The River Orontes in Syria and Turkey: Downstream variation of fluvial archives in different crustal blocks

Abstract

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~200 m 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 1 km by dominantly lacustrine sediments of Pliocene-Quaternary age. Review of the fauna from Latamneh suggests that its age is 1.2-0.9 Ma, 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.

Dating the onset of Lower Tagus River terrace formation using electron spin resonance

“…At the local scale, this phenomenon could be attributed to neotectonic activity, and so used to calculate regional uplift rate or climatic and relative eustatic sea‐level changes (e.g. Santisteban and Schulte, ; Wegmann and Pazzaglia, ; Larue, ; Bridgland et al ., ).…”

Some aspects of the biology of Abu mullet Liza abu (Heckel, 1843) in the Orontes River, Turkey

“…From its source in the Bekaa Valley of Lebanon, on the flank of the Lebanon mountain range, it flows northwards across western Syria through the cities of Homs and Hama and into Antakya (Antioche), Hatay Province, southern Turkey, before turning sharply south-westward to reach the sea ~30 km downstream of Antakya (Antioche) (Bridgland et al, 2012). The Orontes River is the longest river in the province of Antakya (Antioche, Turkey), 380 km in total length, around 94 km of which is in Turkey.…”

Contextualizing Early Urbanization: Settlement Cores, Early States and Agro-pastoral Strategies in the Fertile Crescent During the Fourth and Third Millennia BC

“…The valleys of the Tigris, Euphrates, Orontes, and Afrin Rivers and their tributaries have been eroded through Tertiary and Cretaceous limestone with occasional igneous rocks and are in-filled with deep alluvial sediments flanked by Pleistocene terraces (Bridgland et al 2012;Demir et al 2008;Wilkinson 1999). The fragmented landscapes drained by these riverine corridors provide smaller-scale landscapes of tells with more muted hierarchies than the extensive agricultural plains.…”