Late Tortonian – Piacenzian multi-proxy record of Asian southwest monsoon intensification: evidence from Coastal Makran, southeast Iran

2019 ◽  
Vol 56 (4) ◽  
pp. 347-362
Author(s):  
Mohammad Hadi Modarres ◽  
Hamid Alizadeh Ketek Lahijani ◽  
Nasser Keshavarz ◽  
Yann Lahaye ◽  
Kira Rehfeld ◽  
...  
Keyword(s):  
Organic Matter ◽  
Chemical Weathering ◽  
Gamma Ray ◽  
Southwest Monsoon ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Carbonate Content ◽  
High Precipitation ◽  
Physical And Chemical ◽  
Late Tortonian

This study presents a long-term, multi-proxy reconstruction of the Asian southwest monsoon during the Tortonian to Piacenzian, based on a 4.78 Ma record from Coastal Makran, northwestern Gulf of Oman, southeast Iran. The integration of humidity proxies (clay minerals, Th/K, volume magnetic susceptibility, and grain size analysis), marine redox sensitivity (Th/U), total organic matter, carbonate content, 87Sr/86Sr ratio, and spectral gamma-ray data conducted here provide valuable information that fill the existing gap in marine palaeoclimate records. The results show that a strong winter monsoon condition associated with relatively low precipitation and subsequently low physical and chemical weathering dominated the region during late Tortonian – late Messinian (7.65–5.83 Ma). However, a few episodes of intense physical and chemical weathering related to high precipitation are observed during this period (6.23–6.01 Ma), which is consistent with increased organic matter input from continental reservoirs to the oceans. In addition, the data indicate that from the latest Messinian (5.82–5.33 Ma) to Zanclean–Piacenzian (5.33–2.87 Ma), a strong summer monsoon accompanied by a relatively wetter condition and higher physical and chemical weathering resulted in a high detrital input into the basin. This higher weathering period is associated with the highest rate of Himalayan uplift, causing enhanced precipitation. Wavelet analysis of spectral gamma-ray data revealed notable periodicities at 750 Ka and 1.7 Ma, with significant periodicities centered around 5.75–6.03 Ma over the latest Messinian – Zanclean. Comparison with palaeoclimate records from other sites indicates a teleconnection with respect to precipitation, weathering, and productivity, especially during the Messinian–Zanclean transition.

scholarly journals Lake sedimentation as an agent of postglacial transformation of interfluves and fluvial landscapes of the Borisoglebsk Upland, Central European Russia

2019 ◽  
Vol 381 ◽  
pp. 13-20 ◽  
Author(s):  
Ekaterina V. Garankina ◽  
Vladimir R. Belyaev ◽  
Ilya G. Shorkunov ◽  
Yuliya V. Shishkina ◽  
Pavel V. Andreev ◽  
...  
Keyword(s):  
Organic Matter ◽  
Late Pleistocene ◽  
Organic Matter Content ◽  
Grain Size Analysis ◽  
Middle Pleistocene ◽  
Size Analysis ◽  
Systematic Sampling ◽  
Pleistocene Glaciation ◽  
Characteristic Type ◽  
Lake Sedimentation

Abstract. Borisoglebsk Upland is considered an example of a secondary upland plain in the marginal zone of the last Middle Pleistocene glaciation. Moraine hills and kames were reworked by glaciofluvial processes and incised by small fluvial forms later. Its postglacial surface drift cover is regularly defined as an undivided complex of mantle loams of dominantly subaerial origin with characteristic cryogenic features and remnants of paleosols. However, some previous studies suggest that lake sedimentation played an important role in the postglacial history of the Borisoglebsk Upland. This paper presents results of a detailed investigation of postglacial sedimentary cover of the eastern part of the Borisoglebsk Upland aimed to reconstruct the co-evolution of surface deposits, soil cover and geomorphic landscapes since degradation of the last Middle Pleistocene glaciation about 150 ka (MIS-6). The study is essentially based on a comprehensive lithological, pedological and geocryological description of postglacial deposits in cores (hand or machine-driven) and open sections, systematic sampling for grain size analysis and selective sampling for 14C absolute dating and monoliths structural examination. The results indicate that most of the surface drifts in this feature consists of stratified lacustrine deposits. Their Late Pleistocene age is stratigraphically confined by the underlying paleosols and incorporated peats of the Mikulino interglacial age (MIS-5) and several organic-rich layers within the lake sequence 14C dated to the Middle Valdai interstadial (MIS-3). Overlying mantle loams and colluvial deposits with cryogenic features and low organic matter content those facially substitute lacustrine sediments were attributed to the Late Valdai stadial (MIS-2). After the Mid-Holocene stabilization, relatively thin colluvial cover identified by the increased amount of organic matter also deposited. We conclude that lacustrine sedimentation is the primary Late Pleistocene agent that transformed the initial glacial topography and most characteristic type of lithodynamics of the eastern Borisoglebsk Upland.

scholarly journals A Conversion for Average Grain Size Based on Gamma Ray Well Log: Application in the Second Member of Xujiahe Formation of Anyue Area, Sichuan Basin

2021 ◽  
Vol 9 ◽  
Author(s):  
Liang Chen ◽  
Hancheng Ji ◽  
Nansheng Qiu ◽  
Liang Zhang
Keyword(s):  
Grain Size ◽  
Sichuan Basin ◽  
Gamma Ray ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sediment Grain Size ◽  
Xujiahe Formation ◽  
Average Grain Size ◽  
Logarithmic Relationship ◽  
Clastic Reservoirs

The grain sizes of clastic rock sediments serve as important depositional indicators that are significant in sedimentology and petroleum geology studies. Generally, gamma ray, spontaneous-potential and resistivity well logs are utilized to qualitatively characterize variations in sediment grain size and determine the lithology in clastic reservoirs. However, grain size analysis of modern sedimentary samples collected from active rivers and deltas indicates that the percentage of fine depositional component has a logarithmic relationship with the average grain size in delta and river systems. Using the linear relationship to process the lithology interpretation, siltstones or mudstone is likely to be interpreted as sandstone. Therefore, a logarithmic conversion formula was built up between the gamma ray logs and measured grain size for the second member of the Xujiahe Formation of Anyue Area in the Sichuan Basin. Using the formula, the average grain size and lithology of the exploration wells were determined for the interest intervals. Furthermore, the calculated grain size gives a better understanding of the controlling factors of hydrocarbon-bearing reservoirs in the study area.

scholarly journals Sedimentology and maturity of Ajali formation, Benin flank Anambra basin, Nigeria

2020 ◽  
Vol 22 (1) ◽  
pp. 123-136
Author(s):  
M. Ilevbare ◽  
O.I. Imasuen
Keyword(s):  
Thin Section ◽  
Chemical Weathering ◽  
Source Area ◽  
Silica Content ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Long Distance ◽  
Modal Composition ◽  
Textural Characteristics ◽  
Anambra Basin

The Ajali Sandstone, western flank, Anambra Basin, was studied for textural characteristics and maturity of the sediments. Grain size analysis (51 samples), thin section and heavy mineral analysis (15 samples each) and XRF fusion for metallic oxides (15 samples) were analyzed. The textural parameters show that the Ajali Sandstone are medium sand, poorly to moderately sorted, coarse to strongly coarse skewed with mesokurtic to leptokurtic grains. The thin section analysis reveals grains that are sub-angular to sub-rounded (this typifies grains that have travelled fairly long distance to the deposition site), of moderate to well sorted grains, with both monocrystalline and polycrystalline quarts-grains type, with a modal composition of Q F and L . A mineralogical maturity 90.4, 2.3 2.9 index (MMI) of 17.04, SiO /Al O ratio of 180.24, and a ZTR index of 67.96% were obtained. The values for the 2 2 3 MMI and SiO /Al O indicates mineralogical matured sediments, the ZTR index shows a chemically immature 2 2 3 to sub-mature sandstone, and the modal composition values are consistent with a texturally and compositionally matured sands. The mineralogical maturity is indicative of high degree of chemical weathering of source area. Furthermore, the high quartz and silica content make the sandstone  prospective for glass and glassware production. Key words: Anambra Basin, Maturity, Mineralogical maturity index, Textural characteristics, Glass

scholarly journals Determining the Physical and Chemical Properties of the Soils in Babylon and Al-Qadisiyyah for Manufacturing Clay Bricks

2021 ◽  
Vol 54 (2C) ◽  
pp. 100-116
Author(s):  
Muhsen O. Khalaf
Keyword(s):  
Chemical Properties ◽  
Strength Properties ◽  
Liquid Limit ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Suitable Material ◽  
Clay Bricks ◽  
Physical Chemical ◽  
Physical And Chemical ◽  
And Chemical Properties

The research included conducting a study of eight selected soil Stations in the Babylon and Al Qadisiyyah. The main target of the research is to study the physical, chemical, and compressive strength properties of these soils and their suitability for manufacturing ordinary clay bricks. It was found through the evaluation of the soils of the studied samples that their physical properties ranged as follows: the water content (13.52-31.88%) and the grain size analysis of the proportions of sand, silt, and clay as follows: (5-27%) (38-48%) (33-47%), respectively. The values of the Atterberg limits ranged as follows: the plastic limit ratios (13-21%), liquid limit (34-49%), plasticity index (13-28%), and the specific gravity ranged between (2.43-2.67). As for the chemical properties of the studied samples, they consist of a lot of silicates, carbonate calcium, and calcium oxide. Studied samples were characterized by water absorption 15-24%, and the efflorescence is varied from medium, low to nil. The soil samples are consequently considered as a suitable material for the manufacture of ordinary bricks in grades A and B based on Iraqi Standard specifications No. 25.

scholarly journals Evolution of sedimentation in the Vistula Lagoon of the Baltic Sea due to anthropogenic impact

2021 ◽  
Vol 12 (33) ◽  
pp. 131-148
Author(s):  
Vladimir A. Chechko
Keyword(s):  
Organic Matter ◽  
Bottom Sediments ◽  
River Runoff ◽  
Fine Sand ◽  
Test Sample ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Vistula Lagoon ◽  
The Baltic ◽  
The Vistula Lagoon

The work pursued basic objectives: to study the structure of the sedimentary strata, identify the sediment units corresponding to specific sedimentation stages of the late Holocene and evaluate the factors that influenced their formation in the Vistula Lagoon. For the achievement of the goals, well-known methods were used. The thickness of the silt deposits was measured by a hand drill. The grain size analysis of bottom sediments was determined by the mass content of particles of various sizes as a percentage of the test sample mass. The content of the total amount of organic matter in the bottom sediments and the mass loss during calcination was determined by the weight method, the determination of the mineral vivianite was carried out by standard methods accepted in geology. The Research results showed that in the lower part of the cores, organic-rich silts of olive shades are common, formed under the influence of river runoff. The sediment composition in the upper part of the cores is sharply different due to an anthropogenic factor – artificial river runoff regulation. Instead of silty sediments, the lagoon accumulated poorly consolidated, dark gray fine sand and siltstone sediments with small organic matter.

scholarly journals Vliv říčního dřeva na morfologické a sedimentologické parametry koryta na příkladu meandrujícího toku Odry

2019 ◽  
Vol 26 (1-2) ◽  
Author(s):  
Václav Gurkovský ◽  
Tomáš Galia
Keyword(s):  
Organic Matter ◽  
Coarse Grained ◽  
Grain Size Analysis ◽  
Natural Phenomenon ◽  
Size Analysis ◽  
Bed Sediments ◽  
Odra River ◽  
Instream Wood ◽  
Main Component ◽  
Pool Formation

Instream wood is a natural phenomenon that signifi cantly influences a function of the fluvial system in forested river basins and represents a natural part of this system. However, the majority of these relatios between instream wood and fluvial ecosystems were investigated in mountain streams or gravel-bed rivers and we are lacking field data from lowland meandering rivers. This study deals with the complex assessment of instream wood on morphology and sediment parameters including the content of organic material at spatially detailed scale of the selected bend of the Odra River. Within the site of interest (66.5 river km), 12 instream wood pieces were identified (lenght ≥ 1 m, diameter ≥ 10 cm). Their presence significantly affected river morphology, when they were the main initiator of pool formation. In total, 28 samples of surface bed sediments were collected from the thalweg, bars and lateral pool. In laboratory, samples were subjected to grain size analysis (sieving method) and loss on ignition (LOI) to obtain content of organic matter. The majority of bed sediment samples were coarse grained and these samples were located in the thalweg. The main component of these samples is gravel, often supplemented with admixtures of finer fractions. The analysis of data did not show the effect of instream wood on the deposition of organic matter in bed sediments. One of the reasons may be the presence of coarse grained material which generally contains a small amount of organic matter.

Paleoenvironment of Kuan Kreng peat swamp, Southern Thailand

2020 ◽  
Author(s):  
Kannika Wangritthikraikul ◽  
Smith Leknettip ◽  
Sakonvan Chawchai
Keyword(s):  
Forest Fires ◽  
Agricultural Land ◽  
Plant Macrofossils ◽  
Grain Size Analysis ◽  
Geochemical Data ◽  
Size Analysis ◽  
Carbonate Content ◽  
Fire Control ◽  
Peat Swamp ◽  
Southern Thailand

<p>Peatlands have played an important role in the global carbon cycle. Tropical peatlands are one of the largest reserves of terrestrial organic carbon. Present-day tropical peat swamp forests are, however, under the threat of anthropogenic disturbance or have already been widely degraded. In Southeast Asia, very large areas of peatland have been deforested, drained, converted to extensive and intensive agricultural land uses and exposed to regular wildfires. Khuan Kreng peat swamp is the second largest protected wetland in Thailand. Recent studies in Khuan Kreng peat swamp has focused on present day drought and forest fires, but there is still lack of paleoenvironmental data. In this study, sediment and peat sequences were collected from Forest Fire Control Station area in Khuan Kreng peat swamp, and geochemical data (loss on ignition, grain size analysis and carbonate content) were analyzed. The age of early Holocene were determined based on plant macrofossils using Radiocarbon Dating (<sup>14</sup>C). The preliminary results indicate that this area was Tidal flats. The study of sediment/peat sequences using geochemical data can improve our understanding how past environmental have affected Khuan Kreng peat swamp ecosystems.</p>

scholarly journals Sediment Characteristics of Mergui Basin, Andaman Sea based on Multi-proxy Analyses

2018 ◽  
Vol 32 (2) ◽  
Author(s):  
Rina Zuraida ◽  
Rainer Arief Troa ◽  
Marfasran Hendrizan ◽  
Luli Gustiantini ◽  
Eko Triarso
Keyword(s):  
Andaman Sea ◽  
Carbonate Content ◽  
Sediment Characteristics ◽  
Bottom Part ◽  
Oxic Condition ◽  
Carbonate Production ◽  
High Productivity ◽  
Ocean Ventilation ◽  
High Precipitation ◽  
Physical And Chemical

This paper presents the characteristics of sediment from core BS-36 (6°55.85’ S and 96°7.48’ E, 1147.1 m water depth) that was acquired in the Mergui Basin, Andaman Sea. The analyses involved megascopic description, core scanning by multi-sensor core logger, and carbonate content measurement. The purpose of this study is to determine the physical and chemical characteristics of sediment to infer the depositional environment. The results show that this core can be divided into 5 lithologic units that represent various environmental conditions. The sedimentation of the bottom part, Units V and IV were inferred to be deposited in suboxic to anoxic bottom condition combined with high productivity and low precipitation. Unit III was deposited during high precipitation and oxic condition due to ocean ventilation. In the upper part, Units II and I occurred during higher precipitation, higher carbonate production and suboxic to anoxic condition.Keywords: sediment characteristics, Mergui Basin, Andaman Sea, suboxic, anoxic, oxic, carbonate content Makalah ini menyajikan karakteristik sedimen contoh inti BS-36 (6°55,85’ LS dan 96°7,48’ BT, kedalaman 1147,1 m) yang diambil di Cekungan Mergui, Laut Andaman. Metode analisis meliputi pemerian megaskopis contoh inti, pemindaian contoh inti dengan menggunakan multi-sensor core logger, dan pengukuran kandungan karbonat. Tujuan penelitian adalah untuk mengetahui karakteristik fisik dan kimiawi sedimen untuk menafsirkan kondisi lingkungan pengendapan. Hasil penelitian menunjukkan bahwa contoh inti ini dapat dibagi menjadi 5 unit litologi yang mewakili kondisi lingkungan yang berbeda. Pada bagian bawah sedimen, Unit V dan IV ditafsirkan sebagai hasil endapan pada kondisi suboksik hingga anoksik pada saat produktivitas tinggi dan curah hujan rendah. Unit III diendapkan pada saat curah hujan tinggi dan kondisi oksik yang diperkirakan berkaitan dengan ventilasi samudera. Pada bagian atas, Unit II dan I diendapkan pada saat curah hujan cukup tinggi dengan produksi karbonat yang cukup besar dan kondisi dasar laut suboksik hingga anoksik. Kata kunci: karakteristik sedimen, Cekungan Mergui, Laut Andaman, suboksik, anoksik, oksik, kandungan karbonat 

scholarly journals GEOCHEMICAL AND MINERALOGICAL ANALYSIS OF SEDIMENTS FROM THE GULF OF ELEFSINA -STUDY OF THE ANTHROPOGENIC IMPACT

2018 ◽  
Vol 36 (1) ◽  
pp. 164 ◽  
Author(s):  
Γ. Κανελλοπούλου ◽  
Β. Περδικάτσης ◽  
Α. Φώσκολος
Keyword(s):  
Organic Matter ◽  
Sandy Loam ◽  
Grain Size Analysis ◽  
Geochemical Data ◽  
Size Analysis ◽  
Winter Period ◽  
Anoxic Conditions ◽  
Average Value ◽  
Black Layer ◽  
The Impact

Mineralogical and geochemical data on sediment of three sampling locations in the gulf of Elefsina, have been studied in order to access the impact of inorganic pollutants. The gulf is relatively shallow in depth and is connected to Saronicos bay with two shallow channels. This bottom physiography, worses the depositional environment since it receives pollutants of both the city and the industry without having wide towards the open sea. Grain size analysis of the surface sediments indicates that they are classified as sandy loam. However the main characteristic is the widespread appearance of a silty black layer, rich in organic matter. The thickness of the layer is 12 cm and is related to the oxic-anoxic conditions of the surface of the sediments. During the summer period the anoxic conditions promote an increase of the concentration of the organic matter in the bottom sediments which results in the widespread black coloring. The existence of a black layer in the first 10 to 12 cm of the cored sample is attributed to human activity. During the winter period, in which sampling took place, the increase in soluble O2 was responsible for the appearance of a thin brownish color top of the black layer. The thickness of this coloration is 0.5 mm. The pH of the sediments fluctuated between 7.4 and 8.5. The lower pH values are obtained in the top of the sediments while the higher ones in the bottom of the sediments. Data from the cation exchange capacity measurements have asserted the predominant of clays in the west side of the gulf. The distribution of total organic values yields higher values in the eastern side of the gulf (average value 4%) from the western side (average value 2.5%). Mineralogical composition of the sediments yielded the following minerals; quartz, calcite, dolomite, chlorite, illite, albite and alunite. A characteristic fluctuation of the soluble metals Pb, Ni, Zn, Cu, Μη, Cr, Hg and Cd, was observed, which characterize the environmental condition and pollution of the gulf of Elefsina

Grain-size analysis of surficial sediments from Golfo San Jorge, Argentina

2003 ◽  
Vol 83 (6) ◽  
pp. 1193-1197 ◽  
Author(s):  
M. Fernández ◽  
A. Roux ◽  
E. Fernández ◽  
J. Caló ◽  
A. Marcos ◽  
...  
Keyword(s):  
Third Sector ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Carbonate Content ◽  
Hydrodynamic Conditions ◽  
Surficial Sediments ◽  
Weight Percentage ◽  
Carbonate Concentration ◽  
Components Analysis ◽  
Granulometric Fraction

A detailed cartography of surficial sediments from Golfo San Jorge, Argentina is presented. Cluster analysis and principal components analysis (PCA) were applied considering the weight percentage of every granulometric fraction, carbonate concentration and the depth of 39 stations carried out during research cruises on board the RV ‘Captain Oca Balda’ (INIDEP).  The results defined three sectors: Sector 1, an area near the coast including Dos Bahías and Tres Puntas capes; Sector 2, a deep area far from the coast; and Sector 3, a coastal area and a south-east area between Tres Puntas cape and the inner area of the gulf. The first sector is characterized by the predominance of a coarse granulometric fraction and carbonate content. The second is defined by depth and presence of a fine granulometric fraction; while the third sector is considered a transitional sector, between the first and the second, dominated by fine sands. Sectors belong to environments of different kinds of energy or hydrodynamic conditions.

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