About the structure of the Kama-Kinel trough system

Kama-Kinel Trough System (KKTS) — the structure formed in the Frasnian of the Late Devonian in the vast territory of the Volga-Ural province, is distinguished by the Upper Devonian — Lower Carboniferous deposits. The new interpretation of forming conditions of carbonate deposits in the KKTS has been given. The troughs of the KKST were formed in the Late Devonian as basin with gently sloping shelf zones. The deposits of the middle shelf (ramp), gently sinking into the side of the pool, where the layered accumulated precipitation are presented by bioclastic and intraclastic (lumpy) limestones and carbonate breccia, formed under the influence of storms. Three structural-facial zones, central, border and arched, allocated in the structure of deflections of the KKTS, reflect the structure of troughs formed as a result of tectonic restructuring at the beginning of the Visean and reactivated at the neotectonic stage. The uplift of the side zone considered as the reef buildups seem to be horst-shaped structures in fault zones. These features allow us to consider the structure of the KKTS as formed as a result of paleotectonic processes with the appropriate distribution of shallow and deep-water facies, subsequently changed as a result of reactivation of the basement faults.

Download Full-text

Conodont Biostratigraphy of the Lower Carboniferous Deep-Water Facies in the Kokshaal and Djangdjir Ranges, South Tianshan, Kyrgyzstan

Stratigraphy and Geological Correlation ◽

10.1134/s0869593821020052 ◽

2021 ◽

Vol 29 (2) ◽

pp. 169-191

Author(s):

A. V. Neyevin ◽

D. V. Alexeiev

Keyword(s):

Deep Water ◽

Lower Carboniferous ◽

Conodont Biostratigraphy ◽

South Tianshan ◽

Water Facies

Download Full-text

PALEOGEOGRAPHIC RECONSTRUCTIONS OF THE LATE DEVONIAN SEDIMENTS DEPOSITION IN THE SOUTH OF THE VOLGO-URAL PROVINCE CAUSED BY PROSPECTING FOR REEF OIL DEPOSITS

Geology Geophysics and Development of Oil and Gas Fields ◽

10.30713/2413-5011-2020-8(344)-4-18 ◽

2020 ◽

pp. 4-18

Author(s):

Yu.I. Nikitin ◽

◽

Keyword(s):

Late Devonian ◽

The South ◽

Oil Deposits ◽

Ural Province

Download Full-text

Mudrock Microstructure: A Technique for Distinguishing between Deep-Water Fine-Grained Sediments

Minerals ◽

10.3390/min11060653 ◽

2021 ◽

Vol 11 (6) ◽

pp. 653

Author(s):

Shereef Bankole ◽

Dorrik Stow ◽

Zeinab Smillie ◽

Jim Buckman ◽

Helen Lever

Keyword(s):

Grain Size ◽

Deep Water ◽

Sedimentary Facies ◽

X Ray Diffraction ◽

Weak Current ◽

Large Area ◽

Fine Grained ◽

Mean Size ◽

The Mean ◽

Water Facies

Distinguishing among deep-water sedimentary facies has been a difficult task. This is possibly due to the process continuum in deep water, in which sediments occur in complex associations. The lack of definite sedimentological features among the different facies between hemipelagites and contourites presented a great challenge. In this study, we present detailed mudrock characteristics of the three main deep-water facies based on sedimentological characteristics, laser diffraction granulometry, high-resolution, large area scanning electron microscopy (SEM), and the synchrotron X-ray diffraction technique. Our results show that the deep-water microstructure is mainly process controlled, and that the controlling factor on their grain size is much more complex than previously envisaged. Retarding current velocity, as well as the lower carrying capacity of the current, has an impact on the mean size and sorting for the contourite and turbidite facies, whereas hemipelagite grain size is impacted by the natural heterogeneity of the system caused by bioturbation. Based on the microfabric analysis, there is a disparate pattern observed among the sedimentary facies; turbidites are generally bedding parallel due to strong currents resulting in shear flow, contourites are random to semi-random as they are impacted by a weak current, while hemipelagites are random to oblique since they are impacted by bioturbation.

Download Full-text

The origin and early radiation of terrestrial vertebrates

Journal of Paleontology ◽

10.1017/s0022336000017248 ◽

2001 ◽

Vol 75 (6) ◽

pp. 1202-1213 ◽

Cited By ~ 16

Author(s):

Robert L. Carroll

Keyword(s):

Fossil Record ◽

Early Carboniferous ◽

Late Devonian ◽

Lower Carboniferous ◽

Major Transitions ◽

Terrestrial Vertebrates ◽

History Of ◽

Paleozoic Tetrapods ◽

Early Radiation ◽

Ways Of Life

The origin of tetrapods from sarcopterygian fish in the Late Devonian is one of the best known major transitions in the history of vertebrates. Unfortunately, extensive gaps in the fossil record of the Lower Carboniferous and Triassic make it very difficult to establish the nature of relationships among Paleozoic tetrapods, or their specific affinities with modern amphibians. The major lineages of Paleozoic labyrinthodonts and lepospondyls are not adequately known until after a 20–30 m.y. gap in the Early Carboniferous fossil record, by which time they were highly divergent in anatomy, ways of life, and patterns of development. An even wider temporal and morphological gap separates modern amphibians from any plausible Permo-Carboniferous ancestors. The oldest known caecilian shows numerous synapomorphies with the lepospondyl microsaur Rhynchonkos. Adult anatomy and patterns of development in frogs and salamanders support their origin from different families of dissorophoid labyrinthodonts. The ancestry of amniotes apparently lies among very early anthracosaurs.

Download Full-text