scholarly journals Quartz arenites and laterites in the Moesian Group (Upper Triassic), northwestern Bulgaria: possible evidence for the effect of the Carnian Humid Episode

2017 ◽  
Vol 46 (1) ◽  
pp. 3-25
Author(s):  
Athanas Chatalov
Keyword(s):  
Tectonic Setting ◽  
Source Area ◽  
Field Studies ◽  
Upper Triassic ◽  
Gradual Transition ◽  
Humid Climate ◽  
Climate Conditions ◽  
Western Tethys ◽  
Tethys Realm ◽  
Hot Humid Climate

Quartz-rich sandstones and ironstone crusts occur in the lowermost part of the Upper Triassic Moesian Group exposed in the western Balkanides. On the basis of performed field studies, micropetrography, X-ray diffraction, and major-element chemistry, these deposits are defined as first-cycle quartz arenites and laterites, respectively. The former were deposited in an alluvial environment, while the latter developed in gravel-dominated fluvial sediments. The main control on their formation was warm to hot humid climate conditions combined with low relief, quiescent tectonic setting, mixed source area, and slow sedimentation rate. The decreasing compositional maturity of the sandstones forming the Glavatsi Member (quartz arenites→feldsarenites→litharenites), the disappearance of the lateritic crusts upwards in the continental succession, and the presence of thick overlying fluvial and playa deposits in the Komshtitsa Formation (or Chelyustnitsa Formation) reflect gradual transition from humid to subhumid climate, and then to persistent semi-arid climate regime. This irreversible trend correlates with other Upper Triassic strata deposited in the Western Tethys realm and adjacent areas. The coeval formation of quartz arenites and laterites must have been related to the most distinctive climate change during the Triassic, i.e., the global Carnian Humid Episode. The new results and interpretations appear to be the first geological record for the effect of pronounced mid-Carnian humidity reported from Eastern Europe. They also present indirect sedimentological evidence for the stratigraphical range of the Moesian Group in NW Bulgaria.

scholarly journals Provenance Studies of Sandstone Facies Exposed Near Igbile Southwestern Nigeria: Petrographic and Geochemical Approach

2014 ◽  
Vol 6 (2) ◽  
pp. 47 ◽  
Author(s):  
Ikhane P. R. ◽  
Akintola A. I. ◽  
Bankole S. I. ◽  
Oyinboade Y. T.
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Inductively Coupled Plasma ◽  
Tectonic Setting ◽  
Source Area ◽  
Rock Fragment ◽  
Petrographic Analysis ◽  
Humid Climate ◽  
Southwestern Nigeria ◽  
Plagioclase Feldspar

The petrography, as well as the major, trace and rare earth element compositions of ten (10) sandstone samples of Maastrichtian Afowo Formation exposed near Igbile, Southwestern Nigeria, have been investigated to determine their provenance, source area weathering conditions, paleoclimate and tectonic setting using petrographic analysis and Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). Results of the petrographic analysis revealed that quartz is the most dominant detrital mineral with (86%) followed by weathered plagioclase feldspar (5.10%) and rock fragments (10.9%). The quartz grain is sub-angular to sub-rounded in shape and the sandstones were classified as quartz arenites, sublitharenites and subarkoses based on framework composition of quartz, feldspar and rock fragment plots. This suggests a recycled orogen source for the sandstones and deposition in a humid climate, evidenced by the weathered feldspars. Eleven (11) major, seventeen (17) trace and fourteen (14) rare earth elements were obtained from the geochemical analysis. The major elements values range in concentration from 0.01%–81.39% with SiO2 being the dominant oxide followed by Al2O3 and Fe2O3 constituting over 95% of the major oxides; K2O, TiO2, Na2O, CaO, MgO and P2O5 made up the remaining 5%. The average ratio of SiO2/Al2O3 valued 4.31 for the sandstone is appreciably high indicating that it has been heavily weathered. The trace elements range in concentration from 0.2 ppm–1651.2 ppm with Zr being the most dominant element an indication of orogenic recycling. The rare earth elements range in concentration from 0.01 ppm–163.7 ppm with Ce having the highest concentration, depicting that the sandstones were deposited in an oxidizing environment. Also, the trace element relationship illustrated from the spider plot shows chemical coherence and uniformity of the sandstones. The chondrite normalized rare earth elements (REE) plot shows enrichment in the Light REE over the heavy REE for the sediment with strong negative Eu anomaly values between (0.57–0.69) suggesting a felsic provenance derived from upper continental crust for the sandstones.

Upper Triassic Invertebrates from the Antimonio Formation, Sonora, Mexico

1994 ◽  
Vol 68 (S36) ◽  
pp. 1-33 ◽  
Author(s):  
George D. Stanley ◽  
Carlos González-León ◽  
Michael R. Sandy ◽  
Baba Senowbari-Daryan ◽  
Peter Doyle ◽  
...  
Keyword(s):  
North America ◽  
North American ◽  
Weak Link ◽  
Upper Triassic ◽  
Marine Fauna ◽  
Western Tethys ◽  
The North ◽  
Tethys Realm ◽  
First Occurrence ◽  
North American Craton

A diverse Upper Triassic tropical marine fauna from northwestern Sonora, Mexico, includes 31 taxa of tropical invertebrates including scleractinian corals, spongiomorphs, disjectoporoids, “hydrozoans,” thalamid and nonthalamid sponges, spiriferid and terebratulid brachiopods, gastropods, bivalves, coleoids, and anomuran microcoprolites. They occur within the late Karnian to Norian part of the Antimonio Formation (Antimonio terrane), which is juxtaposed against a fragmented portion of the North American craton. Most of the fauna is also known from the Tethys region. Sixteen Sonoran taxa co-occur in the western Tethys and five have never been known outside this region. Four additional taxa (one identified only at genus level) are geographically widespread. Some taxa occur in displaced terranes of North America, especially in west-central Nevada (Luning Formation). A weak link exists with the California Eastern Klamath terrane but stronger ties exist with Peru. Among Sonoran sponges,Nevadathalamia polystomawas previously recognized only from the Luning Formation, western Nevada. SpongesCinnabaria expansa, Nevadathalamia cylindrica, and a coral,Astraeomorpha sonorensisn. sp., are also known from Nevada. The coralsDistichomeandra austriaca, Chondrocoenia waltheri, Pamiroseris rectilamellosa, andAlpinophyllia flexuosaco-occur in central Europe. Two new taxa, a spongiomorph hydrozoan,Stromatoporidium lamellatumn. sp., and a disjectoporoid,Pamiropora sonorensisn. sp., have distinct affinities with the Tethys. The geographically widespread North American brachiopod,Spondylospira lewesensis, andPseudorhaetina antimoniensisn. gen. and sp. are among the Sonoran fauna. The Sonoran coleoid (aulacocerid)Dictyoconites(Dictyoconites) cf.D. reticulatumoccurs in the Tethys realm andCalliconitescf.C. drakeiis comparable with a species from the Eastern Klamath terrane.Calliconites millerin. sp. is the first occurrence of the genus outside Sicily. The bivalvesMyophorigonia jaworskii, M. salasi, andPalaeocardita peruvianaare known from Sonora and Peru. Eight gastropod taxa includeGuidoniacf.G. intermediaandG.cf.G. parvula, both previously known from Peru, andEucycloscala subbisertusfrom the western Tethys. The gastropods are unlike those already known from other North American terranes.

scholarly journals Sandstone petrography and geochemistry of the Nayband Formation (Upper Triassic, Central Iran): Implications for sediment provenance and tectonic setting

2019 ◽  
Vol 112 (1) ◽  
pp. 20-41 ◽  
Author(s):  
Asghar Etesampour ◽  
Asadollah Mahboubi ◽  
Reza Moussavi-Harami ◽  
Nasser Arzani ◽  
Mohammad Ali Salehi
Keyword(s):  
Tectonic Setting ◽  
Active Continental Margin ◽  
Source Area ◽  
Major Elements ◽  
Upper Triassic ◽  
Late Triassic ◽  
Sediment Provenance ◽  
Provenance Areas ◽  
Nayband Formation ◽  
Southwestern Margin

AbstractThe Upper Triassic (Norian–Rhaetian) Nayband Formation is situated at the southwestern margin of Central East Iranian Microcontinent and records Eo-Cimmerian events. The formation is composed of mixed carbonate-siliciclastic deposits. This study presents information on the tectonic reconstruction and palaeoclimate of the southwestern margin of Central East Iranian Microcontinent during the Late Triassic. Petrography and modal analyses of sandstones show a variety of quartz-rich petrofacies including subarkose, lithic arkose, sublitharenite, feldspathic litharenite and litharenite. The combined modal analysis and geochemical results of major and trace elements of the sandstone samples represents mixed sedimentary, intermediate, felsic igneous rocks and moderate- to high-grade metamorphic provenance areas. The major elements and modal analyses of the Nayband Formation sandstone samples suggest an active continental margin tec-tonic settings. The palaeoclimatic conditions were sub-humid to humid with relatively low to moderate weathering in the source area which is in agreement with the palaeogeography and palaeotectonic history of southwestern margin of Central East Iranian Microcontinent during the Late Triassic.

scholarly journals Provenance of the Sawa Formation Sandstones, Vindhyan Super Group, Southeast Rajasthan, India

2021 ◽  
Vol 38 (1) ◽  
pp. 93-102
Author(s):  
JYOTI MATHUR
Keyword(s):  
Tectonic Setting ◽  
Source Area ◽  
Heavy Minerals ◽  
Humid Climate ◽  
Element Abundances ◽  
Rock Fragments ◽  
High Maturity ◽  
Rifted Continental Margin ◽  
Major Oxide ◽  
Detrital Mineral

Integrated petrographical and geochemical analysis of Sawa Formation sandstones was analyzed to reconstruct their source area weathering, paleoclimate, tectonic setting and provenance conditions. Petrographically, quartz is dominant detrital mineral followed by feldspar, mica, rock fragments and heavy minerals. Sawa Formation sandstones have been classified as quartzarenite with subordinate sub-arkose and sub-litharenite type. Major oxide element abundances revealed the sandstones have high SiO2 concentration, high K2O/ Na2O ratio, which is consistent with the petrographic data. These sandstones were derived mainly from stable cratonic with minor collision suture and fold thrust belt source and deposited in rifted continental margin basin setting, reflecting high maturity of sediments and high stability of the source area. The CIA, CIW and PIA values of these sandstones indicate high intensity of weathering condition in the source area under warm and humid climate.

Sewage Treatment in Helophyte Beds–First Experiences with a New Treatment Procedure

1987 ◽  
Vol 19 (10) ◽  
pp. 1-10 ◽  
Author(s):  
K. Bucksteeg
Keyword(s):  
Waste Water ◽  
Rural Areas ◽  
Root Zone ◽  
Waste Water Treatment ◽  
Sewage Treatment ◽  
Uptake Capacity ◽  
Humid Climate ◽  
Climate Conditions ◽  
Trickling Filters ◽  
Operation Conditions

Waste water treatment in helophyte beds under humid climate conditions has been favoured by some German ecologists for some years. The idea is to cause waste water to flow horizontally through the root zone of helophytes to achieve satisfactory effluent properties. There exist many highly different proposals regarding the choice of soil and helophytes to be applied, bed area, design of inlets and outlets and operation conditions. A few plants have been operated in practice for some years. It appears that clogging is one of the main problems occurring in these plants. The hydraulic uptake capacity of soil is discussed in Darcy's law. Comparisons with observations of plants in operation are drawn. The interactions between soil properties, its uptake capacity, BOD5-, COD-, N- and P-reduction are evaluated. The effluent results of helophyte beds are compared with those of low-loaded trickling filters and of ponds used for sewage treatment in small villages in rural areas of Germany. It has been proved that the total construction costs of sewage treatment plants with helophyte beds used as the biological stage are higher when compared with those of conventional plants in general.

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