Relative palaeointensity and reservoir effect on Lake Esmeralda, Antarctica

2017 ◽  
Vol 29 (4) ◽  
pp. 356-368 ◽  
Author(s):  
M.A. Irurzun ◽  
M.A.E. Chaparro ◽  
A.M. Sinito ◽  
C.S.G. Gogorza ◽  
H. Nuñez ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Remanent Magnetization ◽  
Necessary Conditions ◽  
Organic Matter Content ◽  
Natural Remanent Magnetization ◽  
Matter Content ◽  
Global Models ◽  
Reservoir Effect ◽  
Order Of Magnitude ◽  
Rock Magnetics

AbstractFour cores from the bottom sediments of Lake Esmeralda, Vega Island, Antarctica (60°48'S, 57°37'W) were studied. Analysis of rock magnetics indicates that the main carriers of magnetization are ferrimagnetic minerals, predominantly pseudo-single-domain (titano-) magnetite with a small proportion of paramagnetic and antiferromagnetic minerals. The magnetic grain size of the samples is in the range of 1–5 μm and the variation of the interparametric ratios is less than one order of magnitude. Demagnetization of the natural remanent magnetization shows a stable remanent magnetization in most of the samples. Thus, the samples fulfil the necessary conditions to calculate relative palaeointensity (RPI) and the curves obtained correlated with global models enabling dating of the cores. The 250 cm of sediment recovered spans the last 10 200 yr bp. Finally, some samples with high organic matter content were dated by accelerator mass spectrometry 14C. By comparison with the age defined by the RPI curves, a reservoir effect of c. 5200 years is suggested for this region of Vega Island.

Heavy metal pollution and macrobenthic assemblages in soft sediments in two Sydney estuaries, Australia

1998 ◽  
Vol 49 (6) ◽  
pp. 533 ◽  
Author(s):  
Jonathan S. Stark
Keyword(s):  
Heavy Metals ◽  
Environmental Variables ◽  
Spatial Scales ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soft Sediments ◽  
Lead And Zinc ◽  
Macrobenthic Assemblages ◽  
Order Of Magnitude ◽  
Copper Lead

The influence of heavy metals (copper, lead and zinc) associated with urban runoff, on assemblages of macrofauna in intertidal soft sediments was studied in two estuaries in the Sydney region. The patterns of distribution and abundance of fauna and assemblages was found to vary significantly at several spatial scales: within bays in an estuary, between bays within an estuary and between bays from different estuaries. Significant differences were found in concentrations of heavy metals in sediments, but there was very little difference among bays in other environmental variables: grain-size characteristics and organic matter content of sediments. Bays polluted by heavy metals had significantly different assemblages to unpolluted bays, were generally less diverse and were characterized by an order-of-magnitude greater abundance of capitellids, spionids, nereids and bivalves. Unpolluted bays had greater abundance of crustaceans and several polychaete families, including paraonids and nephtyids and were generally more diverse. There was a significant correlation between patterns of assemblages and concentrations of heavy metals, but not with other environmental variables.

scholarly journals Nitrogen Transformation Processes Taking Place During the Intensive Phase of Composting

2002 ◽  
Vol 51 (1-2) ◽  
pp. 157-166
Author(s):  
László Alexa ◽  
Gy. Füleky
Keyword(s):  
Raw Materials ◽  
Organic Matter Content ◽  
Nitrogen Transformation ◽  
Matter Content ◽  
N Losses ◽  
Total N ◽  
Intensive Phase ◽  
Significant Difference ◽  
Order Of Magnitude ◽  
Transformation Processes

N transformation processes taking place during the intensive phase of composting were analyzed for characteristic compost raw materials in an adiabatic composting bioreactor by analyzing composts (in various stages of maturity), emitted gases and leakage water.  Temperature exhibited a similar curve for all raw materials, with a gradual decrease in compost temperature from day 11-13 on. Measurements of NH 3 indicated a significant difference between the various raw materials, sometimes amounting to an order of magnitude, in the quantitative data of NH 4 volatilization. Analysis of leakage water indicated that ammonification and nitrification processes could be traced satisfactorily, but the quantity of leakage water formed in the adiabatic drum composter and the associated N losses were negligible compared to the total N cycle of compost formation. Analysis of the composts showed that the organic matter content of the samples declined during composting as the result of biodegradation.

scholarly journals Pesticide Residues and Their Degradation Products as Influenced by Acidity and Organic Matter in Kura Irrigation Farmland Soils

2020 ◽  
pp. 63-74
Author(s):  
C. O. Olukanni ◽  
A. A. Audu ◽  
M. Waziri
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Organic Matter ◽  
Degradation Products ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Insecticide Residue ◽  
Farmland Soils

The aim of this research is to determine the insecticide and herbicide residues and their degradation products in Kura irrigation farmland soils. The analyses were carried out during the planting (before harvest) and after the harvesting periods. The insecticide residue analyses were undertaken using Gas chromatography-mass spectrometry (GC/MS) after extraction with a mixture of n-hexane and acetone (1:1) in a soxhlet extractor. The pH levels of the soil samples and the soil organic matter were also determined using standard analytical methods. The acidity and organic matter content of most of the soil samples increased slightly after harvest. The compounds detected as residues include 1-octadecene, 9-heptadecanone, (E)-3-eicosene, (Z)-5-nonadecene, heptadecane, 1-docosene, 1-nonadecene and 1-eicosene. Out of these residues, 1-octadecene and (E)-3-eicosene were detected during planting and after the harvesting periods, showing that they are the most persistent of the residues in the soil samples. The residues detected before harvest were totally different from the residues detected after harvest. This shows that the pesticides, after some time, degraded in the soil into completely different compounds and the total residues were detected in high percentages.

scholarly journals Local Environmental Conditions Promote High Turnover Diversity of Benthic Deep-Sea Fungi in the Ross Sea (Antarctica)

2022 ◽  
Vol 8 (1) ◽  
pp. 65
Author(s):  
Giulio Barone ◽  
Cinzia Corinaldesi ◽  
Eugenio Rastelli ◽  
Michael Tangherlini ◽  
Stefano Varrella ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Deep Sea ◽  
Ross Sea ◽  
Organic Matter Content ◽  
Matter Content ◽  
High Turnover ◽  
Potential Control ◽  
Fungal Abundance ◽  
Order Of Magnitude ◽  
Abundance And Diversity

Fungi are a ubiquitous component of marine systems, but their quantitative relevance, biodiversity and ecological role in benthic deep-sea ecosystems remain largely unexplored. In this study, we investigated fungal abundance, diversity and assemblage composition in two benthic deep-sea sites of the Ross Sea (Southern Ocean, Antarctica), characterized by different environmental conditions (i.e., temperature, salinity, trophic availability). Our results indicate that fungal abundance (estimated as the number of 18S rDNA copies g−1) varied by almost one order of magnitude between the two benthic sites, consistently with changes in sediment characteristics and trophic availability. The highest fungal richness (in terms of Amplicon Sequence Variants−ASVs) was encountered in the sediments characterized by the highest organic matter content, indicating potential control of trophic availability on fungal diversity. The composition of fungal assemblages was highly diverse between sites and within each site (similarity less than 10%), suggesting that differences in environmental and ecological characteristics occurring even at a small spatial scale can promote high turnover diversity. Overall, this study provides new insights on the factors influencing the abundance and diversity of benthic deep-sea fungi inhabiting the Ross Sea, and also paves the way for a better understanding of the potential responses of benthic deep-sea fungi inhabiting Antarctic ecosystems in light of current and future climate changes.

Paleomagnetism of the Pine Point Zn–Pb deposits

1993 ◽  
Vol 30 (5) ◽  
pp. 1028-1036 ◽  
Author(s):  
D. T. A. Symons ◽  
Hairu Pan ◽  
D. F. Sangster ◽  
E. C. Jowett
Keyword(s):  
Late Cretaceous ◽  
Remanent Magnetization ◽  
Natural Remanent Magnetization ◽  
Pole Position ◽  
Mississippi Valley ◽  
Western Canada Sedimentary Basin ◽  
Order Of Magnitude ◽  
Mvt Deposits ◽  
Pine Point ◽  
Host Rocks

The Pine Point Zn–Pb deposits are Mississippi Valley-type (MVT) deposits in Middle Devonian dolostone of the Pine Point Formation. The median natural remanent magnetization intensity from 509 specimens from 40 sites is 3.6 × 10−5 A/m. This intensity is an order of magnitude lower than most MVT deposits and is close to the sensitivity of the cryogenic magnetometer, so only the stronger specimens could be analysed paleomagnetically. Isothermal remanent magnetization testing of ores, host rocks, and monomineralic specimens shows that single domain to pseudosingle domain magnetite in sphalerite is the main remanence carrier; magnetite in galena is the next most significant carrier. In contrast, barren dolostone, limestone, and calcite crystals have a much weaker remanence. Using less stringent criteria than is conventional, 17 acceptable site mean remanence directions were determined. Remagnetization circle data indicate that many of the poorly defined sites retain a reversed but nonisolated characteristic remanence. Of the 17 means, 8 form a coherent cluster, the A component, with a mean direction of D = 339°, I = 78° (α95 = 7°, k = 62), giving a pole position of 79°N, 197°E (α95 = 13°). The A pole indicates with > 95%confidence that the MVT ores at Pine Point are Late Cretaceous to Eocene in age, with a mid-Late Cretaceous to Paleocene age (84–58 Ma) being most likely. The dolostone host rocks were remagnetized at the same time. It is concluded that the A component, carried mainly by sphalerite and galena, was formed during the Laramide orogeny (97–58 Ma) when tectonic uplift forced Zn–Pb-rich basinal brines out of the Western Canada sedimentary basin into the Presqu'ile barrier reef on the adjacent foreland shelf.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

Physico-Chemical Properties of Soil Collected from Chandrabhaga River in Kalmeshwar, Nagpur, Maharashtra

2020 ◽  
Vol 07 (02) ◽  
pp. 1-3
Author(s):  
Amita M Watkar ◽  
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
Agricultural Land ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Matter Content ◽  
Soil Attributes ◽  
Essential Components ◽  
Agricultural Land Management ◽  
Physical And Chemical

Soil, itself means Soul of Infinite Life. Soil is the naturally occurring unconsolidated or loose covering on the earth’s surface. Physical properties depend upon the amount, size, shape, arrangement, and mineral composition of soil particles. It also depends on the organic matter content and pore spaces. Chemical properties depend on the Inorganic and organic matter present in the soil. Soils are the essential components of the environment and foundation resources for nearly all types of land use, besides being the most important component of sustainable agriculture. Therefore, assessment of soil quality and its direction of change with time is an ideal and primary indicator of sustainable agricultural land management. Soil quality indicators refer to measurable soil attributes that influence the capacity of a soil to function, within the limits imposed by the ecosystem, to preserve biological productivity and environmental quality and promote plant, animal and human health. The present study is to assess these soil attributes such as physical and chemical properties season-wise.

UPAYA MEMPERTAHANKAN BUNGA DAN FRUIT SET TANAMAN CABAI (Capsicum annum L.) PADA LAHAN ULTISOL MELALUI PEMBERIAN LUMPUR LAUT DAN PUPUK KANDANG

2017 ◽  
Vol 13 (2) ◽  
pp. 74-77
Author(s):  
Imelda J Lawalatta ◽  
Francina Matulessy ◽  
Meitty L Hehanussa
Keyword(s):  
Fruit Set ◽  
Agricultural Land ◽  
Mineral Soil ◽  
Organic Matter Content ◽  
Nutrient Deficiency ◽  
Matter Content ◽  
Infrastructure Development ◽  
Capsicum Annum ◽  
Factor Effect ◽  
Marine Mud

Chili (Capsicum annum L.) often experience the highest price fluctuations in Indonesia. This is caused by the production that is often disrupted in certain months, especially in the months in the rainy season due to flowers and fruits that fall before the harvest. Since agricultural land has changed its function for infrastructure development, marginal land (Ultisol) is used. The ultisol problem is: high acidity, low organic matter content, nutrient deficiency important for plants (eg N, P, Ca, Mg and Mo) and high solubility of Al, Fe and Mn. The provision of organic materials such as manure and marine mud will overcome the problem of acid-rich mineral soil and play an important role in improving, increased and maintaining sustainable land productivity. Research results for chili flower significantly. the highest number of flowers found in the treatment of L0P3, L1P2, L1P3 and L2P3 that is > 60 flower/plant. There was a single factor effect for the amount of fruit, mostly found in L3 treatment (600 ton/ha marine mud) that is 22.36 fruit/plant. The treatment of manure significantly influenced the formation of the most fruit set in the treatment of P0 and P2 (without manure and manure 20 ton/ha) that is 77.60% and 70.,45%. Keywords: Ultisol, Marine mud, Manure, Flowers and Fruit sets   ABSTRAK Tanaman cabai besar (Capsicum annum L.) sering mengalami fluktuasi harga paling tinggi di Indonesia. Hal tersebut disebabkan oleh produksi yang sering terganggu pada bulan tertentu terutama pada bulan-bulan di musim penghujan dikarenakan bunga dan buah yang rontok sebelum panen. Karena lahan pertanian banyak beralih fungsinya untuk pembangunan infrastuktur, maka digunakan lahan marginal (Ultisol). Masalah ultisol ialah: kemasaman tinggi, kadar bahan organik yang rendah, kekurangan unsur hara penting bagi tanaman (contoh: N, P, Ca, Mg dan Mo) serta tingginya kelarutan Al, Fe dan Mn. Pemberian bahan organik seperti pupuk kandang dan Lumpur laut akan mengatasi persoalan tanah mineral masam berkadar Al tinggi dan berperan penting dalam memperbaiki, meningkatkan serta mempertahankan produktifitas lahan secara berkelanjutan Hasil Penelitian untuk jumlah bunga cabai berpengaruh signifikan. jumlah bunga terbanyak terdapat pada perlakuan L0P3, L1P2, L1P3 dan L2P3 yaitu > 60 bunga/tanaman. Terjadi pengaruh faktor tunggal untuk jumlah buah, terbanyak terdapat pada perlakuan L3 ( 600 ton/ha lumpur laut) yaitu 22,36 buah/tanaman. Perlakuan pupuk kandang berpengaruh signifikan Pembentukan fruit set terbanyak pada perlakuan P0 dan P2 (tanpa pupuk kandang dan pupuk kandang 20 ton/ha) yaitu 77,60% dan 70,45%. Kata kunci: Ultisol, Lumpur Laut, Pupuk Kandang, Bunga dan Fruit set

scholarly journals Soil nitrogen supply of peat grasslands estimated by degree days and soil organic matter content

2020 ◽  
Vol 117 (3) ◽  
pp. 351-365
Author(s):  
J. Pijlman ◽  
G. Holshof ◽  
W. van den Berg ◽  
G. H. Ros ◽  
J. W. Erisman ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Nitrogen ◽  
Organic Matter Content ◽  
Matter Content ◽  
Nitrogen Supply ◽  
Degree Days ◽  
Soil Organic Matter Content ◽  
Soil Nitrogen Supply
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