№ 19, 28 July 2017

Sedimentology

METHODOLOGICAL ASPECTS IN KNOWLEDGE OF VOLCANOGENIC-SEDIMENTARY LITHOGENESIS

It is believed that in the case of systematic-structural investigation of volcanogenic-sedimentary lithogenesis the dialectical law of the unity and conflict of opposites may be used as one of the most important methodological expedient for the events forecast i.e. “dialectical prediction” within the opposite members of geological system which are understudied or inaccessible for a direct investigations, such as endogenic-exogenous, subduction zones – spreading zones. The majority of the ore and non-metallic mineral deposits as well as oil and gas fields appear to be confined to the volcanogenic-sedimentary formations, that is predetermined by the conditions of their generation, accumulation and diakatagenetic changes. As it is well known an important deposits of bentonites, zeolites and their paragenetic associations are related to the upper Cretaceous and mid-Eocene volcanogenic-sedimentary complexes of the Pre-Minor – Caucasian trough and buried structures of southern Middle Kura basin. These deposits location and distribution are the factors which display their dependence on the source volcanic material composition, character of volcanism, their stratigraphic and tectonic confinement and the conditions under which sedimentation basin has been developed.

Ak.A. Ali-zade, Kh.A. Ali-zade, Y.N. Latifova
SUBMARINE FANS AS THE ZONES OF AVALANCHE SEDIMENTATION AND MUD VOLCANISM DEVELOPMENT

The solid runoffs of the world’s largest rivers being served as a source of submarine fans are quantitatively characterized in this paper. The data that have been presented include structure, formation conditions and distribution of two types of submarine fans classified in age as old, Paleogene-Miocene fans and recent, Pliocene-Quaternary fans. From the results of investigations carried out in the zones of their localization all over the world, it is inferred that they mainly contain 12 to 16 km thick terrigenous (sandy-argillaceous) sediments accumulated as a result of subsidence along the fault system as well as intensive (avalanche) sedimentation. As on example it is described a special features of submarine fans of the Nile, Indus, Ganges, Brahmaputra, Niger, Mississippi and Orinoco rivers. It should be noted that not only hydrocarbonic accumulations are linked to these fans but mud volcanoes as well. The coincidence of mud volcano and submarine fans occurrence areas made it possible to come to a conclusion that the fans of paleorives (Volga, Uzboy, Kura, Atrek and oth.) are believed to have played an important role in the South Caspian Basin (SCB) Productive Series (Lower Pliocene) formation.

Ad.A. Aliyev, R.R. Rahmanov
THE GEOCHEMICAL PREREQUISITES FOR PETROLEUM CONTENT IN THE ADJINOHUR PROVINCE OF AZERBAIJAN

The article presents a predictive appraisal of the hydrocarbon potential of the Palaeogene-Miocene rocks and the extent to which such potential can be materialised in the Adjinour Province judging by the generalised and analysed geochemical research findings covering the adjacent petroleum-bearing regions. We have used the findings for geographical demarcation of the territory of the Adjinour Province by the petroleum content prospects. The central and SE parts of the province are recommended for oil-prospecting in the Oligocene-Miocene deposits and the NW part in the Upper (also possibly the Lower) Eocene rocks.

A.A. Feyzullayev

Stratigraphy

ICHNOGENERIC DIVERSITY IN THE JURASSIC DEPOSITS OF THE WESTERN CAUCASUS: A BRIEF SUMMARY

Trace fossils are important tools for practical solution of many geological problems, including those linked to stratigraphy, palaeogeographical reconstructions, etc. This emphasizes the urgency of ichnological research in major sedimentary basins. Five years-long studies in the Western Caucasus have resulted in finding of many Jurassic trace fossils. This paper summarizes the knowledge on their occurrence in the studied sections and the deposits of different age. New findings of Chondrites, ?Chondrites, Nereites, ?Thalassinoides, and unidentified trace fossil in the Toarcian, Aalenian, and Oxfordian–Lower Kimmeridgian deposits are also considered. The available information implies that the ichnogeneric diversity in the Jurassic deposits of the Western Caucasus is low, and the most diverse are the Lower Toarcian trace fossils. In the Early–Middle Jurassic, conditions were generally unfavourable for life development on the sea bottom, which resulted in the low ichnogeneric diversity. Further investigations should aim at the Upper Jurassic carbonates, where trace fossils are rare because of syn- and post-depositional alterations.

D.A. Ruban, J.K. Nielsen, A.V. Mikhailenko, O.V. Nazarenko, P.P. Zayats
THE DIATOM STUDY OF THE MAYKOP SEDIMENTS ON THE WESTERN FLANKOF THE SOUTH CASPIAN DEPRESSION (ALONG THE SHIKHZAGHIRLI SECTION OF THE SHAMAKHI-GOBUSTAN AREA) AND SOME PALAEOECOLOGICAL CONCLUSIONS

The first diatomic analysis of the Upper Maykop sediments (lower Miocene) was done for the the Shikhzaghirli outcrop in the Shamakhi-Gobustan Region as a an example. The sample study findings served as a platform for the diagram that demonstrates the distribution of the diatomic flora along the whole section. The diatoms were differentiated by genera and, less often, by species. About 70 photographs showing diatom algae shells were taken. New species with the unknown ecology were discovered. Consideration of the findings resulted in certain ecological conclusions about the salinity, depth and temperature of the examined basin. Those results were correlated with the Miocene Global Sea Level curve. The findings provide for a more detailed characterization of the palaeoecological conditions of the Miocene basins. The same is true of the diatomic algae registered in this section. Starting from the lower stages, the complex shows the evident tendency for the prevalence of the mesothermophil communities that develop in warm basins at 15—30° centigrade – Triceratium crovei Pont, Cymatosira savchenkoi Pr-Lavr, Biddulphiasp., Mastogloia sp., and Stephanopyxis punctata,). Towards the upper portion of the complex there is the alternation with the more hypothermophil communities that inhabit the cold but never freezing waters. Then again, some species can live and reproduce at the water temperatures above and below zero degrees centigrade alike. Based on those data, one could draw the following paleoenvironmental conclusions: the salinity of the basin declined in the middle of the Lower Miocene but marine conditions returned in that area upwards the section. The depth of the basin varied, too. There is a smooth transition from the deep-water diatomic algae to the shallower-water ones, mainly from the middle of the section to its upper stages.

N.T. Karimova

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  • Dear colleagues, The Editorial Board of the International Scientific Journal "Stratigraphy and sedimentology of oil-gas basins" is pleased to announce the chance to receive an honorarium in 2017 for the publication in our journal. Honorariums for reviewing of the submitted papers will also be granted. The decision on granting of honorariums as well as the amount of payment will be made by the Editorial Board of the Journal on the basis of originality and novelty of the submitted manuscript, and reviewers’ comments, and executed on a contract basis. The amount of honorarium for reviewers is 300 AZN, or the equivalent in US dollars. Please, send your manuscripts, as well as application and CV to review the papers to the following e-mail address info@isjss.com