Facies and seismic analysis of the Late Carboniferous–Early Permian Finnmark carbonate platform (southern Norwegian Barents Sea): An assessment of the carbonate factories and depositional geometries

2017 ◽  
Vol 79 ◽  
pp. 372-393 ◽  
Author(s):  
Matteo Di Lucia ◽  
Jhosnella Sayago ◽  
Gianluca Frijia ◽  
Axum Cotti ◽  
Andrea Sitta ◽  
...  
1997 ◽  
Vol 71 (5) ◽  
pp. 758-779 ◽  
Author(s):  
John R. Groves ◽  
Gregory P. Wahlman

Nearly continuous cores from a 500-meter interval of upper Moscovian through post-Artinskian carbonate strata on the Finnmark Platform have yielded rich assemblages of fusulinaceans and smaller foraminifers. The fusulinaceans provide an independent time framework for evaluating stratigraphic occurrences of associated smaller foraminifers. Information derived from this study has been integrated with that from previous investigations to produce a smaller foraminiferal biostratigraphic model for the High Arctic. Kasimovian strata are characterized by occurrences of Nodosinelloides spp., Protonodosaria spp. and Hemigordius schlumbergeri. Overlying lower Gzhelian beds are identified by the appearances of Raphconilia modificata and Amphoratheca iniqua. Tezaquina clivuli and Cribrogenerina gigas first occur in upper Gzhelian strata, and Asselian rocks contain appearances of Geinitzina postcarbonica and Pachyphloia spp. Phylogenetic reconstructions suggest that the Late Carboniferous-Early Permian pseudovidalinids (Archaediscacea) derived from the Pseudoammidiscidae, as did the older group of predominantly Early Carboniferous archaediscaceans. The repeated development of similar morphologies within the two groups of archaediscaceans includes examples of both convergence and iterative evolution. The Protonodosariidae and Syzraniidae most likely evolved from an earlandiid ancestor. The syzraniids gave rise to the Geinitzinidae, which in turn gave rise to the Pachyphloiidae. As in the archaediscaceans, evolution within and among the Earlandiidae, Protonodosariidae, Syzraniidae, Geinitzinidae and Pachyphloiidae includes multiple examples of repeated patterns. Two key phenotypic developments seemingly led to bursts of diversification in different groups throughout late Paleozoic foraminiferal evolution. The acquisition of an outer hyaline or pseudofibrous wall layer was a morphologic breakthrough followed by taxonomic radiation in both groups of archaediscaceans and in the Earlandia-Syzrania lineage. The second major event was the shift from an undivided tubular morphology to uniserial morphology in both the Earlandiidae-Protonodosariidae and Syzraniidae-Geinitzinidae lines. Nodosinelloides pinardae is proposed as a new name for Nodosaria grandis Lipina, 1949 (preoccupied).


2021 ◽  
Vol 95 ◽  
pp. 72-87
Author(s):  
Qigui Mao ◽  
Songjian Ao ◽  
Brian F. Windley ◽  
Zhiyong Zhang ◽  
Dongfang Song ◽  
...  

Author(s):  
Donghai Zhang ◽  
Baochun Huang ◽  
Guochun Zhao ◽  
Joseph G. Meert ◽  
Simon Williams ◽  
...  

2021 ◽  
pp. jgs2020-223
Author(s):  
Dominique Jacques ◽  
Philippe Muchez ◽  
Manuel Sintubin

Many studies have constrained that late-Variscan buckling produced the arcuate geometry of the Ibero-Armorican belt. Nonetheless, debate remains on the associated geodynamic framework. Poorly studied Late Carboniferous intramontane basins offer an excellent framework to decipher the timing and kinematics of the late- to post-Variscan tectonics. Understanding the latter also helps constrain the structural emplacement mode of contemporaneous W-Sn-Nb-Ta-Li mineralisation. In Iberia, the Porto-Sátão syncline is exemplary of such a Late Carboniferous intramontane basin. We present a structural analysis of the syncline, its basement and the associated W-Sn deposits. The regional structure is dictated by the Alcudian angular unconformity, caused by Cadomian tectonics (575-555Ma) and separating tilted Ediacaran and subhorizontal Lower Palaeozoic formations. Superposed Variscan deformation led to F1-F3 folds with steep and gentle plunges, respectively. The late-orogenic D3 fabric is locally affected by post-orogenic F4 kink folds and a S4 crenulation cleavage. W-Sn bearing vein systems occur along granite-hosted cone sheets, or exploit cross-fold joints associated with the F3 and F4 fold generations, revealing a close kinematic relationship between granite-related mineralisation and the late- to post-Variscan deformation style. This structural history is interpreted as a plate-scale geodynamic change from Late Carboniferous N-S (D3) to Early Permian WNW-ESE (D4) convergence.


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