Gray Sandstone Research Articles

Lithological characteristics of moraine in Torhanovychi 2 section (Forecarpathians)

The main lithological characteristics of the moraine sediments discovered in the Torhanovychi 2 section are analysed. The capacity of the moraine is low (up to 35 cm), in the lower part it is built of the medium, fine-grained sands, and in the upper part, it is mostly coarse-grained. The sands are horizontally layered, and the capacity of the layers varies from 4–5 to 8 cm. The stratification is emphasized by the layered inclusion of coarse fragments, the maximum size of which (granite boulders) reaches 25 cm. Lithological analysis disclosed that the main component of the moraine is a sandy-clay material, the weight of which reaches 60% of the total mass of the sample. Almost a quarter (up to 24 %) is made of pebble and gravel material, and the remaining 16 % is formed by the hard gravel component of the moraine. The petrographic composition of coarse pebbles and gravel (100–40 mm) is represented by fragments of two types of sediments: light gray, gray Carpathian sandstones and pink granites, with a significant predominance of sandstone content. Granites are medium-rounded, and sandstones are medium and well-rounded. The petrographic structure of small pebbles and gravel (40–10 mm) is much more diverse and is represented by fragments of five types of sediments: Carpathian sandstones, silicites (Carpathian flints), siltstones, granites and quartzites. The most common are fragments of Carpathian origin: mainly medium-rounded light gray Carpathian sandstones and multi-coloured medium-rounded silicates. Their total part reaches 74,2 % of the total amount of fragments of the fraction. The second component is formed by erratics – pink, red, often very weathered granites with a variable shape and one well-rounded fragment of quartzite. The total part of erratics reaches 13,4 % of the total amount of fragments of the fraction. The least common in moraine are fragments of local sediments – light gray, gray, weakly cemented siltstones, as well as strong siltstones on siliceous cement with a conchoidal fracture. The total content of fragments of local sediments reaches 12,4 % of the total amount of fragments of the fraction. Medium-rounded siltstones predominate. The petrographic spectrum of hard gravel sediments is generally identical to the composition of small pebbles and gravel. They also contain fragments of five types of sediments: Carpathian sandstones, silicites (Carpathian flints), granites, siltstones and quartz. In addition, fragments of Carpathian-origin sediments also predominate here: medium-, well- and very well-rounded gray sandstones; multi-coloured silicites and milky white, gray quartz, etc. Key words: granulometric composition, petrographic composition, roundness, grain shape, Carpathian material, erratics, sandstones, silicites, siltstones, granites.

Effect of Closely Spaced, Non-Persistent Ubiquitous Joint on Tunnel Boundary Deformation: A Case Study from Himachal Himalaya

The stability of an underground tunnel excavated in a jointed rock mass is studied using the field investigation and numerical modelling. This research aims to numerically analyze the rockmass behavior as a function of closely spaced non-persistent joints. For this purpose, the Kainchi-mod Nerchowck twin tunnels (Himachal Pradesh, India) is chosen for the in-depth analysis. The host rock encountered is mainly gray sandstone and maroon sandstone with many closely spaced, non-persistent joints, dipping critically into the tunnel. The detailed rockmass properties were collected from the field and intact rock properties were tested in the laboratory. A series of finite element numerical simulations were conducted based on the filed/laboratory data with different values of joint spacing, including the actual values of field joint spacing. It was found that the extent of deformation above the excavation was predominantly controlled by the joint spacing. The results of this study provide an explicit correlation between geometrical features of the rock mass with the total displacement values around the excavation. The study will help the engineers to design an appropriate support system for heavily jointed rocmkass.

Monitoring and Conservation plans for monumental stone buildings. The case study of the Baptistery of San Giovanni in Corte in Pistoia

In preventive conservation of cultural heritage, regrettably, only a few concrete examples of conservation and maintenance plans for monumental assets are available. This is attributable both to the particularity of each case, which makes it difficult to draw up a standard conservation plan and to the difficulty of finding specific data to program the cyclicity of the interventions, which requires us to resort almost exclusively to continuous monitoring of monuments. On the Baptistery of San Giovanni in Corte in Pistoia, after a major restoration carried out on the occasion of the Jubilee of 2000, a series of conservation interventions on various fronts have been repeated from 2000 to today. This case was deemed particularly interesting precisely because of this peculiar palimpsest of documented interventions and has, therefore, become the subject of a doctoral research (conducted in collaboration between the University of Florence and the Superintendency of Archaeology, Fine Arts and Landscape), focused on the in situ evaluation of the durability of water-repellent treatments on stone. Starting from the results already obtained with the tests of 2108, and collected in the doctoral thesis, was organized a monitoring plan of water repellent treatments commonly used on white marble, serpentine and Tuscan grey sandstone. The monitoring data should thus merge into the assessments on which the Monument Conservation Plan is founded. This essay presents the choice of the monitoring plan, the designing of test points, the performed treatments, and the planning of the monitoring; it also shows the expected results and how datasets will converge into the drafting and management of the conservation plan. As a result, the study provides useful promptings for implementing a ‘final scientific report’ and a Conservation Plan and, in general, it deepens knowledge on preventive conservation and contributes to the systematization of data for real usefulness for the maintenance of monuments.

Assessment of residual effectiveness for Water-Repellent treatments for building stones. Water absorption tests on the monumental complex Cathedral of San Zeno and the Baptistery of San Giovanni in Corte in Pistoia

Preventive and temporal planning of conservation is rather difficult to perform, especially concerning monumental stone buildings; the choices are often made after the degradation phenomena have already started. Many studies are looking for the reasons for this ‘resistance’. In particular the present study, the result of a doctorate research, is focused on the most operational aspects: • quantifying the residual effectiveness of water-repellent protective agents used in past restorations; • providing elements in the drafting of maintenance plans for monumental heritage; • verifying where critical conservation elements reside. The test site has been the monumental complex formed by the Cathedral of San Zeno and the Baptistery of San Giovanni in Corte in Pistoia, where the Contact Sponge Water Absorption Test (UNI 11432:2011), typically used as treated/untreated test was employed on three lithological types (white marble, serpentine and Tuscan grey sandstone) as comparison test between treatments carried out at different knows times. The test campaign was conducted by Mila Martelli with the involvement of Superintendency of Archaeology, Fine Arts and Landscape; University of Florence DiDA, DST-LAM, Department of Chemistry and, in the phase of organization of the monitoring, with the involvement of Dr. Maria Jose’ Ybañez Worboys, art restorer. The results of this research must be read in consideration of the fact that it is an ex-post survey, for which not all factors have been kept under control from the beginning, but for which it was possible to make assumptions. This study illustrates the methods and the first test results obtained which show a rather rapid decline in the effectiveness of water-repellent treatments, already a few years after their application.

Comparative Study on Dynamic Mechanical Properties and Energy Dissipation of Rocks under Impact Loads

Geological conditions are often complex during rock engineering construction (such as blasting and drilling) and usually involve rocks of several or multiple lithologies. However, comparative studies on the dynamic mechanical response of rocks of different lithologies are relatively few. To study differences in dynamic mechanical properties and energy dissipation of rocks of different lithologies, three kinds of rock that are common in rock engineering and have large differences in wave impedance were selected: red sandstone, gray sandstone, and granite. Samples of these three rocks were subjected to impact compression tests at different impact speeds, and the rock fragments after impact compression were screened to quantify the degree of fragmentation. The characteristics of stress wave propagation, dynamic stress-strain relationships, degree of fragmentation, and energy dissipation laws of the three rock types were compared and studied. The results show the following: (1) affected by the wave impedance matching relationship, the reflected waves, strain rates, and reflected energy of the three kinds of rock showed significant differences under the same incident stress wave. (2) The dynamic mechanical characteristics and energy dissipation laws of the rocks all had obvious strain rate effects, but the dynamic uniaxial compressive strength and energy dissipation density of the three rock types had different sensitivities to the strain rate. (3) The change trend of the energy utilization efficiency of the gray sandstone with incident energy was different from that of the red sandstone and granite; there was no obvious extreme point in the incident energy range. The three kinds of rock required different incident energies to reach maximum energy utilization efficiency. (4) The equivalent average fragment size of the three rock types decreased as a function of power with increasing impact velocity and energy dissipation density. (5) Under the same incident wave, although the reflection energy, transmission energy, and degree of fragmentation of the three kinds of rock showed significant differences, the differences in dissipation energy were small.

The Bigrlyi Tabular Sandstone-Hosted Uranium–Vanadium Deposit, Ngalia Basin, Central Australia

The Bigrlyi deposit is a tabular, sandstone-hosted, uranium–vanadium deposit of Carboniferous age located in the Ngalia Basin of central Australia. The deposit is similar to the continental, fluvial Saltwash-type of sandstone-hosted U-V deposits which are well known from the Colorado Plateau, USA. Most mineralization at Bigrlyi occurs as thin, multiple-stacked, stratiform lenses at the base of fluvial channels near the contact between a grey sandstone succession and a hematitic, purple–red sandstone succession. A larger halo of lower grade vanadium mineralization extends beyond the main U-V-mineralized zone. The host is an immature, feldspathic sandstone, grading into arkose and lithic-rich variants. Lithic ‘rip-up’ clasts of clay-rich sediments are common in the basal parts of fluvial channels, and are frequently the focus of, and have acted as sites for, U-V mineralization. Coffinite and uraninite are the main uranium minerals, with the former dominant. Vanadium is mainly hosted by Fe-V-bearing clays and chlorite, including roscoelite, grading into vanadian illite, the interlayer mineral corrensite, and altered detrital biotite. The V-Fe–oxyhydroxide minerals montroseite, haggite and doloresite, and altered detrital Fe-Ti oxides, are minor V-hosts. Mineralized zones correlate with enrichments in Se, Li, Ba, Be, Mo, Mg and Fe, and elevated Se/S ratios are characteristic of U-mineralized zones. Petrographic studies show that a heterogeneous mixture of variably mineralized lithic clasts is present; in the same rock, some clasts are Fe-rich and only weakly U-V-mineralized, while other clasts are strongly V- and/or U-mineralized. These observations point to mineralization processes that did not take place in-situ in the host sandstone at the site of deposition as required by conventional groundwater models. Lead isotope results provide evidence of the open-system mobility of radiogenic elements in parts of the deposit. In V-bearing zones, radiogenic Pb contents were found to be unsupported by current U levels, suggesting that over time U has been mobilized from these zones and redistributed, resulting in U-enrichment in other parts of the deposit. Mobility pathways were likely open over time from early in the history of the Bigrlyi deposit. A hybrid mineralization model, involving an interplay between solution-precipitation processes, detrital transport and post-depositional U remobilization, is proposed for Bigrlyi. Ferrous-ion-bearing clay minerals and pyrite are considered to be the most likely primary reductants/adsorbents, while the deposit is lacking carbonaceous matter.

Lithostratigraphy of the Siwalik Group along the Muksar Khola section, Siraha-Udayapur District, Eastern Nepal Himalaya

The Siwalik Group extending east to west co-linear to the main Himalayan range is well exposed along the Muksar Khola section, Siraha-Udayapur district, eastern Nepal Himalaya. Siwalik Group in the present study area is divided into the Lower, Middle, and Upper Siwaliks based on grain size and sandstone-mudstone proportion. The Lower Siwaliks is characterized by very fine- to fine-grained, light grey sandstone interbedded with dark grey to olive black mudstone. The Middle Siwaliks, is characterized by the domination of fine- to coarse-grained sandstone, and based on the lithology and bed thickness it is divided into two members. The lower member is dominated by fine- to medium-grained “salt and pepper” sandstone with dark greenish to olive-grey mudstone while, the upper member is dominated by light grey to white medium- to coarse-grained sandstone with grey, dark grey to black mudstone. Increase in the grain size and thickness of sandstone beds, increase in the proportion of mudstone, decrease in induration of sandstone and decrease in the proportion of biotite grain in sandstone makes upper member different from lower member of the Middle Siwaliks. The Upper Siwaliks is characterized by very thick beds of clast supported conglomerate associated with coarse- to very coarse-grained, very thick bedded sandstone and dull yellowish-grey to grey mudstone. The boundary between the Lower Siwaliks and the Middle Siwaliks, lower member and upper member of the Middle Siwaliks, and the Upper Siwaliks are 10.0 Ma, 5.7 Ma, and 3.5 Ma, respectively. The present study records the presence of a large succession of intra-formational conglomerate succession in the Lower Siwaliks.

Dynamic Mechanical Properties and Energy Dissipation Analysis of Sandstone after High Temperature Cycling

In order to study the effect of high temperature cycling on the physical and mechanical properties of rock materials, a box-type resistance furnace was used to conduct high temperature cycling at 400°C 10 times on sandstone specimens in coal mine, and the impact compression tests under 8 loading rates were carried out using a split Hopkinson bar (SHPB) device. Results showed that, with the increase of cycle times, the gray white sandstone specimen gradually showed reddish brown spots, and the volume of specimen increased, while the mass, density, and longitudinal wave velocity decreased; in addition, the volume increase rate, the mass decrease rate, the density decrease rate, and the longitudinal wave velocity decreased rate with cycle times showed quadratic function relationship. The dynamic compressive stress-strain curve of sandstone specimens subjected to high temperature cyclic action under impact load was obviously different from that under normal temperature. The dynamic elastic modulus was obviously larger than that under static load. The failure mode of dynamic and static specimens showed brittleness and ductility characteristics, respectively. In the SHPB test, the impact pressure, reflected energy, transmitted energy, and absorbed energy of the rock specimen all increased linearly with the increase of incident energy. The dynamic compressive strength, elastic modulus, and strain rate of sandstone specimens were positively correlated with the incident energy, while the dynamic strain showed negative correlation.

Triassic lithostratigraphy of the Jameson Land Basin (central East Greenland), with emphasis on the new Fleming Fjord Group

The lithostratigraphy of the Triassic deposits of the Jameson Land Basin in central East Greenland is revised. The new Scoresby Land Supergroup is now composed of the Wordie Creek, Pingo Dal, Gipsdalen and Fleming Fjord Groups. This paper only deals with the lithostratigraphy of the late Early-Late Triassic continental deposits of the latter three groups with emphasis on the vertebratebearing Fleming Fjord Group. The new Pingo Dal Group consists of three new formations, the Rødstaken, Paradigmabjerg and Klitdal Formations (all elevated from members), the new Gipsdalen Group consists of three new formations, the Kolledalen, Solfaldsdal (with the new Gråklint Member) and Kap Seaforth Formations (all elevated from members), and the new Fleming Fjord Group is subdivided into three new formations, the Edderfugledal, Malmros Klint and Ørsted Dal Formations (all elevated from members). The Edderfugledal Formation contains two cyclic bedded, lacustrine members, a lowermost Sporfjeld Member (elevated from beds), and an uppermost Pingel Dal Member (elevated from beds). The lacustrine red beds of the Malmros Klint Formation are not subdivided. The lacustrine and fluvial Ørsted Dal Formation contains three new members. In the eastern and central part of the basin, the formation is initiated by cyclic bedded, red lacustrine mudstones of the Carlsberg Fjord Member (elevated from beds), while in the northwestern part of the basin the lowermost part of the formation is composed of grey fluvial conglomerates and sandstones with subordinate red mudstones of the Bjergkronerne Member (elevated from beds). The uppermost part of the formations in most of the basin is composed of cyclic bedded, variegated lacustrine mudstones and grey to yellowish marlstones of the Tait Bjerg Member (elevated from beds). The sediments in the Fleming Fjord Group contain remains of a rich and diverse vertebrate fauna including dinosaurs, amphibians, turtles, aeotosaurs, pterosaurs, phytosaurs and mammaliaforms. Most vertebrate bones have been found in uppermost Malmros Klint Formation, and in the Carlsberg Fjord and Tait Bjerg Members. The Norian–early Rhaetian, lacustrine Fleming Fjord Group was deposited at about 41° N on the northern part of the supercontinent Pangaea. Lacustrine sedimentation was controlled by seasonal as well as longer-term (orbital) variation in precipitation. Precipitation was probably brought to the basin by southwesterly winds. The lacustrine sediments of the uppermost Fleming Fjord Group show deposition during increasingly humid conditions changing the lake environment from an ephemeral lake-steppe area to a perennial lake. This evolution of lake environment suggests a change from a winter-wet temperate climate to one with precipitation throughout the year.

Triassic lithostratigraphy of the Jameson Land Basin (central East Greenland), with emphasis on the new Fleming Fjord Group

The lithostratigraphy of the Triassic deposits of the Jameson Land Basin in central East Greenland is revised. The new Scoresby Land Supergroup is now composed of the Wordie Creek, Pingo Dal, Gipsdalen and Fleming Fjord Groups. This paper only deals with the lithostratigraphy of the late Early-Late Triassic continental deposits of the latter three groups with emphasis on the vertebratebearing Fleming Fjord Group. The new Pingo Dal Group consists of three new formations, the Rødstaken, Paradigmabjerg and Klitdal Formations (all elevated from members), the new Gipsdalen Group consists of three new formations, the Kolledalen, Solfaldsdal (with the new Gråklint Member) and Kap Seaforth Formations (all elevated from members), and the new Fleming Fjord Group is subdivided into three new formations, the Edderfugledal, Malmros Klint and Ørsted Dal Formations (all elevated from members). The Edderfugledal Formation contains two cyclic bedded, lacustrine members, a lowermost Sporfjeld Member (elevated from beds), and an uppermost Pingel Dal Member (elevated from beds). The lacustrine red beds of the Malmros Klint Formation are not subdivided. The lacustrine and fluvial Ørsted Dal Formation contains three new members. In the eastern and central part of the basin, the formation is initiated by cyclic bedded, red lacustrine mudstones of the Carlsberg Fjord Member (elevated from beds), while in the northwestern part of the basin the lowermost part of the formation is composed of grey fluvial conglomerates and sandstones with subordinate red mudstones of the Bjergkronerne Member (elevated from beds). The uppermost part of the formations in most of the basin is composed of cyclic bedded, variegated lacustrine mudstones and grey to yellowish marlstones of the Tait Bjerg Member (elevated from beds). The sediments in the Fleming Fjord Group contain remains of a rich and diverse vertebrate fauna including dinosaurs, amphibians, turtles, aeotosaurs, pterosaurs, phytosaurs and mammaliaforms. Most vertebrate bones have been found in uppermost Malmros Klint Formation, and in the Carlsberg Fjord and Tait Bjerg Members. The Norian–early Rhaetian, lacustrine Fleming Fjord Group was deposited at about 41° N on the northern part of the supercontinent Pangaea. Lacustrine sedimentation was controlled by seasonal as well as longer-term (orbital) variation in precipitation. Precipitation was probably brought to the basin by southwesterly winds. The lacustrine sediments of the uppermost Fleming Fjord Group show deposition during increasingly humid conditions changing the lake environment from an ephemeral lake-steppe area to a perennial lake. This evolution of lake environment suggests a change from a winter-wet temperate climate to one with precipitation throughout the year.

Mineralogy and geochemistry of carbonate cement in sandstone and implications for mineralization of the Qianjiadian sandstone-hosted uranium deposit, southern Songliao Basin, China

Morphology, concentration, paragenetic sequence, fluid inclusion, and trace element concentrations of carbonate cements in sandstone from the Qianjiadian sandstone-hosted uranium deposit, southern Songliao Basin, are illustrated in order to reveal the properties of ore-forming fluids and the effects of hydrothermal fluids on uranium mineralization. The carbonate cements contain dolomite, siderite, ankerite and calcite. Dolomite with a crystalline granular texture has the greatest average concentration, forming up to 3.3% of the yellow sandstone, and this dolomite has orange red cathodoluminescence. Siderite forms up to 2.7% of the primary grey sandstone, and everywhere forms grains with an idiomorphic shape. Ankerite forms up to 6.6% of the mineralized grey sandstone and commonly have a mosaic granular structure. Calcite characterized by mosaic granular texture reaches the maximum level of average concentration of 10.2% in the non-mineralized grey sandstone, and its cathodoluminescence is orange. Studies of mineral paragenetic sequence indicate that the dolomite, siderite, ankerite and calcite are chronologically generated. Average homogenization temperatures of the fluid inclusions in the ankerite and calcite are 160 °C and 136 °C, respectively, and their average salinities are 9.9 wt% and 7.7 wt%, respectively. The uranium content of the ankerite is up to 11.8 ppm, which is greater than that of the other carbonate cement. This study indicates that the ankerite is associated with uranium mineralization, and the Qianjiadian sandstone-hosted uranium deposit could be mobilized by low-temperature, high-salinity hydrothermal fluids, which can lead to formation of brannerite and coffinite.

A rare and unusual trace fossil from the Lower Jurassic (Lias Group) of Ketton, East Midlands, UK

The top of the Whitby Mudstone Formation (Lias Group, Toarcian, Bifrons ammonite Zone) is exposed low in the geological Site of Special Scientific Interest at Ketton Quarry, East Midlands. A rare burrow of Fustiglyphus annulatus Vialov from this part of the succession, not reported from the Whitby Mudstone Formation hitherto, was collected from float. In the dull brown mudrock, the burrow has a contrasting fill of grey sandstone. The shaft of the burrow is cylindrical, with two broad, bell-shaped chambers. Fustiglyphus annulatus is found in deeper water deposits in the post-Palaeozoic, so its occurrence in the Whitby Mudstone Formation, an offshore shelf deposit, is not unexpected. However, orientation is equivocal; the burrow was either angled at 45° to bedding, based on the evidence of an associated Arenicolites isp., or parallel to bedding, its common configuration.

Novel Approach for Sandstone Acidizing Using in Situ-Generated Hydrofluoric Acid with the Aid of Thermochemicals.

In this study, an in situ-generated hydrofluoric acid (HF) was used for sandstone acidizing, where an acid precursor (ammonium fluoride NH4F) reacted with a suitable oxidizer (sodium bromates NaBrO3) in an exothermic reaction. First, the new chemical mixture was prepared to react with pure quartz samples and the reaction effluent was analyzed to identify the presence of Si+ ions using the inductively coupled plasma (ICP) technique. Core flooding experiments were performed using Gray Berea sandstone cores (6 in. length and 1.5 in. diameter). A preflush stage of 5 PV of 7 wt % HCl was injected to remove any calcite content in the core. The main chemicals were then flushed for 3 successive cycles of 1 PV each. To assure core integrity, scratch tests and NMR scans were run on the core sample before and after the treatment. The new chemical mixture could dissolve the quartz sample and reduce its weight by 80 mg. The concentration of the dissolved Si+ ions was more than 90 ppm. This proves the capability of the chemical mixture to generate HF. The initial core permeability was measured at a stabilized flow rate of 2 cm3/min to be 33 mD. After the acid preflush stage, the core permeability reduced to 31 mD. Core permeability increased immediately after the first treatment cycle and reached 41 mD. At the end, the core flooding results showed a permeability improvement for Gray Berea sandstone cores by almost 40%. The ICP analysis of the effluent showed a total amount of chelated Si+ ions of about 10.5 mg. In addition to the high temperature generated in the near-wellbore area, the pressure increased because of the produced nitrogen gas from the exothermic reaction and reached about 600 psi. The scratch test showed an increase in the sample uniaxial compressive strength from 7432 to 9235 psi. The dynamic Poisson’s ratio and the dynamic Young’s modulus increased as well from 0.17 to 0.19 and from 2159 to 3585 ksi, respectively. The enhancement in the mechanical properties of the core can be attributed to the presence of the potassium element in Berea cores and its solidification reaction with the HF generated. The NMR measurements of the core sample before and after the acidizing process show an increase in the core porosity; however, the core preserved its original pore system. Upon application of this new stimulation technology, the true production potential of sandstone reservoirs can be achieved, well tubular corrosion will be minimized, and handling hazardous chemicals such as HF will be avoided. Most importantly, controlling the reaction rate, by controlling the amount of exothermic chemicals, can ensure deep acid penetration as well.

Wettability measurements on two sandstones: an experimental investigation before and after CO2 flooding

Wettability of rock–fluid systems is an important for controlling the carbon dioxide (CO2) movement and the capacities of CO2 geological trapping mechanisms. Although contact angle measurement is considered a potentially scalable parameter for evaluation of the wettability characteristics, there are still large uncertainties associated with the contact angle measurement for CO2–brine–rock systems. Thus, this study experimentally examined the wettability, before and after flooding, of two different samples of sandstone: Berea and Bandera grey sandstones. For both samples, several sets of flooding of brine (5 wt % NaCl + 1 wt % KCl in deionised water), CO2-saturated (live) brine and supercritical CO2 were performed. The contact angle measurements were conducted for the CO2–sandstone system at two different reservoir pressures (10 and 15 MPa) and at a reservoir temperature of 323 K. The results showed that both the advancing and receding contact angles of the sandstone samples after flooding were higher than that measured before flooding (i.e. after CO2 injection the sandstones became more CO2-wet). Moreover, the Bandera grey samples had higher contact angles than Berea sandstone. Thus, we conclude that CO2 flooding altered the sandstone wettability to be more CO2-wet, and Berea sandstone had a higher CO2 storage capacity than Bandera grey sandstone.

Kaplica grobowa rodziny Trębickich w Zembrowie jako przykład francuskich wpływów w dziewiętnastowiecznym budownictwie sepulkralnym na ziemiach polskich

Kaplica rodziny Trębickich h. Ślepowron powstała w 1884 roku na starym cmentarzu przykościelnym w Zembrowie na Podlasiu (pow. sokołowski). Budowlę wznieśli Stanisław i Emilia Trębiccy, właściciele majątku ziemskiego i murowanego dworu w Kurowicach. Nieznany z imienia i nazwiska architekt nadał wymurowanej z cegły wiśniówki i szarego piaskowca kaplicy formy romańsko-gotyckie, które zaczerpnął z francuskiego czasopisma branżowego „Revue générale de l’architecture et des travaux publics”. Za pierwowzór posłużyły opublikowane na jego łamach w 1876 roku plany budowli grobowej arystokratycznej rodziny Berghesów, którą zaprojektował i wzniósł na cmentarzu w Rânes (rejon Normandia, departament Orne) w latach 1872–1873 architekt Victor Ruprich-Robert (1820–1887). Kaplica w Zembrowie jest jedną z wielu polskich budowli grobowych inspirowanych francuskimi realizacjami. Dotychczasowe badania prowadzone przez autorkę wykazały, że statystycznie najwięcej takich obiektów powstało na cmentarzach katolickich w Warszawie (33) i na terenie Królestwa Polskiego (9).

Effect of surface wetting behavior of ceramic proppant on the two‐phase flow across the interface of sandstone and fracture

AbstractThe objective of this study was to gain an understanding of water‐oil two‐phase flow from sandstone reservoirs to propped hydraulic fractures. The effects of PC (code for provider) oil‐wet and water‐wet fracture proppants on the competing flow of water and oil from Parker Berea and Upper Gray Berea sandstones to proppant‐packed fractures were experimentally investigated in this study. Water and oil were simultaneously injected into core sample, and the injection volume at water breakthrough was used as a measure of phase flow efficiency. The PC oil‐wet ceramic proppants were found to have the property of attracting‐oil‐repelling‐water (AORW) effect on the water‐oil two‐phase flow from sandstones to proppant‐packed fractures. This effect is explained by the theory of oil and water channels in the sandstones. Oil‐wet proppant particles contact oil channels in the sandstone and attract oil into the fracture owing to the affinity between the oil‐wet surface and the oil in the oil channel. The AORW effect of PC oil‐wet proppant was found to drop as the water cut in the sandstone increases. This is attributed to the fact that there are more water channels in high water‐cut sandstones than in low water‐cut sandstones, reducing the chance for the oil‐wet proppant to contact oil channels and attract oil. The PC oil‐wet proppant was found to behave differently in different types of sandstones. Its AORW effect is higher in low‐permeability sandstones than in high‐permeability sandstones. This may be because there are more oil channels in low‐permeability sandstones than in high‐permeability sandstones, increasing the chance for the oil‐wet proppant to contact oil channels and attract oil.

Sedimentary copper mineralization in the upper red formation, Yakhab area, central Iran

ABSTRACTCopper mineralization in the Yakhab area, Central Iran, appears as disseminated copper sulfides along a redox boundary in gray sandstone of Upper Red Formation (URF). The URF formation section was investigated in the study area and report copper mineralization. Geochemical analyses of the Yakhab deposits showed maximum of 7.5 wt. % copper, 1.6 wt. % molybdenum and 116 mg/kg silver in the gray sandstone. In Yakhab section URF exposer reaches a thickness of as much as 1400 m that often copper mineralization is found in Midsection (261-681 m) in the grey sandstone in the form of patches inside plant fossils. Based on X-Ray Diffraction (XRD) analyses, microscopic studies and field observation paratacamite, atacamite, covellite and chalcocite were identified as major copper minerals and Powellite is the major molybdenum mineral in URF sandstone. The main phase of the copper mineralization in the Yakhab area was developed during diagenesis.

Paleoproterozoic (ca. 1.9 Ga) megascopic life on land in Western Australia

Controversial hairpin-shaped trace fossils (Myxomitodes stirlingensis) and discoid fossils (Cyclomedusa davidi) are here reinterpreted in a reassessment of sedimentology and paleosols of the 1.9 ± 0.1 Ga Stirling Range Formation of Western Australia. Paleosols in the Stirling Range Formation were recognized from complex cracking patterns (peds and cutans), chemical and mineralogical zonation (soil horizons), and poikiloblastic crystals (desert roses). Redox profiles of the paleosols are evidence of well-drained profiles of a coastal plain under a low oxygen (433 ± 116 ppmv) and carbon dioxide (564 ± 64 ppmv) atmosphere. Gypsum pseudomorphs in paleosols that are deeply weathered chemically, represent a persistence of acid sulfate weathering, better known in Archean paleosols before the Great Oxidation event at 2.45 Ga. Chemical composition of the paleosols is evidence of a humid (1478 ± 182 mm mean annual precipitation) temperate (11.3 ± 0.5 °C mean annual temperature) paleoclimate. Their paleoenvironmental setting was a coastal plain on a passive tectonic margin. Megafossils were found on paleosols of western red sandstones of the Stirling Range Formation, not in gray shales and sandstones of marine facies to the east. Trace fossils (Myxomitodes stirlingensis) and discoid fossils are both found at the surface of well drained paleosols, and so were not metazoan trails, nor sea jellies. Myxomitodes was more likely a grex (“slug”) trail of soil slime molds, and the Cyclomedusa discoids, were probably microbial colonies. Pervasive microfilamentous structures in the paleosol surface are additional evidence of Paleoproterozoic microbial earth ecosystems.

Early Tree Growth in Reclaimed Mine Soils in Appalachia USA

Surface mining disturbs hundreds of hectares of land every year in many areas of the world, thereby altering valuable, ecologically-diverse forests. Reforestation of these areas after mining helps to restore ecosystem functions and land value. In Appalachia, native topsoil is normally replaced on the surface during reclamation, but waivers allow for brown and gray sandstone materials to be used as topsoil substitutes. Numerous studies report the growth of trees in these substitute mine soil materials, but few studies have compared the height of trees grown in reclaimed mine soils to the heights of trees grown in native soils. This study determined the growth of red oak (Q. rubra L.), white oak (Quercus alba L.), and tulip poplar (Liriodendron tulipifera L.) in two mine soil types which were compared to projected growth in native soils. Heights of tree seedlings in native soils at 11 years were estimated from site indices (SI) from USDA Soil Survey data. At the mine sites, areas with brown and gray mine soils (one site with a mulch treatment) had 12 tree species planted and growth was measured annually for 11 years. Mine soil pH after 11 years was 5.3 for brown mine soils, 6.6 for gray mine soils, 7.0 for mulched mine soils, and 4.1 to 5.2 for native forest soils. After 11 years, tree heights in gray mine soils were significantly lower (0.5 m) than tree heights in brown mine soils (2.8 to 4 m) for all three species. Trees in mulched mine soils were up to 0.7 m taller than trees in un-mulched brown mine soils. After 11 years, red oak height was 6.3 m in native soils and 3 m in brown and mulched mine soils (52% lower); white oak was 7.3 m tall in native soils compared to 3.6 m in brown mine soils (50% lower); and tulip poplar was 11.5 m tall in native soils and 3.5 to 4 m tall in brown and mulched mine soils (70% lower). In gray mine soils, trees were not growing at all. While the trees in brown mine soils are growing, tree growth has not reached projected levels of tree growth in native soils during the first 11 years after planting. The purpose of forestry reclamation is to restore ecosystem diversity and function. This study showed that one measure of ecosystem function, tree growth, was 50% lower on reclaimed mine soils than native forest soils. Maturing mine soils may develop properties over time that are similar to native soils and, with the increased rooting depth, may provide conditions where increased tree growth rates and height may be attained during the next several decades.

Geology of the area between Bardibas and Sindhuli Madi, Sub-Himalaya, Central Nepal

The Siwalik Group (Sub-Himalaya) is the east-west extending youngest mountain belt formed by the sediments derived from the rising Himalaya on the north. The Siwalik Group is separated from the Lesser Himalaya to the north by the Main Boundary Thrust (MBT), and the Indo-Gangetic Plain to the south by the Main Frontal Thrust (MFT). The study was carried out mainly along the Ratu Nadi, Kamala Nadi river sections and was lithostratigraphically divided into the Lower Siwalik, Middle Siwalik, and Upper Siwalik, from the bottom to the top section, respectively. The Lower Siwalik is composed of fine-grained greenish grey calcareous sandstone (subarkose and lithic arenite), variegated mudstone, and calcareous siltstone. The Lower Siwalik is exposed due to the Marine Khola Thrust in the Gadyauli Khola, and sandstone there is more indurated and non-calcareous. The Middle Siwalik is mainly comprised of the medium- to coarse-grained salt-and-pepper sandstone (arkose and subarkose) with large cross lamination, calcareous sand lenses, convolute bedding, dark grey siltstone and mudstone. Plant fossils are also present in the finely laminated clay bed of the Middle Siwalik along the Ratu Nadi section. The Upper Siwalik comprises of mud- to sand-supported pebble to cobble conglomerates.