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1
Molenaar, N., e A. W. Martinius. "Origin of nodules in mixed siliciclastic-carbonate sandstones, the Lower Eocene Roda Sandstone Member, southern Pyrenees, Spain". Sedimentary Geology 66, n. 3-4 (marzo 1990): 277–93. http://dx.doi.org/10.1016/0037-0738(90)90064-z.
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Molenaar, N., G. P. Van de Bilt, E. R. Van den Hoek Ostende e S. D. Nio. "Early diagenetic alteration of shallow-marine mixed sandstones: An example from the lower eocene Roda sandstone member, Tremp-Graus basin, Spain". Sedimentary Geology 55, n. 3-4 (marzo 1988): 295–318. http://dx.doi.org/10.1016/0037-0738(88)90136-4.
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Martinius, Allard W. "Multiscale Gilbert-type delta lobe architecture and heterogeneities: The case of the Roda Sandstone Member". AAPG Bulletin 101, n. 04 (aprile 2017): 453–63. http://dx.doi.org/10.1306/011817dig17024.
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López-Blanco, M., M. Marzo e J. A. Muñoz. "Low-amplitude, synsedimentary folding of a deltaic complex: Roda Sandstone (lower Eocene), South-Pyrenean Foreland Basin". Basin Research 15, n. 1 (28 febbraio 2003): 73–96. http://dx.doi.org/10.1046/j.1365-2117.2003.00193.x.
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Leren, Beate L. S., John Howell, Håvard Enge e Allard W. Martinius. "Controls on stratigraphic architecture in contemporaneous delta systems from the Eocene Roda Sandstone, Tremp-Graus Basin, northern Spain". Sedimentary Geology 229, n. 1-2 (luglio 2010): 9–40. http://dx.doi.org/10.1016/j.sedgeo.2010.03.013.
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Martinius, A. W., e N. Molenaar. "A Coral-Mollusc (Goniaraea-Crassatella) Dominated Hardground Community in a Siliciclastic-Carbonate Sandstone (The Lower Eocene Roda Formation, Southern Pyrenees, Spain)". PALAIOS 6, n. 2 (aprile 1991): 142. http://dx.doi.org/10.2307/3514879.
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Klejment, Piotr, Robert Dziedziczak e Paweł Łukaszewski. "Strength of industrial sandstones modelled with the Discrete Element Method". Studia Geotechnica et Mechanica 43, n. 4 (9 ottobre 2021): 346–65. http://dx.doi.org/10.2478/sgem-2021-0020.
Testo completoAbstract (sommario):
Abstract Sandstone is one of the most popular building materials since the earliest times. It has various textures and colours as well as good technical parameters. Sandstones, having such wide applications, are subjected to various external factors during the period of use. So, it is of utmost importance to have a good knowledge of their strength parameters. We employed a numerical method called Discrete Element Method to examine in a non-invasive manner the mechanical strength of industrial sandstones, that are commonly used as broken stones in road construction, cladding material, paving stones, pavement tiles and so on. Various mechanical external factors were considered, such as breaking, compressional and abrasion forces or impact by external objects and vibrations. Fragmentation of the considered sandstones under compressional regime was a source of knowledge about energy storage inside the material and energy release, as well as appearance of fractures inside the matter and final sandstone fragmentation into crumbs.
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Kovářová, Kateřina, e Zdenek Pala. "The Influence of Mineralogical Composition Changes of Sandstone Cement on Physical-Mechanical Properties". Advanced Materials Research 923 (aprile 2014): 71–74. http://dx.doi.org/10.4028/www.scientific.net/amr.923.71.
Testo completoAbstract (sommario):
The aim of the contribution is to present the results of research focused on cement mineralogical composition changes and their influence on physical-mechanical properties of sandstones. Three types of Czech sandstones were tested during this experiment Hořice, Kocběře and Božanov. The sandstone samples were treated in the climatic chamber in order to simulate weathering processes that are typical for winter period in Prague. The influence of road salts was also taken into consideration. For the purposes of mineralogical changes determination the sandstone cement was separated and subsequently analyzed using X-Ray diffraction a DTA/TG analysis. The physical-mechanical properties such as e.g. uniaxial compressive strength, water absorption and open porosity were determined before and after the climatic treatment to enable evaluation of the influence of weathering processes.
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Yang, Chang-Shu, e Swie-Djin Nio. "An ebb-tide delta depositional model—a comparison between the modern Eastern Scheldt tidal basin (southwest Netherlands) and the Lower Eocene Roda Sandstone in the southern Pyrenees (Spain)". Sedimentary Geology 64, n. 1-3 (agosto 1989): 175–96. http://dx.doi.org/10.1016/0037-0738(89)90091-2.
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Chutia, Ananya, Dimple Moni Kachari e Chaitra Dhar Taye. "Petrography and Geochemistry of the Lower Sylhet Sandstone Member (Therria Sandstone) of Jaintia Group Exposed Along Jowai-Badarpur Road Section, Jaintia Hills District, Meghalaya: Implication for Provenance and Palaeoclimate". Journal Of The Geological Society Of India 100, n. 5 (1 maggio 2024): 661–73. http://dx.doi.org/10.17491/jgsi/2024/173889.
Testo completoAbstract (sommario):
ABSTRACT The Paleogene sediments of the Shillong Plateau are exposed in the southern part of Meghalaya and are designated as the Jaintia Group. The Lower Sylhet Sandstone Member (LSSM) (Therria Sandstone) is the lowermost member of the Shella Formation of Jaintia Group. To understand the depositional history of the studied sandstones, petrographic and geochemical approaches have been made. Petrographically, these sandstones are classified as quartz arenite and quartz wacke. They were derived from intermediate to upper rank metamorphic and plutonic source which were deposited in a craton interior and quartzose recycled tectonic setting. The paleoweathering indices of CIA, CIW, PIA and ICV indicate that the weathering at the provenance was intense. The tectonic discrimination diagrams suggest passive margin setting for their sedimentation and climatic condition during the deposition was humid in nature. The studied sediments were deposited in non-marine conditions as evidenced by the geochemical proxies and primary sedimentary structures existing in the LSSM.
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Schamel, Steven. "Sunnyside bitumen-impregnated sandstone reservoirs at Bruin Point, southwest Uinta Basin, Utah". Geosites 50 (1 settembre 2022): 1–16. http://dx.doi.org/10.31711/ugap.v50i.112.
Testo completoAbstract (sommario):
The south flank of the Uinta Basin in northeast Utah is the high Tavaputs Plateau that dips gently northward towards the basin center and is deeply dissected by the Green River and its tributaries. Where not removed by canyon incision, bitumen-impregnated sandstones in the Green River Formation (lower Eocene) occur along nearly the full length of the plateau. The bituminous sandstones encompass an area greater than 600 square miles and hold an estimated 11.6 to 14.0 billion barrels of bitumen, but the net thickness of bituminous sandstone and the OOIP rarely exceed 70 feet and 80 thousand barrels per acre (MBO/ac), respectively. However, in an exceptional 4.6 square mile area centered on Bruin Point (elev. 10,184 ft) on the southwest basin rim, the net thickness of bituminous sandstone and OOIP are measured in hundreds of feet and MBO/ac, respectively. The estimated bitumen in place in just this small area is 1.16 billion barrels. Bruin Point is an erosional remnant of a structural-stratigraphic trap formed by the superposition of a subtle flexure on a thick stack of deltaiclittoral sandstones. In the 1970s and 1980s, this unique area was extensively investigated to characterize the reservoirs and delineate the hydrocarbon resource. Over 117 test wells with cores were drilled and analyzed. As many as 32 stacked bituminous sandstone bodies were encountered, 15 of which hold nearly all the bitumen. The sandstones were deposited in constantly shifting deltaic lobes and along inter-delta shorelines. They are encased in marsh and floodplain mudstone and littoral-lacustrine calcareous mudstone and bioclastics. The sandstones are poorly sorted, fine-grained feldspathic arenites up to 115 ft thick in distributary channels, but less than 10 ft thick in beach deposits. Average porosity and permeability are 23% and 570 md, respectively, but values vary widely between, and even within, depositional settings. The bitumen at Bruin Point is heavy (8.6o API) and highly viscous (106 cP). Just 25 miles to the north, these same amalgamated deltaic sandstones are the reservoirs in the Greater Monument Butte conventional oil field. Although many operators have attempted to exploit the Bruin Point site for liquid hydrocarbons using both in situ steam flood and mining with solvent extraction, so far only small-scale mining of the bituminous sandstones for road construction has been commercially successful. This paper presents seven cores, several exceeding 1000 ft in length, that graphically display the distribution of bitumen resource as related to stratigraphic heterogeneity and location within the Bruin Point sector of the Sunnyside deposit.
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Azmi, Azyan Syahira, Mohd Suhaili Ismail, Jasmi Ab Talib e Nur Marina Samsudin. "Environment Of Deposition Of The Jurassic-Cretaceous Continental Deposit In Central Pahang (Peninsular Malaysia) By Sedimentary Facies Analysis". Bulletin Of The Geological Society Of Malaysia 70, n. 1 (30 novembre 2020): 153–62. http://dx.doi.org/10.7186/bgsm70202013.
Testo completoAbstract (sommario):
Spatial lithofacies and lithofacies association serves as one of the reliable methods in assessing the depositional process of sediments and interpreting its depositional environment. The method of facies analysis is adapted in this study where four newly exposed stratigraphic sections along the Jerantut-Maran road in Jerantut, Central Pahang of Peninsular Malaysia were studied. Previous studies showed that the environment of deposition of these continental deposits is broadly of braided-meandering river. Sedimentological data from the newly exposed stratigraphic sections had given a better understanding on the sedimentation processes involved in these deposits where interpretation on the environment of deposition is construed up to its sub-environment. The main lithofacies recognized include conglomerate, sandstone, and fine-grained facies. The facies associations identified include (i) massive to laminated silt/mudstone, (ii) massive sandstone, (iii) thin to thick ripple to parallel laminated sandstone, (iv) conglomeratic sandstone, (v) graded channelized sandstone, (vi) coarsening upwards medium bedded sandstone and (vii) heterolithic sandstone. The different facies associations are grouped to four (4) facies assemblages showing characteristics of certain environment: (1) floodplain, (2) channel bar complex, (3) point bar and (4) crevasse splay. Floodplain facies assemblage is marked by fine-grained facies, mainly siltstone/mudstone and fine-grained sands with lower flow regime structures. Channel bar complex is identified by high energy deposits of coarse-to-medium grained sandstones often with scoured bottom and lenticular geometry. Point bar is recognized by the lateral accretion surfaces often consisting of normal graded sandstone with sharp top and bottom contact, sometimes capped with thin mudstones. Crevasse splay facies assemblage is characterized by heterolithic sandstone, dominated by flaser-wavy bedding and coarsening upwards medium bedded sandstone that is overlain by fine-grained facies of the floodplain assemblage. The overall facies based on an outcrop scale suggests general features of fluvial facies with fluctuations in flow energy. The environment of deposition is thus interpreted to be of braided river with floodplains and isolated point bar.
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ABUBAKAR, U., S. MUSA, R. P. TABALE, N. A. YELWA, J. U. IKECHUKWU, A. U. USMAN, M. B. USMAN et al. "DEPOSITIONAL ENVIRONMENT OF THE TERTIARY KERRI – KERRI FORMATION IN THE GONGOLA SUB-BASIN, NORTHERN BENUE TROUGH: PEBBLES MORPHOMETRIC AND GRAIN SIZE ANALYSIS APPROACH". BIMA JOURNAL OF SCIENCE AND TECHNOLOGY (2536-6041) 6, n. 03 (31 dicembre 2022): 176–88. http://dx.doi.org/10.56892/bima.v6i03.65.
Testo completoAbstract (sommario):
Pebbles have been reported in the Sandstones units of the Kerri - Kerri Formation, but their application as a tool for interpreting the depositional environment is limited. In this context, 510 quartz pebbles and 16 sandstone samples were collected for pebble morphometric and grain size analyses in order to assess the depositional environment of the formation. For the pebble morphometric study, the long (L), intermediate (I), and short (C) axes of each pebble were measured. For each pebble, four geometrical parameters related to depositional environmental studies were computed, these are: Maximum Projection Sphericity, Oblate Prolate Index, Coefficient of Flatness, and Disk - Road - Index. The standard sieving method was used to sieve the sandstone samples. Mean grain size (Mz), sorting (I), skewness (SKI), and kurtosis (KG) were determined as statistical parameters of the grain size. The mean value of the computed pebble shape parameters for the pebbles of the Kerri – Kerri Formation indicates that the pebbles were deposited in a fluvial environment. Based on the grain size analysis, the sediments were deposited by fluvial action with moderate to low energy of deposition setting closer to the source of the sediments. The bivariate plots show that all the pebbles and sandstone samples lie clearlywithin the river field, which suggests fluvial origin
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LANDING, E., S. A. BOWRING, K. L. DAVIDEK, A. W. A. RUSHTON, R. A. FORTEY e W. A. P. WIMBLEDON. "Cambrian–Ordovician boundary age and duration of the lowest Ordovician Tremadoc Series based on U–Pb zircon dates from Avalonian Wales". Geological Magazine 137, n. 5 (settembre 2000): 485–94. http://dx.doi.org/10.1017/s0016756800004507.
Testo completoAbstract (sommario):
Two thin volcaniclastic sandstone beds in the Bryn-llin-fawr road section in North Wales overlie an apparent sequence boundary within the uppermost Cambrian Acerocare Zone and are overlain by lowest Ordovician (lower Tremadoc) Rhabdinopora faunas. U–Pb geochronology of zircons from these sandstones yields a maximum Cambrian–Ordovician boundary age of 489±0.6 Ma. This age indicates both that the Tremadoc Series (lowest Ordovician) may be shorter in duration than was previously thought and that the duration of the Middle and Late Cambrian (c. 22 Ma) was much less than that of the Early Cambrian (c. 33 Ma). Cambrian trilobite zones locally had an average duration as short as 1 Ma.
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Minieiev, Serhii, Oleksandr Kostrytsia, Alla Prusova, Roman Skachko, Oleksandr Dykan e Vira Maltseva. "Justification of the parameters for safe blasting of floor rocks in the roadway driven through the hazardous by outbursts sandstones". Geo-Technical Mechanics, n. 159 (2021): 11–29. http://dx.doi.org/10.15407/geotm2021.159.011.
Testo completoAbstract (sommario):
In this article, the authors provide the substantiation of the parameters for safe floor rocks ripping by drilling-and-blasting technique in the roadway driven through the hazardous by outburst sandstones by way of forming an unloaded (nonhazardous by outburst) zone from the side of previously driven roadway. The nomogram of numerical values of stresses is given for the conditions of the Pokrovskoe Mine, 1st northern belt road, panel No. 11. From the given calculations, radius of the unloaded nonhazardous by outburst zone in the vertical and horizontal planes around the driven experimental roadway of the 1st northern belt road, panel No. 11, was obtained with accounting anisotropy, depth of mining operations and rate of deformation. The analysis of the material presented in the article allows to conclude that the unloading effect of the driven roadway predetermines the safety of mining operations conducted in the hazardous by outburst sandstone, and drilling-and-blasting operations within the calculated protected zone can be performed as in the nonhazardous by outburst zone. In this research, regularities of the unloading effect of the roadways were established, and dependences were obtained to determine boundaries of the unloading zones in specific mining and geological conditions, which should be determined for each concrete roadway to perform the blasting operations. The presented justifications come to the fact that drilling-and-blasting operations used for ripping hazardous by outburst rocks in the roadway floor are carried out in the already unloaded (i.e. nonhazardous by outburst) zone, which is created from the same, previously driven, roadway. That is, it follows that drilling-and-blasting operations will be carried out in sandstone with no outburst hazard. This makes it possible to perform the drilling-and-blasting operations without making the forecast of the mine outburst hazard and without introducing the shock blasting mode, which, in turns, cut the time and labor costs and lead to significant savings of material and technical means. A further research is needed for establishing dependence between the size of the formed unloaded (nonhazardous by outburst) zone around the working roadway in sandstone and depth of mining operations, section of the roadway and time passed since the roadway was driven.
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Yang, Fayong, Haibin Li, Guijuan Zhao, Ping Guo e Wenbo Li. "Mechanical Performance and Durability Evaluation of Sandstone Concrete". Advances in Materials Science and Engineering 2020 (1 settembre 2020): 1–10. http://dx.doi.org/10.1155/2020/2417496.
Testo completoAbstract (sommario):
Enlarging local raw material utilization and reducing project costs is a new trend in the construction field. Under this background, sandstone was utilized in a cement-stabilized base in this study. The mineral composition of sandstone and the proportion of each mineral composition in the parent rock were analyzed using X-ray diffraction. To verify its feasibility, sandstone, syenite, marble, and basalt aggregates were selected to test the mechanical properties and road performance of the four aggregate concretes at 7, 28, 90, and 180 days. The test results showed that although the sandstone slump was the lowest at 60, the workability met the requirement. Compressive strength, tensile elasticity modulus, and axial tensile strength of concrete increased with age in all the concrete specimens, and the strength at each inspection time of sandstone was equivalent to that of marble, lower than that of basalt but higher than that of syenite. The early compressive strength of sandstone concrete is slightly lower than the compressive strength of marble concrete, and the 7 d and 28 d strengths were lower than 14% and 11%, respectively, but their 90 d and 180 d compressive strengths were the same. The crack resistance and frost resistance of sandstone were slightly inferior to those of syenite but better than those of basalt and marble. After 300 freeze-thaw cycles of the four aggregate concretes, the mass-loss rate of the test specimens was less than 5%, indicating that the frost resistance can meet the requirements. The various technical indexes of sandstone mixture could meet the current industry standards, and crack resistance, frost resistance, and fatigue resistance were good, which verified the feasibility of using sandstone for cement-stabilized base and provided a low-cost alternative for road construction.
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Latif, Hanif Khoirul, Salahuddin Husein e I. Gde Budi Indrawan. "Geological mapping and stand-up time estimation based on core drill evaluation using RMR89 on Tunnel 3 Sigli Banda Aceh Toll Road". E3S Web of Conferences 325 (2021): 02004. http://dx.doi.org/10.1051/e3sconf/202132502004.
Testo completoAbstract (sommario):
Tunnel 3 of the Sigli Banda Aceh Toll Road has been designed based on several site investigations. The site investigations have not included surface geological investigations. Subsurface geological investigations have been carried out but with less detailed drill core evaluation. This will cause less accuracy on the assessed tunnel stand-up time. This research aims to evaluate the engineering geological conditions at the tunnel construction site by conducting geological mapping with 1:5,000 scale and re-evaluating drill core using RMR89 method more thoroughly so that it can produce more accurate assessment of the tunnel stand-up time. The geological mapping result shows that the research area has three rock units, namely lapili, tuffaceous sandstones, and interbedded sandstone-siltstones, with moderate to fresh weathering degree. The drill core evaluation shows that research area has poor to good rock mass classes (34 – 67). The drill core evaluation results also indicate possible geological structures that may influence subsurface rock mass strength. The tunnel stand-up time obtained from the lowest RMR89 value for each drill core shows a value of 5 - 90 hours, implying immediate application of support system after tunnel excavation.
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Edmunds, W. M. "Bromine geochemistry of british groundwaters". Mineralogical Magazine 60, n. 399 (aprile 1996): 275–84. http://dx.doi.org/10.1180/minmag.1996.060.399.03.
Testo completoAbstract (sommario):
AbstractThe concentrations of Br in potable groundwaters in the United Kingdom range from 60 to 340 µg 1-1. The occurrence of Br is described in terms of the Br/Cl weight ratio which enables small changes in bromide concentrations to be assessed in terms of salinity. Median values of Br/Cl in groundwaters range from 2.60 to 5.15 × 10−3 compared with a sea water ratio of 3.47× 10−3. In recent shallow groundwaters the Br/Cl ratio is rather variable in response to a range of natural and anthropogenic inputs (marine and industrial aerosols, industrial and agricultural chemicals including road salt). Some slight enrichment in Br/Cl also occurs naturally during infiltration as a result of biogeochemical processes.Evolution of Br/Cl along groundwater flow lines reflects the sources of increasing salinity; either the influence of marine sedimentary formations or evaporites. The groundwaters in the Triassic sandstones of the English Midlands show significant Br depletion due to the evaporite source, in contrast to groundwaters in Cumbria. Br/Cl ratios in the Sherwood Sandstone of the East Midlands mainly reflect the natural input sources and can be used to help understand the palaeohydrology.
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Khairul Amri Kamarudin, Mohd, Musa Garba Abdullahi, Mohd Hariri Arifin, Roslan Umar, Muhammad Hafiz Md Saad e Iya Garba. "Investigation of Road Bank Failures based on Mineralogical Composition Studies in Kano-Abuja Road Northern, Nigeria". International Journal of Engineering & Technology 7, n. 4.34 (13 dicembre 2018): 167. http://dx.doi.org/10.14419/ijet.v7i4.34.23852.
Testo completoAbstract (sommario):
This article investigated the general compositions of the areas (the road) including the geology, mineralogy, and geochemistry to explore the reason for the road failure. The zone is underlain basement (storm cellar) and sedimentary rocks of different textures, mineralogy, and geochemistry. The results implies that the areas that is most stable along the road portions is underlain by the granite-gneiss, granites, amphibole schist and quartz, schist and small sandstone while portions with the failures are underlain by mica schist, phyllite, and coarse-grained granite. It is apparently sure from this study that poor quality metasedimentary rocks constitute the formation of the failed portions. However, the high numbers of the sediment and sandstone present in the area that can easily be weathered due to the climate variation have increased the failure. In conclusion, the result will help the engineers during reconstruction of these parts need to be excavating deeply and replace with granite-gneiss, granites, amphibole schist and quartz for better result.
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Du, Qiang, Ting Pan, Jing Lv, Jie Zhou, Qingwei Ma e Qiang Sun. "Mechanical Properties of Sandstone Cement-Stabilized Macadam". Applied Sciences 9, n. 17 (22 agosto 2019): 3460. http://dx.doi.org/10.3390/app9173460.
Testo completoAbstract (sommario):
Application of sandstone in cement-stabilized macadam (CSM) is an effective way to utilize sandstone. To determine the feasibility of using sandstone as a CSM aggregate, a series of experimental investigations, such as unconfined compressive strength (UCS) tests, Brazilian splitting tests and freeze-thaw cycle tests, were conducted on sandstone cement-stabilized macadam (SCSM). Three mixed variables, covering the cement content, aggregate type and curing period, were set as influence factors. The testing results indicated that the UCS, indirect tensile strength (ITS) and frost resistance property of the test-pieces increased with cement content and curing age. Considering the asphalt pavement design specifications for China, the UCS and ITS values of the SCSM complied with the requirements of light traffic road construction before freeze-thaw cycles. However, the SCSM subjected to freezing and thawing meets the requirements only when the cement content is 4.5%. Therefore, it is noteworthy that CSM containing sandstone aggregates should be applied with caution in cold region because of insufficient freeze resistance.
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Qasim, Muhammad, Javed Iqbal Tanoli, Luqman Ahmad, Lin Ding, Qasim Ur Rehman e Umbreen Umber. "First U-Pb Detrital Zircon Ages from Kamlial Formation (Kashmir, Pakistan): Tectonic Implications for Himalayan Exhumation". Minerals 12, n. 3 (26 febbraio 2022): 298. http://dx.doi.org/10.3390/min12030298.
Testo completoAbstract (sommario):
This study reports the first-ever detrital zircon provenance investigation of sandstones of the Kamlial Formation, exposed in Kashmir Basin along the Kohala–Bagh road section (Muzaffarabad, Pakistan). Analysis of probability density plots of detrital U-Pb zircon ages displayed a major age population clustered around ≈400–1200 Ma and a minor age population clustered around ≈1600–1900 Ma. In addition, scattered ages existed between ≈2000 and 3000 Ma. This age pattern resembled strongly the Himalayan sources, including the Tethys Himalaya, Greater/Higher Himalaya, and Lesser Himalaya. The younger ages (<150 Ma) present in the studied samples indicated the Asian provenance. The Lesser Himalayan component (≈166–1900 Ma) was more pronounced in the 2015KM03 and 2015KM04 samples, representing the middle to the upper portion of the formation. The recycled orogen provenance of the Kamlial Formation as deduced from the sandstone petrography supports the mixed detrital zircon provenance. Considering the provenance, we propose a tectonic model that suggests that large-scale exhumation occurred in the Himalaya as a result of Panjal thrust activation during 25–14 Ma (age of Kamlial Formation), which uplifted the hinterland zone that acted as a source area that fed the foreland basin, where the Kamlial Formation deposited.
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Juhari, Aisyah Shahirah, I. Gde Budi Indrawan, Dr. e Wahyu Wilopo. "The Engineering Characteristics and Classifications of Rock Masses along Road Section from Prambanan to Patuk, Yogyakarta, Indonesia". Journal of Applied Geology 6, n. 2 (31 dicembre 2021): 119. http://dx.doi.org/10.22146/jag.58034.
Testo completoAbstract (sommario):
Several attraction places and agriculture area that essentials for tourism and villager to do their activities are located approximately 6 km along the road of Candi Ijo to Ngoro-Oro in between Prambanan and Patuk sub-districts, Yogyakarta, Indonesia. Many jointed rock masses along the road have the potential to fail. This paper describes the rock mass characteristic and quality determined using the Geological Strength Index (GSI) and Rock Mass Rating (RMR) classifications. The rock mass characteristic and quality were essentially the preliminary results of a study to evaluate stability of the rock slopes along the road of Candi Ijo to Ngoro-Oro. Field observation and laboratory tests were carried out to determine parameters of the GSI and RMR. The results show that the slopes in the study area consisted of tuffaceous sandstone, vitric tuff, lithic tuff, cemented tuffaceous sandstone, lapilli tuff, subarkose, laminated mudrock, and laminated tuffaceous sandstone. The intact rocks were classified as weak to very strong. The research area consisted of three rock mass qualities, namely fair rock mass quality having GSI between 30 and 45 and RMR between 41 and 60, good rock mass quality having GSI between 46 to 65 and RMR between 61 and 80, and very good rock mass quality having GSI > 65 and RMR between 81-100. The relationship between GSI and RMR obtained in this study was in good agreement with that proposed by Hoek et al. (1995).
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Mebrahtu, Gebreslassie, Solomun Atsbaha e Berihu Abadi Berhe. "Vertical Electrical Sounding (VES) investigation for road failure along Mekelle – Abi-Adi road segment, northern Ethiopia". Momona Ethiopian Journal of Science 13, n. 1 (15 agosto 2021): 134–46. http://dx.doi.org/10.4314/mejs.v13i1.7.
Testo completoAbstract (sommario):
Roads constructed along the mountainous terrains of Ethiopia are susceptible to landslides mostly during rainy season. Mekelle – Abi Adi road is one of the economically important road corridors that connects many towns with Mekelle city. However, the asphalt road segment is heavily affected by quasi-translational type of landslide which hinders traffic flow of the area. Vertical electrical sounding (VES) method was applied to investigate subsurface geology of the road failure along Mekelle – Abi-Adi asphalt road, northern Ethiopia. The geo-electric section result revealed that the shallow subsurface geology of the site is characterized by four distinct geological formations, from top to bottom are: shale, shale-limestone intercalation, limestone and shale-gypsum units. The subgrade of the failed road section is shale unit which is overlain by jointed sandstone unit. The sandstone unit serves as a recharge zone to the bottom shale layer by percolating water via sub-base fill materials which in turn blocks vertical percolation and promote seepage force to the overlying soil mass. Hence, the road failure in the study area seems to be caused due to the development of pore water pressure in the shale layer which soaked water during heavy rainfall. The recommended remedial method for the road failure is re-designing of the affected route from chainage 48 km+850 m to 49 km+250 m towards the northwest of the study area and excavates the top 6 m shale unit.
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McGuire, Joseph D., John P. Craddock, David H. Malone e Shawn J. Malone. "Detrital zircon U-Pb geochronology of the Ordovician Lander Sandstone, Bighorn Mountains, Wyoming". Mountain Geologist 56, n. 3 (1 agosto 2019): 231–46. http://dx.doi.org/10.31582/rmag.mg.56.3.231.
Testo completoAbstract (sommario):
The Ordovician Lander Sandstone, which occurs unconformably above the Cambrian Gallatin Limestone and beneath the Bighorn Dolomite, occurs in the Bighorn, Powder, and Wind River basins of Wyoming. The Lander ranges from 0-10 m in thickness and consists of texturally and compositional mature, cross bedded quartz arenite. This study uses detrital zircon U-Pb geochronology to elucidate its provenance. Samples were collected from two localities along the eastern flank of the Bighorn Mountains near Buffalo, Wyoming: a roadcut on US 16 just west of the Clear Creek thrust and from along Crazy Woman Canyon Road. The results showed a statistical similarity between the two samples, and that zircon ages are predominantly Proterozoic in age (~75%) while the minority ages were Archean (25%). Probability density plots of the two-source areas show that the peak ages for Crazy Woman Canyon (n=90) are ~1840, 2075 and 2695 Ma and the US 16 peak ages (n=141) are ~1825, 2075, and 2725 Ma. The detrital zircon age spectra for these samples indicate that the Lander was not derived from local Archean basement and was not recycled from the underlying Cambrian. The Lander has a provenance in either the Trans-Hudson Province and adjacent rocks in present day Saskatchewan and Manitoba more than 1000 km to the north or from the Peace River Arch, an early Paleozoic highlands in northwestern Alberta and northeastern British Columbia. The Lander zircons have a similar provenance to eolian zircons in the Bighorn Dolomite and to other Ordovician sandstones on the Cordilleran Continental margin and central Idaho. The Lander provenance is distinct from the Ordovician St. Peter Sandstone, which occurs extensively east of the Transcontinental Arch. We interpret that the Lander was derived on the late Ordovician shoreline, and then transported via prevailing winds across the Laurentian shelf from east to west during sea level low stand, and then distributed throughout the shelf by currents.
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McGuire, J. D., David Malone, John Craddock e Shawn J. Malone. "Detrital Zircon U-Pb geochronology of the Ordovician Lander Sandstone, Bighorn". Mountain Geologist 56, n. 3 (1 agosto 2019): 231–46. http://dx.doi.org/10.31582/rmag.mg.56.2.231.
Testo completoAbstract (sommario):
The Ordovician Lander Sandstone, which occurs unconformably above the Cambrian Gallatin Limestone and beneath the Bighorn Dolomite, occurs in the Bighorn, Powder, and Wind River basins of Wyoming. The Lander ranges from 0-10 m in thickness and consists of texturally and compositional mature, cross bedded quartz arenite. This study uses detrital zircon U-Pb geochronology to elucidate its provenance. Samples were collected from two localities along the eastern flank of the Bighorn Mountains near Buffalo, Wyoming: a roadcut on US 16 just west of the Clear Creek thrust and from along Crazy Woman Canyon Road. The results showed a statistical similarity between the two samples, and that zircon ages are predominantly Proterozoic in age (~75%) while the minority ages were Archean (25%). Probability density plots of the two-source areas show that the peak ages for Crazy Woman Canyon (n=90) are ~1840, 2075 and 2695 Ma and the US 16 peak ages (n=141) are ~1825, 2075, and 2725 Ma. The detrital zircon age spectra for these samples indicate that the Lander was not derived from local Archean basement and was not recycled from the underlying Cambrian. The Lander has a provenance in either the Trans-Hudson Province and adjacent rocks in present day Saskatchewan and Manitoba more than 1000 km to the north or from the Peace River Arch, an early Paleozoic highlands in northwestern Alberta and northeastern British Columbia. The Lander zircons have a similar provenance to eolian zircons in the Bighorn Dolomite and to other Ordovician sandstones on the Cordilleran Continental margin and central Idaho. The Lander provenance is distinct from the Ordovician St. Peter Sandstone, which occurs extensively east of the Transcontinental Arch. We interpret that the Lander was derived on the late Ordovician shoreline, and then transported via prevailing winds across the Laurentian shelf from east to west during sea level low stand, and then distributed throughout the shelf by currents.
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Wijayanti, H. D. K., e S. Husein. "Stratigraphy of Salodik Formation in Batutambung section, Toili, Luwuk, Central Sulawesi". IOP Conference Series: Earth and Environmental Science 1373, n. 1 (1 luglio 2024): 012065. http://dx.doi.org/10.1088/1755-1315/1373/1/012065.
Testo completoAbstract (sommario):
Abstract Salodik Formation is one of the formations representing a continental drift sequence prior to the collision of Banggai Basin, and it was widely cropped out in the East Arm of Sulawesi. The published geological maps of Luwuk dan Batui describe the Salodik Formation as massive and bedded limestone with marl intercalated and sandstone in the lower part, ranging from Eocene to Late Miocene. In Batutambung, Toili, the geological maps showing the Salodik Formation distributed in a NW-SE trend between two ophiolitic land masses, and suggesting intensive tectonic deformation along the trend. Preliminary geological investigations in this area show that Salodik rock sequences varied from other Salodik outcrops in different areas. Detailed stratigraphic measurements and rock sampling have been carried out along the road connecting Toili and Ampanan Tete., yielding a measured stratigraphy of 70 m vertically thick. Nine lithofacies were identified, i.e., coarse-grained sandstone (cS), micritic sandstone (mcS), fine-medium-grained sandstone (fmS), sandstone with coal spar (SMms), Mudrock (mM), micritic mudrock (mcM), Mudstone (MS), Wackestone (WS) and Packstone (PS). Facies association shows the rock sequence has shallowing upward or prograding pattern with depositional environment varies from an open marine, tidal channel, shoal, and restricted marine/ lagoon Based on foraminifera and nannofossil analysis, Salodik Formation in Batutambung section was deposited in Early Miocene (N6 or NN4-NN6), with paleobathymetry from middle to outer neritic. Based on its age and lithology character, the Salodik Formation in Batutambung is equivalent with Matindok Formation in Tomori PSC.
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Bittner, Tomáš, Milan Hrabánek, Šárka Nenadálova e Jiří Kolísko. "Diagnosis of Myslinka Stone Railway Bridge". Key Engineering Materials 714 (settembre 2016): 186–91. http://dx.doi.org/10.4028/www.scientific.net/kem.714.186.
Testo completoAbstract (sommario):
Within the solution of the research project GAČR P105/12/G059 a detailed diagnosis of the stone railway bridge on the railway line Plzeň - Tachov was performed. The bridge is created by two parallel vaulted tubes made from sandstone where a frequented road of second category goes through under one of them and Myslinsky brook flows under the second. The bridge was built approximately in 1978 and in 2006 a reinforced concrete frame structure was built to the bridge portal. Length of both tubes is about 45.5 m, width about 5.7 m, height of the tube above the road is about 6.0 m and above the brook 7.8 m. The arch is made as an annular vault. On the basis of the diagnostic works the structure is evaluated from the point of view of moisture, amount of water soluble salts, strengths of sandstone and there is also a visual observation of a condition of the structure itself performed. In the end there recommendations for a consequent procedure in case of the revitalization are stated.
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Satria, Jabnes, I. Gde Budi Indrawan e Nugroho Imam Setiawan. "Engineering geological characteristics based on rock mass rating (RMR) and geological strength index (GSI) in Tunnel Number 1 of the Sigli-Aceh toll road". E3S Web of Conferences 325 (2021): 01014. http://dx.doi.org/10.1051/e3sconf/202132501014.
Testo completoAbstract (sommario):
This paper presents engineering geological investigation results in the form of rock mass characteristics for tunnel number 1 of the Sigli-Aceh toll road. The investigation was carried out through geological mapping, core drill evaluation, and laboratory tests. In this research, the rock mass rating (RMR) and Geological Strength Index (GSI) were applied for the rock mass classifications. The measurement of rock mass quality is then used to determine the excavation method and tunnel support system on the SigliAceh toll road. The results showed that the research location consisted of calcareous sandstone with poor to good-quality (GSI (21.7 - 85.5), RMR (32.0 - 67.6)), and sandstone with good quality (GSI (86.3 - 86.9), RMR (64.0 - 65.0)). The poor quality rock masses were mainly caused by weathering effect. In addition, this research also analyzes the relationship between RMR and GSI based on the type and quality of rocks in the research location so that this correlation can be used in other areas with similar rock type and quality to this research location.
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Kirkland, James, Donald DeBlieux, ReBecca Hunt-Foster, John Foster, Kelli Trujillo e Emily Finzel. "The Morrison Formation and its bounding strata on the western side of the Blanding basin, San Juan County, Utah". Geology of the Intermountain West 7 (4 giugno 2020): 137–95. http://dx.doi.org/10.31711/giw.v7.pp137-195.
Testo completoAbstract (sommario):
In 2016 and 2017, the Utah Geological Survey partnered with the U.S. Bureau of Land Management to conduct a paleontological inventory of the Morrison Formation south and west of Blanding, Utah, along the eastern margin of the Bears Ears National Monument. The Morrison in this region is critical to understanding Upper Jurassic stratigraphy across the Colorado Plateau because it is the type area for the Bluff Sandstone, Recapture, Westwater Canyon, and Brushy Basin Members of the Morrison Formation, which are the basis for nomenclature in New Mexico and Arizona as well. Researchers have disagreed about nomenclature and correlation of these units, which transition northward in the study area into the Tidwell, Salt Wash, and Brushy Basin Members. Numerous vertebrate localities make inclusion of the Bluff Sandstone and Recapture Members in the Middle Jurassic San Rafael Group, as suggested by some previous workers, unlikely. The Salt Wash Member does not separate the Bluff Sandstone and Recapture Members at Recapture Wash, but sandstone lenses of Salt Wash facies occur higher in northern Recapture exposures. Northward, along the outcrop belt east of Comb Ridge, the Bluff-Recapture interval thins, interlenses, and pinches out into the Tidwell and lower Salt Wash, with the main lower sandstone interval of the Westwater Canyon merging northward into the upper Salt Wash Member.
The partly covered, 1938 type section of the Brushy Basin Member is identified along Elk Mountain Road at the southern end of Brushy Basin. We describe a detailed, accessible Morrison Formation reference section about 11.2 km (7 mi) to the south along Butler Wash. There, 81.68 m (268 ft) of Brushy Basin Member is well exposed along a road between the top of the Westwater Canyon Member and the base of the Lower Cretaceous Burro Canyon Formation. We informally call the upper sandstone bed(s) of the Westwater Canyon Member that cap mesas and benches in the region “No-Mans Island beds.” Smectitic mudstones between the No-Mans Island beds and the main sandstone body of the Westwater Canyon suggest that the Salt Wash-Brushy Basin contact to the north may be somewhat older than the base of the Brushy Basin Member as originally defined in its type area. Determining whether the No-Mans Island beds pinch out to the north or are removed by erosion below the regional basal Brushy Basin paleosol requires further research. Several significant fossil vertebrate and plant sites have been documented in the Brushy Basin type area. Newly identified volcanic ashes provided zircons for U-Pb ages of 150.67 ± 0.32 Ma from near the top of the Brushy Basin Member and of 153.7 ± 2.1 Ma and 153.8 ± 2.2 Ma for two zircons in lower part of Recapture Member. At the top of the Brushy Basin Member, ferruginous paleosols commonly overlying conglomeratic sandstone are speculated to be of Early Cretaceous age (detrital zircon age pending) and are assigned herein to the Yellow Cat Member of the Burro Canyon Formation. These iron-rich paleosols suggest wetter climatic conditions during the Jurassic-Cretaceous transition in the Blanding basin.
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Hagadorn, James, Mark Longman, Richard Bottjer, Virginia Gent, Christopher Holm-Denoma e Jonathan Sumrall. "The type section of the Codell Sandstone". Mountain Geologist 58, n. 3 (2 agosto 2021): 211–48. http://dx.doi.org/10.31582/rmag.mg.58.3.211.
Testo completoAbstract (sommario):
We formally assign, describe and interpret a principal reference section for the middle Turonian Codell Sandstone Member of the Carlile Shale near Codell, Kansas. This section, at the informally named Pumpjack Road, provides the thickest surface expression (9 m, ~30 ft) of the unit in Ellis County. The outcrop exposes features that typify the Codell throughout the southern Denver Basin and vicinity. At this reference section, the Codell conformably overlies the Blue Hill Shale Member of the Carlile Shale and is unconformably overlain by the Fort Hays Limestone Member of the Niobrara Formation or locally by a thin (<0.9 m, <3 ft) discontinuous mudstone known as the Antonino facies. The top contact of the Codell is slightly undulatory with possible compaction features or narrow (<30.5 m, <100 ft), low-relief (0.3-0.6 m, 1-2 ft) scours, all of which hint that the Codell is a depositional remnant, even at the type section. At Pumpjack Road, the Codell coarsens upward from a recessive-weathering argillaceous medium-grained siltstone with interbedded mudstone at its base to a more indurated cliff-forming muddy, highly bioturbated, very fine-grained sandstone at its top. The unit contains three informal gradational packages: a lower Codell of medium to coarse siltstone and mudstone, a middle Codell of muddy coarse siltstone, and an upper muddy Codell dominated by well-sorted very fine-grained sandstone. The largest grain fractions, all <120 mm in size, are mostly quartz (40-80%), potassium feldspar (7-12%), and albite (1-2%), with some chert (<15%), zircon, and other constituents such as abraded phosphatic skeletal debris. Rare fossil fish teeth and bones also occur. Detrital and authigenic clays make up 9 to 42% of the Codell at the reference section. Detrital illite and mixed layer illite/smectite are common, along with omnipresent kaolinite as grain coatings or cement. As is typical for the Codell, the sandstone at the type section has been pervasively bioturbated. Most primary structures and bedding are obscured, particularly toward the top of the unit where burrows are larger, deeper and more diverse than at its base. This bioturbation has created a textural inversion in which the larger silt and sand grains are very well sorted but are mixed with mud. Detrital zircons from the upper Codell are unusual in that they are mostly prismatic to acicular, euhedral, colorless, unpitted, and unabraded, and have a near-unimodal age peak centered at ~94 Ma. These characteristics suggest they were reworked mainly from Cenomanian bentonites; their ultimate source was likely from the Cordilleran orogenic belt to the west and northwest.
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Zilmer, Kristel, e Krister S. K. Vasshus. "Runic fragments from the Svingerud grave field in Norway". NOWELE / North-Western European Language Evolution 76, n. 2 (12 dicembre 2023): 233–303. http://dx.doi.org/10.1075/nowele.00080.zil.
Testo completoAbstract (sommario):
Abstract In 2021–2023, several rune-inscribed sandstone fragments were discovered by archaeologists of the Museum of Cultural History, University of Oslo, at a Roman Iron Age grave field by the Svingerud road at Hole in eastern Norway. Several of these fragments fit together as parts of one larger sandstone slab. The main fragment with multiple inscriptions was unearthed in a flat grave (cremation) in November 2021. Radiocarbon dating of the organic material dated the burial to before 300 CE (Solheim et al., forthcoming). This article provides a detailed runological and linguistic account of the inscribed fragments, as of July 2023. The focus is on the main finds, while the work on numerous small fragments is ongoing. This find may shed new light on the features and functions of early runic writing.
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Chima, Priscilla, Christopher Baiyegunhi, Kuiwu Liu e Oswald Gwavava. "Petrography, modal composition and tectonic provenance of some selected sandstones from the Molteno, Elliot and Clarens Formations, Karoo Supergroup, in the Eastern Cape Province, South Africa". Open Geosciences 10, n. 1 (20 dicembre 2018): 821–33. http://dx.doi.org/10.1515/geo-2018-0064.
Testo completoAbstract (sommario):
Abstract The Late Triassic - Early Jurassic non marine clastic sediments of the Molteno, Elliot and Clarens Formations were studied to deduce their mineralogy and tectonic provenance. The study is based on road-cut exposures of the formations in the Eastern Cape Province of South Africa. Petrographic studies based on quantitative analysis of the detrital minerals shows that the clastic sediments (mostly sandstones) are predominantly made up of quartz, feldspars, and metamorphic and igneous rock fragments. Among the main detrital framework grains, quartz constitutes about 62-91%, feldspar 6-24% and 3-19% of lithic fragments. The sandstones can be classified as both sublitharenite and subarkose. Although, most of the sandstones (> 70 %) plotted in the sub-litharenite field. Petrographic and XRD analyses revealed that the sandstones originated from granitic and metamorphic rock sources. The QFL (Quartz-feldspar-lithic fragments) ternary diagrams indicate that the sandstones were derived from recycled or quartzose source rocks reflecting a craton interior or transitional continental setting which probably came from the Cape Fold Belt. This possibly revealed that most of the sandstones might have been derived as a result of weathering and erosion of igneous and metamorphic rocks in the Cape Supergroup. The study has revealed the depositional environments, and provide a basis for the description and interpretation of the sedimentology of the Molteno, Elliot and Clarens Formations.
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Jamwal, Monika, S. K. Pandita, Meera Sharma e G. M. Bhat. "Petrography, Provenance And Diagenesis Of Murree Group Exposed along Basohli- Bani Road, Kathua District, Jammu and Kashmir". Journal of The Indian Association of Sedimentologists 37, n. 2 (31 dicembre 2020): 15–26. http://dx.doi.org/10.51710/jias.v37i2.79.
Testo completoAbstract (sommario):
Sandstones of Murree Group of rocks exposed along Bani- Basohli road, Kathua District in Jammu were analyzed for petrography, petrofacies and provenance. These sandstones are classified as sublithic arenites and have been derived from mixed provenance including plutonic basement, sedimentary and metasedimentary rocks. Different types of quartz grains and other constituent minerals suggest the source from lower and middle and upper rank metamorphic terrains of the continental block-recycled orogen and subduction zone complex. The imprints of shallow burial diagenesis suggest low mechanical compaction probably just before cementation leading to moderate packing and reduction of porosity.
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Agoha, Chidiebere Charles, Tochukwu Innocent Mgbeojedo, Eze Martins Okoro, Francis Begianpuye Akiang, Chukwuebuka Nnamdi Onwubuariri e Latifa Shaheen Al-Naimi. "Geologic mapping and basement–sediment contact delineation along Profile X, Igarra–Auchi area, Southern Nigeria using ground magnetic and electromagnetic methods". Journal of Petroleum Exploration and Production Technology 11, n. 6 (giugno 2021): 2519–37. http://dx.doi.org/10.1007/s13202-021-01207-0.
Testo completoAbstract (sommario):
AbstractOutcrop mapping as well as electromagnetic and ground magnetic surveys was carried out within Auchi and Igarra localities in order to attempt an interpretation of the geology of the areas and to delineate the boundary between basement and sedimentary terrains. Geologic mapping was done by collecting samples of outcrops at five different locations within the areas. Three lithofacies were identified within Auchi area and they are the basal shale unit, tabular cross-bedded sandstone unit and ferruginized sandstone unit. The pebbly shale is greyish black in colour; the cross-bedded sandstone unit is greyish white, coarse-grained at the base and finer at the top with pockets of clay, while the ferruginized sandstone is dark red. Rocks of the Precambrian basement complex underlie Igarra area. The area is underlain by metasediments that have been intruded by igneous rocks. Results show the presence of three major groups of igneous and metamorphic rocks within the area, and they are the migmatite–gneiss complex, metasediments and porphyritic granites. The electromagnetic and ground magnetic data acquired along Profile X located along Auchi–Igarra–Ibillo road were processed using Microsoft Excel Software and the resulting plots delineated areas with lower electrical conductivities and higher magnetic susceptibilities, as well as areas with higher electrical conductivities and lower magnetic susceptibilities. The areas with lower electrical conductivities and higher magnetic susceptibilities are interpreted to be underlain by basement rocks, while the areas with higher electrical conductivities and lower magnetic susceptibilities are underlain by sedimentary rocks. The plots also delineated the most likely basement–sedimentary boundary in the area.
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Wang, Jianqiang, Jie Liang, Qingfang Zhao, Jianwen Chen, Jian Zhang, Yong Yuan, Yinguo Zhang e Heping Dong. "Characteristics of Deepwater Oil and Gas Distribution along the Silk Road and Their Controlling Factors". Water 16, n. 2 (10 gennaio 2024): 240. http://dx.doi.org/10.3390/w16020240.
Testo completoAbstract (sommario):
Deepwater regions have emerged as pivotal domains for global oil and gas exploration and development, serving as strategic alternatives to conventional resources. The Silk Road region is distinguished by its abundant oil and gas reserves and stands as a leading arena for worldwide exploration and development in the oil and gas sector. Since 2012, a series of atmospheric fields have been discovered in the deep sea of the Luwuma Basin and the Tanzania Basin, with cumulative recoverable reserves reaching 4.4 × 1012 and 8.3 × 1011 m3, including multiple oil and gas fields ranking among the top ten global discoveries at that time. Profound advancements have been achieved in the exploration of deepwater oil and gas reserves along the Silk Road. However, deepwater oil and gas exploration presents challenges, such as high development costs and risks, leading to certain areas remaining underexplored and exhibiting a relatively low level of exploration activity, thereby hinting at considerable untapped potential. Deepwater sedimentary basins along the Silk Road predominantly adhere to a distribution pattern characterized as “one horizontal and one vertical”. The “horizontal” dimension refers to the deepwater basin grouping within the Neo-Tethys tectonic domain, primarily extending from east to west. Conversely, the “vertical” dimension denotes the deepwater basin grouping along the East African continental margin, predominantly extending from north to south. Recent discoveries of deepwater oil and gas reserves validate the presence of foundational elements within Silk Road basins conducive to the formation of substantial oil and gas reservoirs and the establishment of efficient migration pathways. Despite these achievements, exploration activities in deepwater oil and gas resources along the Silk Road remain relatively limited. Future exploration endeavors in deepwater regions will predominantly focus on identifying structural and lithological traps. In the deepwater areas of the Bay of Bengal, the emphasis is on lithological traps formed by Neogene turbidite sandstone deposits. In the deepwater regions of Pakistan, the focus shifts to lithological traps emerging from Neogene bio-reefs and river-channel sandstone accumulations. Along the deepwater coastline of East Africa, the focus is on lithological traps formed by nearshore Mesozoic–Cenozoic bio-reefs and seafloor turbidite sandstone formations. Within the deepwater regions of Southeast Asia, the primary objective is to locate large structural-type oil and gas fields. Analyzing the characteristics of oil and gas discoveries in deepwater areas aims to enhance the theory of the control of the formation of deepwater oil and gas, providing valuable insights for predicting future exploration directions.
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Lyashenko, A. Yu. "Rubble Sandstone Unloading and Screening Unit with Non-Volatile Auxiliary Equipment Drive". World of Transport and Transportation 21, n. 3 (14 novembre 2023): 59–64. http://dx.doi.org/10.30932/1992-3252-2023-21-3-5.
Testo completoAbstract (sommario):
For the road industry, it is quite important to reduce costs and energy consumption, as well as energy recovery in process plants. To solve this problem at one of the stages of the industrial process, which is production of road metal, an important material for road construction, it is proposed to develop autonomous power unit based on recuperation of the kinetic energy of dump trucks, namely a unloading and screening unit of crushing and screening plant with non-volatile drive of auxiliary equipment.A non-volatile unloading and screening unit separates the feedstock at the primary stage of production in a non-volatile operating mode, using recovery of the kinetic energy of trucks been unloaded. After loading rubble sandstone into the receiving hopper, the unit activates the process of material segregation into coarse and fine fractions. The respective fractions are fed to the appropriate feeders for subsequent technological processing. The advantage of the unit is the autonomy of the vibrator and feeders’ drives, which helps to raise the efficiency of the process of unloading and separation of the rubble sandstone and reduce energy costs for production of the finished product.The evaluation of the functional capabilities of the non-volatile hydraulic drive of the unloading and screening unit was carried out for hydraulic motors of the screening and conveying equipment. The apron feeder of KM PP-2–10–60B type providing a continuous and uniform supply of feedstock was assumed as the basic equipment, and the volume of working fluid in the hydraulic accumulator supplied by hydraulic jacks was calculated. The results showed that two hydraulic jacks with the specified parameters can provide the required flow and allowed determining the amount of energy stored in the accumulator during feedstock loading. The calculated power of the hydraulic motor allows its use in the feeder. The economic efficiency of the installation with an autonomous drive is estimated considering the mode of operation, the number of shifts and the tariff for electricity.
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Tongkul, F., H. Benedick e F. K. Chang. "Geology of slopes in the Crocker Range, Sabah, Malaysia". Journal of Nepal Geological Society 34 (9 ottobre 2006): 73–80. http://dx.doi.org/10.3126/jngs.v34i0.31881.
Testo completoAbstract (sommario):
Slope failures are frequent occurrences along roads in Malaysia. Not until recently, geological inputs were rarely sought when designing and constructing roads on mountainous areas. This paper highlights the result of a geological study on selected slopes along a major road across Sabah's main mountain range, the Crocker Range, which is comprised mostly of folded Eocene sedimentary rocks. A total of 48 slopes facing potential failure problems were studied. The following four main potential sources of failures were recognised: 1) related to intensely sheared mudstones within a localised fault zone; 2) related to unfavourable orientation of discontinuity planes whereby bedding and joint planes of sandstone beds occur parallel or sub-parallel to the slope face; 3) related to the presence of intensely fractured and sheared sandstone and mudstone beds within a regional fold hinge; and 4) related to the presence of old landslide deposits. The recommendations to stabilise problematic slopes include covering the unstable slope face with concrete or vegetation and cutting back the slopes further.
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Botfalvai, Gábor, Orsolya Győri, Emília Pozsgai, Izabella M. Farkas, Tamás Sági, Márton Szabó e Attila ősI. "Sedimentological Characteristics And Paleoenvironmental Implication Of Triassic Vertebrate Localities In Villány (Villány Hills, Southern Hungary)". Geologica Carpathica 70, n. 2 (1 aprile 2019): 135–52. http://dx.doi.org/10.2478/geoca-2019-0008.
Testo completoAbstract (sommario):
Abstract There are two Triassic vertebrate sites in Villány Hills (Southern Hungary), where productive and continuous excavations have been carried out in the last six years resulting in a rich and diversified assemblage of shallow marine to coastal animals. The studied formations belong to the Villány–Bihor Unit of the Tisza Megaunit, which was located at the passive margin of the European Plate during the Triassic. The relatively diverse vertebrate assemblage was collected from a Road-cut on Templom Hill and a newly discovered site at a construction zone located on the Somssich Hill. Four main lithofacies were identified and interpreted in the newly discovered Construction vertebrate site consisting of dolomite (deposited in a shallow, restricted lagoon environment), dolomarl (shallow marine sediments with enhanced terrigenous input), reddish silty claystone (paleosol) and sandstone (terrigenous provenance) indicating that the sediments of the Construction vertebrate site were formed in a subtidal to peritidal zone of the inner ramp environment, where the main controlling factor of the alternating sedimentation was the climate change. However, the recurring paleosol formation in the middle part of the section also indicates a rapid sea-level fall when the marine sediments were repeatedly exposed to subaerial conditions. In the Road-cut site the siliciclastic sediments of the Mészhegy Sandstone Formation are exposed, representing a nearshore, shallow marine environment characterized by high siliciclastic input from the mainland.
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Sarkar, Suman, Amit K. Ghosh e Madhav Kumar. "Recognition of algal rich facies from the Umlatdoh Limestone of Shella Formation, Jaintia Group, Meghalaya". Journal of Palaeosciences 60, n. (1-2) (31 dicembre 2011): 315–21. http://dx.doi.org/10.54991/jop.2011.178.
Testo completoAbstract (sommario):
The carbonate rocks of the Shella Formation (Middle Eocene) belonging to the Jaintia Group in the Jaintia Hills of Meghalaya are represented by two sandstone units in alternation with three limestone units, viz. Lakadong Limestone, Umlatdoh Limestone and Prang Limestone respectively in chronological order. Umlatdoh Limestone, the middle limestone unit of Shella Formation is conformably underlain by the Lakadong Sandstone and overlain by Narpuh Sandstone. Samples from the Umlatdoh Limestone were collected from the outcrop on the Jowai-Badarpur Road, about 1 km southwest of Lumshnong. Calcareous algae have been recovered from four samples and two distinct facies have been recognized. One of the facies is dominated by non-geniculate coralline red algae and benthic foraminifera. The non-geniculate corallines are represented by Lithothamnion and Mesophyllum (Family Hapalidiaceae), Lithoporella (Family Corallinaceae) and Sporolithon (Family Sporolithaceae). The other facies is rich in calcareous green algae along with benthic foraminifera. The green algal genera belong to families Dasycladaceae, Udoteaceae and Halimedaceae. Previously, a green algal assemblage was recorded from the Umlatdoh Limestone Member of Shella Formation exposed in the low lying hills between Sutnga and Litang valleys of Jaintia Hills. However, this is the first report on the occurrence of non-geniculate coralline red algae from the Umlatdoh Limestone Member of the Shella Formation. Based on the algal-foraminiferal assemblages, interpretation has been made on the palaeoenvironment and palaeobathymetry.
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Hydzik-Wiśniewska, Joanna, Anna Wilk, Łukasz Bednarek e Sebastian OIesiak. "Mixture of Crushed- Stone Aggregate as Material For Substructure Layers". Studia Geotechnica et Mechanica 40, n. 2 (4 agosto 2018): 154–62. http://dx.doi.org/10.2478/sgem-2018-0014.
Testo completoAbstract (sommario):
AbstractOne of the most important elements of road construction is its substructure, which constitutes the base on which the next layers of road are placed. Mixture of crushed-stone aggregate is very often used as material for substructure. The most frequently used type of aggregate is magma rocks, due to its good physical-mechanical properties. However, it is not always available, so it is substituted by sandstone or even concrete rubble aggregates. The bearing ratio CBR is a parameter determining the suitability of a certain aggregate for road substructure. It is also one of the most popular quality tests of aggregate as it does not require complex apparatus. This paper analyses the results of physical and geotechnical tests with particular focus on CBR bearing ratio of crushed aggregates and their application as substructure for road construction. There has also been an attempt to find the correlation between CBR bearing ratio and other physical and geometrical properties.
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Lao, Virginia Claudia. "Perbandingan Metode Perencanaan Tebal Perkerasan Lentur pada Jalan Batas Provinsi". Rekayasa Sipil 16, n. 3 (11 ottobre 2022): 191–97. http://dx.doi.org/10.21776/ub.rekayasasipil.2022.016.03.6.
Testo completoAbstract (sommario):
Due to getting development and improvement zone area in West Sulawesi Province, the Kalumpang–Bonehau-Batas South Sulawesi route is planned to be upgraded to a national road from a district road. The purpose of this study was to compare the 2017 pavement design manual method and component analysis in planning the flexible pavement thickness of inter-provincial roads. The design of flexible pavement thickness uses the 2017 road pavement design manual method, namely AC-WC 40 mm, AC-BC 60 mm, AC-Base 80 mm, and class A top layer 300 mm. The results of the component analysis method, namely the thickness of the surface layer using a mixture of laston is 5 cm, the top foundation layer uses 20 cm class A crushed stone and the lower foundation layer uses 10 cm class A sandstone.
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IKHANE, Phillips Reuben, Odunayo Christy ATEWOLARA-ODULE, Olalekan Olayiwola OYEBOLU e Omotoso Richard FAKOLADE. "Chemostratigraphic Architecture of Sandstone Facies Exposed along Auchi-Ighara Road, Mid-Western Nigeria". GeoScience Engineering 68, n. 1 (giugno 2022): 33–45. http://dx.doi.org/10.35180/gse-2022-0067.
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Quinn, L., A. R. Bashforth, E. T. Burden, H. Gillespie, R. K. Springer e S. H. Williams. "The Red Island Road Formation: Early Devonian terrestrial fill in the Anticosti Foreland Basin, western Newfoundland". Canadian Journal of Earth Sciences 41, n. 5 (1 maggio 2004): 587–602. http://dx.doi.org/10.1139/e04-021.
Testo completoAbstract (sommario):
More than 100 m of nearly flat-lying, fluvially derived, thick-bedded and lensoid, clast-supported conglomerate and sandstone are found on Red Island, off the coast of the Port au Port Peninsula, western Newfoundland. Formally described herein and named Red Island Road Formation, the strata represent a unique lithologic formation not exposed or known anywhere else in the region. Characteristic features include abundant, rounded, highly weathered and varnished cobbles and boulders derived from an unknown mixed volcanic and very low to low-grade metamorphic terrane. Although the unit is largely unfossiliferous, a thin sandstone bed near the top of the type section contains primitive dichotomously branched plant remains and biostratigraphically significant palynomorphs. Among more than 25 species of spores, it is the diversity of Emphanisporites, Dictyotriletes, and Dibolisporites, and in particular Dibolisporites echinaceus, Dictyotriletes canadensis, Emphanisporites annulatus, E. erraticus, and E. schultzii that indicate the Red Island Road Formation was deposited during the early and early late Emsian Emphanisporites annulatus Camarozonotriletes sextantii Assemblage Zone. Biostratigraphy places age constraints on Acadian tectonism, local thrusting, and foreland basin development in this part of the Anticosti Basin. The suite of clasts indicates a radical shift in provenance as compared with siliciclastic units lower in the foreland basin sequence. Clearly, the source for these clasts is not local. Terranes farther afield, such as the La Poile Group in southwestern Newfoundland, should be examined as possibilities for the provenance of these rocks.
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Nahaichuk, Vasyl. "Non-rigid road pavement made of local stone materials strengthened by slag alcaline binder". Dorogi i mosti 2021 (25 marzo 2021): 102–16. http://dx.doi.org/10.36100/dorogimosti2021.23.102.
Testo completoAbstract (sommario):
Abstract Introduction.Road pavement is one of the most material-intensive and expensive elements of the road. The quality and durability of the road as a whole depend on the type of road construction material and the method of its application. Considering the significant needs of the road industry in construction materials, there is a need to find effective materials, the use of which allows building the road pavement that can resist the loadings of modern vehicles during the standard service life of pavement. In order to minimize the cost of construction and the negative impact on the environment, it is advisable to use local stone materials, the use of which allows obtaining the efficient road structures on their basis, requires minimal transportation costs and contributes to environmental protection.Problem statement. On the territory of Ukraine there are many deposits of stone materials and products of their associated processing in the form of crushing screenings [1–5]. These materials can be used as the stone materials for pavement layers arrangement without reinforcing binders, also for improving of their properties by strengthening with various types of binders.For strengthening and improving the properties of stone materials can be used the following:–inorganic binders, which include cement, lime and slag alkaline binder;organic binders, which include bitumen, bituminous emulsions and foamed bitumen–complex binders in the form of combination of cement with bitumen, as well as cement with bitumen emulsion or foamed bitumen.Considering the growth of transport loadings on road structures, it is necessary to provide the use of reliable and durable structures, for the construction of which it can be used available domestic raw materials. Organic binders, which include bitumen imported to Ukraine, are quite expensive and their cost is constantly rising. One of the perspective ways for solving this problem is the use of slag alkaline binders and concretes on their basis in the road construction, using local stone materials of different genesis as aggregates.Purpose. The purpose is to study the possibility of obtaining effective slag alkaline concrete with use as a mineral aggregate the stone materials of different mineralogical composition and strength, suitable for non-rigid pavement layers arrangement, capable to operate under repeated short-term loadings.Materials and methods. The erupted and sedimentary rocks that most widespread in Ukraine were used for study, namely: organic-hemogenic limestones, quartzite-like sandstones and granite materials. Blast furnace granulated slag and soda alkali flux were used as binder components. The mechanical properties and physical and chemical processes that occurred during the slag alkaline hardening were studied, and the technological parameters and the features of preparation of such concretes were studied. The state of the contact zone between the slag alkaline stone binder and various aggregates was determined by a set of methods allowed studding the physical and mechanical characteristics of the contact zone (micro hardness) and determining the distribution of the concentration of basic chemical elements in the contact zone, the composition of new formations and its microstructure.Results. The possibility of obtaining of effective slag alkaline concrete on aggregates of different mineralogical composition and strength that are suitable for non-rigid pavement layers arrangement that are capable for operating under repeated cyclic loadings, was theoretically determined and experimentally confirmed.Keywords: slag alkaline concrete, limestone, granite, sandstone, blast furnace milled granulated
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TAKAHATA, Osamu, Shinji MIYAGUCHI, Takuya HARADA, Mitsuru KUWABARA, Seiya MUNAKATA, Yoshifumi AKIYAMA, Mariko MONMA, Tetsuo YASUTAKA e Hideo KOMINE. "Inference of acidification mechanism inside the road embankment using the Neogene Sandstone containing Pyrite". Japanese Geotechnical Journal 18, n. 2 (1 giugno 2023): 123–38. http://dx.doi.org/10.3208/jgs.18.123.
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Wang, Xiao, Ke Sun, Xin Li, Juntao Ma e Zhongtao Luo. "The Effect of Red Mud on Sintering Processes and Minerals of Portland Cement for Roads". Crystals 11, n. 10 (19 ottobre 2021): 1267. http://dx.doi.org/10.3390/cryst11101267.
Testo completoAbstract (sommario):
As a solid waste generated in the alumina industry, red mud poses a significant environmental hazard and a storage problem. In this study, red mud was added to road cement clinker in order to utilize it. The sintering red mud was first de-alkalized, and then mixed with fly ash, clay, limestone, and sandstone, among other materials, to make Portland cement for road clinker. The effect of the addition of red mud on the thermal decomposition characteristics of Portland cement for roads was studied. The existent states of alkali and radioactive elements in Portland cement for road clinker were investigated by XRD and SEM analysis. The research results showed that the addition of red mud in Portland cement for road raw material significantly promoted the decomposition of carbonates in raw material. The major mineral phases of Portland cement for road clinker were C3S with a polyhedral morphology, quasi-spherical C2S, and tubular C4AF. A small part of the alkali combined with the silicate phase to form a solid solution, and most of the alkali combined with S to form vermiform sulfate in the intermediate phase. The radionuclide 226Ra was mainly distributed in the silicate phase. 232Th was mainly distributed in interstitial phases and then silicate phases, while 40K was mainly distributed in the interstitial phases.
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Náñez, Carolina, e Norberto Malumián. "Foraminíferos miocenos en la cuenca Neuquina, Argentina: implicancias estratigráficas y paleoambientales". Andean Geology 46, n. 1 (6 giugno 2018): 183. http://dx.doi.org/10.5027/andgeov46n1-3142.
Testo completoAbstract (sommario):
At the Bajada del Jagüel and Opaso sections (Añelo low, Neuquén basin), the Maastrichtian to Danian mudstones of the Jagüel Formation, are overlain by a succession of ostreid coquinas, sandstones, and mudstones. This succession has been usually referred to the Roca Formation, a Paleocene marine unit with its type section located about 120 km to the southeast. A contrasting interpretation proposed by the late seventies suggests that the beds assigned to the Roca Formation in the Añelo low were actually the base of the overlying Barranca de los Loros Formation, of terrestrial paleoenvironment and Miocene age, and that their very abundant Paleocene invertebrate remains were reworked. In the present revision, the specimens of the foraminiferal family Elphidiidae recovered from a muddy horizon intercalated between the coquinas at the Opaso and Bajada del Jagüel sections, previously assigned to Protelphidium sp. cf. P. hofkeri Haynes, are identified as Porosononion granosum (d’Orbigny). Porosononion granosum is one of the most common foraminiferal species of the shallow Paranense transgression, which covered large part of Argentina during the middle-late Miocene. It has been traditionally referred to as Protelphidium tuberculatum (d’Orbigny) in Argentina. The occurrence of this species indicates that the coquinas, sandstones and mudstones overlying the Jagüel Formation at the Opaso and Bajada del Jagüel sections should not be assigned to the Roca Formation, but are related to the Miocene Paranense transgression, thus supporting the later stratigraphic interpretation. In the muddy horizon, Porosononion granosum constitutes a monospecific assemblage, and its paleoenvironment might be either marginal marine or lacustrine. The elphidiid specimens from the Roca Formation at the Sierras Blancas area, ca. 12 km southwest from the Opaso section, remain identified as Protelphidium sp. cf. P. hofkeri. Both species, P. sp. cf. P. hofkeri and P. granosum, are described and illustrated, and paleoenvironmental and paleogeographic features are considered.
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Baiyegunhi, Christopher, e Kuiwu Liu. "Sedimentary facies, stratigraphy, and depositional environments of the Ecca Group, Karoo Supergroup in the Eastern Cape Province of South Africa". Open Geosciences 13, n. 1 (1 gennaio 2021): 748–81. http://dx.doi.org/10.1515/geo-2020-0256.
Testo completoAbstract (sommario):
Abstract The stratigraphy of the Ecca Group has been subdivided into the Prince Albert, Whitehill, Collingham, Ripon, and Fort Brown Formations in the Eastern Cape Province, South Africa. In this article, we present detailed stratigraphic and facies analyses of borehole data and road-cut exposures of the Ecca Group along regional roads R67 (Ecca Pass), R344 (Grahamstown-Adelaide), R350 (Kirkwood-Somerset East), and national roads N2 (Grahamstown-Peddie) and N10 (Paterson-Cookhouse). Facies analysis of the Ecca Group in the study area was performed to deduce their depositional environments. Based on the lithological and facies characteristics, the stratigraphy of the Prince Albert, Whitehill, Collingham, and Fort Brown Formations is now subdivided into two informal members each, while the Ripon Formation is subdivided into three members. A total of twelve lithofacies were identified in the Ecca Group and were further grouped into seven distinct facies associations (FAs), namely: Laminated to thin-bedded black-greyish shale and mudstones (FA 1); Laminated black-greyish shale and interbedded chert (FA 2); Mudstone rhythmite and thin beds of tuff alternation (FA 3); Thin to thick-bedded sandstone and mudstone intercalation (FA 4); Medium to thick-bedded dark-grey shale (FA 5); Alternated thin to medium-bedded sandstone and mudstone (FA 6); and Varved mudstone rhythmite and sandstone intercalation (FA 7). The FAs revealed gradually change of sea-level from deep marine (FA 1, FA 2, FA 3 and FA 4, FA 5, and FA 6) to prodelta environment (FA 7). This implies that the main Karoo Basin was gradually filling up with Ecca sediments, resulting in the gradual shallowing up of the water depth of the depositional basin.
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Hussain, Mahbub, Lameed O. Babalola e Mustafa M. Hariri. "Heavy minerals in the Wajid Sandstone from Abha-Khamis Mushayt area, southwestern Saudi Arabia: implications on provenance and regional tectonic setting". GeoArabia 9, n. 4 (1 ottobre 2004): 77–102. http://dx.doi.org/10.2113/geoarabia090477.
Testo completoAbstract (sommario):
ABSTRACT The Wajid Sandstone (Ordovician-Permian) as exposed along the road-cut sections of the Abha and Khamis Mushayt areas in southwestern Saudi Arabia, is a mediun to coarse-grained, mineralogically mature quartz arenite with an average quartz content of over 95%. Monocrystalline quartz is the dominant framework grain followed by polycrystalline quartz, feldspar and micas. The non-opaque heavy mineral assemblage of the sandstone is dominated by zircon, tourmaline and rutile (ZTR). Additional heavy minerals, constituting a very minor fraction of the heavies, include epidote, hornblende, and kyanite. Statistical analysis showed significant correlations between zircon, tourmaline, rutile, epidote and hornblende. Principal component R-mode varimax factor analysis of the heavy mineral distribution data shows two strong associations: (1) tourmaline, zircon, rutile, and (2) epidote and hornblende suggesting several likely provenances including igneous, recycled sedimentary and metamorphic rocks. However, an abundance of the ZTR minerals favors a recycled sedimentary source over other possibilities. Mineralogical maturity coupled with characteristic heavy mineral associations, consistent north-directed paleoflow evidence, and the tectonic evolutionary history of the region indicate a provenance south of the study area. The most likely provenances of the lower part (Dibsiyah and Khusayyan members) of the Wajid Sandstone are the Neoproterozoic Afif, Abas, Al-Bayda, Al-Mahfid, and Al-Mukalla terranes, and older recycled sediments of the infra-Cambrian Ghabar Group in Yemen to the south. Because Neoproterozic (650-542 Ma) rocks are not widespread in Somalia, Eritrea and Ethiopia, a significant source further to the south is not likely. The dominance of the ultrastable minerals zircon, tourmaline and rutile and apparent absence of metastable, labile minerals in the heavy mineral suite preclude the exposed arc-derived oceanic terrains of the Arabian Shield in the west and north as a significant contributor of the sandstone. An abundance of finer-grained siliciclastic sequences of the same age in the north, is consistent with a northerly transport direction and the existence of a deeper basin (Tabuk Basin?) to the north. The tectonic and depositional model presented in this paper differs from the existing model that envisages sediment transportation and gradual basin filling from west to east during the Paleozoic.
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White, J. E. "Biot‐Gardner theory of extensional waves in porous rods". GEOPHYSICS 51, n. 3 (marzo 1986): 742–45. http://dx.doi.org/10.1190/1.1442126.
Testo completoAbstract (sommario):
Many measurements have been made on fluid‐saturated porous rods executing extensional, flexural, and torsional motion. Measurements for extensional and flexural motion yield a loss parameter for Young's modulus waves [Formula: see text], and the measurement for torsional motion yields [Formula: see text] for shear waves. [Formula: see text] has then been calculated for compressional waves in bulk rock, on the assumption that the fluid‐saturated rock is an isotropic solid. I point out the fallacy of computing [Formula: see text] from these measurements and also urge workers to recognize the losses due to simple fluid viscosity in interpreting their data on extensional waves in rods. By application of published theory, I show that peaks in attenuation of extensional waves are to be expected at frequencies of several hertz to several kilohertz, depending upon rod radius. Computed curves are compared with published measurements on Navajo sandstone saturated with water, ethanol, and n‐decane. In each case, computed peak frequency agrees with published measurements. Shift of the peak frequency with temperature from 4 °C to 25 °C is due to change of viscosity of the saturating fluid (water).