Miocene Clays Research Articles

Mineralogy and physico-chemical properties of Wadi Badaa clays (Cairo-Suez district, Egypt): a prospective resource for the ceramics industry

The Wadi Badaa (WB) Upper Miocene clays, Cairo-Suez district, Egypt, represent materials for the ceramic production. The clay raw materials are composed mainly of smectite and kaolinite with minor quartz, calcite, and rare feldspar. The plasticity indices vary between 24 and 30%, suggesting that these clays are plastic raw materials. IR bands of the investigated clays were observed at 3695, 3619, 1032, 916, 794, 690, 534, 466, and 423 cm−1 for kaolinite; at 3436, 1635, 916, and 466 cm−1 for smectite; and at 1179, 1104, 794, 690, and 466 cm−1 for quartz. The <2 μm particle sizes of samples are relatively abundant in clays (∼33%), which is adequate for uses of the ceramic products because of containing fine particle sizes. The studied WB clays contain 7.95 and 12.35% moisture water and interlayer water, respectively, with a maximum drying shrinkage of 7.87% at room temperature; therefore, the WB clays could be used in the ceramic manufacture.

New Cenozoic dragonflies from the Most Basin and Středohoří Complex volcanic area (Czech Republic, Germany)

ABSTRACTDiscovery of new dragonflies from Oligocene and Miocene deposits of the Most Basin and České Středohoří Complex volcanic area in northern Bohemia and Saxony (Germany) is reported. Aeshna zlatkokvaceki sp. nov. is the first described dragonfly from early Miocene salmon-pink baked clays of Želénky near Duchcov. Its fore wing venation pattern seems to be closely related to that of Aeshna turoliana Riou and Nel, 1995, known from late Miocene of La Montagne d’Andance in Ardèche, France, and Aeshna solida Scudder, 1890, known from late Eocene of Florissant in Colorado, USA. A new occurrence of a libellulid dragonfly ?Onychothemis rihai in the Libkovice Member of Most Basin confirms the links to the Cypris Formation in Sokolov and Cheb basins reflecting similar habitats as was already shown on the basis of reconstructed palaeovegetation and shared thermophilous and accessory floristic elements. Other fragmentary fossil material from different localities are discussed.http://zoobank.org/urn:lsid:zoobank.org:pub:7A3BB1C3-5A70-4058-86A5-731B58C0ADC3

Carbonate karst and its relationship with geodynamic conditions of the Odessa city (Ukraine)

A connection between karst and geodynamic features in the area of the city of Odessa (Black Sea karst region) was considered. The geodetic, geological and hydrogeological researches showed divergent vertical and horizontal movements of the individual units of the Neogene–Quaternary structural stage. It was found that the main orientations of passages in the caves in the Moldavansky and Kryvobalkovsky sites are NNW–SSE, WNW–ESE and NNE–SSW. This agrees well with the direction of the diagonal lineament network disclosed in recent years. The main directions of cave passages in the Bugaevsky site coincide with the main directions of the lineaments WNW–ESE, NNW–SSE located in the immediate vicinity of the zones of influence of the lineaments of the orthogonal networks N–S, SSW–NNE, and W–E. These findings suggest that caves developed along the directions of the lineaments of two tectonic networks of Neogene structural stage—diagonal and orthogonal. These networks of tectonic fractures were mapped and analyzed previously by applying the geological and hydrogeological methods and analyzing digital maps of the Neogene surfaces. Results of the research were compared to a map of isolines of long-term average velocity of vertical deformations of ground surface, and of zones of influence of lineaments identified in the surface topography of Upper Miocene clay, limestone and Pliocene red-brown clay. They show that the karst areas are mainly located in the gradient zones of vertical deformation of ground surface, and zones where Upper Miocene limestone is compartmentalized by diagonal and orthogonal lines of fracture. These areas could be considered as tectonically weakened.

Potentiality of clay raw materials from Gram area (Northern Tunisia) in the ceramic industry

The geological study of Miocene clays from Gram area, North West of Tunisia shows an important series of clay materials to use them in the faience ceramic. Selected samples were studied with the objective of analyzing their chemical and mineralogical composition, morphology, particle size, plasticity, thermal analysis and their ceramic aptitude to be used in the faience ceramic. Raw materials are mainly composed of illite and kaolinite are the dominant clay minerals with minor quartz and dolomite.The plasticity indexes are lower than 15.40%, suggesting that these clays are not plastic. Technical characterization was carried out on one representative mixture of Miocene clay samples. The firing characteristics (shrinkage and water absorption) were measured. The optimum firing temperature of clay mixture (M) has been established. These clays could be used in the manufacture of ceramic pieces.

On the Possibility of Testing Miocene Clay from Cracow Area using Weight Sounding Test (WST)

Abstract Polish standards concerning field investigation with the use of a Weight Sounding Test (WST) probe give interpretation of results for non-cohesive soils only. The lack of such interpretation for cohesive soils excludes this testing equipment from use. This paper presents the results of geotechnical site investigation and laboratory tests performed for Miocene clays in Carpathian Foredeep in the Cracow area. Based on the analysis of the results a correlation was determined between the characteristic values for the WST probe (number of half-turns NWST) and the selected properties of Miocene clays. The article is an attempt to create a complete interpretation of test results obtained for cohesive soil with WST equipment.

Conditions Favoring the Occurrence of Ignis Fatuus Phenomenon Over a Mass Grave in Niepołomice (S Poland)

A phenomenon of glowing clouds occurred at the border of Puszcza Niepołomicka in the vicinity of Niepołomice near Craco. Especially at spring and autumn nights, The most plausible explanation includes oxidation of gaseous P–bearing compounds with formation of phosphine, diphosphine and hydrogen. In the environment of variable water conditions in Pleistocene sands bedded by Miocene clays, phosphorus contained in bone remnants of the mass grave in the form of calcium hydroxyapatite alters to phosphides in the subsoil to gaseous forms of phosphor hydrogen compounds. This phenomenon is favored by microorganisms, including those from human digestive system, slightly acidic reaction of the soil (pine tree needles), the presence of heavy elements in soil (also from ammunition cartridges), high relative moisture of the air at night and the presence of the inversion air layer.

Procesos erosivos intensos en las áreas marginales de la Depresión del Ebro y el Pirineo : Interpretación de los patrones de la vegetación

This article reviews the current knowledge about erosion processes in badlands and other strongly eroded areas in the northern half of Aragón (Spain), from the Middle Ebro Basin to the Pyrenees. The four most extensive lithologies with the strongest erosion processes were selected: pure gypsum from the Central Ebro Valley, Miocene clays from Hoya de Huesca and Somontano, Eocen marls from the Prepyrenees and Eocen flysch from the Pyrenees. The climate of each substratum was studied, as well as the most important edaphic and lithological characteristics in arder to explain the erosion processes. Sorne information about erosion rates and vegetation characteristics from each substratum were included. Also vegetation patterns in these areas and their interactions with erosion processes and other factors were interpretted.&#x0D; Very strong differences between the lythologies were found. Pure gypsum has high infiltration and low erosion rates, but the ion exportation by dissolution is high. These characteristics and the low annual rainfall mean that the vegetation has to resist a high water stress. The vegetation pattern is very uniform and topography is the most important factor to explain this.&#x0D; However, in the gullies of eocen marls, infiltration is very low anderosion rates are very high. These strong erosion processes cause formation of a mosaic with stable, depositional and eroded areas in close proximity to each other. This implies that the vegetation is very heterogeneous in small spatial scales, and typically there is a "species mixture". &#x0D; Generally, Miocen clays are characteristic between eocen marls and pure gypsum, and the characteristics of eocen flysch are usually similar to eocen marls.

Magnetostratigraphic importance of secondary chemical remanent magnetizations carried by greigite (Fe3S4) in Miocene sediments, New Jersey shelf (IODP Expedition 313)

Paleomagnetic and mineral magnetic analyses were carried out on Miocene clays from upper unit II at Sites M0027 and M0028 recovered during Integrated Ocean Drilling Program Expedition 313 on the New Jersey shallow shelf. A zone of mixed polarity in the lower section of Hole M0028A and dual overlapping magnetization components in upper Hole M0027A indicate that the sediments may have been chemically remagnetized during one or several events. Mineral magnetic investigations reveal that the magnetization is carried by the ferrimagnetic iron-sulfide greigite (Fe3S4), possibly with traces of titano-magnetite. We find that several changes in polarity coincide with variations in magnetic mineral grain size and/or concentration. We interpret these variations as different stages of greigite growth, which were triggered by changes in pore-water chemistry and/or upward migration of methane.

An Experimental Design for the Optimization of Brick Manufacturing Procedure: Application on the Late Miocene Clays, Southern Tunisia

Clay deposits of the Segui formation (Jebel Stah of the Gafsa basin, Southwestern Tunisia) were used as natural material for brick manufacturing. Factors influencing the preparation procedure were optimized by an experimental design to find out the most propitious conditions for the preparation of bricks of high quality. The collected clay samples were characterized by various techniques, including X-ray diffraction (XRD), Fourier transform infrared (FTIR) and pycnometry. The optimum conditions for the preparation of high quality materials were investigated by studying the effects of clay minerals percentage, sintering time and temperature. Then various tests including sintering shrinkage, water absorption and compressive strength of the newly prepared brick samples were evaluated to determine the optimum preparation conditions. Results showed that the optimized conditions were: 80% illite, 830°C sintering temperature and 2 h sintering time. The same results showed that brick shrinkage depended mainly on water absorption, illite and smectite percentages. These results suggested that clay samples from Jebel Stah are promising natural materials that could be used to prepare bricks with better mechanical properties.

Albertona balkanica from Early Miocene of Snegotin (Serbia) – implications for the distribution and evolution of Miocene Ochotonidae

Remains of Albertona balkanica from the Early Miocene clays of eastern Serbia have shifted the range boundary of this species in direction of Central Europe. The peculiarities in tooth morphology were used for comparison and defining of the possible evolutionary connection with other representatives of fossil Ochotonidae. Due to the similarity with fauna of Aliveri in Greece, the association of small mammals of Snegotin (which includes Albertona) was included in the MN4 zone.

Iron in the kaolinites from kaolin and bauxite weathering crusts after granites: EPR data

Kaolinite is an economically important clay mineral. It is proposed to use electron paramagnetic resonance (EPR) in order to estimate the quality of kaolin concentrate while studying deposits [1]. This is related to the fact that most EPR signals of kaolinite are ascribed to Fe 3+ ions. Some of them occur as an isomorphic impurity in the mineral structure, while others are incorporated in various micro- and nanoinclusions. The iron admixture significantly affects the physical, chemical, and, of particular importance, technological properties of kaolins. One of the main kaolin sources is weathering crusts, whose formation is accompanied by structural, morphological, and chemical transformations of kaolinite [2, 3]. However, the reasons for its transformation in the weathering profiles of different mineralogical-genetic types and ages remain insufficiently studied. In this work, we present the results of EPR study of kaolinites from the Zhuravlinyi Log (South Urals) and Chaimat (South Vietnam) deposits, which are confined to the weathering crusts after compositionally similar leucocratic granites. The weathering crust of the Zhuravlinyi Log deposit is made up of one kaolin zone up to 40 m thick with a subzone of 10 m and more of alkali kaolins in its lower part. The eluvial kaolin is overlain by the Miocene clays of the Svetloe Formation. The weathering crust at the Chaimat deposit consists of two zones: the lower 10- to 16-m-thick kaolin zone and laterite bauxites in the upper 1‐4 m. The ages of the weathering crusts are respectively, Cretaceous and Middle Miocene. Samples for study were taken from the lower, middle, and upper horizons of the kaolin zones of the considered objects, as well as from laterite bauxites of the Chaimat deposit. Samples were collected through intervals along borehole 2005 at the Zhuravlinyi Log deposit and the section of the Chaimat deposit (Fig. 1). EPR spectra of clay fractions (<63 µ m) of the studied kaolinite samples were recorded on a compact PS-100 radiospectrometer in the X-range at room temperature.

Cultivation of flax in spoil‐bank clay: Mycorrhizal inoculation vs. high organic amendments

AbstractA greenhouse experiment was focused on the application of arbuscular mycorrhizal fungi (AMF) in effective crop production during reclamation of coal‐mine spoil banks. The aim of the study was to find out whether mycorrhizal inoculation improves growth of flax (Linum usitatissimum L.) and whether it can compensate for high doses of expensive organic amendment. Flax was planted in original spoil‐bank gray Miocene clay amended with organic matter used for spoil‐bank reclamation (mixture of composted urban waste and lignocellulose papermill waste). This amendment was applied in four descending doses equivalent to the application of 500, 200, 100, and 0 t ha–1. The plants received either a mixed inoculum of three AMF species (Glomus mosseae, G. claroideum, and G. intraradices) or were left uninoculated. Growth of flax was significantly increased by mycorrhizal inoculation in pure clay (by 60%) as well as in clay with all amendment doses (by 119% on average). Also, the addition of organic matter increased plant growth but, interestingly, the biomass production was comparable regardless the dose of amendment. Our results suggest that similar yields are attainable with only one fifth of the usual fertilization dose, which can significantly decrease costs related to the reclamation of spoil banks. If mycorrhizal inoculation is applied together with the optimized fertilization, growth of flax planted in spoil‐bank clay can be further improved.

Plant traits enabling survival in Mediterranean badlands in northeastern Spain suffering from soil erosion

AbstractQuestion: This study analysed the effect of severe soil erosion on species composition of plant communities by favouring species showing certain growth forms, root‐sprouting and clonal growth abilities.Location: The study area was located between the middle Ebro Valley and the Pre‐Pyrenees (northeastern Spain).Methods: Root‐sprouting and shoot‐rooting abilities, clonal reproduction and growth form were assessed for the 123 most common plant species from eroded lands in the study area. We obtained 260 vegetation relevés in three different substrata (gypsum outcrops, Miocene clays and Eocene marls) on areas with different degrees of soil erosion. The frequency of every plant trait in each relevé was estimated according to species presence. The effect of soil erosion on the frequency of plant attributes was assessed by correlation analyses.Results: Bipolar, non‐clonal plants and annual species decreased their frequency with increasing soil erosion in the three substrata analyzed, whereas root‐sprouters and woody plants (mostly sub‐shrubs) increased their frequency in most of the substrata analysed.Conclusions: Woody sub‐shrubs, root‐sprouters and clonal species are favoured in eroded lands in NE Spain. Bipolar species and annual plants might not be plastic enough to survive the high stress and frequent disturbances prevailing in such eroded areas.

Stratigraphy and sedimentology of the Upper Cretaceous to Paleogene Kilwa Group, southern coastal Tanzania

The geology of southern coastal Tanzania has remained poorly understood since the first comments on its stratigraphy were made over 100 years ago. However, new field surveys combined with shallow drilling along the coast between Kilwa and Lindi are beginning to resolve the depositional history and structural evolution of this region over the past 85 Ma. Here we present the first attempt to synthesize the results of these studies to provide a coherent sedimentological, litho- and sequence stratigraphic framework, including new geological maps, for the Upper Cretaceous and Paleogene of the coastal zone. Santonian to Oligocene sediments crop out along a broad coastal belt south of the Rufiji River from the Kilwa peninsula to Lindi Creek in southern Tanzania. During ∼55 Ma, over 1 km of a broadly homogeneous, mid to outer shelf clay-dominated succession was deposited across the passive margin, which we define here as the Kilwa Group. This lies disconformably across the shelf on Albian marls and is itself unconformably overlain by shallow water Miocene clays and more recent limestones, sands and gravels. Four formations can be identified within the Kilwa Group on the basis of characteristic secondary lithologies and facies, described here for the first time; the Nangurukuru, Kivinje, Masoko and Pande Formations. These formations include conformable stratigraphic intervals through both the Paleocene–Eocene and Eocene–Oligocene boundaries. Within the Kilwa Group, 12 sequence stratigraphic cycles can be identified at present, demonstrating relatively uniform and continual subsidence across the margin from Santonian to Early Oligocene time. A further major bounding surface is present between the Upper Cretaceous and Paleogene, but this may become partly conformable in the Lindi area. Although the principal lithology in all formations is clay or claystone, there are more permeable intervals containing pervasive coarser siliciclastic sediments and these have yielded traces of crude oil which is likely to have migrated from lower in the succession. The Kilwa Group thus also provides important new evidence for petroleum play development in the southern coastal zone.

Late Neogene low-angle thrusting on the northwestern margin of the South Carpathians (Poiana Rusca, West Romania)

Mineral exploration drillholes and geoelectric prospecting provide for the first time evidence for thrusting of the South Carpathian Paleozoic basement over northerly adjacent Middle Miocene sediments. Investigations were carried out in two locations, 30 km apart, along the northern margin of the Poiana Rusca Mountains, Romania, southwestern Carpathians. Drill holes in both locations encountered weakly consolidated Middle Miocene clay, sand, and fine gravel below Paleozoic low-grade metamorphic rocks. Intersections from various drill holes demonstrate the presence of low-angle thrusting. Kinematic indicators are so far lacking, but with a thrust direction oriented roughly normal to strike of the Poiana Rusca Mountains, minimum displacement is 1–1.4 km in northwestern or northern direction, respectively. Thrusting occurred most likely during the Late Miocene–Pliocene, whereafter Quaternary regional uplift dissected the thrust plane. In the tectonic framework of Neogene dextral translation of the Tisza–Dacia Block against the southerly adjacent Moesian Platform, transtension appears responsible for Middle Miocene basin formation along the northern margin of the Poiana Rusca region. Proceeding collision of the Tisza–Dacia Block with the East European Craton introduced stronger impingement of the Tisza–Dacia Block against the Moesian Platform, leading to a Late Miocene–Pliocene transpressional regime, in which the northern Poiana Rusca basement was thrust over its adjacent Middle Miocene sediments.

Un nouveau gisement miocène à ichthyofaune au sud de la chaîne des Chotts (Tunisie méridionale). Paléoenvironnement et paléobiogéographie

A new fish-bearing Miocene site, south of the ‘Chaîne des Chotts’ (southern Tunisia). Palaeoenvironment and palaeobiogeography. A systematic excavation in the Miocene continental sands of the Béglia Formation (southwestern Tunisia), south of the ‘Chaîne des Chotts’, yielded a rich fossil-fish assemblage. These sands, with soft rollers and oblique stratifications are in unconformity on the Cretaceous and are covered by Miocene clays. The organisation and the nature of the facies, as well as the palaeocurrent figures testify to a proximal fluvial-deltaic regime. It is SW–NE prograding. The three fish taxa (polypterid, clariid, latid) are typical of modern Nilo-Sudanese assemblages, but are absent from Maghreb. The regional palaeobiogeographic relations are discussed. To cite this article: B. Mannaï-Tayech, O. Otero, C. R. Palevol 4 (2005) .

Comparison of floristic changes on vegetation affected by different levels of soil erosion in Miocene clays and Eocene marls from Northeast Spain

Increased soil erosion on Eocene marls from N Aragon (NE Spain) tends to reduce vegetation cover and plant species number, but little is known about its effect in the neighbouring Miocene clays. In this study, the vegetation of strongly eroded areas on Miocene clays was analysed in terms of erosion intensity and compared with Eocene marls. Releves were carried out on uniform patches of vegetation affected by different levels of erosion. The degeneration of vegetation cover explained 34% of the variation in species number as opposed to 48% in marls, and a clear pattern of species replacement through the destruction of the vegetation cover was not observed. Approximately 25% of the species decreased significantly and 4% increased, as opposed to 47% and 0% in marls, respectively. Erosion on marls may be more severe (more disturbance) and less stressing for vegetation (more water availability) than on clays. The few species that colonized intermediate degeneration stages and highly eroded sites were more common in non-eroded areas in drier bioclimatic belts. Thus, the degeneration of vegetation by soil erosion favoured the establishment of xeric species. The ecological range of erosion-resistant species was not wider than non-resistant species. Overall, increased soil erosion selected for different plant species in marls than in clays.

Age and flow pattern of groundwater in a Jurassic limestone aquifer and related Tertiary sands derived from combined isotope, noble gas and chemical data

Multi-tracer study of the Malm (Upper Jurassic) limestone aquifer in north-western part of Cracow, Poland, revealed the existence of much older waters than those estimated from Darcy's law. The following environmental tracers were used: 3H, 14C, δ 13C, δ 18O, δ 2H, 4He, Ne, Ar, Kr, Xe, 3He/ 4He and 40Ar/ 36Ar in combination with water chemistry. The natural drainage of unconfined parts of the aquifer is by springs and streams, with a dominant presence of modern and pre-bomb era Holocene waters, whereas the confined part is drained only by upward leakage through thick Miocene clays in river valleys, mainly in the Vistula (Wisła) river valley. As a consequence, the confined part contains much older waters. Their glacial ages are indicated by δ 18O and δ 2H values significantly more negative than those found for modern recharge and by noble gas temperatures reduced by ca. 4.5 °C when compared to the present-day mean annual air temperatures. Quantitative age interpretation of 14C is regarded unreliable due to isotope exchange between dissolved and solid carbonates as suggested by δ 13C values of DIC in the range of −0.6 to −6.1‰ for the confined part of the aquifer. Similarly, quantitative 4He dating turned out to be unreliable, though 4He excess values (0.93–5.45×10 −6 cm 3 STP/g) and very low 14C contents (0.0–5.5 pmc) suggest glacial ages. Changes in hydrochemistry also indicate a long-lasting water–rock interaction probably dominated by diffusion-controlled exchange with overlying and underlying formations. Admixture of older water ascending from underlying formations is observed at two sites. That older water is also supposed to be of Quaternary age as the 40Ar/ 36Ar of the mixture remains equal to the atmospheric ratio. Great tracer ages are shown to result mainly from the delay of solute velocity with respect to the velocity of mobile water, caused by diffusive exchange between mobile water in the fissures (porosity of 0.0001–0.001) and stagnant water in the matrix (porosity of ∼0.06). This stagnant water in the porous matrix is the main water reservoir in the Malm aquifer. In the erosion structures of the Malm limestones, close to the Cracow centre on the southern side of the Vistula river, Tertiary sands are deposited under clay cover. Prior to this study, the origin and age of mineral water exploited from these sands was controversial. However, tracer data indicated meteoric water recharged at the end of the last glacial, and excluded an admixture of connate marine water from adjacent formations. In one well a 10% admixture of modern water was observed with the mean age of about 30 years as determined from the lumped-parameter modelling of the tritium data. The recharge is supposed to take place indirectly through nearby Malm horsts and/or by seepage through Miocene clays in unidentified areas, with dissolution of evaporites as the main source of chemical components. The glacial ages of waters in the confined parts of the Malm aquifer and in Tertiary sands indicate their low vulnerability to anthropogenic pollution.

The source of raw materials for Roman pottery from Leptiminus, Tunisia

AbstractLeptiminus, a Roman port city on the west coast of Tunisia, North Africa, exported olive oil and a garum fish paste to Rome. Excavations have uncovered many facilities including kilns and a potter's workshop, indicating an extensive ceramic industry. The vessels, manufactured at Leptiminus, included African red‐slip fineware, coarseware, and amphorae. A petrographic study of pottery sherds showed them to contain very similar temper, rounded aeolian sand grains and limestone, but varying in proportions to produce different textures. An investigation of the source of raw materials for the pottery found three distinct types of clay within a 50 km radius of Leptiminus: grey Miocene, brown Pliocene, and green Late Pliocene clay. Statistical analysis of trace element compositions, using induced neutron activation, of clays and sherds showed that the Pliocene brown clay was used to create all types of pottery. The specific clay horizon, used in Roman times, has apparently been removed by quarrying. However, a lateral continuation of this bed was found 7 m beneath the Leptiminus site 290. © 2002 Wiley Periodicals, Inc.

The Badenian calcareous nannoplankton from Turda and Ocna Dej mines (Transylvanian Basin, Romania)

1 ABSTRACT. Middle Miocene (Middle Badenian, respectivelly Wielician) clays interlayered with the salt deposits from Turda and Ocna Dej salt mines of the Transylvanian Basin have been analysed. The assemblages of calcareous nannoplankton/nannofossils and their significance are presented. Nannofloras are scarce and poorly preserved. The fossil index for NN5 Zone - Sphenolithus heteromorphus appears very rarely, only in few samples. The assemblages can be considered to belong to the upper part of the NN5 Zone and also to the lower part of the NN6 Zone.