PROBLEMS OF AGE AND GENETIC DIAGNOSTICS OF QUATERNARY DEPOSITS IN THE VALLEY OF THE YENISEI RIVER MIDDLE COURSE (YENISEI – LOWER ANGARA STRATIGRAPHIC REGION AND THE MINUSINSK BASINS AREA)

The article is devoted to the state of stratigraphic exploration maturity of the Eopleistocene – Neo-Рleistocene Quaternary deposits on the boundary of mountain and plain territories in the non-glacial area. The material analysis shows an inadequate rationale of the existing stratigraphic schemes, according to which the ladder of alluvial terraces of these territories was formed sequentially during the Eopleistocene, Neo-Pleistocene and Holocene. The revising of representative sections was carried out, the provision of them with geochronological data, the accuracy of age and genetic diagnostics were evaluated.

THE VERTICAL DISTRIBUTION OF THE ALLUVIAL CHEMO-FACIES OF BOUMERZOUG WADI, CONSTANTINE, NORTHEASTERN ALGERIA: PALEOENVEROMENTAL SIGNIFICANCE AND CLIMATE EVOLUTION

The authorities of Constantine city have been working on the redevelopment and calibration of the Rhumel and Boumerzoug wadis since 2015. The latter calebrage works caused great damage to the banks, thus affecting the Quaternary geological formations in place (alluvial terraces, flood plains). A multidisciplinary research project based on a geomorphological and sedimentological approach was quickly set up to create a scientific data base before their total destruction and loss of physical traces all along the wadis. The present study focuses on the sedimentological and geochemical analysis of the alluvial deposits of Boumerzoug wadi in order to describe the sediments, to reconstitute their nature, and to interpret both the climatic evolution and the paleo-environments of the region. Sedimentological and geochemical results confirm the succession of deposition cycles linked to progressive climate change.

Design of a Technical-Artisanal Dike for Surface Water Storage and Artificial Recharge of the Manglaralto Coastal Aquifer. Santa Elena Parish, Ecuador

Manglaralto parish communities are supplied with drinking water extracted from shallow aquifers (associated with alluvial terraces) recharged by seasonal rivers. The companies responsible for extracting and distributing water are the Manglaralto Regional Drinking Water Administration Board (JAAPMAN, for its acronym in Spanish) and Olon Regional Board of Drinking Water (JRAPO, for its acronym in Spanish). However, due to population growth and tourism (floating population) of Manglaralto parish, water demand has increased. This has meant that, during the dry season, the water stored in these underground reservoirs is not enough to meet the growing demand. The case study presented is that of the Manglaralto community. The aim is to design, in a technical way, an artisanal dyke (tape) by performing geological-geotechnical studies that allow optimal surface storage and artificial recharge of aquifers for the provision of water to communities. The methodology is as follows: i) Analysis of the technical starting information, ii) Recognition of the study site and the choice of sampling sites, iii) Conducting laboratory tests and analysis of information obtained in the field, and iv) Technical design of the tape. According to laboratory results and the field data analysis, the design of a spillway dyke equipped with a dentellon was defined, which acts as a screen to block the subsurface flow. The rescue of ancestral knowledge, used as a solution to current problems in this coastal community, allows storing a volume of 4,641.88 m3 and an artificial recharge of 15%, with low costs and great social acceptance.

Morphological evolution of the middle and lower Seine valley during the Quaternary period.

<p>The Seine river (France) drains today a catchment area of 80,000 km<sup>2</sup> covering almost the northern part of France. Despite its importance, few studies focused on the Seine catchment and its landscape evolution, unlike the Somme basin, which remains a European reference for the Quaternary, because of to the numerous archaeological sites it contains. The middle and lower Seine valley in Normandy shows nevertheless a particular meandering fluvial dynamic and a succession of fluvial terraces over 120 m height, dated back to Early Quaternary. Previous works focused on the stratigraphy of alluvial sequences and led to the accurate characterization of lower fluvial and estuarine levels from Marine Isotope Stage (MIS) 1 to MIS 11. The alluvial terraces comprise also various Acheulean industries, showing human settlements in the valley for at least 400,000 years. Such archaeological remnants were retrieved in Saint-Pierre-Lès-Elbeuf, Tourville-la-Rivière, Vernon and La Celle.</p><p>Nowadays, the Seine connects to the drowned lower Seine course which continues in the Channel. This submerged part was subaerial during the last glacial cycle. Presently, the lower Seine course is still under the influence of marine tidal effects up to la Bouille (around 30 km from the coast). Additionally, estuarine deposits filled the valley up to Les Andelys (around 80 km from the coast) during the Holocene transgression and cover the penultimate and last glacial alluvial terraces. Nevertheless, the dynamic of the Seine river is broadly identified with few chronological constraints, but without any morphometric analysis combined with stratigraphical study.</p><p>This work provides a review of the stratigraphy of the quaternary alluvial deposits in the lower part of the Seine Valley, together with new morphometrical analysis of the paleo-meanders located at higher altitudes. The analysis of the paleo-morphologies compared with high-resolution digital elevation model (DEM), provides new means for constraining the fluvial incision and deposition over long distances and periods, and helps to discuss the river evolution related with quaternary uplift, catchment evolution and glacio-eustatic dynamics.</p>

Metallogeny of the Zahedan-Nehbandan magmatic belt and implications to porphyry Cu exploration in southeastern Iran

<p>The Late Cretaceous to Eocene Sistan suture zone in southeastern Iran separates the Lut continental block in the west from the Afghan continental block in the east. A major belt of Oligocene to Miocene igneous rocks occurs between the cities of Zahedan and Nehbandan, stretching for ~200 km from south to north parallel to the border with Pakistan and Afghanistan. Known porphyry Cu mineralization is associated with the intrusions and intrusive complexes at Kuh-e Janja (16.5+2.0 Ma), Kuh-e Seyasteragi (19.2+ 1.4 Ma), Kuh-e Assagie (27.5+2.0 Ma), and Kuh-e Lar (32.8+3.0 Ma).</p><p>Small intrusions and intrusive complexes in the Zahedan-Nehbandan magmatic belt are mostly intermediate to felsic in composition and have calc-alkaline or shoshonitic affinities. Associated volcanic and volcaniclastic rocks are common. The igneous rocks are hosted by deformed late Cretaceous to Eocene flysch sequences that formed in the Sefidabeh forearc basin developed during the subduction and closure of the Sistan ocean. The geochemical composition of the intrusive rocks and their ages suggest that igneous activity and related mineralization in the Zahedan-Nehbandan magmatic belt may have formed as a result of post-collisional processes. The locations of the intrusive centers in the Kuh-e Assagie and Kuh-e Lar may be controlled by strike-slip faults, which are major post-collisional structures.</p><p>The recent discovery of the Janja porphyry Cu-Au-Mo deposit below Quaternary alluvial terraces highlights the exploration potential of the Zahedan-Nehbandan magmatic belt. In addition to post-collisional porphyry deposits, other deposit types such as skarns, polymetallic veins, or epithermal deposits may be hidden below the regionally extensive Quaternary cover.</p>

Anthropogenic impact on the Himalayan marmot population in Nepal

Anthropogenic impact on the Himalayan marmot population in Nepal is discussed. Above the upper border of the forest, human shares the same habitats with marmots on the alluvial terraces of river valleys. Human buildings and farmland lead to fragmentation of the marmot population, and overgrazing leads to pasture digression, worsening the food supply of these rodents. At the same time, people regularly catch marmots with loops, while, in accordance with the criteria of the IUCN Red List, the population of the Himalayan marmot in Nepal should be classified as Endangered (EN) - a very high risk of extinction in the wild.

Palm grove groundwater assessment and hydrodynamic modelling Case study: Beni Abbes, South-West of Algeria

This paper presents the groundwater modelling of Beni Abbes palm grove in Southwest Algeria. Beni Abbes oasis alluvial aquifer is part of the Saoura Valley aquifer system, including a loose slick contained in a Quaternary alluvial embankment that fills the Beni Abbes basin. To address local needs, industry and agriculture, groundwater has been intensively exploited in recent years. Groundwater of the Beni Abbes oasis in the Saoura Valley oasis chain, is composed of a complex system, whose layer of alluvial terraces ensures a vital role for a 40-hectare palm grove. Due to its architectural position in the local aquifer system, the alluvial aquifer is mainly fed by the Great Western Erg and sometimes by the Saoura River floods. Based on the hydrogeological, hydrochemical characterisation and hydrodynamic modelling of the alluvial aquifer system of the Beni Abbes oasis, the mathematical model of finite difference and finite difference at steady state leads to the estimation of the hydrodynamic parameters of the aquifer and the evaluation of the complete water balance. The main results of this study provide a better understanding of the geometry and functioning of this aquifer currently in a state of concern. Furthermore, it is necessary to undertake integrated water resource management in this oasis in order to ensure sustainable development.