Calcareous Sandstone Research Articles

Microenvironmental constraint on δ13C depletion: Garudamangalam Sandstone, Cauvery Basin, India

Within the hydrocarbon-producing Cretaceous marine Uttatur Group, Cauvery Basin, India, the Garudamangalam Sandstone Formation is at top of a TST-HST transit. The δ13C value is expectedly depleted within the calcareous Garudamangalam Sandstone, which is the top most unit of the Uttatur Group, overlying the Karai Shale. The calcareous sandstone was deposited in a coastal setting around a shore-parallel river mouth bar. Instances of excessive depletion of δ13C up to −44.5‰ in the carbonate cement is suggestive of methane generation and its subsequent sequestration. The common occurrence of early diagenetic pyrite in these rocks testifies to the proliferation of sulfate-reducing bacteria and is suggestive of methane generation beneath the sulfate reduction zone. Upward-moving diffusive methane was possibly consumed by methanotrophs at the base of the sulfate-reduction zone. Abundant fabric-selective carbonate cement corroborates microbially-controlled anaerobic oxidation of methane. The presumed high rate of nutrient supply, abundance of vegetative material and moderately high organic carbon content in sediments (av. 1.6%), support this contention. All the samples which have the greatest δ13C depletion are characterized by enriched organic carbon and are derived from a tidal inlet-mouth facies, and selectively from mud drapes on cross-bedding in tidal strata. Calcarenite at the base of the same cross-strata are invariably much less depleted in δC13. This range of relationships indicates the transport of methanotrophs that settled on foreset beds mostly as tides slackened under the broader control of neap-spring cycles.

A Unique association of scheelite and magnetite in the Tiemuli W-Fe skarn deposit: Implications for Early Cretaceous metallogenesis in the Nanling Region, South China

The Tiemuli scheelite-magnetite deposit in the central part of the Nanling region, South China, is genetically related to a porphyritic biotite granite pluton. The W-Fe orebodies are hosted within upper Cambrian calcareous sandstone or impure limestone in the external zones. LA-ICP-MS U-Pb dating of zircons from the granite yielded a weighted mean age of 136.6 ± 1.1 Ma. The main ore minerals are magnetite, scheelite and arsenopyrite, and the gangue minerals are clinopyroxene, grossularite, vesuvianite, amphibole and mica. Three paragenetic stages of skarn formation have been recognized: I. a skarn stage; II. a retrograde stage, and III. a quartz-sulphide-calcite stage. Massive magnetite and scheelite orebodies associated with hydrous minerals formed during Stage II. Molybdenite grains separated from Tiemuli skarns yielded Re-Os model ages of 136.3–133.8 Ma, with a weighted mean age of 135.1 ± 0.8 Ma. Biotite associated with fine-grained magnetite from the ores has a 40Ar/39Ar plateau age of 132.67 ± 0.43 Ma. These three independent dating techniques show that the granitic magmatism and tungsten mineralization were coeval (within error), whereas the late-stage alteration recorded by biotite could be ca. 2 m.y. younger than the early stage. The granite is classified as an A-type body on the basis of its geochemistry and mineralogy. Zircon grains from the granite show negative εHf (t) values of −7.7 to −2.3, and molybdenite grains from the skarn ores contain low Re contents of 0.93 to 2.97 ppm. These data indicate that the magma and ore-forming components at Tiemuli were derived mainly from crustal materials, although mafic xenoliths in the granites are consistent with some mantle contribution. The Tiemuli deposit was produced by crust-mantle interaction in an extensional regime, possibly caused by rollback of the subducting Paleo-Pacific plate during Early Cretaceous. The skarn scheelite and magnetite association formed by interaction between magmatic fluids and calcite-bearing sandstone or impure limestone of the host strata.

Quality of natural waters in carbonate aquifers at a densely populated Odukpani area of cross river state, Southern Nigeria

The study area, Odukpani is underlain by cretaceous sediments of the Calabar Flank. The main aquifers are fractured black shales that are inter-bedded with calcareous sandstones. The aquifers range...

Alteration mineralogy of eocene volcanic and volcaniclastic rocks from Sivas basin in Turkey

The study area covers volcanic-volcanosedimentary units of Eocene age in the Sivas-Ulas area from Turkey. The pyroclastic (tuffaceous claystone/siltsone/sandstone, crystal ash tuff) and volcanic (basalt, basaltic andesite, andesite) rocks of the Karacalar member from the Kalekoy Formation include volcanogenic (plagioclase, augite, hornblende, biotite), diagenetic (K-feldspar, mixed-layered chlorite-smectite/C-S, chlorite, analcime) and post-volcanic (calcite, dolomite, quartz) minerals. The volcanogenic (plagioclase), diagenetic (K-feldspar, C-S, chlorite), postvolcanic (quartz, calcite, dolomite) and detrital (illite) minerals were observed in the epiclastic (shale, siltstone, calcareous siltstone, sandstone, calcareous sandstone) and chemical (limestone, gypsum) rocks of the Yapali member from this formation. C-S + K-feldspar zoning is widely developed by due to the interaction between sea-water and volcanic glass in basic-intermediate composition, on the basis of optic and electron microscopes and also X-rays data. This zone corresponds to the deeper parts of the Sivas basin in the Eocene period and show vertically a transition into zeolite zone in approximately northern parts of the basin (Yavu area).

OS CORPOS DE ARENITOS PRAIAIS QUE SUSTENTAM O FORTE DOS REIS MAGOS, PRINCIPAL CONSTRUÇÃO HISTÓRICA DA CIDADE DE NATAL-RN

Ao longo de toda a história do homem, as rochas se fizeram presente. Inicialmente, utilizadas como instrumentos de caça, hoje esse elemento da geodiversidade do planeta tem importância econômica, funcional e cultural intrínsecos com o cotidiano da sociedade. Em Natal, capital do Rio Grande do Norte, a percepção do possível uso das rochas locais para o desenvolvimento da cidade se iniciou ainda no processo de construção da primeira edificação local que é o Forte dos Reis Magos. Por muitos anos um ponto de importância para a manutenção do domínio português na região Norte e Nordeste do Brasil, o Forte dos Reis Magos possui quase 400 anos de história em suas paredes erguidas com os arenitos calcíferos encontrados em seus arredores, que já foram objetos de estudo desde o início do século XX. O trabalho aqui apresentado foi realizado a partir de trabalhos arqueológicos orquestrados pelo IPHAN e se propõe a analisar as rochas utilizadas na construção do Forte, mostrando também a forte relação da geodiversidade com a cidade e com as ciências.

Petrographic Characteristics and Depositional Environment Evolution of Middle Miocene Sediments in the Thien Ung - Mang Cau Structure of Nam Con Son Basin

DOI: 10.17014/ijog.4.3.143-157This paper introduces the petrographic characteristics and depositional environment of Middle Miocene rocks of the Thien Ung - Mang Cau structure in the central area of Nam Con Son Basin based on the results of analyzing thin sections and structural characteristics of core samples. Middle Miocene sedimentary rocks in the studied area can be divided into three groups: (1) Group of terrigenous rocks comprising greywacke sandstone, arkosic sandstone, lithic-quartz sandstone, greywacke-lithic sandstone, oligomictic siltstone, and bitumenous claystone; (2) Group of carbonate rocks comprising dolomitic limestone and bituminous limestone; (3) Mixed group comprising calcareous sandstone, calcarinate sandstone, arenaceous limestone, calcareous claystone, calcareous silty claystone, dolomitic limestone containing silt, and bitumen. The depositional environment is expressed through petrographic characteristics and structure of the sedimentary rocks in core samples. The greywacke and arkosic sandstones are of medium grain size, poor sorting and roundness, and siliceous cement characterizing the alluvial and estuarine fan environment expressed by massive structure of core samples. The mixed calcareous limestone, arenaceous dolomitic limestone, and calcareous and bituminous clayey siltstone in the core samples are of turbulent flow structure characterizing shallow bay environment with the action of bottom currents. The dolomitic limestones are of relatively homogeneous, of microgranular and fine-granular texture, precipitated in a weakly reducing, semi-closed, and relatively calm bay environment.

The role of landslides in downslope transport of caprock-derived boulders in sedimentary tablelands, Stołowe Mts, SW Poland

Escarpment slopes in sedimentary tablelands are often mantled by extensive boulder blankets. While lithology shows beyond doubt that caprock is the source of boulders, the processes involved in boulder movement and their distribution patterns are rarely examined. In this paper we investigate the role of landslides initiated within middle and lower escarpment slopes in redistributing boulder covers, on the example of the Stołowe Mountains in SW Poland. Quartz sandstones form caprock and give rise to precipitous, albeit rather low (30m high at most, typically 10–15m) uppermost slope sections, and are the source of boulders which occur at distances even 1km away from the caprock, on the nearly flat footslope. Sedimentary series beneath caprock include fine-grained rocks such as mudstones, claystone and calcareous sandstones. Geomorphological mapping and geomorphometric analysis of a high-resolution DEM allowed us to identify landform patterns interpreted as resulting from landslides, both rotational and translational. The latter produced distinctive tread-and-riser topography, with risers up to 10m high. Results of geophysical prospecting using Electrical Resistivity Tomography (ERT) confirm the presence of allochthonous, sandstone-derived upper layer that wedges out downslope and indicate resistivity contrasts at depth of 5–15m, interpreted as basal boundaries of landslide material. Sandstone boulders rafted on top of slid masses and reached very distant footslope settings. The primary role of landsliding consists of transporting allochthonous boulders further than would be possible otherwise and accumulating boulders in clusters and linear belts across the slope, notably on risers.

Calpionellid biostratigraphy and microfacies analysis of a Tithonian–Berriasian carbonate succession in the Western Srednogorie (Bulgaria)

In the eastern part of the Western Srednogorie Unit, around Dragovishtitsa Village, a specific succession of the Gintsi and Glozhene–Slivnitsa formations has provided micropalaeontological evidence for late Tithonian (Chitinoidella, Praetintinnopsella and the base of Crassicollaria zones) and mid-Berriasian (the Elliptica Subzone of the Calpionella Zone) age on the basis of 45 chitinoidellid and calpionellid species. A significant stratigraphic hiatus is documented within the Glozhene–Slivnitsa Formation, since a part of the Crassicollaria Zone, as well as the Alpina+Remaniella subzones of the Calpionella Zone, is absent from the Dragovishtitsa 1 section. The conformably overlying Salash Formation is of mid-Berriasian age (Elliptica Subzone) and is locally characterized by the presence of calcareous sandstones (Dragovishtitsa 2 section). The Salash–Cherni Osam Formation, as well as the clayey limestone unit covering the Slivnitsa Formation, is also of mid-Berriasian age (Elliptica Subzone). The Slivnitsa and Glozhene–Slivnitsa formations, which underlie the Salash–Cherni Osam Formation in the Dragovishtitsa East section, correspond to the Crassicollaria Zone and the Alpina Subzone, respectively. Reworking of calpionellids from the Crassicollaria Zone is documented in the Alpina and Elliptica subzones in all three studied sections. Eight microfacies types are distinguished, which suggests that the carbonate sediments were deposited in a carbonate platform rather than in a pelagic basin environment, althought the upper part of the studied sections reveals an upward-deepening trend. The Slivnitsa Formation is covered by highly diachronous sediments from more distal settings: from mid-Berriasian around Dragovishtitsa Village to the Berriasian/Valanginian transition at the Tri Ushi section to late Valanginian in the Dragoman and Kalotina sections. This fact, together with the significant stratigraphic hiatus within the Glozhene–Slivnitsa Formation, is interpreted here as tectonically controlled. The presence of transitional depositional settings from carbonate platform to deeper-marine environments caused deposition of specific lithostratigraphic units not always corresponding to the diagnostic features of the Glozhene, Salash and Cherni Osam formations.

The uppermost Carboniferous (Gzhelian)–Lower Permian (Asselian–Sakmarian) stratigraphy and smaller foraminifers of the Ozbak‐Kuh region (Tabas Block, east central Iran)

The uppermost Carboniferous (Gzhelian)–Lower Permian (Asselian to Sakmarian) Anarak Group of the Zaladou section in central Iran is more than 180‐m thick and includes thick units of shale, calcareous sandstone, fusulinid limestone, sandy limestone, and dolomite. The Zaladou and Tigh‐e‐Madanu formations of this group were dated as Gzhelian to Sakmarian. A review of the smaller foraminifers of the Zaladou section is presented. Five foraminiferal subzones grouped in three biozones are proposed in this work: The first assemblage zone (I) is Gzhelian; the second zone (II) corresponds to the Gzhelian–Asselian boundary interval, and the third biozone (III) is Asselian in age. Biozone I is subdivided informally into two subzones: the Hemigordius spirilliniformis‐Bradyina cf. samarica subzone IA (probably early Gzhelian in age) and the Raphconilia modificata and Globivalvulina spp. subzone IB (middle to late Gzhelian); biozone II is the Nodosinelloides spp. zone; biozone III is subdivided informally into two subzones: IIIA with Pseudoacutella partoazari‐Bradyina lucida and IIIB with Planoendothyra persica n. sp.‐Rectogordius sp. The studied assemblages are correlated with those from the Carnic Alps (Austria–Italy), East European Platform of Russia, the Urals (Russia), Darvas (Uzbekistan), the northern and central Pamirs (Tajikistan), northern Iran (Alborz), northern Afghanistan, and other classical regions of the Tethyan realm. The genera Raphconilia and Planoendothyra are revised, and Planoendothyra persica n. sp. is described.

Detrital provenance, depositional environment, and palaeogeographic implications of Lower Triassic marine sediments in central Tibet

ABSTRACTWe present our new investigation into the depositional environment and provenance of the Yingshuiquan Formation in the central Qiangtang region of northern Tibet, in order to further our understanding of the environment of the Longmu Co–Shuanghu Palaeo–Tethys during the Early Triassic. The Yingshuiquan Formation is composed of oolitic limestone, calcareous sandstone, calcarenite, thin-bedded ribbon limestone, bioclastic limestone, and coarse oolite limestone that were deposited in a shallow-marine basin and contain abundant Lower Triassic conodont fossils (e.g. Hadrodontina anceps, Pachycladina sp., gen. et sp, Pachyclaina oblique, Hibbardelloides sp). We selected detrital zircons from four calcareous sandstone samples for U–Pb dating, yielding minimum age peaks of 263, 269, 275, and 280 Ma, respectively, and a minimum age of 249 Ma, based on several zircons around the same age. Analysis of the conodont biofacies and zircon LA-ICP-MS dating of calcareous sandstone indicates that the data is consistent with deposition in the Early Triassic. The Yingshuiquan Formation records Early Triassic shallow-water sediment in the Longmu Co–Shuanghu Palaeo–Tethys, and has a Southern Qiangtang and Northern Qiangtang terranes provenance. During the Early Triassic, the carbonate sediments of the Yingshuiquan Formation were deposited in an active environment around the Longmu Co–Shuanghu Palaeo–Tethys, which has became a residual sea basin.

Nanggulan Formation and Its Problem As a Basement in Kulonprogo Basin, Yogyakarta

DOI: 10.17014/ijog.4.2.71-80Nanggulan Formation consists of the oldest clastic rock sequence exposed in Kulonprogo area, Yogyakarta. This paper discusses the position of Nanggulan Formation as a basement. The method used in this research is surface and subsurface investigations based on gravity surveys. The rock assemblage is exposed and distributed partly in the east flank of Kulonprogo Mountains with weak undulated morphology. The rock sequence is composed of sand to clay grain sizes such as sandstone, quartz sandstone, calcareous sandstone, claystone, fossiliferous claystone, calcareous claystone, siltstone, and coal seam intercalations. The total thickness of the sequence is less than 200 m. Based on the fossil and palynology investigations, previous investigators concluded the age of the rock was Eocene to Middle Miocene. The geological structures developed in the rocks are the lithological stratification, fractures, folding, and faulting. The subsurface interpretation based on gravity data revealed the rock was located under the andesite breccias with 2.44 g/cc density. The density of the rock sequence was 2.63 g/cc. The gravity interpretation shows a strong indication that Nanggulan Formation underlies the andesitic breccias presumably associated with Old Andesite Formation exposed in Kulonprogo Mountains. The limited distribution, the thickness, and the closed environmental deposition of Nanggulan Formation found in the present investigation raised problems on the position of the formation as the basement of Old Andesite Formation occurring in the Kulonprogo Mountain.

High-grade calcareous metasediments from the Sawtooth Metamorphic Complex, Idaho, USA: evidence for passive margin strata and polymetamorphism within the Idaho batholith

ABSTRACTThe Sawtooth Metamorphic Complex (SMC) of central Idaho contains exposures of metasupracrustal rocks, in a crucial location between the Archaean Wyoming craton to the east and the adjacent Mesozoic terranes to the west, that provide constraints on Precambrian crustal evolution in the northwestern United States. Mineral textures, whole-rock geochemistry, and thermobarometry of calc-silicate gneisses record multiple stages of crustal evolution, including protolith deposition, burial and multiple metamorphic and deformational overprints. Whole-rock signatures are consistent with derivation from post-Archaean, continental sources that have undergone sedimentary maturation and recycling typical of clastic sedimentation in passive-margin environments and with a metamorphosed sequence of calcareous sandstones and marls, containing varying proportions of clay and quartzo-feldspathic detritus. The sandstone-to-marl continuum may reflect a shallow-to-deep water transition in the depositional environment of the calc-silicate protoliths. Two metamorphic events and three deformational events are preserved. The assemblage clinopyroxene + quartz + plagioclase + K-feldspar + rutile represents peak metamorphic conditions (M1), estimated at 750–775°C with relatively oxidized metamorphic fluids, during development of D1a foliation. Deformation twinning in clinopyroxene records a widespread, high strain D1b event at high temperature. A second static thermal event (M2), associated with randomly oriented amphiboles overprinting M1 and D1b features, records conditions of ~550–725°C and H2O-rich fluids. Late-stage, brittle–ductile D2 deformation is characterized by mylonitic lenses of quartz, fractures within M1 clinopyroxenes that crosscut D1b deformation twins, and localized fracturing of M2 amphiboles. Geochemical and mineral chemical signatures of SMC calc-silicates preserve fingerprints of the original protolith through burial to mid-crustal conditions and high-grade metamorphism and suggest crustal thickening to about 20 km. The SMC may reflect rocks at depth beneath the Idaho batholith. These data, indicative of newly recognized post-Archaean terrain with passive-margin, continental sediments suggest that a continuous Cordilleran passive margin sequence may have extended along the western edge of Laurentia.

The influence of fish ponds and salinization on groundwater quality in the multi-layer coastal aquifer system in Israel

This study focuses on the impact of surface reservoirs (fish ponds) on a multi aquifer coastal system, and the relation between the aquifer and the sea. The study was conducted in an Israeli Mediterranean coastal aquifer, which includes a sandy phreatic unit and two confined calcareous sandstone units. The geological description is based on 52 wells, from which 33 samples were collected for stable isotope analysis and 25 samples for organic and inorganic parameters. Hydraulic head and chemical measurements suggest that there is an hydraulic connection between the fish ponds above the aquifer and the phreatic unit, whereas the connection with the confined units is very limited. The phreatic unit is characterized by a low concentration of oxygen and high concentrations of ammonium and phosphate, while the confined units are characterized by higher oxygen and much lower ammonium and phosphate concentrations. Organic matter fluorescence was found to be a tool to distinguish the contribution of the pond waters, whereby a pond water signature (characterized by proteinaceous (tryptophan-like) and typical humic-matter fluorescence) was found in the phreatic aquifer. The phreatic unit is also isotopically enriched, similar to pond waters, with δ18O of −1‰ and δD of −4.6‰, indicating enhanced evaporation of the pond water before infiltration, whereas there is a depleted isotopic composition in the confined units (δ18O=−4.3‰, δD=−20.4‰), which are also OM-poor. The Phreeqc model was used for quantitative calculation of the effect of pond losses on the different units.The Dissolved Inorganic Nitrogen (DIN) in the upper unit increases downstream from the ponds toward the sea, probably due to organic matter degradation, suggesting contribution of DIN from shallow groundwater flow to the sea. 87Sr/86Sr and Mg/Ca in the brackish and saline groundwater of the lower confined units increase toward seawater value, suggesting that the salinization process in the region is connected to seawater intrusion and not to old brine from the underlying Cretaceous aquitard.

Geochemical characteristics of sandstones from Cretaceous Garudamangalam area of Ariyalur, Tamilnadu, India: Implications of provenance and tectonic setting

The Trichinopoly Group (later redesignated as Garudamangalam) has unconformable relationship with underlying Uttatur Group and is divided into lower Kulakanattam Formation and upper Anaipadi Formation. These calcareous sandstones are analysed major, trace and rare earth elements (REEs) to find out CIA, CIW, provenance and tectonic setting. The silica content of fossiliferous calcareous sandstone show wide variation ranging from 12.93 to 42.56%. Alumina content ranged from 3.49 to 8.47%. Higher values of Fe2O3 (2.29–22.02%) and low MgO content (0.75–2.44%) are observed in the Garudamangalam Formation. CaO (23.53–45.90) is high in these sandstones due to the presence of calcite as cementing material. Major element geochemistry of clastic rocks (Al2O3 vs. Na2O) plot and trace elemental ratio (Th/U) reveal the moderate to intense weathering of the source rocks. The Cr/Zr ratio of clastic rocks reveal with an average of 1.74 suggesting of felsic provenance. In clastic rocks, high ratios of \(\sum \)LREE/\(\sum \)HREE, La/Sc, Th/Sc, Th/Co, La/Co and low ratios of Cr/Zr, and positive Eu anomaly ranges from (Eu/Eu* = 1.87–5.30) reveal felsic nature of the source rocks.

PRELIMINARY STUDY ON THE SLUMP STRUCTURES OF THE EARLY OLIGOCENE SEDIMENTS OF THE PRE-APULIAN ZONE (ANTIPAXOS ISLAND, NORTH-WESTERN GREECE)

A spectacular slump is observed in the Alpine sediments of the Antipaxos Island (Pre-Apulian zone, Western Greece). It can be followed in a zone of about 2000 m, in the eastern coast of the island. The slumped unit exposure length extends for more than 200 m, and is directly overlain and underlain by undeformed strata. The slump has an average thickness of 15 m and is composed, as the surrounding undeformed units, of calcareous mudstones and fine-grained calcareous sandstones. Synsedimentary folds that very often are transformed to contorted beds affect slump sediments. Fold and contorted bed axes present a NNW-SSE direction, coinciding with the general direction of the Pre-Apulian zone. Slump and overlain/underlain undeformed sediments originate from the flux of clastic mainly pelagic/neritic biogenic particles, emanating from turbidity currents. More than 50 samples have been collected and analyzed for calcareous nannofossil content. All samples were featured by the contemporaneous presence of abundant nannofossil flora implying the biostratigraphic correlation with the NP23 nannofossil biozone. The biostratigraphic assignment places the slump and the surrounding sediments to the Early Oligocene. As the Pre-Apulian zone corresponds to the slope between the Apulian Platform and the Ionian Basin, the presence of the slump is directly related to the same age sloping and tectonic mobility of this domain. The Antipaxos turbidites sediments are well integrated to the flysch deposition of the external Hellenide foreland basin system.

Logging Characteristics and Identification Methods of Low Resistivity Oil Layer: Upper Cretaceous of the Third Member of Qingshankou Formation, Daqingzijing Area, Songliao Basin, China

This study focuses on low resistivity thick layer sandstone in the X~XII groups of the third member of Qingshankou Formation at Daqingzijing oilfield, along with comprehensive data of logging, core, oil test, and production test. Based on the current data, we characterized the logs of low resistivity thick-layer sandstone, quantitatively identified calcareous sandstone and low resistivity reservoir, predicted the reservoir thickness, and further explored the causes of low resistivity reservoir of the region. The resistivity of thick layer sandstone in the X~XII groups of Qingshankou Formation can be classified into low amplitude logfacies, middle amplitude logfacies, and sharp high amplitude logfacies. Sharp high amplitude logfacies sandstone is the tight sandstone of the calcareous cementation. Low amplitude logfacies sandstone is water layer. For the middle amplitude logfacies sandstone, water layer or oil-water layer can be identified with the identification standard. Low amplitude structure, high clay content, high irreducible water saturation, and high formation water salinity are attributed to the origin of low resistivity oil layer.

Geotechnical and Geophysical Study of Ain Harrouda New City (Morocco)

A reconnaissance study of soil properties is realized in the implantation area of the future town of Ain Harouda (Morocco). This study used two approaches: geotechnic and geophysic. The geotechnical approach begins with 11 mechanical core drilling and 5 wells using mechanical shovel with sampling for laboratory testing and particularly identification tests. This study showed that the settlement area of the new city of Ain Harrouda consists of a primary base consisting of schists and quartzites. These are surmounted by conglomerates and calcarenites plio-quaternary age. It also determined the intrinsic characteristics of the each geological formation that make up the study area, include water content, density, particle size analysis by sieving, sedimentation particle size analysis, the value of methylene blue (VBS), the equivalent of sand, limits Atterberg. The geophysical approach consists of electrical resistivity technique with 5 vertical electric sounding and 8 electrical tomography profiles. This approach was used to determine the resistivity corresponding to each type of land and also the consistency of the soil. It allowed to distinguish the substratum characterized by high resistivity (more than 3000 ohm.m), and the sedimentary cover represented by three classes of average resistivity: 200 to 1600 Ohm.m for calcareous sandstones, 50 to 100 Ohm.m for silty sands, and very low for clays (less than 50 ohms. m). The results obtained shows that the study area appears healthy and suitable for the construction of the new town of Ain Harrouda.

Smaller benthic foraminifera Analysis of Kudat Formation, Kudat, Sabah: Preliminary Interpretation

Small benthic foraminifera have been fully extracted from the mudstone of Kudat Formation, Kudat, Sabah. The Kudat Formation comprise thick-bedded, quartzose to feldspathic, locally calcareous sandstone, an overall abundance of lignitic and carbonaceous layers, and the presence of red shales and detrital calcarenites. A total of 22 mudstone samples of Kudat Formation in difference localities have been collected for foraminifera analysis. All samples are processed according to standard micropaleontological method. Twenty-five species of small benthic foraminifera consisting of the agglutinated and hyaline group have identified. Almost all mudstone samples of Sikuati Member and Matunggong Member are consisting of deep-sea agglutinated foraminifera assemblage indicative of bathyal to abyssal. K21 sample of Tajau member and K9 sample of Sikuati Member consist of deep-sea agglutinated foraminifera together with reworked calcareous foraminifera. Foraminifera analysis shows that the Kudat Formation sediment was deposited in deep marine setting ranging from bathyal to neritic.

The Tyrrhenian Calcareous Sandstone Quarries In The Eastern Coast Of The Cap Bon Peninsula (Northeast Tunisia)

Activities related to the extraction and exploitation of natural resources are varied in Tunisia. But the most important numerically and spatially are stone quarries, which, once abandoned, are considered as low-value land and, in most cases, become an environmental nuisance, even though they have the potential to be of great natural, scientific, or cultural interest. The abandoned calcareous sandstone quarries that were opened in the Tyrrhenian barrier beach on the eastern coast of the Cap Bon peninsula (northeast Tunisia) illustrate this. The industrial quarrying started in the 1970s, but more detailed observations of the site reveal that the recent quarries often overlap with older ones dating back to antiquity. The site is very rich in archaeological remains and offers the opportunity not only to analyze and understand the variety of the landscape, but also the evolution of extraction techniques over time. This paper is devoted to sharing better knowledge and valuation of the quarries and their heritage, landscape, and environmental assets. It also aims to provide ideas for reintegrating them into their environment and making them useful spaces for the towns of the east coast of the peninsula, which are undergoing very rapid urbanization.

Reservoir characterization utilizing the well logging analysis of Abu Madi Formation, Nile Delta, Egypt

The petrophysical evaluation of the Late Miocene Abu Madi Formation were accomplished based on the open hole logs of eighteen wells in Abu Madi–El Qar’a gas fields, onshore Nile Delta, Egypt. The lithological contents of this rock unit were analyzed using the cross plots of petrophysical parameters including shale volume, porosity and hydrocarbon saturation. The neutron /density cross-plots, M-N and RHOMAA–DTMAA and litho-saturation cross plots of the studied wells show that the main lithology of the lower part of Abu Madi Formation is calcareous sandstones with shale intercalations in most of the studied wells while its lithology is mainly shale with sand intercalations in wells AM-13, AM-21 and AM-7. The lithology of the upper part of Abu Madi Formation in most wells is composed mainly of shale while its lithology in AM-13, AM-21 and AM-7 wells is composed of sandstone with shale intercalations. The thorium-potassium cross plots indicate that, Abu Madi Formation was deposited mostly in fluvial to shallow marine environments according to the presence of mica and illite in the southern area and montmorillonite at the northern area as dominant clay minerals. Contour maps of several petrophysical parameters such as effective thickness, average shale volume, average porosity and hydrocarbon saturation showed that both lower and upper parts of Abu Madi Formation in the study area have promising reservoirs characteristics; in which the prospective area for gas accumulation located toward the central part.