NE Part Research Articles

Review of cultivated and spontaneousBrassicaceaespecies for use as medicinal in NE part of Romania

Review of cultivated and spontaneous<i>Brassicaceae</i>species for use as medicinal in NE part of Romania

Coastal lateral spreading in the world heritage site of the Tramuntana Range (Majorca, Spain). The use of PSInSAR monitoring to identify vulnerability

The Balitx area is located on the steep coastal side of the Tramuntana Range (Majorca), a mountainous region which was declared a World Heritage Site by UNESCO in 2011 in the cultural landscape category. The Balitx site was occupied by farming areas with dry stone constructions and water storing systems of both Roman and Islamic origin. The coastal landscape is characterised by a large fault escarpment of up to 260 m in height. Lateral spreading processes are favoured by local stratigraphy and tectonics in an energetic coastal dynamics scenario. Block spreading morphologies are identified along the escarpment, with large, rocky blocks of volumes up to 60 × 103 m3 moving very slowly until their collapse. Consequently, a thick and highly karstified breccia deposit is accumulated at the base of the scarp. The lowest, oldest breccia outcrop has been dated (Th/U), and an age of 82.5 ± 5.6 kyr was obtained, reflecting the time span this process has been active. Additionally, numerous geomorphological slope features are identified in the area: landslides, rockfalls, and, more specifically, long and deep cracks in the hanging wall block of the fault, which also reveal active lateral spreading processes. Coastal dynamics have been investigated by interpreting offshore geophysical studies, bathymetry data and borehole information to determine the role of wave energy in the stability of the slope. Additionally, 14 SAR images from the ALOS PALSAR satellite have been exploited for the present work, covering a period spanning from 2007 to 2010, an anomalous rainy period in the region. Images were processed using the Persistent Scattered Interferometry (PSI) technique. PSInSAR results reveal that the rate of movement for the Balitx lateral spreading is extremely low (− 5.2 mm/year on average), but major activity has been detected in the NE sector, where velocity rates can reach values of up to − 16 mm/year Coastal dynamics in the area can explain this, as a small island generates wave refraction and reflection determining more intense erosive processes in the NE part, which lead to a greater destabilising effect on the slopes. A simple vulnerability approach has been developed to take the elements of cultural heritage into account. Vulnerability increases from SW to NE, in accordance with landslide activity. The Balitx case study could provide a testimony to the effects of mass movements and coastal dynamics in an exceptional example of Mediterranean agricultural landscape.

A Reappraisal of the Poya Terrane (New Caledonia): Accreted Late Cretaceous‐Paleocene Marginal Basin Upper Crust, Passive Margin Sediments, and Early Eocene E‐MORB Sill Complex

AbstractThe Poya Terrane of New Caledonia is a composite lithotectonic unit made of (i) Campanian‐Paleocene enriched mid‐ocean ridge basalt (E‐MORB) and BABB‐type (back‐arc basin basalt) basalts and abyssal argillite (Poya Terrane basalts) and (ii) Coniacian‐Santonian sandstone, turbidites, and abyssal argillite (Kone Facies) intruded by early Eocene E‐MORB sills. Remapping reveals that the Kone Facies is more extensive than previously thought. Field data, petrography, and U‐Pb geochronology of detrital zircons show that Kone Facies sediments have the same provenance as coeval autochthonous sediments (Formation a Charbon), albeit with more abundant contemporaneous zircons. They accumulated on the eastern continental slope of the Norfolk Ridge and eventually mixed with abyssal argillite. Temporally, sill emplacement is related to subduction inception at circa 56 Ma, thus suggesting a possible genetic link. We postulate that either (i) E‐MORB intrusion was related to oblique extension and thinning of the down going plate or, alternatively, (ii) the “enriched” (off axis?) partial melt zone of the ancient ridge swept the lower plate continentward, generating E‐MORB dikes in the upper marginal basin crust, and sills in passive margin sediments before it became extinct. Thereafter, sliced marginal basin upper crust, passive margin sediments, and associated dolerite sills were obliquely accreted to the fore‐arc region, and in the NE part of the terrane, subducted and recrystallized into the blueschist facies. The Poya Terrane was eventually thrust onto the Norfolk Ridge when the latter reached the subduction zone and debris from the thrust sheet fed middle to late Eocene syntectonic basins. At the same time, mafic portions of the Poya Terrane were subducted at depth where they recrystallized into the eclogite facies, mixed with serpentinite to form the Pouebo mélange, and, finally, were exhumed in the fore‐arc region. Finally, late Oligocene faulting and hydrothermal events overprinted the NE part of the terrane in probable connection with postobduction granitoid emplacement.

Erosional valleys at a major Late Jurassic–Early Cretaceous unconformity offshore Germany and The Netherlands: potential reservoirs or deteriorated seals?

Abstract Joint results of two independent international studies on the erosional impact of the ‘Late Cimmerian Unconformity’ (LCU), a Late Jurassic–Early Cretaceous erosional event, are presented. The potential impact on the reservoir and sealing potential of adjacent strata are discussed. Results are based on a seismic mapping campaign in the NE part of the Dutch offshore region and the Central German North Sea sector. The geological evolution of potential traps at the level of the LCU was studied to obtain a better understanding of reservoir potential. Erosion or leaching of the evaporitic Triassic intervals at the LCU caused a locally strong topographical relief with prominent elongated depressions along Permian salt structures (interpreted as erosional valleys). The infill of the erosional valleys may consist of remnants of initial strata as breccia or material from nearby eroded strata, possibly Lower Triassic sandstone or clays. These valleys may be overlain conformably by Upper Jurassic–Early Cretaceous sediments or may be filled with a combination of both. The lithological composition of the infill determines the sealing or the reservoir potential of the valleys, which is essential for further evaluation of the resource exploration possibilities in this locality and across the basin.

Preliminary Data of Fluvial Geomorphological Evolution and Its Link with Hazards and Human Impact: The Case of Peiros River, North Western Peloponnese, Greece

River channel dynamics are the result of the complex interaction between natural and human factors, at both local and regional scale. The study of river channel dynamics may be an important way to better understand the mechanisms that rule the functioning of fluvial systems, allowing predictions of its future evolution to be made and appropriate adaptation measures to be taken, remediating the risks related to the fluvial dynamics. The purpose of this study is to present specific aspects concerning the river channel dynamics of Peiros River, NW Peloponnese, Greece and to reveal the role of various control factors. Peiros, the longest river in Achaea, has sources at the NE part of the Erymanthos mountains flowing into Patras gulf. This study traces the various stages of geomorphological evolution of the low part of Peiros's river channel and enables us to study the links between human activity, local tectonics, morphology and fluvial dynamics. The study area belongs to the geotectonic zone of Gavrovo-Tripoli flysch, consisting mainly of medium-bedded fine-grained sandstones and mudstones and influenced by ENE and WNW trending faults aligned with the river flow. The spatial and temporal variability of sediment transport is controlled by various variables, including the natural features of the catchments and human activity. The latter is an important control factor for both the processes of sediment generation, transfer and accumulation and for channel dynamics. At the same time, these processes are responsible on short and long run for the alteration of the river channels, which entail negative environmental consequences. The study revealed restriction of sediment supply, coastal retreat, lateral erosion and migration of the rivers channel that complies with the local tectonics of the area, although major stream offsets are not created. The morphological changes although, are mainly attributed to human intervention factors, such as the construction of a dam and transversal bars that restricted the water flow and consequently the sediment supply. That factor combined with the climate change, had as result to drastically alter the morphology of the area. These morphological changes, except of loss of property and boundary problems, also made the area vulnerable to flush flood events. Structures close to the coast are exposed to more risk because of the measured coast retreat. No remediation measures have been taken, except the installation of rip-rap of limited length and one groin, in an attempt to slow down the coastal retreat and diminish wave action.

Mineralogie krupníkového tělesa v Medvědím dole u Koutů nad Desnou v Jeseníkách

Soapstone bodies are relatively common in the Sobotín Massif in the Hrubý Jeseník Mts. (NE part of the Bohemian Massif). There was a small soapstone body found near Kouty nad Desnou in the northern spur of the Sobotín Massif composed dominately of amphibolites. The article focuses on mineralogy and petrology of this body and rocks in its surroundings (mainly hornblendite). Studied soapstone body is composed of these four types of rocks: i) talc schists with variable content of chlorite (clinochlore) and amphibole (actinolite, magnesiohornblende); ii) soapstone (mineral association talc + dolomite); iii) chlorite schist; iv) actinolite schist. Chromite is a typical accessory mineral of soapstone body rocks as well as hornblendite. This soapstone body does not show mineralogical and petrographical zonality typical for well-known soapstone bodies of the Sobotín Massif – former soapstone deposits Smrčina and Zadní Hutisko. However there is no mineralogical or petrographical difference between those deposits and studied soapstone body. Formation of the soapstone body at Kouty nad Desnou is probably connected to hydrothermal alteration of hornblendite running along shear zones.

Lithospheric mantle beneath NE part of Bohemian Massif and its relation to overlying crust: new insights from Pilchowice xenolith suite, Sudetes, SW Poland

The Oligocene/Miocene basanite from Pilchowice (Sudetes Mts., SW Poland) carries numerous small xenoliths of mantle peridotite, mostly harzburgite. The Pilchowice xenolith suite is dominated by harzburgites and dunites containing olivine Fo 90.2–91.5 (group A). The peridotites of group B (olivine Fo 88.6–89.4), and C (olivine Fo 83.2–86.5) are subordinate. The peridotites suffered from significant melt extraction (20–30%) and were subsequently subjected to metasomatism. Three different trace element compositional patterns of group A clinopyroxene occur, which are typical of silicate melt, carbonatite melt and silicate–carbonatite melt metasomatism, whereas groups B and C were affected by silicate melt metasomatism only. The Pilchowice basanite occurs at the contact of Karkonosze–Izera Block and Kaczawa Complex, two major geological units of Sudetes. The Pilchowice xenolith suite documents underlying lithospheric mantle of composition and depletion degree similar to those described in the whole Lower Silesian mantle domain, which forms NE termination of Saxo–Thuringian zone of the European Variscan orogen. The crustal structure of the orogen is, therefore, not mirrored in the mantellic root.

Multiphase magmatic activity in the Variscan K\u0142odzko\u2013Z\u0142oty Stok intrusion, Polish Sudetes: evidence from SHRIMP U\u2013Pb zircon ages

The Kłodzko–Złoty Stok intrusion (KZSI), located in the NE part of the Bohemian Massif of Central Europe, has preserved records of the magmatic and tectonic activity of the Variscan orogeny in the Sudetes. KZSI is extraordinarily complex texturally, and shows a very wide range of chemical, isotopic and mineralogical compositions which indicates a complex, multiphase history of intrusion. New SHRIMP U–Pb zircon ages provide evidence of two magmatic episodes with a distinctive hiatus between them at ~ 326–308 Ma. The youngest dated zircons (303.8 ± 3.8/4.2 Ma) are from the Laski leucocratic hornblende–biotite monzogranite and mark a short interval of post-collisional reactivation of the magma system. Zircons from a biotite–hornblende diorite sheet from the northern part of KZSI yielded an age of 349 ± 3.4/3.7 Ma, interpreted as indicating the initial phase of an early Carboniferous, multi-pulse episode. The evolution of the magmatic system can be tied to a 334.4 ± 2.9/3.3 Ma zircon age for melanocratic syenites from Podzamek which represent lamprophyric melt. Based on textural and compositional data and field relationships we interpret the intrusion as having been tilted post-emplacement towards the NW. This, together with the new dating results, ties the early Carboniferous episode of KZSI activity and the Jawornik granitoids (5 km to the SE) to the same magmatic system and arguably to bentonites of the Paprotnia beds (5 km to the NW), all representing different levels of such a system. The newly estimated late Carboniferous age from Laski ties part of the KZSI to other late Carboniferous Sudetic intrusions and late Carboniferous–Permian volcanism.

Los grandes terremotos del siglo XV en Cataluña: Claves para la peligrosidad sísmica regional

Catalonia, in the NE part of the Iberian Peninsula, was shaken by large earthquakes in the XV Century. As these are the largest events consigned in the regional catalogues of seismicity, a proper knowledge of their epicentral parameters and their effects is essential for any further analysis of regional seismic hazard and risk. We review the present knowledge of these important events and some applications of the obtained results for the calculation of scenarios and other products really useful for civil protection for present earthquakes.

Application of stepwise weight assessment ratio analysis (SWARA) for copper prospectivity mapping in the Anarak region, central Iran

Nowadays, using Multi-Criteria Decision-Making (MCDM) techniques are common in all fields of study because of their advantage for finding optimal results. Some of the MCDM techniques like analytic network process (ANP), factor relationship (FARE), and analytic hierarchy process (AHP) are so popular in mining exploration due to the obtaining of geochemical anomalies and mineral prospectivity maps. The aim of this study is to utilize the stepwise weight assessment ratio analysis (SWARA) method for prospecting copper in the Anarak region, central Iran. The SWARA method is a developed MCDM knowledge-based technique in accordance with ratio of the different criteria. Informative layers include geological, geochemical, geophysical, and remote sensing data and have been integrated in this study. The data was classified according to the relation of copper occurrences/deposits in the Anarak region by the geographical information system (GIS). Following that, the every classified sub-criteria was weighted by the SWARA method and the weighted classified factors for determination of copper prospects were overlapped. Subsequently, the gained results illustrated the main copper prospects in the NW and NE parts of the region. Furthermore, the prospectivity map has a meaningful correlation with copper occurrences/deposits in the Anarak region. As a result, using the operating receiver characteristics (ORC) technique validates copper prospects derived via the SWARA method in the study region as high as 70% and validation result shows that the area under curve (ROC) is 0.79. Results derived via the SWARA were compared with the AHP method and the SWARA method is validated especially in NW part.

Structural and Stratigraphic Study of the Nahr Umr Formation (Lower Cretaceous) Using 3D seismic Survey in Abu Amood Oil Filed, Southern Iraq

3D seismic reflection study was applied to Abu Amood oil field which is located at the southern part of Iraq within DhiQar province that carried out by oil Exploration Company to an area of 1534.88 Km2 for studying Nahr Umr Formation. Synthetic seismogram was prepared by using available data of well (AAM-1) in order to define and picking the reflectors on the seismic section. These reflectors are (Top of Nahr Umr Formation and middle unit of Nahr Umr Formation which represents the layer of sand). The seismic section time slice maps confirmed that the Nahr Umr Formation was not affected by faults and the faults may probably present in the Ratawai and Yamama Formations, where the variance attribute applied on seismic sections showed that the area was affected by normal fault, this fault was very deep. The time, velocity, and depth maps are drawn for the top of Nahr Umr Formation to get the structural picture: these maps showed that Abu Amood oil field was a semi symmetrical structure that has an axis trending NW-SE, the slope of NE limb is greater than SW limb. Isochrone and Isopach maps are drawn for Nahr Umr Formation to display thickness of Nahr Umr Formation which gradually increases to the west as well as NW and SW parts of the study area and more gradually increases to the East and NE part of the study area. Seismic attributes were applied to the study area (instantaneous phase, instantaneous frequency and variance attribute) these attributes showed the presence of Direct Hydrocarbone Indicator at Nahr Umr Formation in Lower Cretaceous age as a Dim spot at In-lines 51500 and 49500 by applying instantaneous phase and bright spot at AAM-1 well by applying instantaneous frequency.

Environmental baselines and reconstruction of Atlantic Water inflow in Bjørnøyrenna, SW Barents Sea, since 1800 CE

Metal concentrations, sediment properties and benthic foraminiferal assemblages were investigated in sediment cores in the SW Barents Sea, to reconstruct environmental baselines and natural variability of Atlantic Water inflow since 1800 CE. Metal concentrations correspond to no effect levels and do not influence the foraminifera. Increased Hg and Pb was linked to inflow of Atlantic Water. The data set is considered to reflect the pre-impacted environmental baseline and range in natural variability of the study area. The foraminiferal assemblages in the SW part of the study area showed warming and presence of Atlantic Water towards 1900 CE. The NE part of the region indicate presence of cold Artic Water influenced conditions. Between 1900 and 1980 CE, the SW region indicates reduced inflow of Atlantic Water. From 1980 CE towards the present the assemblages of the entire study area show warming of Atlantic Water and northward retreat of the Arctic Front.

Tectono-geomorphic indices of the Erin basin, NE Kashmir valley, India

The present study aims to assess the tectonic activity in the Erin basin (NE Kashmir) on the basis of several relevant geomorphic indices and field observations. We use Digital Elevation Model (SRTM) and Survey of India (SoI) topographic maps in GIS environment to compute the geomorphic indices. The indices i.e., convex hypsometric curve, high hypsometric integral value (Hi > 0.5), low basin elongation ratio (Eb = 0.17), low mountain front sinuosity values (Smf = 1.08 average), low valley floor width ratios (Vf < 1), topographic assymetric character (T < 1), uneven basin asymmetry factor (AF < 50), elongated shape (Bs > 4) suggest that the area is tectonically active. Moreover, prominent irregularities (knickpoints/knickzones) along longitudinal profile of the Erin River even in homogenous resistant lithology (Panjal trap) and anomalous stream gradient index (SL) values reflect that the Erin basin is dissected by two faults (EF-1 and EF-2) with NNW-SSE and SSW-NNE trends respectively. The results of this preliminary study further substantiate the recent GPS studies, which argue that the maximum strain is accumulating in the NE part of the Kashmir Himalaya.

Determination of lithium prospects using fractal modeling and staged factor analysis in Torud region, NE Iran

The main purpose of this study was to outline the different lithium prospects in Torud district (NE Iran) using the staged factor analysis (SFA) and power spectrum-area (S-A) fractal modeling based on stream sediments and lithogeochemical data. Results obtained by the SFA represent that Li was situated in a factor 2 from stage 2 (F2-2) with Cs, Rb and F which was modelled and classified by the S-A fractal modeling for determination of the Li anomalies. There are three classes for geochemical anomalies. Major anomaly for Li was located in the NE part of this region which equal to F2-2≥2.8. Moreover, Li values of lithogeochemical data were classified by the concentration-number (C-N) fractal model for validation of the F2-2 anomalies using logratio matrix. These anomalies were correlated with lithogeochemical data utilizing logratio matrix which show that the main Li prospect based on the SFA and S-A fractal model is located in the NE part of the Torud region within magmatic rocks.

Geochronological and geochemical signatures of the granitic rocks emplaced at the north‐eastern fringe of the Eastern Dharwar Craton, South India: Implications for late Archean crustal growth

Geochemical and zircon U–Pb age data on granites of the Chitrial area, situated at the NE part of the Eastern Dharwar Craton, are presented to elucidate their petrogenesis, time(s) of emplacement, and role in crust formation. Based on field and geochemical characters, these granites are classified as alkali feldspar/monzo‐granite. Whole‐rock data of selected samples show evolved calc‐alkaline and peraluminous characters with high SiO2, K2O, large‐ion lithophile element, and light rare earth elements (LREE), depleted heavy rare earth elements (HREE) and strongly negative Eu anomaly. One sample shows slightly different character with low SiO2, enriched light rare earth elements, and depleted heavy rare earth elements without Eu anomaly. Geochemical analyses suggest that the rocks are S‐type granite with syn‐collisional and volcanic arc signatures. These granites define a coherent trend favouring low pressure crystallization of the magma. U–Pb zircon data show that the crystallization ages of the granites vary within 2514 ± 10 to 2525 ± 24 Ma. The geodynamic evolution of the Eastern Dharwar Craton is discussed wherein subduction and deep burial of sediment is envisaged to cause partial melting and granite genesis in the craton.

Cretaceous geological evolution of the Pontides

Abstract The Pontides forming the southern continental margin of the Black Sea consist of the Strandja, İstanbul and Sakarya zones. The Zonguldak-Ulus Basin, located in the NE part of the İstanbul Zone, has traditionally been viewed as opening during the Barremian and deepening until the Albian under the control of normal faults. New outcrop data indicate that the southern and eastern parts of this basin facing towards the Intra-Pontide Ocean in the south were already open during the Berriasian or earlier. Uplift and erosion of the Zonguldak-Ulus Basin during the Cenomanian is attributed to collision of the İstanbul and the Sakarya zones along the Intra-Pontide Suture. The Sinop Basin in the Sakarya Zone opened during Hauterivian–Barremian time. Sedimentation in this basin continued in a deepening environment until the development of the Pontide Magmatic Belt during the Turonian. The contact between the İstanbul and the Sakarya zones is represented by a shear zone that consists of siliciclastic distal turbidites, debris-flow deposits and radiolarian cherts imbricated with Middle Jurassic–Lower Cretaceous magmatic arc fragments. This shear zone is interpreted as being the eastern continuation of the Intra-Pontide Suture, separating the İstanbul and the Sakarya zones. The Western Black Sea Basin to the north of the Pontides possibly opened in two stages. In the first stage, coeval with the opening of the Zonguldak-Ulus Basin, the rifting was a wide-rift style and caused thinning of the continental crust. During the Turonian–Santonian, the Pontide Magmatic Belt started to develop as an extensional arc, and caused break-up of the already thinned crust and the start of oceanic spreading in the Western Black Sea Basin.

MINERALOGICAL FINDINGS FROM MANGANESE DEPOSITS IN THE ARTOVA OPHIOLITE COMPLEX, DERBENT-EYMIR AREA, YOZGAT, TURKEY

The Artova Ophiolitic Complex (AOC), which formed in association with Alpine Ophiolites, is exposed in the NE part of central Anatolia, in the interior of the central Black Sea region and within the borders of Çorum and Yozgat. The Derbent-Eymir manganese- oxide deposit under investigation occurs within this ophiolitic complex. The mineral association in Derbent ore is composed chiefly of pyrolusite, manganite and lesser amounts of ramsdellite, magnetite and goethite. Calcite is the main gangue mineral. The mineral association in Eymir ore is represented by pyrolusite, braunite, neltnerite, jacobsite, psilomelane and trace amount of limonite accompanied by some gangue minerals such as quartz and calcite. Electron microprobe analysis was carried out on pyrolusite, braunite and psilomelane minerals. While pyrolusite from Eymir has higher Si, Al, Mn and Ca, pyrolusite from the Derbent ore has lower Fe, K and Ba contents. Pyrolusite in the Eymir ore has higher Si, Al, Mn and Ca (10.28-7.06; 3.19-1.28; 87.98-81.88; 2.38-1.97 respectively) and lower Fe, K and Ba (0.31-0.16; 0.02-0.00; 0.07-0.00 respectively) contents in comparison to pyrolusite in the Derbent ore. Element variations in core-rim zones of spherical pyrolusites and manganite crystals elongated towards the gangue are quite noticeable. Both Eymir and Derbent ore deposits are low-temperature hydrothermal deposits. Geochemical variations recorded in various manganese minerals are found to be strongly dependent on the changes in pH and temperature of the ore-forming solution and distance to the spreading center.

Single center experience of urinary bladder malignancy: a 10-year retrospective analysis of hospital data

Background: Albeit the EAU, NCCN and AUA guidelines provide an excellent evidence-based protocol for the management of MIBC and NMIBC, these guidelines differ with respect to critical issues such as risk level definitions and management strategies. The NE part of the country has always bore the brunt of heavy oncological catastrophe like urinary bladder carcinoma related to extensive tobacco and pesticide usage. MIBC treatment usually encompasses RC with AC/NAC (Level I evidence for NAC use in MIBC exist) but the majority of patients seen at our center have already progressed to advanced stage at presentation and could not undertake full treatment.Methods: Cancer registry of the last 10 yrs at Dept. of Urology and Renal Transplant Gauhati Medical College Hospital was searched for demographic, clinical, pathological and prognostic data and results summarized using statistical parameters of univariate analysis.Results: There were a total of 168 patients in the NMIBC group with a majority in the 60-70-year age group. The most common grade was G2 and all DM type 2 and CKD were significantly associated in all the patients analyzed. Chemical exposure in the form of pesticide and smoking was a constant phenomenon in all patients of NMIBC and MIBC (n=66) population. CKD was significantly associated in the MIBC population along with positive urine cytology.Conclusions: Despite a paucity of high level evidence regarding the majority of management topics in Urinary Bladder cancer in NE part of the country, there was general agreement among the various guideline panels and management guidelines at our institution. Identification of the upfront clinical parameters suggesting severity of disease and time to progression are the two most important domains which will decide the future of UB carcinoma treatment in this part of the world. Categories of evidence synthesized and grades of recommendations will have to be constantly gazed upon to modify and enhance treatment strategies.

Distribution of base metals and the related elements in the stream-sediments around the Ahar area (NW Iran) and their implications

The study area is located in the Ahar region, NW Iran. Volcanic rocks of Eocene cover major parts of the area, within which granitic-granodioritic intrusive bodies of Oligocene intruded and produced hydrothermal alterations and Cu-Au mineralization. This paper aims to explore anomalies of base metals and related elements across the region based on systematic sampling of stream sediments and using the secondary geochemical halos. In this regard, by taking into account factors such as stratigraphy, lithology, tectonics and the topologic center of the drainage system, 620 samples were taken from stream sediments and analyzed by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES) method.All the distinguished anomalies correlate well with Oligocene granitic-granodioritic rocks and the related hydrothermal alterations occurred within the Eocene andesitic-basaltic volcanics, especially at the NE part of the quadrangle, as well as with alterations within trachy-andesitic and andesitic volcanics of Pliocene at the SE part of the quadrangle, where epithermal gold and Pb-Zn mineralization is found. Most of he studied elements also show moderate to strong anomalies over the Sonajil porphyry-type Cu mineralization. Copper, and to some extent Mo, as well as Pb, Zn, Sn, W, As and Sb are the best examples of this association. Bismuth has more limited anomalies across the region, showing correlation with the granitoid intrusion at the east of Ahar and the hydrothermal alterations within the Pliocene andesitic and basaltic rocks at SE of Ahar quadrangle which, considering the presence of epithermal gold and Pb-Zn veins in both areas, can be attributed to epithermal processes. However, anthropogenic pollutions are also found for As, Fe, V, Ti, Ni and Co downstream the urban and rural areas. In this regard, besides the Sonajil area, where porphyry-type Cu mineralization is discovered, the NE and SE parts of the quadrangle present promising areas for further investigations.

A structural scheme proposal derived from geophysical data in the epicentral area of the Boumerdes (Algeria) earthquake of May 21, 2003

In this study, we processed and interpreted gravity and aeromagnetic data of the epicentral area of the Boumerdes earthquake (May 21, 2003). The joint interpretation of both data allowed the development of a structural scheme that shows the basement undulations offshore and onshore. The shape of the eastern part of the Mitidja Basin is better defined; its northern edge is represented by a large “sub-circular” uplifted basement located offshore. The rise of this basement indicates that this basin does not extend towards the sea. At the eastern part of the study area, aeromagnetic data have revealed that the Sid-Ali-Bounab basement is individualized in a “sub-circular” shape, while the Dellys basement, located in the NE part, is elongated in the NE-SW direction and extends offshore. The aeromagnetic data also highlighted two EW basement uplifts which divide Isser depression into three parts. The northern part of this depression extends offshore. The southernmost uplift is an extension of the Thenia Fault (TF), suggesting the continuity of this fault to the east. It is important to note that the active Reghaia Fault (RF), which runs through the Boudouaou and Reghaia urban centers, is bounded by two faults suggesting that its length does not exceed 12 km. Moreover, alluvial terraces observed west of the active Zemmouri Fault (ZF) are in agreement with the reverse component of this fault.