the southern end of the former. The similarities in the records from these two seismic lines confirm the continuity of the principal offshore geological structures in the region, this being the main reason why we looked into these seismic data in the first place.

We present the results of detailed field investigations of the fluvial succession exposed along the Euphrates valley adjoining the Ataturk Dam in the northern part of the Arabian Platform within SE Turkey. This work, which has used Differential GPS surveying to obtain accurate heights of deposits and Shuttle Radar Topographic Mission imagery for location purposes, has included documentation of many fresh sections exposed by quarrying. The work has been supplemented by unspiked KAr dating of late Middle Miocene to Late Miocene basalt flows, which are widespread in the region, providing a chronology for the early stages of development of this river system following regional emergence above sea-level in the early Middle Miocene. For example, beside the Ataturk Dam Lake at Siverek Iskelesi, basalt dated to 10.24 ± 0.22 Ma (± 2σ) caps a polymict Euphrates gravel some 80 m above the modern river; this is the oldest Euphrates terrace currently recognised. However, amounts and rates of fluvial incision are shown to vary across the northern Arabian Platform in a complex manner, due to the interaction between regional uplift and localised vertical crustal motions caused by slip on active reverse faults beneath anticlines. The study reach downstream of the Ataturk Dam includes the footwall of one such fault, beneath the Bozova Anticline; we estimate that the resulting rate of localised subsidence, superimposed onto the regional uplift that has also been occurring, has been ~ 0.01 mm a− 1 during the present phase of crustal deformation, which began at ~ 3.7–3.6 Ma, but was higher, maybe ~ 0.03 mm a− 1, during the previous phase, which began at ~ 6 Ma, when the pattern of plate motions in the surrounding region was different. A large palaeo-lake centred north of the present study region around the city of Adiyaman is inferred to have existed during this ~ 6 Ma to ~ 3.7–3.6 Ma phase of plate motion, apparently because the relatively rapid localised hanging-wall uplift on the northern flank of the Bozova Anticline ‘dammed’ the Euphrates valley near the site of the modern Ataturk Dam. The uppermost part of a thick fluvial aggradation west of the Euphrates near Karababa Bridge, inferred to date from around the Mid Pliocene, reaches ~ 100 m above the modern river and, after correction for an estimated ~ 30 m of localised subsidence and by ~ 50 m for subsequent downstream lengthening of the Euphrates channel, indicates ~ 180 m of subsequent regional uplift. The Euphrates then incised to within ~ 20 m of its present level by the mid Early Pleistocene, then a switch to regional subsidence accompanied the deposition of a second thick fluvial aggradation, the top of which is ~ 70 m above the modern river. Subsequent renewed regional uplift, following the Mid-Pleistocene Revolution, has resulted in the development of a succession of fluvial terraces, typically inset into these older aggradations, which are correlated with the cold stages of Milankovitch climate cycles. The early part of the Euphrates chronology, constrained mainly by the disposition of basalt flows, indicates ~ 800 m of regional uplift since the early Middle Miocene, of which an estimated ~ 330 m is masked by the subsequent downstream lengthening of the river. Components of localised uplift and subsidence, caused by slip on reverse faults beneath anticlines, are superimposed onto this regional pattern, the hanging-wall uplift being much larger (in one case, roughly five times larger) than the footwall subsidence. Our results provide, for the first time, detailed documentation of the complex development of the Euphrates valley in SE Turkey during the Late Cenozoic, due to the interaction between regional uplift and localised crustal deformation. This work also demonstrates the benefits of applying multidisciplinary techniques to investigate an important, but hitherto poorly documented, river system.

Unspiked K–Ar dating makes the age of the Cakmakozu basalt in eastern Turkey 1818 ± 39 ka (± 2σ). This basalt overlies a staircase of four terraces of the River Murat, a Euphrates tributary, each separated vertically by ∼ 20 m. We deduce from the relationship with the basalt that these fluvial deposits aggraded during successive ∼ 40 ka climate cycles around the Pliocene–Pleistocene boundary (probably MIS 72-66). The incision and rock uplift at ∼ 0.5 mm a− 1, thus indicated, are roughly consistent with the ∼ 500 m of entrenchment of this ∼ 1.8 Ma Murat palaeo-valley into a former lake basin since the Mid-Pliocene climatic optimum. We infer that the ∼ 130 m of incision in this locality since ∼ 1.8 Ma dramatically underestimates the associated rock uplift, estimated as ∼ 600 m. The ∼ 1100 m of rock uplift and ∼ 800 m of surface uplift thus estimated since the Mid-Pliocene indicate (assuming Airy isostatic equilibrium) ∼ 5 km of thickening of the continental crust, from ∼ 37 km to the present 42 km. Eastern Anatolia was thus at a much lower altitude in the Mid-Pliocene than at present, consistent with the low-relief lacustrine palaeo-environment. We infer that the subsequent development of topography and excess crustal thickness are being caused by coupling between surface processes and induced flow in the lower crust: climate change following the Mid-Pliocene climatic optimum resulted in faster erosion that has drawn mobile lower crust beneath the study region.

We document the staircase of terraces of the River Tigris in the Diyarbakir area of SE Turkey, in the northern Arabian Platform, and improve control on the ages of these terrace deposits by dating of overlying basalt flows using the unspiked K–Ar technique. These fluvial terraces are formed of polymict gravel, including clasts derived from the Anatolian metamorphic terrane farther north as well as of local basalt. At least 9 Tigris terraces have been recognised so far, the highest of which, ∼200 m above present river level, marks the local transition from stacked deposition to fluvial incision, the timing of which is bounded between the mid Late Miocene and the Middle Pliocene. Our K–Ar dating indicates a hiatus in fluvial incision in the late Early Pleistocene, as basalts dated to 1.22 ± 0.02 and 1.07 ± 0.03 Ma overlie Tigris gravels at very similar levels, ∼60–70 m above the present river. The lower terraces record the subsequent entrenchment of the modern Tigris valley following an increase in incision rates in the early Middle Pleistocene, evident from the disposition of younger basalt, dated to 0.43 ± 0.02 Ma, capping fluvial gravel only ∼21–22 m above the present river level. Numerical modelling can account for the observed uplift history, as the response to coupling between surface processes and induced flow in the lower crust, with the mobile lower-crust thin (∼5–7 km thick), consistent with the known presence of a thick layer of mafic underplating at the base of the crust beneath the Arabian Platform.

Using the Ar-Ar technique, we have obtained the first numerical dates for the Pleistocene volcanism along the valley of the River Ceyhan in the Düziçi area of southern Turkey, in the western foothills of the Amanos Mountains. Our six dates indicate a single abrupt episode of volcanism at ~ 270 ka. We have identified a staircase of 7 fluvial terraces, at altitudes of up to ~ 230 m above the present level of the Ceyhan. Using the disposition of the basalt as an age constraint, we assign these terraces to cold-climate stages between marine oxygen isotope stages 16 and 2, indicating rates of fluvial incision, equated to surface uplift, that increase upstream through the western foothills of this mountain range at between 0.25 and 0.4 mm a- 1. Extrapolation of these uplift rates into the axis of the range suggests that the entire ~ 2300 m of present-day relief has developed since the Mid-Pliocene, a view that we confirm using numerical modelling. Since ~ 3.7 Ma the Amanos Mountains have formed a transpressive stepover along the northern part of the Dead Sea Fault Zone, where crustal shortening is required by the geometry. Using a physics-based technique, we have modelled the overall isostatic response to the combination of processes occurring, including crustal thickening caused by the shortening, erosion caused by orographic precipitation, and the resulting outward flow of mobile lower-crustal material, in order to predict the resulting history of surface uplift. This modelling suggests that the effective viscosity of the lower crust in this region is in the range ~ 1-2 × 1019 Pa s, consistent with a Moho temperature of ~ 590 ± 10 °C, the latter value being in agreement with heat flow data. This modelling shows that the nature of the active crustal deformation is now understood, to first order at least, in this key locality within the boundary zone between the African and Arabian plates, the structure and geomorphology of which have been fundamentally misunderstood in the past. © 2007 Elsevier B.V. All rights reserved. 428 This work was supported in part by HÜBAK (Harran University Scientific Research Council) grant 428 (A.S.). We thank the personnel at the DSİ regional headquarters in Adana and Kahramanmaraş for granting access to, and permission to publish, their documents relating to the construction of the Aslantaş Dam. We are also grateful to the manager of the Aslantaş hydro-electric power station, now operated by EÜAŞ (the Turkish state electricity generation company), for his hospitality and for fieldwork permission. Bill Olszewski helped with documentation of the Ar–Ar dating results. We also thank both anonymous reviewers for their thoughtful and constructive comments. This study contributes to IGCP 518 ‘Fluvial sequences as evidence for landscape and climatic evolution in the Late Cenozoic’. Appendix A

We report four new Ar/Ar dates and 18 new geochemical analyses of Pleistocene basalts from the Karasu Valley of southern Turkey. These rocks have become offset left-laterally by slip on the N20°E-striking Amanos Fault. The geochemical analyses help to correlate some of the less-obvious offset fragments of basalt flows, and thus to measure amounts of slip; the dates enable slip rates to be calculated. On the basis of four individual slip-rate determinations, obtained in this manner, we estimate a weighted mean slip rate for this fault of 2.89 ± 0.05 mm/a (± 2?). We have also obtained a slip rate of 2.68 ± 0.54mm/ a (±2?) for the subparallel East Hatay Fault farther east. Summing these values gives 5.57 ± 0.54mm/a (±2?) as the overall left-lateral slip rate across the Dead Sea fault zone (DSFZ) in the Karasu Valley. These slip-rate estimates and other evidence from farther south on the DSFZ are consistent with a preferred Euler vector for the relative rotation of the Arabian and African plates of 0.434 ± 0.012° Ma -1 about 31.1°N, 26.7°E. The Amanos Fault is misaligned to the tangential direction to this pole by 52° in the transpressive sense. Its geometry thus requires significant fault-normal distributed crustal shortening, taken up by crustal thickening and folding, in the adjacent Amanos Mountains. The vertical component of slip on the Amanos Fault is estimated as c. 0.15 mm/a. This minor component contributes to the uplift of the Amanos Mountains, which reaches rates of c. 0.2-0.4mm/a. These slip rate estimates are considered representative of time since. 3.73 ± 0.05Ma, when the modern geometry of strike-slip faulting developed in this region; an estimated 11 km of slip on the Amanos Fault and c. 10km of slip on the East Hatay Fault have occurred since then. It is inferred that both these faults came into being, and the associated deformation in the Amanos Mountains began, at that time. Prior to that, the northern part of the Africa-Arabia plate boundary was located further east. © The Geological Society of London 2007.

WOS: 000245967300007 New high-precision Ar-Ar dating of basalt underlying the city of Diyarbakir, southeast Turkey, constrains the Quaternary incision history of the River Tigris, strengthening the pre-existing chronology based on magnetostratigraphy and K-Ar dates. The basalt, which overlies Tigris terrace gravel 70 m above the river, is part of the Karacadag shield volcano complex centred ca. 60 km to the southwest. The reverse-magnetised Diyarbakir basalt, one of relatively few flow units to reach the Tigris valley axis, has been dated to 1196 +/- 19 ka (+/- 2 sigma). Two lower terraces have been recognised in the Diyarbakir area, 46 and 32 m above the present river, with at least one other further downstrearn. From this evidence the rate of Middle-Late Pleistocene incision by the Tigris can be estimated; it probably reached ca. 0.07 mm a(-1), reflecting the characteristic global increase in uplift rates observed at that time. Copyright (C) 2007 John Wiley & Sons, Ltd.

The geomorphology and Quaternary history of the River Orontes in western Syria and south-central Turkey have been studied using a combination of methods: field survey, differential GPS, satellite imagery, analysis of sediments to determine provenance, flow direction and fluvial environment, incorporation of evidence from fossils for both palaeoenvironments and biostratigraphy, uranium-series dating of calcrete cement, reconciliation of Palaeolithic archaeological contents, and uplift modelling based on terrace height distribution. The results underline the contrasting nature of different reaches of the Orontes, in part reflecting different crustal blocks, with different histories of landscape evolution. Upstream from Homs the Orontes has a system of calcreted terraces that form a staircase extending to ~200m above the river. New U-series dating provides an age constraint within the lower part of the sequence that suggests underestimation of terrace ages in previous reviews. This upper valley is separated from another terraced reach, in the Middle Orontes, by a gorge cut through the Late Miocene–Early Pliocene Homs Basalt. The Middle Orontes terraces have long been recognized as a source of mammalian fossils and Palaeolithic artefacts, particularly from Latamneh, near the downstream end of the reach. This terraced section of the valley ends at a fault scarp, marking the edge of the subsiding Ghab Basin (a segment of the Dead Sea Fault Zone), which has been filled to a depth of ~1km by dominantly lacustrine sediments of Pliocene–Quaternary age. Review of the fauna from Latamneh suggests that its age is 1.2–0.9Ma, significantly older than previously supposed, and commensurate with less uplift in this reach than both the Upper and Lower Orontes. Two localities near the downstream end of the Ghab have provided molluscan and ostracod assemblages that record somewhat saline environments, perhaps caused by desiccation within the former lacustrine basin, although they include fluvial elements. The Ghab is separated from another subsiding and formerly lacustrine depocentre, the Amik Basin of Hatay Province, Turkey, by a second gorge, implicit of uplift, this time cut through Palaeogene limestone. The NE–SW oriented lowermost reach of the Orontes is again terraced, with a third and most dramatic gorge through the northern edge of the Ziyaret Dağı mountains, which are known to have experienced rapid uplift, probably again enhanced by movement on an active fault. Indeed, a conclusion of the research, in which these various reaches are compared, is that the crust in the Hatay region is significantly more dynamic than that further upstream, where uplift has been less rapid and less continuous.