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 

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 Community structure and carbonate production of a temperate rhodolith bank from Arvoredo Island, southern Brazil

2004 ◽  
Vol 52 (3-4) ◽  
pp. 207-224 ◽  
Author(s):  
Douglas F. M. Gherardi
Keyword(s):  
Community Structure ◽  
Coralline Algae ◽  
Carbonate Content ◽  
Production Rates ◽  
Percentage Cover ◽  
Coralline Red Algae ◽  
Carbonate Production ◽  
Random Dispersal ◽  
Long Run ◽  
Main Bank

A small (100,000 m²) rhodolith bank located at the Arvoredo Marine Biological Reserve (Santa Catarina, Brazil) has been surveyed to determine the main bank components, the community structure, and carbonate production rates. Data from five photographic transects perpendicular to Arvoredo Island shore were complemented with sediment samples and shallow cores, all collected by scuba diving. The main bank component is the unattached, nongeniculate, coralline red algae Lithophyllum sp., used as substrate by the zoanthid Zoanthus sp. Percentage cover of living and dead coralline algae, zoanthids and sediment patches account for nearly 98% of the investigated area. Classification and ordination of samples showed that differences in the proportion of live and dead thalli of Lithophyllum sp. determine the relative abundances of zoanthids. Results also indicate that similarity of samples is high and community gradients are subtle. Significant differences in percentage cover along transects are concentrated in the central portion of the bank. Low carbonate content of sediments from deeper samples suggests low rates of recruitment and dispersal of coralline algae via fragmentation. However, carbonate production of Lithophyllum sp ranging from 55-136.3 g m-2 yr-1 agrees with production rates reported for other temperate settings. In the long run, rhodolith density at Arvoredo Is. is likely to be dependent upon random dispersal of spores and/or fragments from other source areas.

Multicentury-Scale Records of Carbonate (Hydrographic?) Variability on the Northern Iceland Margin over the Last 5000 Years

2001 ◽  
Vol 56 (2) ◽  
pp. 199-206 ◽  
Author(s):  
J.T. Andrews ◽  
Gudrun Helgadottir ◽  
Aslaug Geirsdottir ◽  
Anne E. Jennings
Keyword(s):  
Average Length ◽  
Vertical Mixing ◽  
Atlantic Water ◽  
Ice Age ◽  
Carbonate Content ◽  
High Productivity ◽  
Low Salinity ◽  
Marine Carbonate ◽  
Salinity Water ◽  
Marine Productivity

AbstractThe waters off northern Iceland are subjected to extreme hydrographic variability on annual to decadal timescales. In years when cold low-salinity water moves coastward and sea ice is prevalent (i.e., the late 1960s), marine productivity of surface waters is low because the water column is well stratified. In the opposite oceanographic mode, warm, salty Atlantic Water dominates the shelf and vertical mixing results in high productivity. We track these two contrasting modes by measuring the carbonate content of marine sediments, a proxy for productivity, in three cores from northern Iceland. The fjord record (B997-328PC) is anchored by eleven 14C AMS dates and has a resolution of one sample every 50 yr. Thirteen oscillations occurred over the last 4800 cal yr with an average length of 370 yr; these are superimposed on a long-term decrease in net carbonate accumulation. The Little Ice Age is marked by the largest decrease in carbonate content and in flux, with smaller minima at 2300 and 3000 cal yr B.P. Marked peaks in carbonate (optima) occurred at 2000 and 3800 cal yr B.P. The carbonate record from B997-328PC can be correlated with records on the inner shelf (B997-330PC) and midshelf (B997-327PC), indicating that significant regional changes in oceanography occurred at the southern margin of the Norwegian–Greenland Sea. The marine carbonate fluctuations closely track temperature reconstructions from the Greenland Summit site for the last 2000 cal yr and show similar, but slightly offset, oscillations between 2000 and ca. 4800 cal yr B.P.

scholarly journals Distribusi Foraminifera Bentonik Hidup dalam Hubungannya dengan Sedimen Dasar Laut di Selat Sumba, Nusa Tenggara Timur

2019 ◽  
Vol 20 (1) ◽  
pp. 17
Author(s):  
Purna Sulastya Putra ◽  
Septriono Hari Nugroho
Keyword(s):  
Benthic Foraminifera ◽  
Research Area ◽  
Carbonate Content ◽  
Sediment Characteristics ◽  
Coarse Silt ◽  
Sediment Grain Size ◽  
Sea Floor ◽  
Floor Surface ◽  
Sediment Types ◽  
Box Corer

Marine geological survey of Ekspedisi Widya Nusantara (EWIN) LIPI 2016 was conducted by using RV Baruna Jaya VIII in the Sumba Waters from 4 to 26 August 2016. One of the aim of this survey is to understand the sea floor surface sediment characteristics and its influence to the benthic foraminifera distribution. Seven sediment samples were collected from sea floor surface in Sumba Strait, at the different location and depth using grabbing method with box corer. The samples have analyzed for the foraminifera content, sediment grain size, organic matter and carbonate content, and chemical element by XRF method. The living benthic foraminifera distribution increase to the east of the research area, which have higher content of the organic material and Fe, Rb, Zr, Zn and Sr elements in the sediment. The benthic foraminifera distribution most abundance founded at the depth of 800-1000 m with sediment types are sandy coarse silt  to sandy very coarse silt.Keywords: Benthic foraminifera, distribution, sea floor sediment, Sumba Strait.

scholarly journals Physical and Chemical Indicators of Meadow Brown Soils

2021 ◽  
Vol 7 (7) ◽  
pp. 39-42
Author(s):  
M. Sadykhova
Keyword(s):  
Calcium Content ◽  
Middle Part ◽  
Carbonate Content ◽  
Silt Fraction ◽  
Chemical Indicators ◽  
Physical And Chemical

The research has established that the carbonate content of meadow brown soils in the upper and lower horizons varies between 1–9–11%. Where in, the calcium content reaches 85–90%. The content of physical day and silt fraction is 42–75% and 24–36% respectively and is concentrated mainly in the middle part of the profile.

Primary versus carbonate production in the Toarcian, a case study from the Llanbedr borehole (Mochras Farm, Wales)

2021 ◽  
pp. SP514-2021-19
Author(s):  
Alessandro Menini ◽  
Emanuela Mattioli ◽  
Stephen P. Hesselbo ◽  
Micha Ruhl ◽  
Guillaume Suan
Keyword(s):  
Sea Water ◽  
Initial Perturbation ◽  
Carbonate Production ◽  
Nutrient Delivery ◽  
Content Type ◽  
High Productivity ◽  
Oceanic Anoxic Event ◽  
The Core ◽  
C Isotopes ◽  
Supplementary Material

AbstractThe leading hypothesis for the Toarcian oceanic anoxic event (T-OAE; ∼183Ma) and the associated negative C-isotope excursion is the massive release of 12C favouring greenhouse and continental weathering. The nutrient delivery to shallow-basins supported productivity and, because of O2-consumption by organic-matter respiration, anoxia development. However, several works showed that calcareous nannoplankton experienced a decrease during the T-OAE. Nannofossil fluxes measured in the Llanbedr borehole (Mochras Farm; Wales, UK) were the highest prior to the negative C-isotope excursion, along with high amounts of taxa indicative of nutrient-rich environments (Biscutaceae). Such conditions attest to high productivity. Fluxes show the lowest values in the core of the event, along with a size decrease of Schizosphaerella and a peak in Calyculaceae. The recovery of nannofossil fluxes and Schizosphaerella size occurred concomitant with the return of C-isotopes to more positive values. Concomitantly, deep-dwellers (Crepidolithus crassus) dominated, indicating a recovery of the photic-zone productivity. These observations demonstrate that the cascade of environmental responses to the initial perturbation was more complex than previously considered. In spite of elevated nutrient delivery to epicontinental basins in the early Toarcian, carbonate and primary productions of nannoplankton were depressed in the core the T-OAE likely because of prolonged thermohaline sea-water stratification.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5541440

scholarly journals Successive processes at quarry waste dumps of various ages

2021 ◽  
Vol 63 (4) ◽  
pp. 289-299
Author(s):  
Aleksandr Smirnov ◽  
Gavakhirat Mutalibova ◽  
Vyacheslav Leontyev ◽  
William Lozano-Rivas
Keyword(s):  
Chemical Properties ◽  
Carbonate Content ◽  
Quantitative Composition ◽  
Ph Values ◽  
Basal Soil Respiration ◽  
Waste Dumps ◽  
The Russian Federation ◽  
Physical And Chemical ◽  
Succession Processes ◽  
Rate Of Succession

Abstract This work is dedicated to the study of the succession processes in quarries of different ages in the territory of the Russian Federation and neighbouring countries, namely, Kazakhstan and Ukraine. In selected soil samples from the areas studied, certain physical and chemical properties, the quantitative composition of microbial communities and the diversity of floral species from the quarries were studied. The pH values for the Kuzbass area were found to decrease to 4.8, and in the area of the younger quarries – Inguletsky and Sokolovsky – higher pH values were recorded. The basal soil respiration rate of the Kuzbass quarry was approximately 0.2 mg CO2/g/h. The CO2 carbonate content ranged from 0.05% to 0.6%. The microbial biomass in Kuzbass soil was from 0.87 to 5.10 μg C/g soil, while its quantity in other quarries was 6 times lower, which is associated with the relatively young age of these sites. The study of the diversity of floral species in the Kuznetsk coalfield identified 120 species of upper plants belonging to 34 families. Among them, cereals, legumes and mosses, lichens and algae were predominant. In the territory of Inguletsky and Sokolovsky quarries, the diversity of plant species was much poorer. In this regard, further research will focus on increasing the rate of succession and maintaining ecosystem stability by increasing the share of microorganisms. Also, the study of the possibility to accelerate the restoration of younger flora in the discharges of age careers at the expense of the mycorrhizal communities formation is of high relevance.

scholarly journals New data on lithology, organic geochemistry and accumulation conditions of the Bazhenov formation in Western Siberia

Georesursy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 129-142 ◽  
Author(s):  
Vika G. Eder ◽  
Elena A. Kostyreva ◽  
Anna Yu. Yurchenko ◽  
Natalia S. Balushkina ◽  
Inga S. Sotnich ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbonate Rocks ◽  
Western Siberia ◽  
Organic Geochemistry ◽  
Carbonate Content ◽  
Reservoir Properties ◽  
Bottom Part ◽  
Bazhenov Formation ◽  
Lithological Composition ◽  
Transformation Of Organic Matter

This paper presents data on lithological composition, distribution, reservoir properties, geochemistry of organic matter and genesis of carbonate rocks of the Bazhenov formation within the central part of Western Siberia (the region of the Khantei hemianteclise). The following types of carbonates are distinguished: a) primary biogenic – shell rock interlayers and residues of coccolith; b) dia- and catagenetic – in varying degrees, recrystallized rocks with coccoliths, nodules and aporadiolarites; c) catagenetic – cracks healed with calcite in limestone of the foot of the Bazhenov formation. It was determined that the crystallization of the carbonate material of nodules took place in various conditions: in the bottom part of the sediments and in the later stages of diagenesis. The source of calcite for nodules was calcareous nanoplankton or bivalve shells. The carbonate content of the cuts decreases in the following sequence: Yuzhno-Yagunsky → Povkhovsky → Novortyagunsky → Druzhny areas, which are associated both with facial features and various physicochemical conditions of diagenesis and catagenesis. Transformation of organic matter increases in the northeast direction from South Yagunsky to Povkhovsky area, which is confirmed by molecular parameters of catagenesis. The carbonate rocks of the bottom part of the Bazhenov formation in the South Yagunsky area are similar in structure to the main oil-bearing reservoirs of the Salym and Krasnoleninsky fields.

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