scholarly journals Lower Permian basaltic agglomerate from the Tsengel River valley, Mongolian Altai

2020 ◽  
Vol 51 ◽  
pp. 1-11
Author(s):  
Kristýna Hrdličková ◽  
Altanbaatar Battushig ◽  
Pavel Hanžl ◽  
Alice Zavřelová ◽  
Jitka Míková
Keyword(s):  
River Valley ◽  
Lower Permian ◽  
Basalt Lava ◽  
Volcanic Arc ◽  
Lower Carboniferous ◽  
Upper Carboniferous ◽  
Mongolian Altai ◽  
Icp Ms ◽  
Volcaniclastic Rocks ◽  
Data Yield

A new occurrence of Permian volcanic and volcaniclastic rocks in the Mongolian Altai south of the Main Mongolian Lineament was described between soums of Tugrug and Tseel in Gobi-Altai aimag. Studied vitrophyric pyroxene basalt lies in a layer of agglomerate and amygdaloidal lavas, which is a part of NE–SW trending subvertical sequence of varicolored siltstones and volcaniclastic rocks in the Tsengel River valley. This high-Mg basalt is enriched in large ion lithophile elements, Pb and Sr and depleted in Nb and Ta. LA-ICP-MS dating on 44 spots reveals several concordia clusters. The whole rock geochemistry of sample fits volcanic arc characteristic in the geotectonic discrimination diagrams. Dominant zircon data yield Upper Carboniferous and Permian magmatic ages 304.4 ± 2.3 and 288.6 ± 1.9 Ma. Two smaller clusters of Upper Devonian (376 ± 4.7 Ma) to Lower Carboniferous ages (351.9 ± 3.5 Ma) indicate probably contamination of ascending magmatic material. Youngest Triassic age found in three morphologically differing grains reflects probably lead loss. Described high-Mg basalt lava represents sub-aerial volcanism in volcanic arc environment developed over the N dipping subduction zone in the southwestern Mongolia in the time span from Uppermost Carboniferous to Permian during terminal stage of its activity.

scholarly journals Stratigraphy and depositional history of the Upper Palaeozoic and Triassic sediments in the Wandel Sea Basin, central and eastern North Greenland

1989 ◽  
Vol 143 ◽  
pp. 21-45
Author(s):  
L Stemmerik ◽  
E Håkansson
Keyword(s):  
Early Carboniferous ◽  
Upper Permian ◽  
Lower Permian ◽  
Late Permian ◽  
The West ◽  
Depositional History ◽  
Lower Carboniferous ◽  
Upper Carboniferous ◽  
Lithostratigraphic Units ◽  
History Of

A lithostratigraphic scheme is erected for the Lower Carboniferous to Triassic sediments of the Wandel Sea Basin, from Lockwood Ø in the west to Holm Land in the east. The scheme is based on the subdivision into the Upper Carboniferous - Lower Permian Mallemuk Mountain Group and the Upper Permian - Triassic Trolle Land Group. In addition the Upper Carboniferous Sortebakker Formation and the Upper Permian Kap Kraka Formation are defined. Three formations and four members are included in the Mallemuk Mountain Group. Lithostratigraphic units include: Kap Jungersen Formation (new) composed of interbedded limestones, sandstones and shales with minor gypsum - early Moscovian; Foldedal Formation composed of interbedded limestones and sandstones -late Moseovian to late Gzhelian; Kim Fjelde Formation composed of well bedded Iimestones - late Gzhelian to Kungurian. The Trolle Land Group includes three formations: Midnatfjeld Formation composed of dark shales, sandstones and limestones - Late Permian; Parish Bjerg Formation composed of a basal conglomeratic sandstone overlain by shales and sandstones - ?Early Triassic (Scythian); Dunken Formation composed of dark shales and sandstones - Triassic (Scythian-Anisian). The Sortebakker Formation (new) is composed of interbedded sandstones, shales and minor coal of floodplain origin. The age is Early Carboniferous. The Kap Kraka Formation (new) includes poorly known hematitic sandstones, conglomerates and shales of Late Permian age.

I. The lower Carboniferous microsaurs

1967 ◽  
Vol 252 (776) ◽  
pp. 107-129 ◽  
Keyword(s):  
New Genus ◽  
Early Carboniferous ◽  
Lower Permian ◽  
New Genus And Species ◽  
Lower Carboniferous ◽  
Upper Carboniferous ◽  
Present Evidence ◽  
Branchial Arches ◽  
Full Sense ◽  
Cervical Ribs

Redescriptions of Adelogyrinus simnorhynchus and Dolichopareias disjectus are given. The skulls of these forms are characterized by the very anteriorly placed small orbits and long post-orbital skull table. Further diagnostic characters are the exclusion of the ‘post-orbital’ from the orbit, the long straight suture between the squamosal and parietal and the absence of anotic notch. A parasternal process is present on the interclavicle. A new genus and species Palaeomolgophus scoticus of early Carboniferous age is described. It is an aquatic form with branchial arches, yet the characters it displays are essentially reptiliomorph, quite unlike those of the labyrinthodonts and resembling more those of lower Permian reptiles. It has microsaur-type vertebrae in which the centrum is a pleurocentrum, winged ribs, a differentiated series of cervical ribs and an interclavicle with a posterior parasternal process. The limbs are small, but well developed, with ossified condylar surfaces. Comparisons are made with Microbrachis from the Upper Carboniferous of Nyran, the type microsaur, which is represented mainly by larval forms, but the disappearance of the lateral line canals in larger skulls indicates a metamorphosis. Microbrachis is more primitive than Palaeomolgophis in that small pre-sacral as well as post-sacral intercentra are present. Evidence is given which leaves little doubt that in microsaurs generally the vertebrae are of apsidospondylus type and the centrum is a pleurocentrum. They are not lepospondylous and the validity and usefulness of the term ‘Lepospondyli’ is questioned. The evidence presented here supports the view that there was a deep and early split in tetrapods separating the labyrinthodonts (batrachomorphs) from the reptiliomorph types, (the Lower Carboniferous microsaurs, microbrachids, gymnarthrids, seymouriomorphs, etc.). All display more or less a series of structures never found in any labyrinthodont and which indicate either a very early divergence from the labyrinthodont stock or a separate origin from fishes. The emergence of essentially reptilian characters in Palaeomolgophis , an apparently aquatic form of Lower Carboniferous age contradicts the assumption that these characters arose as adaptations to land life and indicates that the first move toward the reptilian condition was structural and that it was only at a later date that the life-history was modified and that terrestrial tetrapods, reptiles in the full sense, arose.

An Integrated Approach to Well Logging: The Case of the Bazhenov Formation

2021 ◽  
Author(s):  
Dmitry Mikhailovich Lazutkin ◽  
Oleg Vladimirovich Bukov ◽  
Denis Vagizovich Kashapov ◽  
Albina Viktorovna Drobot ◽  
Maria Alexandrovna Stepanova ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Integrated Approach ◽  
Donets Basin ◽  
Lower Carboniferous ◽  
Upper Carboniferous ◽  
Salt Domes ◽  
Axial Part ◽  
Gravity And Magnetic ◽  
Play Elements ◽  
Hydrocarbon Reserves

Abstract New geological structures – displaced blocks of salt diapirs’ overburden – were identified in the axial part of the Dnieper-Donets basin (DDB) beside one of the largest salt domes due to modern high-precision gravity and magnetic surveys and their joint 3D inversion with seismic and well log data. Superposition of gravity lineaments and wells penetrating Middle and Lower Carboniferous below Permian and Upper Carboniferous sediments in proximity to salt allowed to propose halokinetic model salt overburden displacement, assuming Upper Carboniferous reactivation. Analogy with rafts and carapaces of the Gulf of Mexico is considered in terms of magnitude of salt-induced deformations. Density of Carboniferous rocks within the displaced flaps evidence a high probability of hydrocarbon saturation. Possible traps include uplifted parts of the overturned flaps, abutting Upper Carboniferous reservoirs, and underlying Carboniferous sequence. Play elements are analyzed using analogues from the Dnieper-Donets basin and the Gulf of Mexico. Hydrocarbon reserves of the overturned flaps within the study area are estimated to exceed Q50 (Р50) = 150 million cubic meters of oil equivalent.

scholarly journals First record of tetrapod footprints from the Carboniferous Mesters Vig Formation in East Greenland.

2016 ◽  
Vol 64 ◽  
pp. 69-76
Author(s):  
Jesper Milàn ◽  
Hendrik Klein ◽  
Sebastian Voigt ◽  
Lars Stemmerik
Keyword(s):  
Natural History ◽  
North Africa ◽  
Morphological Difference ◽  
First Record ◽  
Lower Permian ◽  
Upper Carboniferous ◽  
History Museum ◽  
East Greenland ◽  
Continental Deposits ◽  
Significant Morphological Difference

A single slab with Late Palaeozoic tetrapod footprints from East Greenland has been housed at the Natural History Museum of Denmark for decades without scientific notice. The specimen comes from the Mesters Vig Formation of northern Scoresby Land in East Greenland and contains a monospecific assemblage of tetrapod footprints that we assign to Limnopus Marsh 1894. As there is no significant morphological difference from other records of this ichnogenus from North America, Europe and North Africa, the described tetrapod footprints can be referred to eryopoid temnospondyl trackmakers. Limnopus is well-known from Upper Carboniferous and Lower Permian continental deposits of palaeoequatorial Pangea. Identification of Limnopus tracks is in agreement with the supposed Late Carboniferous age of the Mesters Vig Formation and thereby also the first evidence of Carboniferous tetrapods from Greenland.

A further strange Archaeorthoptera from the Moscovian of Nord-Pas-de-Calais (France) (Insecta, Polyneoptera)

Zootaxa ◽  
2021 ◽  
Vol 5047 (2) ◽  
pp. 165-170
Author(s):  
ANDRE NEL ◽  
PATRICK ROQUES ◽  
HERVE DUQUESNE
Keyword(s):  
Lower Permian ◽  
Upper Carboniferous ◽  
Northern France

The new Archaeorthoptera Duquesnia gallica gen. et sp. nov. Nel & Roques, is described from the upper Carboniferous of Northern France. It shows several putative synapomorphies with the three genera Contracladus Dvořák et al., 2021 (Pennsylvanian of Germany), Nugonioneura (lower Permian of USA), and Avionugonioneura from the Moscovian of Avion (France).  

La question des conditions probables du climat de l'Autunien et du Saxonien de l'Europe centrale et occidentale

1961 ◽  
Vol S7-III (5) ◽  
pp. 463-467 ◽  
Author(s):  
Horst Falke
Keyword(s):  
Middle Permian ◽  
Lower Permian ◽  
Prevailing Wind ◽  
Great Care ◽  
Atmospheric Conditions ◽  
Humid Climate ◽  
Upper Carboniferous ◽  
Sedimentary Deposits ◽  
Hot Humid Climate ◽  
Desert Climate

Abstract The similarity of upper Carboniferous and Autunian (lower Permian) floras and of faunas, and most of the Autunian sediments, indicates a hot, humid climate interrupted by several dry periods during the Autunian. Saxonian (middle Permian) fauna and sediments show increasing dryness without reaching actual desert climate until the end of the epoch. Conditions differed from basin to basin during both the Autunian and the Saxonian, and relief greatly influenced the climate. Thus flora, fauna, and climate require interpretation with great care. Textures of eolian sedimentary deposits of the Permian give some information concerning prevailing wind directions and atmospheric conditions, but paleomagnetic conditions are poorly known.

Using Mineral Chemistry to Aid Exploration: A Case Study from the Resolution Porphyry Cu-Mo Deposit, Arizona

2020 ◽  
Vol 115 (4) ◽  
pp. 813-840 ◽  
Author(s):  
David R. Cooke ◽  
Jamie J. Wilkinson ◽  
Mike Baker ◽  
Paul Agnew ◽  
Josh Phillips ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Mineral Chemistry ◽  
Three Dimensions ◽  
Temperature Sensitive ◽  
Blind Test ◽  
Inductively Coupled ◽  
Porphyry Cu ◽  
The North ◽  
Icp Ms ◽  
Volcaniclastic Rocks

Abstract The giant, high-grade Resolution porphyry Cu-Mo deposit in the Superior district of Arizona is hosted in Proterozoic and Paleozoic basement and in an overlying Cretaceous volcaniclastic breccia and sandstone package. Resolution has a central domain of potassic alteration that extends more than 1 km outboard of the ore zone, overlapping with a propylitic halo characterized by epidote, chlorite, and pyrite that is particularly well developed in the Laramide volcaniclastic rocks and Proterozoic dolerite sills. The potassic and propylitic assemblages were overprinted in the upper parts of the deposit by intense phyllic and advanced argillic alteration. The district was disrupted by Tertiary Basin and Range extension, and the fault block containing Resolution and its Cretaceous host succession was buried under thick mid-Miocene dacitic volcanic cover, obscuring the geologic, geophysical, and geochemical footprint of the deposit. To test the potential of propylitic mineral chemistry analyses to aid in the detection of concealed porphyry deposits, a blind test was conducted using a suite of epidote-chlorite ± pyrite-altered Laramide volcaniclastic rocks and Proterozoic dolerites collected from the propylitic halo, with samples taken from two domains located to the north and south and above the Resolution ore zone. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data of epidote provided indications of deposit fertility and proximity. Competition for chalcophile elements (As, Sb, Pb) between coexisting pyrite and epidote grains led to a subdued As-Sb fertility response in epidote, consistent with epidote collected between 0.7 and 1.5 km from the center of a large porphyry deposit. Temperature-sensitive trace elements in chlorite provided coherent spatial zonation patterns, implying a heat source centered at depth between the two sample clusters, and application of chlorite proximitor calculations based on LA-ICP-MS analyses provided a precisely defined drill target in this location in three dimensions. Drilling of this target would have resulted in the discovery of Resolution, confirming that epidote and chlorite mineral chemistry can potentially add value to porphyry exploration under cover.

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