scholarly journals Trace Elements and Palynomorphs in the Core Sediments of a Tropical Urban Pond

10.5772/55703 ◽  
2013 ◽  
Author(s):  
Sueli Yoshinaga ◽  
Melina Mara de Souza ◽  
Fresia Ricardi- Branco ◽  
Paulo Ricardo Brum Pereira ◽  
Fabio Cardinale ◽  
...  
Keyword(s):  
Trace Elements ◽  
Core Sediments ◽  
The Core ◽  
Urban Pond

scholarly journals The Geochemistry of 1 ky Old Euxinic Sediments of the Western Black Sea

Geosciences ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 455
Author(s):  
Octavian G. Duliu ◽  
Carmen I. Cristache ◽  
Ana-Voica Bojar ◽  
Gheorghe Oaie ◽  
Otilia-Ana Culicov ◽  
...  
Keyword(s):  
Trace Elements ◽  
Black Sea ◽  
Epithermal Neutron ◽  
Prompt Gamma Activation Analysis ◽  
Unconsolidated Sediments ◽  
Prompt Gamma ◽  
The Core ◽  
North American Shale Composite ◽  
Unconsolidated Sediment ◽  
Continental Origin

To get more data on the geochemistry of Black Sea euxinic sediments, a 50-cm core was collected at a depth of 600 m on a Western Black Sea Continental Platform slope. The core contained unconsolidated sediments rich in cocoolithic ooze and mud. Epithermal Neutron and Prompt Gamma Activation Analysis were used to determine the content of nine major (Na, Mg, Al, Si, K, Ca, Ti, Mn, and Fe as oxides) and 32 trace elements (Cl, Sc, V, Cr, Co, Ni, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Sn, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Yb, Hf, Ta, W, Th, and U) with a precision varying between 3 and 9%. The core contained unconsolidated sediment rich in coccolithic ooze and mud. Previous 210 Pb geochronology suggests an age of ∼1 ky of considered sediments. Major components distribution showed that, except for Cl and Ca, the contents of all other elements are similar to Upper Continental Crust (UCC) and North American Shale Composite (NASC). The distribution of the 32 trace elements showed similarities to the UCC, except for redox-sensitive metals Fe, Se, Mo, and U, of which the significantly higher content reflects the presence of euxinic conditions during deposition. A chondrite normalized plot of nine rare earth elements indicated a similarity to UCC and NASC, suggesting a continental origin of sedimentary material.

scholarly journals Distribution of heavy metals in the core sediments of a tropical wetland system

2009 ◽  
Vol 6 (2) ◽  
pp. 225-232 ◽  
Author(s):  
P. S. Harikumar ◽  
U. P. Nasir ◽  
M. P. Mujeebu Rahman
Keyword(s):  
Heavy Metals ◽  
Core Sediments ◽  
The Core ◽  
Wetland System

scholarly journals Molecular Characterization of Potential Nitrogen Fixation by Anaerobic Methane-Oxidizing Archaea in the Methane Seep Sediments at the Number 8 Kumano Knoll in the Kumano Basin, Offshore of Japan

2009 ◽  
Vol 75 (22) ◽  
pp. 7153-7162 ◽  
Author(s):  
Junichi Miyazaki ◽  
Ryosaku Higa ◽  
Tomohiro Toki ◽  
Juichiro Ashi ◽  
Urumu Tsunogai ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Clusters ◽  
Rrna Gene ◽  
Methane Seep ◽  
Core Sediments ◽  
The Core ◽  
Group 2

ABSTRACT The potential for microbial nitrogen fixation in the anoxic methane seep sediments in a mud volcano, the number 8 Kumano Knoll, was characterized by molecular phylogenetic analyses. A total of 111 of the nifH (a gene coding a nitrogen fixation enzyme, Fe protein) clones were obtained from different depths of the core sediments, and the phylogenetic analysis of the clones indicated the genetic diversity of nifH genes. The predominant group detected (methane seep group 2), representing 74% of clonal abundance, was phylogenetically related to the nifH sequences obtained from the Methanosarcina species but was most closely related to the nifH sequences potentially derived from the anoxic methanotrophic archaea (ANME-2 archaea). The recovery of the nif gene clusters including the nifH sequences of the methane seep group 2 and the subsequent reverse transcription-PCR detection of the nifD and nifH genes strongly suggested that the genetic components of the gene clusters would be operative for the in situ assimilation of molecular nitrogen (N2) by the host microorganisms. DNA-based quantitative PCR of the archaeal 16S rRNA gene, the group-specific mcrA (a gene encoding the methyl-coenzyme M reductase α subunit) gene, and the nifD and nifH genes demonstrated the similar distribution patterns of the archaeal 16S rRNA gene, the mcrA groups c-d and e, and the nifD and nifH genes through the core sediments. These results supported the idea that the anoxic methanotrophic archaea ANME-2c could be the microorganisms hosting the nif gene clusters and could play an important role in not only the in situ carbon (methane) cycle but also the nitrogen cycle in subseafloor sediments.

scholarly journals Three-stage modification of lithospheric mantle: Evidence from petrology, in-situ trace elements, and Sr isotopes of mantle xenoliths in the Cenozoic basalts, northeastern North China Craton

2021 ◽  
Author(s):  
Xinran Xu ◽  
Yanjie Tang ◽  
Jifeng Ying ◽  
Xinmiao Zhao ◽  
Yan Xiao
Keyword(s):  
Trace Elements ◽  
North China Craton ◽  
Lithospheric Mantle ◽  
North China ◽  
Major Elements ◽  
Mantle Xenoliths ◽  
Sr Isotopes ◽  
The Core ◽  
Concentration Changes ◽  
Hydrous Melt

We present mineralogical and geochemical compositions of mantle xenoliths from two Cenozoic basalt localities of the northeastern North China Craton. These xenoliths include lherzolite, harzburgite, and websterite. They are generally fertile in major elements and different from the typical cratonic lithosphere, which is consistent with previous hypotheses regarding craton destruction. The ratios of 87Sr/86Sr and (La/Yb)N of clinopyroxenes (Cpx) in one lherzolite are relatively low in the core but high in the rim. The center of the Cpx grain has a high U concentration. Changes in trace elements and Sr isotopes indicate that later stage high 87Sr/86Sr melt metasomatism superimposed on the early hydrous melt/fluid. The Cpxs in some xenoliths are low in Ti/Eu but high in Ca/Al and light rare earth elements, which indicates carbonate melt metasomatism. 87Sr/86Sr is increased in the core and decreased in the rim of most Cpx grains, which reflects the superposition of two-stage metasomatism. The early agent should be high in 87Sr/86Sr, and the recent agent should be low in 87Sr/86Sr. The Cpxs in olivine websterite are low in 87Sr/86Sr (0.70220−0.70320), which reflects the recent metasomatism of asthenosphere-derived melt. Collectively, these observations reflect a three-stage modification of the lithospheric mantle. First-stage hydrous melt/fluid could come from the dehydration of young subducted plates. Second-stage melt/fluid of high 87Sr/86Sr could derive from the partial melting of the subducted altered oceanic crust, and the recent melt/fluid of low 87Sr/86Sr should be from the asthenosphere.

scholarly journals Ratios of Organic Carbon to Nitrogen in the Core Sediments from Lake Kojima

1978 ◽  
Vol 39 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Motomu NIKAIDO
Keyword(s):  
Organic Carbon ◽  
Core Sediments ◽  
The Core

Core scanner technologies: take everything without breaking

2016 ◽  
Vol 56 (2) ◽  
pp. 595 ◽  
Author(s):  
Sandra Rodrigues ◽  
Joan Esterle
Keyword(s):  
Trace Elements ◽  
Data Acquisition ◽  
Spectral Reflectance ◽  
The Other ◽  
Mineral Matter ◽  
Radiographic Image ◽  
Coal Quality ◽  
X Ray ◽  
The Core ◽  
The Past

Modern core scanning technologies, such as hyperspectral CoreScan™ or X-ray fluorescence (XRF) Itrax, which allow data acquisition without the necessity of breaking the core for speciality analysis, are receiving increasing interest in coal and CSG industries in the past few years. Such technologies are able to characterise and evaluate mineral matter in greater detail than conventional sampling and analyses, producing mineral maps and mineral/elemental profiles throughout the core. Although mineralogical information is the main output from both techniques, CoreScan™ has the ability of producing organic profiles that allow the recognition of the different lithotypes in the coal based on the spectral reflectance as well as rank, which makes a potential technique for coal quality. On the other hand, XRF Itrax core scanner allies the chemical elemental profile, from major to trace elements, with an X-radiographic image, creating a dynamic duo between stony partings and coal, and within the coal between bright and dull lithotypes, through contrasting image properties. These emerging technologies will allow coal reservoirs to be analysed quickly and reliably without subsampling that could introduce bias from the user.

Glacial–interglacial records from sediments in Powell Basin, Antarctica

2018 ◽  
Vol 30 (6) ◽  
pp. 371-378
Author(s):  
Young-Suk Bak ◽  
Kyu-Cheul Yoo ◽  
Jae Il Lee ◽  
Ho Il Yoon
Keyword(s):  
Sea Ice ◽  
Sediment Cores ◽  
Ice Cover ◽  
Marine Isotope Stage ◽  
Core Sediments ◽  
The Core ◽  
Diatom Abundance ◽  
Glacial Periods

AbstractPalaeoenvironmental history is reconstructed from diatoms in two sediment cores, GC01-PW02 and GC03-PW02, recovered from Powell Basin, Antarctica. A total of 43 species belonging to 21 genera are identified from GC01-PW02. A total of 61 species belonging to 27 genera are identified from GC03-PW02. The number of diatom valves g-1 of dry sediment ranges from 0.1–48.3 × 106 valves g-1. Based on diatom abundance, six assemblage zones were identified from GC01-PW02, and five diatom zones were identified from GC03-PW02. Barren intervals represent glacial periods, while intervals with higher diatom abundances were deposited during interglacial periods and reduced sea ice cover. The occurrence of Rouxia leventerae only within the deepest zone of each of the cores indicates that the core sediments were deposited since marine isotope stage (MIS) 6.

Partitioning experiments in the laser-heated diamond anvil cell: volatile content in the Earth's core

2008 ◽  
Vol 366 (1883) ◽  
pp. 4295-4314 ◽  
Author(s):  
Andrew P Jephcoat ◽  
M. Ali Bouhifd ◽  
Don Porcelli
Keyword(s):  
Trace Elements ◽  
Diamond Anvil Cell ◽  
The Core ◽  
The Earth ◽  
Wide Range ◽  
Recent Developments ◽  
Mantle Reservoir ◽  
History Of ◽  
Diamond Anvil ◽  
Laser Heated

The present state of the Earth evolved from energetic events that were determined early in the history of the Solar System. A key process in reconciling this state and the observable mantle composition with models of the original formation relies on understanding the planetary processing that has taken place over the past 4.5 Ga. Planetary size plays a key role and ultimately determines the pressure and temperature conditions at which the materials of the early solar nebular segregated. We summarize recent developments with the laser-heated diamond anvil cell that have made possible extension of the conventional pressure limit for partitioning experiments as well as the study of volatile trace elements. In particular, we discuss liquid–liquid, metal–silicate (M–Sil) partitioning results for several elements in a synthetic chondritic mixture, spanning a wide range of atomic number—helium to iodine. We examine the role of the core as a possible host of both siderophile and trace elements and the implications that early segregation processes at deep magma ocean conditions have for current mantle signatures, both compositional and isotopic. The results provide some of the first experimental evidence that the core is the obvious replacement for the long-sought, deep mantle reservoir. If so, they also indicate the need to understand the detailed nature and scale of core–mantle exchange processes, from atomic to macroscopic, throughout the age of the Earth to the present day.

Variation characteristics of heavy metals and nutrients in the core sediments of Taihu Lake and their pollution history

2006 ◽  
Vol 49 (S1) ◽  
pp. 82-91 ◽  
Author(s):  
Enfeng Liu ◽  
Ji Shen ◽  
Xingqi Liu ◽  
Yuxin Zhu ◽  
Sumin Wang
Keyword(s):  
Heavy Metals ◽  
Taihu Lake ◽  
Pollution History ◽  
Core Sediments ◽  
The Core ◽  
Variation Characteristics
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