Sedimentation Environment Research Articles

Geochemical evidence of an oceanic provenance of cherts in accretionary complexes in the Sikhote Alin

The paper reports pioneering data on the distribution of REE in cherts in the Taukha terrane of the Late Jurassic–Early Cretaceous accretionary prism in the Sikhote Alin and a calculated value of the Ce anomaly. The values of the Ce anomaly, the ratios of certain major components, and the ratios of these components and REE are used to estimate the facies environments in which the cherty material was accumulated. This material is proved to have started accumulating within a zone adjacent to the spreading ridge and continued on the abyssal plane. The uppermost portion of the vertical section, which is made up of siliceous mudstone, was deposited in the marginal part of the paleoocean adjacent to the continental marginal sedimentation region. The sedimentation environments systematically alternating in a single geologic section suggest that the part of the seafloor on which the cherty sediments were accumulated moved from the spreading cen-ter to the margin of the paleocontinent, and this caused the drift of the stratigraphic section across various oceanic facies zones.

The heterogeneity of 3-D vertical hydraulic conductivity in a streambed

The heterogeneity of vertical hydraulic conductivity (Kv) is a key attribute of streambed for researchers investigating surface water–groundwater interaction. However, few three-dimensional (3-D) Kv models with high spatial resolutions have been achieved. In this study, in-situ permeameter tests were conducted to obtain Kv values. A 3-D model with 443 Kv values was built comprising 10 lines, 10 rows, and five layers. Statistical analysis was done to reveal the spatial characteristics of Kv. The influence of bedform on Kv values was restricted to the near-surface streambed. Kv increased with the increasing distance from the south river bank for the upmost layer, but it was not the case for other layers and the combined Kv values of five layers; the spatial pattern at transects across the channel did not differ significantly. The Kv values of each layer pertained to different populations; the sediments of individual layers were formed under different sedimentation environments. The coupling of erosion/deposition process and transport of fine materials primarily contributed to a reduction of the mean and median of Kv values and an increase of heterogeneity of Kv values with depth. Thus, a collection of Kv values obtained from different layers should be considered when characterizing the heterogeneity of streambed.

Microfossils and biofacies of the Vendian fossil biota in the southern Siberian Platform

Based on the study of the litho- and biofacies of the Vendian Nepa Horizon in the central area of the Siberian Platform inland, a paleoecological model for the Vendian microbiota has been developed. The sedimentation environments of the Katanga saddle have been reconstructed, and three sedimentary systems have been recognized: (1) lower continental, formed by the deposits of proluvial fans and riverbeds of temporary streams; (2) middle transgressive, made up of littoral sand facies in the lower part and of fine-clastic shelf strata in the upper part; and (3) upper, of sea highstand, composed of alternating sand bank facies and fine-clastic lagoon deposits. Four biofacies have been recognized in the fine-terrigenous deposits of the Nepa Horizon: (1) Appendisphaera, represented by a Doushantuo-Pertatataka acanthomorph assemblage; (2) Transitional, with a great diversity of plankton and benthic (including complex) taxa; (3) Vanavarataenia, dominated by Vanavarataenia complex benthic algae; and (4) Oscillatoriopsis, represented by taxonomically poor biotas with morphologically simple (mainly prokaryotic) remains. These biofacies are confined to the following sedimentation environments: Appendisphaera is widespread in the distal open-sea areas; the Transitional biofacies is localized in the distal environments of the semi-isolated inner basin; Vanavarataenia occurs in the proximal areas; and Oscillatoriopsis is typical of the shallow-water environments, both extended (corresponding to the highstand period) and local.

Влияние позднеголоценовых колебаний климата на обстановки седиментации в акватории Антарктического полуострова

Влияние позднеголоценовых колебаний климата на обстановки седиментации в акватории Антарктического полуострова

Some encrusted hardgrounds from the Ordovician of Estonia (Baltica)

The Ordovician hardground faunas of Estonia are not diverse. They include echinoderm holdfasts (i.e., eocrinoids and crinoids), edrioasteroids, bryozoans (both hemispherical trepostomes and stalked ptilodictyids) and cornulitids. The earliest hardground faunas appeared in the Dapingian (i.e., bryozoans and echinoderms). The Estonian hardground faunas are less diverse than the North American ones. North American hardgrounds seem to be more heavily encrusted than the Estonian ones. These differences may be due to the paleogeographic distances, different climates and different sedimentation environments of the paleocontinents.

Facies and sedimentation model of iron-ore sequence in Bakchar deposit

This article describes the investigation in the behavior and structure features of the iron-ore sequence in Bakchar ore deposit. Five facies characterizing the typical sedimentation environments were identified based on the analysis of typomorphic attributes of ore-bearing and barren deposits. The facies where oolitic ores are localized have been determined. A conceptual sedimentation model of the Bakchar ore mineralization has been proposed. Two facies- littoral argillo-arenaceous ferriferous sediments and mobile shallow alluvium oolitics were proposed as prospecting indicators of oolite hydrogoethite ore deposits.

Carbonate formation of the Lower Carboniferous in Central Part of Volga-Ural Basin

Carbonate rocks of the Lower Carboniferous (Tournaisian stage) of the central Volga-Ural basin (the eastern portion of the East European platform) are of practical scientific interest to geologists, particularly because they contain large reserves of oil. Although such layers have been studied, various questions pertaining to development of sedimentation schemes for the rocks have not been answered. We have attempted to resolve these by studying a wealth of drill core materials. The study involved structural and genetic analysis of rocks and facies reconstructions. The rocks are mainly represented by different types of shallowwater limestone. The thickness of coeval layers and their lithological structures changes from well to well within an oilfield, primarily due to the different environments of sedimentation during the Tournaisian stage. Therefore, to identify the characteristics of carbonate sedimentation, we have studied the sequences of different types of limestone and analysed their thickness. As a result, we have developed principle schemes of sedimentation for shallow-water carbonate rocks of the Tournaisian stage. This may help in the predictive search for reservoir rocks in the region of study.

Zechstein in Lithuanian–Latvian Border Region

The Southern Permian Basin in Central Europe extended from the area of the present-day North Sea towards the territory of Lithuania and Latvia. The Zechstein rocks from the eastern margin of the basin outcrop in three places: the Sudetes and the Holy Cross Mts. (Poland), and at the Lithuanian / Latvian border. Abundant fauna containing foraminifers, ostracods, molluscs, brachiopods, bryozoans, echinoderms, and vertebrates was documented from this area; some new taxa have been found in the present study. The palaeoecological analysis of the fauna assemblages was carried out in order to characterise the sedimentation environment.

Analysis of Resistivity Characteristics of Sediments in Northwestern of South Yellow Sea

The resistivity characteristics of sediments are important to analyze marine sedimental environment and material source. A kind of penetration multiple parameter micro-probe which is designed to measure the resistivity of sediment sample in the northwestern of South Yellow Sea. In this paper, shelf sediment resistivity property off northwest of the South Yellow Sea is studied by analyzing the influence factors and relations, for providing valuable information to the marine sedimental environment around this area.

メスバウアースペクトロメトリーの地球化学・環境化学への応用―堆積物中の鉄の化学状態を指標とした堆積環境の推定―

鉄は地殻の主な構成元素の一つであって，岩石，土壌，堆積物などのような種々の地球環境試料中に％オーダーで含まれていることが多い。これらの鉄は周囲の環境によって様々な化学状態を示すため，それを指標として環境中における化学変化をモニターしたり，試料の置かれてきた環境を推定したりすることができる。ここでは，東京湾の貧酸素水塊環境下にある堆積物，南極海の海洋堆積物及び遠洋深海層状チャート中に含まれる鉄の化学状態を57Feメスバウアー分光法により分析し，それぞれの堆積環境の推定を試みた例を紹介する。

패류 양식장 퇴적물의 광합성색소 분포 특성

This study researched and compared the sedimentation environment and photosynthetic pigments at Gomso (GS) -bay, Yoja (YJ) -bay and KangJin (KJ) -bay in May, 2012. It was shown that KJ-bay consist of C (clay) and M (mud), and GS-bay consists of Zs (silty sand) and Sz (sandy silt). Averagely, IL of YJ-bay was 4.98%, KJ-bay 6.10%, and GS-bay 1.45%. As for COD concentration, there were no places that exceeded Japanese sediment contamination standard 20 mg/g-dry. As for AVS concentration, in case of KJ-bay, two places exceeded Japanese sediment contamination standard 0.2 mg/g-dry. If we look into the average C/N ratio of bays, YJ-bay showed 8.50, KJ-bay 6.60, and GS-bay 5.52, thus all of them showed the characteristic of oceanic origin. As for the plankton make-up classified by photosynthetic pigments, diatom was dominant, and both ratios of pigment and C/chlorophyll. a showed the relatively lower distribution at GS-bay than at KJ-bay and YJ-bay. It is judged that this is related to the characteristic of flow-in, and it implies that predation process and decomposition by organic matters actively occurs at YJ-bay and KJ-bay.

Productive horizon differentiation by litho-facial zones based on the SP-log electrometric models for justification of the enhanced oil recovery technologies

Using the litho-facial analysis, based on the SP-log (self-polarization method) electrometric models and modern geoinformational systems, the paleogeographic environment of the productive horizon plot with residual mobile oil deposits have been reconstructed, made sector sections in different directions through permeability property changing. Current researches have allowed to estimate the impact of RPM system, determine the causes of its ineffectiveness and give the recommendations of enhanced oil recovery. The region with residual mobile oil deposits have been divided to 8 litho-facial zones by the same SP-log shapes, then the regional sedimentation environment have been defined and the wells ranging was made by this environment and technological parameters like average daily productive horizon oil production at well start, what allowed to define the litho-facial zones borders more precisely not only by the SP-logs, but by their filtration properties. The conceptual paleogeographic model of the work area have been built, based on the made litho-facial analysis, the zones borders have been refined and their confinement to the different sedimentation environments, using wells ranging by initial average daily productive horizon oil production at well start. By made conceptual paleogeographic model of the work area and sector sections through permeability property changing the effectiveness analysis of acting RPM system was made. Identified the perspective wells and given the recommendations of enhanced oil recovery.

Recovery of productive horizon litho-facial environment forming with using of modern geoinformation technologies

Basing on the core material and geophysical research methods in wells data, was made the comparing analysis of electrometric facies models. Developed the express method of databases preparation with using of MS Excel software and MS-DOS software environment. Chosen the methodic of adequate sediments affiliation to varying litho-facial sedimentation environment definition. Made the plot of Alymskaya formation productive horizon paleogeographic map. Made the assessment of made work productive importance. Developed data bases express preparation method allow to significantly reduce the time spending on the data preparation and operatively supplement and reconstruct the litho-facial environment. On example of 51 wells was made the litho-facial analysis with using of electrometric models and core data, as well as with using of electrometric models only, what allowed to fully and precisely define the confinement of those or other sediments to certain litho-facial sedimentation environments. Experimental plot of productive horizon was defined by litho-facial zones by common similarity of electrometric models SP-logs in wells. Using of this methodic can make possible to make litho-facial analysis much adequate and qualitatively, with absence and inaccessibility of input information part and basing only on the few number of core and electrometric facial model data. The further using of methodic will allow not only to create the full and detailed conceptual paleogeographic deposit model, but to make the work of bad extraction causes definition and enhanced oil recovery.

PROSPECTIVE SEISMIC LITOFACIES OF CARBON DEPOSITS IN THE NORTHERN EDGE OF DNIEPER AND DONETS SEDIMENTARY BASINS’ JUNCTION ZONE WHILE EXPLORING UNCONVENTIONAL HYDROCARBON DEPOSITS

Authors substantiate that this territory in carbon time developed mainly in the alluvial plain situation. Also we analyzed prospective for oil and gas sedimentation environment. The most prospective areas evaluated to be distributed in branched rivers. 

Transformation of the group composition of organic matter from the channel deposits of a small river affected by anthropogenic activity

The group composition of organic matter (OM) was studied in the channel sediments of the Pakhra River under natural condition and in the zone affected by the town of Podol’sk, Moscow oblast. It was found that the natural alluvium is poor in OM (Corg = 0.65%), the composition of which is dominated by humus acids (81.8% of Corg) at minor fractions of residual OM (16.7%) and lipids (1.5%). Anthropogenic muds formed in the river channel in the zone affected by urban pollution are conspicuous in high OM content (Corg = 1.26–2.60%), the composition of which is enriched in lipids (up to 10–20%) and residual OM (up to 27.3–48.6%), whereas the fraction of humus acids decreases to 29.6–57.1%. The muds are most significantly enriched in lipids (their specific concentration increases by factors of 6–59 compared with the natural alluvium) and residual OM (by factors of 3–11). The amount and character of the group composition of OM from anthropogenic muds are controlled by the specific features of the sources of sedimentary material in the river and the character of the environment of alluvium sedimentation in the zone affected by an industrial town.

The Aghajari (Upper Fars) Formation in the Folded Zagros Zone, Iran: Insights to Identify Facies, Architectural Elements, Fluvial Systems, Petrography and Provenance

Abstract:The Aghajari Formation, called also the Upper Fars, develops throughout the Folded Zagros Zone and its thickness in the type section in southwest of Iran is 2966 meters. To analyze the sedimentary basin of this Formation, lithofacies, architectural elements and petrofacies of the related deposits in a section in southeast of Sarvestan in Fars Province of Iran with a thickness of 2221.45 meters were examined. Microscopically studying thin sections, the petrography and the occurrence of the deposits were determined. In this section, 16 lithofacies, 10 architectural elements and 2 sandstone petrofacies were identified. The lithofacies were divided into two major and minor groups, in which the major lithofacies consist of coarse‐grained (Gh, Gp, Gt and Gm), medium‐grained (Sh, Sp, St, Sl, Sm, Sr and Ss and fine‐grained ones (Fm, Fl and Fsm), and the minor lithofacies were evaporative and mixed silisiclastic‐carbonate. The identified architectural elements are CH, SB, GB, LA, DA, CR, CS, LV, LS, CH (FF) and FF. By combining evidences from facies analysis and architectural elements together, the Aghajari Formation was divided into three parts in which the related sedimentation environments, from top to bottom, are gravel, gravel‐sand and fine‐grained meandering river respectively. There have also been playas and shoreface in the lower part. Based on petrography, the sandstones of this formation were classified into two groups: litharenite and sublitharenite. The origin of these deposits (sandstones) was appointed to the recycled orogeny and the source of quartz is low and medium to high metamorphic rank. Using the field evidences, the paleocurrent direction was achieved indicating the direction of the paleocurrent from northwest to southeast at the time of deposition. It is hoped that these data can be used in the interpretation of the basin and reconstruction of the paleogeography in the local and regional scales.

A Correlation Analysis between a Swim Zone Width and Beach Survey Data in Sokcho Beach

ABSTRACT Lee, H.S., Kim, I.H., Song, D.S. and Lee, J.L., 2013. A Correlation Analysis between a Swim Zone Width and Beach Survey Data in Sokcho Beach Sokcho Beach is the 3 km-long sand beach located on the east coast of South Korea. Beach profile surveying and grain size sampling in four control sections were carried out in order to investigate the relationships of swim zone width between the median size, beach face slope, and scale factor. It is found that temporal variation in the southern part of beach is the most severe due to the presence of Oeongchi headland. As the result of the correlation analysis, the correlation factor of the swim zone width to the scale factor was estimated rather high (0.596). The present study shows the grains size is not an adequate indicator in estimating the swim zone width. Regular monitoring of the region is required to determine the seasonal changes, the sediment transport, and the changes in the sedimentation environment, and to acquire an accurate understanding of th...

Reef corals in a high sedimentation environment on the ‘Mainland’ coast of Brunei, Northwest Borneo

Reef corals in a high sedimentation environment on the ‘Mainland’ coast of Brunei, Northwest Borneo

Comment on “Sandstone caves on Venezuelan tepuis: Return to pseudokarst?” by R. Aubrecht, T. Lánczos, M. Gregor, J. Schlögl, B. Smída, P. Liscák, Ch. Brewer-Carías, L. Vlcek, Geomorphology 132 (2011), 351–365

In the recent work of Aubrecht et al. (2011) the presence of “unlithified or poorly-lithified beds” of sands in the quartz-sandstone stratigraphic succession is proposed as a key factor for speleogenesis in the Venezuelan tepuis. In this comment we observe that in the cited work the geologic history of the region, in terms of sedimentation environment, diagenesis and low grade burial metamorphism, has not been considered. Furthermore, the peculiar “pillar flow” columns that Aubrecht et al. describe as a proof of the unlithification are lacking in many other different cave systems in the same area.Four critical points are discussed: the burial metamorphism of the Mataui Formation, the significance of the Schmidt Hammer measurements, the cave morphologies and the role of SiO2 dissolution. Finally we suggest that weathering, in its wider significance, is probably the triggering process in speleogenesis, and there is no need to invoke a differential diagenesis of the sandstone beds.

Sedimentation models for the Jurassic stratum in the Potanai oilfield (Western Siberia)

The sedimentation models for the upper part of the Tyumen Formation (the J2–3 productive layers) and the Abalak Formation (J12 and J11) were constructed on the basis of data from lithological studies of Jurassic stratum cores (the Potanai oilfield in the northeast Shaim megaswell). The models show that the sedimentation environment sequentially changed from the continental to the deltaic, lagoonal, and shelf types through the Middle and Late Jurassic.