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The present study attempts to identify the sources of Cr(VI) in a coastal alluvial fan soil and soil from a chromite mine. In addition investigates the effect of photochemically oxidized organic matter in the Cr(VI) mobilization in soil. The alluvial bulk soil samples contain several evidence of weathered products of the ophiolite nappe like serpentine and amphiboles. For better characterization we separated different soil fractions with magnetic separation. The results showed that magnetic fraction exhibits high amount of serpentine. The XRF-analysis showed Mg and Cr to be enriched on average by 2.5 and 6 times, respectively. The produced fractions were mixed with glucose to simulate organic carbon and then leached with KH2PO4/Na2HPO4 for the exchangeable Cr in all fractions before and after the exposure of the samples in the sun for several days. The results showed that soils from chromite mine were influenced by oxidation of organic matter with 20-30% reduction in Cr(VI) release, while alluvial fun soils showed very high capacity to immobilize Cr(VI) without any effect from organic matter oxidation.

The tectonic evolution of the Oman Mountains as of the Neoproterozoic begins with a major extensional event, the Neoproterozoic Abu Mahara rifting. It was followed by the compressional Nabitah event, still during the Neoproterozoic, in Oman but possibly not in the study area. During the earliest Cambrian, the Jabal Akhdar area was affected by the Cadomian Orogeny, marked by NE--SW shortening. It is unclear, whether the Saih Hatat area was exposed to the Cadomian deformation, too. Still during the lower Cambrian, the Angudan Orogeny followed, characterized by NW--SE shortening. An episode of rifting affected the Saih Hatat area during the mid-Ordovician. During the mid-Carboniferous, both dome areas were deformed by tilting and large-scale open folding in the course of the ‘Hercynian’ event. As a consequence, a major unconformity formed. As another Late Paleozoic event, the Permian break-up of Pangaea and subsequent formation of the Hawasina ocean basin, are recorded in the Southeastern Oman Mountains. As a result, a passive margin formed which existed until the mid-Cretaceous, characterized by deposition of mostly shelfal carbonates. This interval of general tectonic quiescence was interrupted during the early Jurassic by uplift and tilting of the Arabian Platform. The platform collapsed during the late Cretaceous, related to the arrival of the obducted allochthonous nappes including the Semail Ophiolite, transforming the passive margin to an active margin. The Semail Ophiolite formed most likely above a subduction zone within the Neo-Tethys Ocean during the Cenomanian while parts of the Arabian Plate were subducted to the NE. Formation of oceanic lithosphere and SW-thrusting was broadly coeval, resulting in ophiolite obduction onto the Hawasina Basin. The Semail Ophiolite and the Hawasina rocks combined were thrust further onto the Arabian Plate. Their load created a foreland basin and forebulge within the Arabian Platform. Once the continental lithosphere of the Arabian Platform was forced into the subduction zone, a tear between the dense oceanic lithosphere and the buoyant continental lithosphere developed. This led to rapid uplift and exhumation of subducted continental lithosphere of the Saih Hatat area, while obduction was still going on, causing in multiple and intense folding/thrusting within the eastern Saih Hatat Dome. Exhumation of the Saih Hatat Dome was massive. The emplacement of the ophiolite was completed during the Campanian/Maastrichtian. For completeness, we also present alternative models for the developmental history of the Semail Ophiolite. Immediately after emplacement, the Arabian lithosphere underwent intense top-to-the-NE extensional shearing. Most of the Saih Hatat Dome was exhumed during the latest Cretaceous to Early Eocene, associated with major extensional shearing at its flanks. Further convergence during the late Eocene to Miocene resulted in exhumation of the Jabal Akhdar Dome and some gentle exhumation of the Saih Hatat Dome, shaping the present-day Southeastern Oman Mountains. In the coastal area, east and SE of the Saih Hatat Dome, some late Cretaceous to present-day uplift is evident by, e.g., uplifted marine terraces. The entire Oman Mountains are uplifting today, which is evident by the massive wadi incision into various rock units, including wadi deposits which may form overhangs.

This chapter provides comprehensive descriptions of 52 numbered formations/rock units of the Southeastern Oman Mountains, based on available literature. The oldest eight siliciclastic and carbonate formations are positioned below the ‘Hercynian’ Unconformity. The overlying formation (9–16) mostly represent carbonates which accumulated in a passive margin platform setting during or after the opening of the Neo-Tethys Ocean. The passive margin slope and platform collapsed during the late Cretaceous because of the obduction of the Semail Ophiolite along with the deep marine Hawasina sedimentary rocks. The collapsing passive margin interval was recorded within the syn-obductional Aruma Group (17; Muti Formation). Above this formation are the allochthonous units (18–42) of the tectonically lower Hawasina deep-sea basin and the structurally overlying Semail Ophiolite. The former contains Permian to Upper Cretaceous formations, while the latter is Cenomanian in age. Above the allochthonous rocks, the Neo-autochthonous formations were deposited, starting with the post-obductional uppermost Cretaceous Aruma Group (43; Al-Khod Formation) until the Quaternary deposits (52). All these formations/rock units are depicted on an accompanying map and stratigraphic chart.

This chapter is concerned with the main faults and folds within the Southeastern Oman Mountains based on available literature. The main, best and most widely exposed thrusts are those related to the SW-directed late Cretaceous obduction of the allochthonous nappes onto the Arabian platform and margin. These thrusts are related to obduction of rocks, which had formed hundreds of kilometres offshore Oman. The thrusts were active from the Cenomanian to the Campanian. Obduction-related thrusts and folds are spectacularly exposed within the rocks of the Arabian platform in the eastern part of the Saih Hatat Dome, including large-scale recumbent cylindrical folds and sheath folds. At least six fold sets can be studied in the Southeastern Oman Mountains. At least two of them had formed prior to obduction and are exposed in the Pre-Permian formations of the Jabal Akhdar Dome. At least three fold sets formed in the course of obduction, while at least one fold set is postobductional in age. Besides the compressional structures, the Oman Mountains expose major post-obductional extensional faults, mostly at the margins of the Jabal Akhdar and Saih Hatat domes. The throw of these faults amounts to a few to several kilometres. Finally, this chapter provides an overview of the enigmatic Batinah Melange which consists of slivers of Hawasina rocks, resting (unusually) structurally above the Semail Ophiolite.

The Southeastern Oman Mountains are dominated by two major culminations: the Jabal Akhdar and Saih Hatat domes, surrounded by allochthonous and/or neo-autochthonous rocks. In the cores of both domes, folded autochthonous and par-autochthonous pre-Permian metasedimentary rocks are exposed, subjacent to the ‘Hercynian’ Unconformity. Above the unconformity are Permo--Mesozoic shelfal sedimentary rocks, characterized by carbonates. These sedimentary rocks were openly folded. The open folds are large-scale elongate structures that define the shapes of both domes. The main elongation direction is NW--SE. Doming is syn- to post-obductional. Most margins of the domes are marked by major post-obductional, extensional faults. Reactivated basement faults along the eastern margin of the Jabal Akhdar Dome may be responsible for the straight NNE-striking eastern margin which is perpendicular to the main elongation direction of the domes. The deep structure of both domes is poorly known. However, the Moho depth below the centre of the Jabal Akhdar Dome is at 50 km. We present a geological map of both domes, depicting the main faults and folds, and schematic cross-sections, parallel and perpendicular to the Oman Mountains.

This chapter provides the conclusions/outlines of the tectonics, affecting the Southeastern Oman Mountains, including the Jabal Akhdar and Saih Hatat domes. The main tectonic events include amongst others (1) Neoproterozoic rifting, (2) two distinct early Paleozoic compressive events, (3) large-scale open ‘Hercynian’ folding and formation of a pronounced unconformity during the late Paleozoic, (4) rifting preceding the opening of the Neo-Tethys Ocean during the late Paleozoic, (5) late Cretaceous obduction of the Semail Ophiolite and the response of the Arabian lithosphere as well as (6) post-obductional tectonics. Also of major geological significance are the three major glaciations (Sturtian, Marinoan and Late Paleozoic Gondwana glaciation) which have been recorded in the rocks of northern Oman. Moreover, major lithological, structural and metamorphic differences exist between the Jabal Akhdar and Saih Hatat domes. It appears likely that a major fault, striking parallel to the eastern margin of the Jabal Akhdar Dome, probably originating during Neoproterozoic terrain accretion, acted as a divide between both domes until present. This fault was multiple times reactivated and could explain the differences between the two domes. A catalogue of unanswered questions is included in chronological order to express that many geological aspects need further investigation and future research projects.

The extraordinary outcrop conditions provide a unique opportunity to study the geology and tectonics of the Oman Mountains, which record a geological history of more than 800 million years. We provide a summary of the geological evolution of the Oman Mountains with the emphasis on the Jabal Akhdar and Saih Hatat domes. This Memoir comprises seven chapters. This first chapter summarizes the former studies and the tectonic framework. This is followed by a comprehensive description of all geological formations/rock units (Scharf et al. 2021a, Chapter 2, this Memoir) including the famous Semail Ophiolite, the fault and fold pattern (Scharf et al. 2021b, Chapter 3, this Memoir) and the overall structure (Scharf et al. 2021c, Chapter 4, this Memoir). Chapter 5 (Scharf et al. 2021d) explains the varied tectonic evolution of the study area, ranging from the Neoproterozoic until present, while Chapter 6 (Scharf et al. 2021e) contains the conclusions and a catalogue of open questions. Finally, Chapter 7 (Scharf et al. 2021f) provides two over-sized geological maps (1 : 250 000 version available online) and a correlation chart, providing an overview of the geological units/formations. This volume is of interest for all geoscientists, geoscience students and professionals studying the Oman Mountains on the surface as well as in the subsurface because it represents a comprehensive and detailed reference.

As part of the International Geoscience IGCP-715 project, we present the core objective and preliminary analyses on the karst development of the study areas. Our aim is to further characterize the geomorphologic features of the extended karst of Koiliaris Critical Zone Observatory (KCZO), Crete, Greece. Simultaneously to better understand the main drivers of karst development we compare the CKZO karst system with other areas in different tectonic contexts such as Oman (Salma Plateau), the northern UAE and southern China (Guilin karst area).Hydrological studies and previous geomorphologic analysis of KCZO suggest that 27% of the total water budget is coming from the adjacent watershed in the east where an extensive karst system with two explored super-deep caves is situated (Liontari Cave - 1100 m, Gourgouthakas Cave - 1200 m). The area is build up by a continuous carbonate succession exceeding 5 km in depth, lying on top of the Hellenic subduction zone. Field work and Google Earth mapping show two dominantly striking directions of failures (fault, fracture surfaces), trending E-W to ESE-WNW (90-120°) and N-S to NNE-SSE (0-22.5°). The N-S surfaces are mainly fractures while the E-W ones are mainly thrusts and/or strike-slip faults with obvious large displacements of hundreds of meters. The karst development in a subduction zone with dramatic thrusting on the overriding plate has created super-deep caves which are controlled by the vertical bedding and a series of faults and fractures. The area exhibits two layers with different hydraulic properties, a fast water-transferring zone and a slower one which is consistent and supports the hypothesis of the hydrologic model. At the Salma Plateau, in Oman, the karstic system is related to rapid uplifted Eocene limestones that overlay the Semail Ophiolite. There is a large cave (Majilis Al Jinn) at an area of interconnected fractures (and/or faults?). It is the only karstic system presented inhere which has similarities with the karstic system in the KCZO.At the UAE and northern Oman (Musandam) is an active collision zone between Arabia and Eurasia with 2000-m-thick allochthonous Mesozoic limestones. The area lacks a subsurface karst system, and the only karst has developed in steep wadis.Finally, the Guilin area in China represents a former passive margin with a Devonian limestone. It features a spectacular karst of conical peaks (fengcong) and tower peaks (fenglin). Caves exhibit mainly a horizontal development and there is no similarities to the KCZO.

Summarization: The agricultural soils in the Mediterranean are characterized by low stocks of soil organic matter (SOM) because of the intensive management practices and constraints on litter inputs to the soil imposed by environmental conditions (low precipitation, high evapotranspiration). To date, several studies have provided evidence for a low potential of Mediterranean agroecosystems, especially on its southern part, to store C, even under soil conservation practices (e.g., non-tillage), questioning the capacity of commonly applied practices to restore soil health, mitigate climate change and improve resilience of agroecosystems to climate extremes. Using paired orchards of avocado and olive trees, we show that soils in the South Mediterranean have a high potential for C storage that depends strongly on crop type and soil properties. Soils planted with avocado trees showed higher SOM contents compared to olive trees mainly in the upper soil layer (0–10 cm) which were linked to higher inputs and litter chemistry. Our findings enable us to re-define achievable thresholds of SOC (≈8%) in Southern Mediterranean soils to store C, to quantify the effect of different cropping systems, and the period required to reach this potential and how this potential is affected by soil properties. Thus, the findings have profound implications for the design of soil conservation practices compatible with Mediterranean conditions and developing initiatives describing achievable targets of SOM restoration depending on soil properties and cropping systems. Presented on: Sustainability

See foldout. A more detailed topographic map can be found in the online publication. Figure A.3 provides a correlation/comparison of Permian ages between the ‘International Stratigraphic Chart’ and the ‘Tethyan Time Scale’. Prof. Christopher Bailey (College of William & Mary, USA) creates and provides a number of helpful and interesting blogs about the fascinating geology of Oman: 1. https://wmblogs.wm.edu/cmbail/inside-ghubrah-bowl-oman-dropstones-double-duckbills-pencil-structures-oh/ 2. https://wmblogs.wm.edu/cmbail/omans-geological-triple-point/ 3. https://wmblogs.wm.edu/cmbail/the-road-to-the-moho/ 4. https://wmblogs.wm.edu/cmbail/wadi-bani-ghafir-at-sidaq-gorge-water-versus-rock-in-oman/ 5. https://wmblogs.wm.edu/cmbail/omans-mega-sheath-folds/ 6. https://wmblogs.wm.edu/cmbail/dispatches-from-oman-juxtaposition/ 7. https://wmblogs.wm.edu/cmbail/dispatches-from-oman-fodder-for-the-tectonic-cannon/ 8. https://wmblogs.wm.edu/cmbail/dispatches-from-oman-wadi-jizzi-standing-at-the-bottom-of-the-tethys-ocean/ 9. https://wmblogs.wm.edu/cmbail/dispatches-from-oman-ophiolite-to-aflaj/ 10. https://wmblogs.wm.edu/cmbail/finding-sharqiya-sands-oman/ Inconsistencies are found between the BRGM 1:100 000 and 1:250 000 maps within the Hawasina formations. In all cases we have followed the 1:100 000 maps rather the 1:250 000 map. 1. The geological map of Nazwa (1:250 000; Bechennec …

The geology of the Oman Mountains, including the Jabal Akhdar and Saih Hatat domes, is extraordinarily well-exposed and diverse, spanning a geological record of more than 800 Ma. The area is blessed with first-class outcrops and is well known in the geological community for its ophiolite. The Oman Mountains have much more to offer; including, Neoproterozoic diamictites (“Snowball Earth”), fossil-rich Permo-Mesozoic carbonates and metamorphic rocks. The arid climate and deep incision of wadis allow for nearly complete rock exposure which can be investigated in all three dimensions. The diverse geology is also responsible for the breathtaking landscape. New roads and the nature of the friendly Omani people make fieldwork unforgettable. This Memoir provides a thorough state-of-the-art overview of the geology and tectonics of the Southeastern Oman Mountains, and is accompanied by an over-sized geological map and a correlation chart.

For the first time, Quaternary thrusts are documented within the Central Oman Mountains to the northwest of the Jabal Akhdar Dome. Thrusts with a throw of up to 1.1 m displace Quaternary alluvial fan conglomerates. These conglomerates have an Optical Stimulate Luminescence (OSL) age of 159 &plusmn, 7.9 ka BP and were deposited during MIS 6 (Marine Isotope Stage). The thrusts occur in two sets. Sets 1 and 2 formed during NE/SW and NW/SE shortening, respectively. Set-1-thusts correlate with the present-day stress field of NE/SW shortening which is related to subduction in the Makran Subduction Zone, and they strike parallel to the main continuous fold axis of the Jabal Akhdar and Hawasina windows. Set-2-thrusts correspond to NW/SE shortening and Plio-Pleistocene contractional structures in the southwestern Jabal Akhdar Dome. Set-2-thrusts are probably related to local variations of the present-day stress field originating from the Musandam area which is a part of the Zagros Collision Zone. Both thrust sets mimic the main thrust directions (NW/SE and NE/SW) within the Permo-Mesozoic allochthonous units (Semail Ophiolite, Hawasina napps) of the larger study area. The investigated thrusts imply some reactivation of the Hawasina and Semail thrusts due to far-field stress either from the Makran Subduction Zone and/or the Zagros Collision Zone. The ongoing tectonic activity of this part of the Oman Mountains, which has been considered of moderate activity, is for first time identified by structural data as contractional.

The changing climatic conditions are imposing a vital re-consideration on the hydro-chemical pathways for contaminants. The circumference Mediterranean countries will be possibly under imminent water stress. The present study attempts to identify the sources and the leaching capacity of Cr(VI) in a coastal alluvial fan and aeolian soil and in a serpentine soil in an area offering an aridity analogue, like Oman. Magnetic separation and different leaching media were applied along with Cr(VI) sorption experiments in daylight (open air) and in laboratory conditions (without direct sunlight). In most of the samples the released Cr(VI) concentration was higher that the drinking water standard (50 μg L−1). Magnetic soil fraction has the highest bulk Cr concentration, however, the leaching of Cr with phosphate extraction solution was high in the no-magnetic fraction. Immobilization of Cr(VI) was higher in the sunlight conditions for the serpentine soil and not for the alluvial/aeolian soils.

This work explores the uplift history of the best exposed marine terraces in the northeastern Arabian Peninsula (eastern Al Hajar Mountains). A multidisciplinary approach was employed, including a topographic survey,14C dating, thin section studies, and scanning electron microscopy analyses. Six distinctive marine terraces with widths ranging from tenth of meters to kilometers and elevations from 5 to ~400 m were studied. These terraces record an along-strike heterogeneous uplift history, while they show temporally variable uplift rates ranging between 0.9 to 6.7 mm/yr, which correlates well with other published uplift rates of marine terraces of the eastern Arabian Peninsula. We attribute the variable uplift along strike of the terraces, to a combination of uplift mechanisms: (1) during early to mid-Miocene along deep-rooted reverse faults that bound large crustal-scale blocks, (2) Pliocene or post-Pliocene uplift on the outer wall of the forebulge of the lower Arabian Plate as it bends to enter the Zagros-Makran subduction zone, and (3) a possible slowdown of subduction for the past ~40 ka.

We investigated two coral patch reefs of probably Weichselian age (Wyns et al., 1992a) which have been uplifted above sea-level in the coastal setting of uplifted marine terraces adjacent to the Oman Mountains. Uplift is also manifested in raised beach conglomerates and a wave-cut notch. We document some of the main reef features in the apprehension that building/development will preclude the study of the reefs in the near future. The reefs formed above a hardground of bioclastic limestone (mudstone to wackestone), characterized by intense bioerosion and red algae . The red algae may occur so plentiful to form (very localized) bafflestones. The diagenetic history of the rocks includes a transition from a marine environment (first cement) to meteoric conditions (dissolution and second cement). The reefs are 1.5 m thick and display planar as well as gently ocean-dipping reef tops, suggesting exposure to the wave-cut activity and, thus, shallow and nearshore deposition. The reefs are dominated by one coral species, identified as Cyphastrea serailia . On the protected side of the reefs the corals developed wavy and columnar growth forms while on the ocean facing side irregularly shaped exoskeletons developed. Our GPS-based topographic survey revealed an elevation of the two reefs of 21.5 m ± 0.06 m above sea-level. Taking into account (1) the global Holocene sea-level rise of 120 m ± 20 m (Pirazzoli and Pluet, 1991), (2) formation of the reefs slightly below sea-level (∼1.5 m) as well as (3) their present position above sea-level, we quantify the total upward transfer of the reefs to be 143 m and the average uplift rate to be 6.8 or 4.6 mm/yr depending on the correct age (either ∼21,000 or ∼31,000 yr B.P.). As the causes of uplift we mainly consider isostatic rebound following the late Cretaceous formation of the Oman Mountains (Yuan et al., 2016). The terrace development went through the following stages: (1) The patch reefs formed in shallow water. (2) Initial, gentle uplift caused abrasion of the reef tops. (3) Uplift continued and beach conglomerate 1was deposited on top of the reefs. (4) Abrasion continued, creating an abrasion platform. Uplift and creation of borings in platform required time and an interval of relatively slow uplift and tectonically and climatically stable conditions. (5) Uplift took place, and a wave-cut notch formed below the reefs. (6) Notch formation, including the borings into the notch, required time and stable conditions and was followed by deposition of beach conglomerate 2. (7) Finally, emergence/exposure of the notch and conglomerate 2 above sea-level ensued due to pronounced uplift, possibly associated with faulting and earthquakes. Formation of the reefs and the abrasion platform can be correlated with MIS 3 (Marine Isotope Stage 3) and notch formation with MIS 1.

Summarization: Submarine groundwater discharge (SGD) contributes to the physical and chemical characters of coastal waters by discharging nutrients and contaminants, significantly impacting regional marine ecosystems and contributing to ocean chemical budgets. However, such groundwater discharge varies dramatically across scales and is often not comparable due to different model assumptions and field designs. We used a hydrologic model with integration of fundamental surface and subsurface processes to simulate the coastline level fresh SGD for the Crete Island in the Mediterranean Sea. The modeled hydrological processes suggested that fresh SGD substantially contributes to water flow entering the Mediterranean Sea (2.3 × 108 m3/yr), amounting to 31% of river discharge and 14% of precipitation. Spatially, fresh SGD varied from 2.4 m3/yr/m to 13.4 × 104 m3/yr/m, with an average of 2.6 × 103 m3/yr/m. The local maxima were commonly associated with river mouths reflecting larger hydraulic gradients and higher permeable structures. Temporally, fresh SGD was impacted by episodic precipitation in a delayed and prolonged pattern. We found that fresh SGD variability at the coastline segment level was compared to point measurements and fresh SGD magnitudes summered up to the catchment level were consistent with global products. Our results suggest the coupled surface–subsurface hydrologic modeling approach is a promising strategy to quantify and partition large-scale water budgets down to point observations that typically do not capture the full range of fresh SGD dynamics. Presented on: Journal of Hydrology

Microbial mats are rarely reported for chromium-polluted ecosystems, hence information on their bacterial diversity and role in chromium removal are very scarce. We investigated the role of nine microbial mats, collected from three quarry sumps of chromium mining sites, in the removal of hexavalent chromium (Cr(VI)). Bacterial diversity in these mats and community shifts after incubation with Cr(VI) have been investigated using MiSeq sequencing. In nature, a chromium content of 1,911±100 mg kg-1 was measured in the microbial mats, constituting the third highest source of environmentally available chromium. The mats were able to remove 1 mg l-1 of Cr(VI) in 7 days under aerobic and anaerobic conditions. MiSeq sequencing of the original mats yielded 46-99% of the sequences affiliated to Proteobacteria, Firmicutes and Actinobacteria. When the mats were incubated with Cr(VI), the bacterial community shifted in the favor of Alphaproteobacteria and Verrucomicrobiae. We conclude that microbial mats in the quarry sumps harbor diverse microorganisms with the ability to remove toxic Cr(VI), hence these mats can be potentially used to remove chromium from polluted waters.

Summarization: Koiliaris CZO is a European Critical Zone Observatory (CZO) typical of the Mediterranean karstic geomorphology, which represents watersheds affected by humans over the centuries. This study aims to provide information that underpins the hydrologic and geochemical processes functioning at Koiliaris CZO. Linking geomorphologic and tectonic analysis improved the delineation of a karstic area which extends outside of the Koiliaris watershed and identified how structural elements influence the regional hydrology. The fluctuation in the river flow represents processes occurring in the karst and the periodic signal is related to Earth tide stressing of the karstic reservoirs. The conceptualization of a two-reservoir, well-mixed karstic system is confirmed by both the geomorphologic and tidal analysis. The hydrologic response is fast and it is manifested especially during extreme events where 70% of the precipitation becomes surface runoff, creating major flood events. The different sampling sites in the Koiliaris CZO were geochemically clustered and the quantification of the weathering fluxes showed that 25 mm/1000 years and 39 mm/1000 years of carbonate were removed by chemical weathering for the Keramianos ephemeral river and the springs, respectively. These studies illustrate the importance of critical zone science and transdisciplinary studies on water and soil management. Παρουσιάστηκε στο: Water

In the Sultanate of Oman remnants of deteriorating terrace agricultural systems offer important insights into long-term human adaptation in the arid tropics. Irrigation and terrace agriculture in the mountainous Jabal Akhdar region reveal historic agricultural practices in a rugged, high elevation context. The present study examines soil quality and regolith provenance in abandoned agricultural soil terraces. Three soil profiles in each of the Villages of Hadash and Wijma were excavated and analyzed. Physical, chemical and mineralogical analyses were conducted for all soil horizons. In addition, six other soils, 3 possible soil parent rocks (regolith) and soil’s bedrock were collected. Soil ages were constrained by 14C assays and stable isotope, (13C and 18O) on the bulk carbonates in the calcrete (caliche). The results demonstrate that both sites display poor soil quality with very low average total organic carbon (TOC) (6.2–5.0 g kg−1) and mean weight diameter (MWD; 0.27–0.48 mm), with low water stable aggregate content (

This study presents a new approach for detection and mapping of ancient slag heaps using 16-band multispectral satellite imagery. Understanding the distribution of slag (a byproduct of metal production) is of great importance for understanding how metallurgy shaped long-term economic and political change across the ancient Near East. This study presents results of slag mapping in Oman using WorldView-3 (WV3) satellite imagery. A semi-automated target detection routine using a mixed tuned matched filtering (MTMF) algorithm with scene-derived spectral signatures was applied to 16-band WV3 imagery. Associated field mapping at two copper production sites indicates that WorldView-3 satellite data can differentiate slag and background materials with a relatively high (>90%) overall accuracy. Although this method shows promise for future initiatives to discover and map slag deposits, difficulties in dark object spectral differentiation and underestimation of total slag coverage substantially limit its use. Resulting lower estimations of combined user’s (61%) and producer’s (45%) accuracies contextualize these limitations for slag specific classification. Accordingly, we describe potential approaches to address these challenges in future studies. As sites of ancient metallurgy in Oman are often located in areas of modern exploration and mining, detection and mapping of ancient slag heaps via satellite imagery can be helpful for discovery and monitoring of vulnerable cultural heritage sites.

Δημοσίευση σε επιστημονικό περιοδικό Summarization: The use of compost in enhancing organic carbon content and aggregation in soil has been widely studied in the last decades. Recently, compost is used in new environmental applications for the remediation of both contaminated groundwater and soil. However, compost addition increases by 10 orders of magnitude the soil electrical conductivity and the nutrient content such as potassium. Subsequently, nutrient leaching in groundwater may increase water salinity. The present study investigates the effect of zeolite application on potassium release in sandy soils amended with municipal compost. Kinetic experiments show that zeolite addition in soil-compost mixtures have no effect on potassium desorption rate while it results in an 18-fold increase in bio-available potassium. Column tests show that zeolite application results up to six times decrease in total potassium leaching. Experimental results show high potassium affinity for the mixture soil-compost-zeolite in pH > 7, which is of paramount importance, considering that soils in southern Europe (Italy, Spain, south France, Albania and Greece) exhibit slightly alkaline pH in most cases. The findings of this study may be also used to predict the potential of groundwater contamination in agricultural areas as well as during the implementation of preventive measures. Παρουσιάστηκε στο: Desalination and Water Treatment

Summarization: The purpose of this study was the investigation of sediment provenance and soil formation processes within a Mediterranean watershed (Koiliaris CZO in Greece) with particular emphasis on natural and manmade terraces. Koiliaris CZO is characterised by steep slopes, abrupt climatic changes, complex geology and most importantly by a significant anthropogenic influence. Material and methods Five sites (K1-K5) were excavated and analysed for their pedology (profile description), geochemistry (including Rare Earth Elements and other trace elements), texture and mineralogy along with chronological analysis (optical luminescence dating). The selected sites have the common characteristic of being flat terraces where soil formation has been taking place and erosion is low. The selected sites differed with regard to bedrock lithology, elevation and land use. Soils were classified as, Fluvisol (K1-K2), Leptosol (K3) and Cambisol (K4-K5). Results and discussion Three characteristic processes of soil genesis were identified: i) sediments transportation from outcrops of metamorphic rocks and sedimentation to fluvial sites (K1-K2), ii) in situ soil development in terraces with metamorphic rocks as parent material (K3) and in terraces with limestone as parent material (K4), and iii) strong eolian input and/or material transported through gravity from upslope at the mountainous site (K5). Only two sites revealed pedogenic processes such as a) calcite deposition in the fluvial environment (K1) which was a relict evidence of dry period and b) clay illuviation and REE horizonization at site K4 which corresponded to wetter period in Greece (medieval warm period). The REE patterns revealed strong 58 characteristics inherited from the bedrock at sites K4 and K5, while MREE and HREE depletion were observed at K1, K2 and K3 sites. Carbon sequestration throughout the soil profile was high at manmade terraces at higher elevation compared to fluvial environments due to both climatic effects and possibly intensive anthropogenic impact. Conclusions Soils at Koiliaris CZO are rather new soils with limited evolution. Pedogenic processes were identified in the older sites like K1 site. The manmade terraces at higher elevation have much higher carbon sequestration compared to the anthropogenic impacted fluvial areas. The intense agriculture activities have discernible impact in the upper soil horizon even at higher elevation sites like the site K3. Παρουσιάστηκε στο: Journal of Soils amd Sediments

Most of soil functions depend directly or indirectly on soil water retention and transmission, which explains their importance for many environmental processes within Earth's Critical Zones. Soil hydraulic properties are essential in irrigation and drainage studies for closing water balance equation, for predicting leaching of nutrients, for water supply to plants, and for other agronomical and environmental applications. Soil hydraulic properties reflect the structure of the soil porous system comprising pores of different geometry and sizes. This investigation comprises a detailed analytical study of soil hydraulic properties and climate conditions at 18 methodologically selected sites in Damma Glacier, Slavkov Forest, Marchfeld, and Koiliaris Critical Zone Observatories of SoilTrEC project. The local moisture regimes were assessed on a long-term basis by the Newhall model. The experimental data for soil water content at different potentials were used for assessing water storage capacity, pore size distribution, parameters of fitted retention curve equation, curve slope at the inflection point, and water permeability characteristics of each soil horizon. The differences of soil water retention and transmission characteristics—as fundamental properties describing soil structure—were explained by the different stages of soil profile development, parent materials, organic matter content, and land use histories.

The extent to which climate, eustacy and tectonics interact to shape the late Quaternary landscape is poorly known. Alluvial fans often provide useful indexes that allow decoding the information recorded on complex coastal landscapes, such as those of Eastern Mediterranean. In this paper we analyse and date (using optically stimulated luminescence – OSL) a double alluvial-fan system in Crete, an island straddling the forearc of the Hellenic subduction margin, in order to constrain the timing of, and quantify the contributing factors to, its landscape evolution. The studied alluvial system is unique because each of its two juxtaposed fans records individual phases of alluvial and marine incision, providing, thus, unprecedented resolution in the formation and evolution of its landscape. Specifically, our analysis shows that the fan sequence at Domata developed during the last glaciation (Marine Isotope Stage 3; 57–29 kyr) due to five distinct stages of marine transgressions and regressions and associated river incision, as a response to climatic changes and tectonic uplift at rates of ~ 2.2 mm/yr. Comparison of our results with published tectonic uplift rates from Crete shows, however, that vertical movement on Crete was minimal during 20–50 kyr BP and mot uplift was accrued during the last 20 kyr. This implies that eustacy and tectonism impacted on the landscape at Domata over mainly distinct time-intervals (e.g. sequentially and not synchronously), forming and preserving the coastal landforms, respectively.

The increase in the number of heavy metal emitting sources in industrial areas is a serious issue in pollution science. Sohar Industrial Port (SIP) area is located in the northern part of Oman where different industrial activities like petrochemical production, metal processing, and waste disposal are prevalent. This study comprehensively identified the presence and quantities of heavy metals in the soils of Sohar Industrial Port area and traced their origin to geogenic or anthropogenic sources. Bulk geochemical and mineralogical analyses were carried out on all samples. Environmentally available and bioavailable heavy metals were extracted by diethylenetriaminepentaacetic acid (DTPA) and were finally analyzed using Inductively Coupled Plasma-Optical Emission spectrometry (ICP-OES). The environmentally available metals that showed higher concentrations when compared to international standards were Ni and Cd. The geochemical evidence showed a strong geochemical signature of the ophiolite rocks in the soils as indicated by the significant correlation between Cr and Ni (P< 0.05). In addition, the Cd content showed significant correlations with Ni and Cr (P< 0.05). Other metals like Pb and Zn, possibly also were geogenic in origin, but with significantly elevated concentrations in samples close to a national highway (P< 0.05). The present study demonstrated the significance of understanding the geological framework of an industrial area, which is already imposing high background concentrations of Cr, Ni and Cd, and also the possible anthropogenic impacts in the cases of Pb and Cd that exceeded internationally permissible limits.

The aim of this study is to identify the chemical and physical characteristics in uncultivated soils derived from different parent materials under semiarid Mediterranean climatic conditions which favoured the formation of fragile soils. The current work is of great interest in the agriculture and environmental stakeholders for providing a “benchmark” of undisturbed soil quality regarding organic content and nutrients availability. Principal Component Analysis (PCA) was used as the primary tool to demonstrate the soil quality stage, regarding nutrient availability. The statistical analysis revealed that one of the major physicochemical characteristics such as cation exchange capacity (CEC) is controlled exclusively from mineralogy and not from organic matter. Mineralogy and bulk chemical analysis is directly related to soil parent material lithology. The availability of inorganic nutrients (macro- and micronutrients) is low and relatively identical to most of the soils. PCA shows the unusual correlation of K+with not only illite content but also the OM in soils. The development of soils which are already of low quality in respect of organic content and nutrients is evident in Crete in most of the 54 samples investigated.

Summarization: This research is aimed at elucidating the removal mechanisms of nutrients due to natural attenuation in drainage canals in Evrotas River delta in Greece. We investigated nutrients fluxes in groundwater, sediments, and reeds (Phragmites Australis and Arundo Donax) of the drainage canal. Groundwater fluxes indicated that the rate of mineralization was 37.6 mg N/m(2) day. The accumulation of toxic ammonia was prevented through the nitrification process (26.6 mg N m(-2) day(-1)). The decrease of NO(3)-N flux in groundwater in the riparian zone was calculated to be 56.1 mg N m(-2) day(-1) (20.48 g N m(-2) year(-1)). Phosphate was adsorbed to sediments and its load to the drainage canal was minimized. Harvesting of above ground reed biomass in mid June, when maximum standing stock of nutrients was attained for both plants, would remove 2.73 g P m(-2) and 11.2 g N m(-2). All the phosphorous (1.39 g P/m(2) year(-1)) and 76.5% of the nitrate nitrogen (14.64 g N m(-2) year(-1)) entering the drainage canal was taken up by plants. Drainage canal management is suggested as an efficient low cost-high gain agri-environmental measure, which is easy to be adapted by farmers, to reduce diffuse nutrient pollution. Presented on: Journal of Environmental Monitoring

Summarization: Thermodynamic calculations of ion exchange for divalent cations were made for clinoptilolite in natural state and after irradiation with three different doses of β-radiation (1012, 1015 and 3 × 1016 e/cm2) and γ-radiation (70 Mrad). The samples were equilibrated with binary systems of divalent cations, namely Sr2+ ↔ 2Na+, Ca2+ ↔ 2Na+ and Mg2+ ↔ 2Na+ at 25 ◦C and total solution normality of 0.025 N. The selectivity order Sr2+ > Ca2+ > Mg2+ was observed in non-irradiated clinoptilolite. After irradiation with γ-radiation the affinity of clinoptilolite for Sr2+ increased and that for Mg2+ decreased, whereas the affinity for Ca2+ remained unchanged. Irradiation with β-radiation influences selectivity order and clinoptilolite affinity decreases for Sr2+, whereas it increases for Ca2+. For the sample irradiated with maximum dose of β-radiation the selectivity was almost identical for Ca2+ and Sr2+. The crystallographic parameters and exchangeable cation site coordinates were refined for all samples with the Rietveld method. The structure refinement of Sr2+-saturated samples yielded changes both in exchangeable sites and site occupancy in channels A and B after irradiation with β-and γ-radiation. The cation sites Sr1 and Sr3 exhibit major changes both in site coordinates and site occupancy after irradiation with β-radiation. In addition, irradiation with γ-radiation yielded major changes in Sr1 occupancy, whereas coordinates changed only slightly. These structural modifications control the observed changes in thermodynamic parameters after irradiation. Presented on: European Journal of Mineralogy

Περίληψη: Thermodynamic calculations of ion-exchange reactions were applied for clinoptilolite in a natural state and after irradiation with three doses of β-radiation (1012, 1015, 3 × 1016 e/cm2) and γ-radiation (70 Mrad). Samples were equilibrated with binary systems of K+ ↔ Na+ and Cs+ ↔ Na+ at 25° and a total normality of 0.025 N. Selectivity for K was not affected after β-radiation with doses of 1012 and 1015 e/cm2 (ΔG° = –6.37 kJ/equiv, lnKα = 2.58 for the original clinoptilolite), whereas it increased considerably after 70 Mrad of γ-radiation (ΔG° = –7.88 kJ/equiv, lnKα = 3.18). Selectivity for Cs+ increased for the clinoptilolite irradiated with β-radiation (1012, 1015, 3 × 1016 e/cm2) and γ-radiation (70 Mrad). ΔG° and lnKα for original sample and Cs+ ↔ Na+ were –7.33 kJ/equiv and 2.96, respectively. Irradiated samples with β-radiation 1012, 1015, 3 × 1016 e/cm2 and 70 Mrad γ-radiation yielded ΔG° and lnKα –7.41, –8.83, –8.60, –8.25 kJ/equiv and 2.99, 3.57, 3.47, 3.33 for Cs+ ↔ Na+, respectively. Remarkable amorphization of clinoptilolite was observed after exposure at the highest dose of β-radiation (3 × 1016 e/cm2) with a concomitant decrease in cation-exchange capacity (CEC). Crystallographic parameters and especially exchangeable cation site coordinates were refi ned for all samples with the Rietveld method. Cesium-saturated samples exhibited changes in the cation sites Cs2 and Cs3, which are next to clinoptilolite channel walls with lower Al3+ for Si4+ substitution. The observed changes include a shift in cation sites Cs2 and Cs3 toward channel walls and occupancy decrease in site Cs2. Presented on: American Mineralogist

Land use and soil management practice can have strong effects on soil quality, defined in terms of soil fertility, carbon sequestration and conservation of biodiversity. In this study, we investigate whether ecological soil quality parameters are adequate to assess soil quality under harsh conditions, and are able to reflect different land uses and intensities of soil management practices. We selected three sites as main representatives for the dominant types of land use in the region: an intensively cultivated olive orchard (annually tilled), an extensively used olive orchard (not tilled) and a heavily grazed pasture site in the Koiliaris catchment (Crete/Greece). Soil quality was analysed using an ecosystem approach, studying soil biological properties such as soil organism biomass and activity, and taxonomic diversity of soil microarthropods, in connection to abiotic soil parameters, including soil organic matter contents, and soil aggregate stability. The intensively cultivated olive orchard had a much lower aggregate water stability than the extensive olive orchard and the pasture. Contents of soil organic C and N were higher in the extensively used olive orchard than in the intensively cultivated orchard, with intermediate concentrations in the pasture. This was mainly caused by the highest input of organic matter, combined with the lowest organic matter decomposition rate. Soil organism biomasses in all sites were relatively low compared to values reported from less harsh systems, while microarthropod richness was highest in the pasture compared to both the intensive and extensive olive orchards. From the present results we conclude that microarthropod taxonomic richness is a very useful indicator for ecological soil quality, because it is not only able to separate harsh sites from other systems, but it is also sensitive enough to show differences between land management practices under harsh conditions. Microbial biomass and especially microarthropod biomass were much lower in our harsh study sites than reported from less affected areas, and have therefore also potential as biological indicators for degradation.

Summarization: Three HEU-type zeolites from Armenia, Georgia and Greece formed from alteration of volcanic glass were treated with dilute KOH and subsequently either reacted with 6N HCl or heated at 700 jC. The raw materials and the reaction products were examined with X-ray diffraction (XRD), infrared spectroscopy (FTIR) and N2 gas adsorption. The cation exchange capacity (CEC) of the zeolites was also determined. The Greek zeolite has thermal characteristics typical for heulandite I, while the Armenian and Georgian zeolites have characteristics typical for heulandite III (clinoptilolite). KOH treatment increased slightly specific surface area (SSA) and microporosity due to dissolution of amorphous material. Acid treatment increased significantly both specific surface area and microporosity, as determined by t-plots, and decreased CEC. This is attributed to partial dissolution of both Si-tetrahedra and free linkages, which yielded secondary micropores and destroyed specific exchange sites of the HEU-type zeolites. Heating decreased both specific surface area and microporosity. Presented on: Applied Clay Science

International audience; The late-Cenozoic kinematic and late-Pleistocene paleoearthquake history of the Spili Fault is examined using slip-vector measurements and in situ cosmogenic (Cl-36) dating, respectively. The Spili Fault appears to have undergone at least three successive but distinct phases of extension since Messinian (similar to 7 Ma), with the most recent faulting resulting in the exhumation of its carbonate plane for a fault-length of similar to 20 km. Earthquake-slip and age data show that the lower 9 m of the Spili Fault plane were exhumed during the last similar to 16,500 years through a minimum of five large-magnitude (Mw > 6) earthquakes. The timing between successive paleoearthquakes varied by more than one order of magnitude (from 800 to 9000 years), suggesting a highly variable earthquake recurrence interval during late Pleistocene (CV = 1). This variability resulted to significant fluctuations in the displacement rate of the Spili Fault, with the millennium rate (3.5 mm/yr) being about six times faster than its late-Pleistocene rate (0.6 mm/yr). The observed variability in the slip-size of the paleoearthquakes is, however, significantly smaller (CV = 0.3). These data collectively suggest that the Spili Fault is one of the fastest moving faults in the forearc of the Hellenic subduction margin. (C) 2014 Elsevier Ltd. All rights reserved.

Data on soil microbial community distribution at large scales are limited despite the important information that could be drawn with regard to their function and the influence of environmental factors on nutrient cycling and ecosystem services. This study investigates the distribution of Archaea, Bacteria and Fungi as well as the dominant bacterial phyla ( Acidobacteria , Actinobacteria , Bacteroidetes , Firmicutes ) , and classes of Proteobacteria ( Alpha- and Betaproteobacteria ) across the Koiliaris watershed by qPCR and associate them with environmental variables. Predictive maps of microorganisms distribution at watershed scale were generated by co-kriging, using the most significant predictors. Our findings showed that 31–79% of the spatial variation in microbial taxa abundance could be explained by the parameters measured, with total organic carbon and pH being identified as the most important. Moreover, strong correlations were set between microbial groups and their inclusion on variance explanation improved the prediction power of the models. The spatial autocorrelation of microbial groups ranged from 309 to 2.226 m, and geographic distance, by itself, could explain a high proportion of their variation. Our findings shed light on the factors shaping microbial communities at a high taxonomic level and provide evidence for ecological coherence and syntrophic interactions at the watershed scale.

Οι σπάνιες γαίες και το ύτριο (REE-Y) θεωρούνται καλοί δείκτες για τον προσδιορισμό σεισμικών ζωνών κατά μήκος της επιφάνειας ενός ασβεστολιθικού ρήγματος (καθρέφτης ρήγματος). Η συγκεκριμένη τεχνική θεωρείται αποτελεσματική στην αναγνώριση του αριθμού και του μεγέθους των σεισμών. Πρόσφατες εργασίες έχουν επαληθεύσει την ύπαρξη ενός μηχανισμού εμπλουτισμού των ασβεστόλιθων σε σπάνιες γαίες όταν είναι σε επαφή με το έδαφος. Τα πρώτα αποτελέσματα από την διερεύνηση του μηχανισμού εμπλουτισμού του ασβεστόλιθου σε REE-Y παρουσιάζονται στην υποβαλλόμενη εργασία. Τα πειράματα προσομοίωσης βροχής πέντε ετών (σε γλάστρες) έδειξαν ταχύ εμπλουτισμό της επιφάνειας ασβεστόλιθου σε REE-Y. Τα πειράματα κινητικής έδειξαν επίσης ταχεία ρόφηση REE-Y, ενώ οι δοκιμές ισόθερμης ρόφησης έδειξαν μεγαλύτερη επιλεκτικότητα σε ελαφριές (LREE) σπάνιες γαίες σε σχέση με τις βαριές (HREE). O μηχανισμός ρόφησης των σπανίων γαιών με τη μορφή ανθρακικών συμπλόκων θεωρείται πιθανός μηχανισμός ρόφησης των REEY στην επιφάνεια των ασβεστολίθων., The Rare Earth Elements and Yttrium (REE-Y) have recently been proposed as good proxies for identifying rupture zones on carbonate fault scarps. Indeed, fluctuations in the REE-Y concentrations along a fault plane may be linked to the number and size of earthquakes that ruptured the fault. The enrichment is attributed to the contact of the soil with the carbonate fault scarp. Our study presents preliminary results from a series of experiments that aim to shed light on the mechanism associated with the REE-Y sorption on the limestone-soil interface. Rain simulation pot experiments, kinetic and isotherm batch experiments were employed to describe the mechanism of REE-Y sorption in calcite. Results reveal fast REE-Y sorption on the limestone surface after the simulation of five years of rainfall. The fast REE-Y sorption is also supported by the kinetic experiments. Isotherm tests show the higher affinity of calcite in the Light Rare Earth (LREE) compared to the Heavy Rare Earth Elements (HREE). The sorption of the REE in the form of carbonate complexes is proposed as a plausible mechanism of REE-Y incorporation into the limestone.

Η παλαιοσεισμική δραστηριότητα στο ρήγμα του Σπηλίου μελετήθηκε χρησιμοποιώντας μία πρωτοποριακή μέθοδο που συνδιάζει μετρήσεις Σπανίων Γαιών (REE) και κοσμογενών ισοτόπων 36Cl πάνω στην σεισμικά αποκαλυμμένη επιφάνεια του ρήγματος. Η ανάλυση των δεδομένων δείχνει ότι το ρήγμα είναι ενεργό και έχει φιλοξενήσει τουλάχιστον 5 μεγάλου-μεγέθους σεισμούς τα τελευταία 16500 χρόνια. Οι δύο πιο πρόσφατοι σεισμοί έλαβαν χώρα κατά την περίοδο 100-900 ετών πρίν από σήμερα και άθροισαν συνολικά 3.5 μέτρα σεισμικής μετατόπισης. Η χρονολογία των παλαιότερων 3 σεισμών προσδιορίσθηκε στα 7300, 16300 και 16500 χρόνια πριν από σήμερα με σεισμικές ολισθήσεις 2.5, 1.2 και 1.8 μέτρα, αντίστοιχα. Από το μέγεθος των σεισμικών ολισθήσεων συμπεραίνουμε ότι το μέγεθος των σεισμών που προκλήθηκαν από το ρήγμα του Σπηλίου κυμάνθηκε από Μ 6.3-7.3 ενώ ο μέσος ρυθμός επανάληψης τους ήταν ~4200 χρόνια. Τα παραπάνω δεδομένα αποκαλύπτουν ότι το ρήγμα του Σπηλίου είναι ένα από τα πιο ενεργά ρήγματα στην Κρήτη και οι σεισμικές παράμετροί που σχετίζονται με την δραστηριότητά του πρέπει να συμπεριληφθούν στο μοντέλο σεισμικής επικινδυνότητας της Ελλάδας., The paleoearthquake activity on the Spili Fault is examined using a novel methodology that combines measurements of Rare Earth Elements (REE) and of in situ cosmogenic 36Cl on the exhumed fault scarp. Data show that the Spili Fault is active and has generated a minimum of five large-magnitude earthquakes over the last ~16500 years. The timing and, to a lesser degree, the slip-size of the identified paleoearthquakes was highly variable. Specifically, the two most recent events occurred between 100 and 900 years BP producing a cumulative displacement of 3.5 meters. The timing of the three older paleoearthquakes is constraint at 7300, 16300 and 16500 years BP with slip sizes of 2.5, 1.2 and 1.8 meters, respectively. The magnitude of the earthquakes that produced the measured co-seismic displacements, ranges from M 6.3-7.3 while the average earthquake recurrence interval on the Spili Fault is about 4200 years. The above data suggest that the Spili is among the most active faults on Crete and its earthquake parameters may be incorporated into the National Seismic Hazard Model.