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1081
Distribution characteristics, exploration and development, geological theories research progress and exploration directions of shale gas in China
Publicado em 2022-01-01“…The Sichuan Basin and its surrounding areas have the highest geological resources of shale gas, and the commercial development of shale gas has been achieved in the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in these areas, with a shale gas production of up to 20×109 m3 in 2020. …”
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1082
Geochemical characteristics and resource potential of shale gas in Sichuan Basin, China
Publicado em 2021-12-01“…Accelerating shale gas exploration and development is of great practical significance to improve China's energy structure and achieve the goal of “2030 carbon peak and 2060 carbon neutralization”. The Ordovician Wufeng Formation to Silurian Longmaxi Formation in Sichuan Basin is the key strata for shale gas exploration and development in China. …”
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1083
Structural deformation characteristics and its influence on shale gas preservation of the Wufeng−Longmaxi Formation in the Wuxi area, Chongqing, China
Publicado em 2023-01-01“…The Upper Ordovician Wufeng to Lower Silurian Longmaxi Formation has a good material basis for marine shale gas development, and the structural preservation condition is the key factor to control the rich and integrated shale gas reservoirs in the Wuxi area of Chongqing City, China. …”
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1084
Palynostratigraphy and Palaeoecology of the Shishtu Formation, Kuh-e-Tir, northwestern Kerman
Publicado em 2017-03-01“…During Silurian and Devonian, parts of the Iran Plate including Alborz, central Iran, and Sanandaj-Sirjan as well as Afghanistan and Turkey joined Saudi Arabia and Africa, forming the southern shorelines of Palaeotethys along the northwestern margin of Gondwana. The Late Ordovician-Late Devonian palaeogeographic maps of northern Saudi Arabia allude to the existence of a vast stable shelf along the northern margin of the Gondwana, i.e., northern Africa and Saudi Arabia (Berberian and King 1981; Husseini 1991; Sharland et al. 2001; Ruban et al. 2007; Al-Juboury and Al-Hadidy 2009; Torsvik and Cocks 2009). …”
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1085
Treshold-controlled three-stage hydraulic behaviour of a mantled shallow carbonate aquifer (Tuhala karst area, North Estonia)
Publicado em 2017-12-01“…These characteristics also apply to the Silurian-Ordovician aquifer system, composed of diverse carbonate rocks, in Estonia. …”
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1086
Petrogenesis, U-Pb zircon geochronology and tectonic evolution of the Malaysian granite provinces in the Southeast Asian tin belt
Publicado em 2014“…In addition, the U-Pb zircon analysis of the Malaysian granitoids suggests that both granitic provinces have Cambro-Ordovician and Mesoproterozoic inheritance signatures, which match the ages of the Kontum intraplate ortho-amphibolites and para-gneisses, the two source end-members of the suspected Indochina basement.…”
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1087
Crystal chemistry of Belgian ardennites
Publicado em 2024-08-01“…Under the polarizing microscope, most ardennites form lamellae or needles included in quartz veins or constituting the matrix of red Ordovician schists. Electron-microprobe analyses, as well as single-crystal structure refinements, show a homovalent substitution of As<span class="inline-formula"><sup>5+</sup></span> by V<span class="inline-formula"><sup>5+</sup></span> at the <span class="inline-formula"><i>T</i></span>4 tetrahedral site, leading to a complete solid solution between ardennite-(As) and ardennite-(V). …”
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1088
Deficiências de magnésio em solos e culturas do Norte de Portugal Magnesium deficiencies in soils and crops in Northern Portugal
Publicado em 2007-07-01“…In the Trás-os-Montes and Alto Douro region and in the Entre-Douro and Minho region, Mg deficiencies in crops have been detected predominantly in soils located on schists of the Siluric and Ordovician, on schists of Precambrian and Cambrian of the Schist and Greywacke complex, and soils derived from two-mica alkaline granite. …”
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1089
THE SOUTHERN FRAGMENT OF THE SIBERIAN CRATON: “LANDSCAPE” HISTORY OVER TWO BILLION YEARS
Publicado em 2015-09-01“…In the Early Cambrian, carbonate sedimentation occurred throughout the Siberian Platform and in the area adjacent to the SSC (see Fig. 3Д).The Paleozoic sediments preserved mainly in the central and northern regions of the Siberian Platform reflect a complex evolution of internal and epicontinental seas and shallower basins of the Siberian continent named Angarida. In the Ordovician, predominating were carbonate rocks with marine fauna. …”
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1090
Pb-Zn Deposits in Ruchun-Mazar Region, Kerman Province: Geology, Alteration and Mineralization
Publicado em 2023-09-01“…Mineralization in Howard’s Pass district (Late Ordovician to Early Silurian) was hosted by carbonaceous, calcareous and, to a lesser extent, siliceous mudstones. …”
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1091
Mineralogy and sulfide mineral chemistry of Khabr iron ore, Southwest of Baft (Southeast of Sanandaj-Sirjan Zone)
Publicado em 2024-06-01“…The host rock units in this area are an alternation of carbonate rocks, phyllite, greenschist, mica schist and quartz-schist ranging in age from Upper Cambrian to Ordovician. The dominant minerals in these rock units are calcite, quartz, biotite and muscovite including sericite, paragonite, chlorite and clay minerals. …”
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1092
Petrology and Geochemistry of the Aroud Granitoid Pluton, North of Alam Kuh, Central Western Alborz
Publicado em 2024-12-01“…These include Precambrian sedimentary sequences, Paleozoic conglomerates and shales (equivalent to the Lalun Formation), Paleozoic dolomites and limestones, Ordovician micaceous sandstones, and Carboniferous (Mubarakeh Formation) carbonate units. …”
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1093
Biostratigraphy and palaeoecology of marine microphytoplankton cysts from Member 4 of the Mila Formation, Mila Kuh, eastern Alborz
Publicado em 2019-12-01“…The former Member 5 of this unit was later considered to be equivalent of the Lashkarak Formation (Early Ordovician). The Mila Formation at the its type section is underlain and overlain by the Lalun and Jeirud formations, respectively. …”
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1094
Role of authigenic clay minerals in preserving primary porosity and permeability of the sandstone hydrocarbon reservoirs
Publicado em 2019-09-01“…The case studies includes the Late Cretaceous Lower Tuscaloosa sandstone reservoir in the USA and the Cambrian-Ordovician Lower Sandstone Unit in Egypt. The sandstone intervals of the Lower Tuscaloosa Formation are high quality reservoir zone in subsurface of the Mississippi Interior Salt Basin, with average porosity of 25%, and average permeability of 50 md while the Lower Sandstone Unit in Egypt have very low porosity and permeability. …”
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1095
Estratigrafía de las rocas metasedimentarias (Neoproterozoico-Cámbrico) de la Sierra de Mojotoro, Cordillera Oriental Argentina
Publicado em 2010-12-01“…<br>The basement of Argentine Eastern Cordillera is an heterogeneous succession of siliciclastic and chemical rocks of Neoproterozoic-Early Cambrian age, identified as the "Precambrian basement" (Keidel, 1910) underlying with angular unconformity the Cambrian and Ordovician deposits of the Mesón and Santa Victoria Groups. …”
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1096
Sedimentary environment, sequence stratigraphy, diagenesis and geochemistry of the carbonate Ruteh Formation in north of Mahabad section
Publicado em 2019-06-01“…Palaeomagnetic evidences from the Upper Precambrian rocks and iron ores of Bafq area in central Iran (Becker et al. 1973), the Lower Paleozoic rocks of kuh-e-Gahkom and Surmeh of the Zagros (Burek and Furst 1975), the Cambrian purple sandstone of the salt range of Pakistan (McElhiny 1970), the Upper Devonian–Lower Carboniferous of the Alborz Mountain in north Iran (Geiroud Formation; Wensink et al. 1978) and from the Upper Precambrian, Ordovician and Permian rocks of central Iran (Soffel et al. 1975; Soffel and Forster 1977) show similar geomagnetic poles with those of Afro-Arabia. …”
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1097
Provenance, protolith and metamorphic ages of jadeite-bearing orthogneiss and host paragneiss at Tavagnasco, the Sesia Zone, Lower Aosta Valley, Italy
Publicado em 2023-08-01“…The cores have <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M19" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">Th</mi><mo>/</mo><mi mathvariant="normal">U</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="29pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="66336532033b9fae90efac8c3cb90ed2"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="ejm-35-645-2023-ie00002.svg" width="29pt" height="14pt" src="ejm-35-645-2023-ie00002.png"/></svg:svg></span></span> <span class="inline-formula">=</span> 0.1 and negative Eu anomalies indicative of an igneous protolith, which we interpret to have crystallized in the Ordovician at 780 <span class="inline-formula"><sup>∘</sup></span>C, based on Ti-in-zircon measurements. …”
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1098
Complex <sup>40</sup>Ar ∕ <sup>39</sup>Ar age spectra from low-grade metamorphic rocks: resolving the input of detrital and metamorphic components in a case study fro...
Publicado em 2022-07-01“…<p>In this study, we provide <span class="inline-formula"><sup>40</sup></span>Ar <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="fb147fccdcf98a9911cf3d26a8f6dc33"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="gchron-4-471-2022-ie00004.svg" width="8pt" height="14pt" src="gchron-4-471-2022-ie00004.png"/></svg:svg></span></span> <span class="inline-formula"><sup>39</sup></span>Ar geochronology data from a suite of variably deformed rocks from a region of low-grade metamorphism within the Cambro–Ordovician Delamerian Orogen, South Australia. Low-grade metamorphic rocks such as these can contain both detrital minerals and minerals newly grown or partly recrystallised during diagenesis and metamorphism. …”
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1099
Stratigraphic position and diversity occurrences of basic alkaline igneous rocks in the Permian sedimentary strata, Central Alborz Zone
Publicado em 2018-12-01“…One of the most widespread events is the magmatic activity of the Ordovician–Silurian in the Eastern Alborz (Sultan Meydan Complex), which can be certified on the occurrence of extensional tectonics in the early stages of opening of the Paleo-Tethys ocean (Ghasemi and Khanalizadeh 2012; Ghasemi and Kazemi 2013; Derakhshi and Ghasemi 2013, 2014; Derakhshi et al. 2014, 2015; 2017). …”
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