Cretaceous – Paleogene boundary Fish Clay at Højerup (Stevns Klint, Denmark): trace metals in kerogen

2007 ◽  
Vol 178 (5) ◽  
pp. 411-421 ◽  
Author(s):  
Pavle I. Premović ◽  
Bratislav Ž. Todorović ◽  
Mirjana S. Pavlović
Keyword(s):  
Rare Earth ◽  
Trace Metals ◽  
Rare Earth Elements ◽  
Humic Substances ◽  
Rare Earths ◽  
Land Surface ◽  
Coastal Areas ◽  
Geochemical Analyses ◽  
The Impact ◽  
Fish Clay

Abstract Geochemical analyses of trace metals (Ir, Ni, Co, Cr, Zn, Au and Pb) and rare earth elements (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) in kerogen of the black marl at the Cretaceous–Paleogene boundary Fish Clay at Højerup have been undertaken. Substantial proportions of the trace metals and rare earths were probably contained in terrestrial humic substances (the kerogen precursor) arriving at the marine sedimentary site. This is in accord with a previous hypothesis that kerogen is mainly derived from humic acids of an oxic soil in of the adjacent coastal areas of eastern Denmark. It is also suggested that humics were transported mainly through fluvial transport into the site of the deposition of the Fish Clay. The local weathering/leaching of the impact-ejecta fallout on the land surface or local terrestrial rocks by impact-induced? acid surface waters perhaps played an important role in providing trace metals and rare earths for these humic substances. Apparently, chondritic Ir, Au, Ni, Co, Cr and chondritic and non-chondritic Zn originated from the impact fallout; Pb and rare earth elements were most likely sourced by the rocks exposed in the coastal areas of eastern Denmark.

scholarly journals Cretaceous-Paleogene boundary Fish Clay at Højerup (Stevns Klint, Denmark): Zn, Pb and REE in kerogen

2008 ◽  
Vol 73 (4) ◽  
pp. 453-461
Author(s):  
Pavle Premovic ◽  
Maja Stankovic ◽  
Mirjana Pavlovic ◽  
Milos Djordjevic
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Humic Substances ◽  
Rare Earths ◽  
Land Surface ◽  
Coastal Areas ◽  
Previous Hypothesis ◽  
Geochemical Analyses ◽  
The Impact ◽  
Fish Clay

Geochemical analyses of Zn, Pb and rare earth elements (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) in the kerogen of the black marl at the Cretaceous - Paleogene boundary Fish Clay at H?jerup were performed. Substantial proportions of the Zn, Pb and rare earths were probably contained in terrestrial humic substances (the kerogen precursor) arriving at the marine sedimentary site. This is in accord with a previous hypothesis that kerogen is mainly derived from humic acids of an oxic soil in of the adjacent coastal areas of eastern Denmark. It is also suggested that humics enriched in Zn, Pb and rare earth elements were transported mainly through fluvial transport into the deposition site of the Fish Clay. Local weathering/leaching of the impact-eject fallout on the land surface and local terrestrial rocks by impact-induced? acid surface waters perhaps played an important role in providing Zn, Pb and rare earths to these humic substances. Apparently, chondritic and non-chondritic Zn originated from the impact fallout; Pb and rare earth elements were most likely sourced by exposed rocks in the coastal areas of eastern Denmark.

scholarly journals Geochemistry of the cretaceous-tertiary boundary (Fish Clay) at Stevns Klint (Denmark): Ir, Ni and Zn in kerogen

2006 ◽  
Vol 71 (7) ◽  
pp. 793-806 ◽  
Author(s):  
Pavle Premovic ◽  
Milena Krsmanovic ◽  
Bratislav Todorovic ◽  
Mirjana Pavlovic ◽  
Nikola Nikolic ◽  
...  
Keyword(s):  
Trace Metals ◽  
Surface Waters ◽  
Shallow Marine ◽  
Asteroid Impact ◽  
Impact Ejecta ◽  
Previous Hypothesis ◽  
Geochemical Analyses ◽  
The Impact ◽  
Fish Clay ◽  
Marine Basin

Geochemical analyses of trace metals (Ir, Ni and Zn) in the kerogen of the black marl of the Cretaceous-Tertiary boundary succession (Fish Clay) at Stevns Klint (H?jerup Church) were undertaken. The data for this kerogen were in accordance with a previous hypothesis that this (insoluble) geoorganic polymer was derived from humic substances (mainly humic acids) of a nearshore soil. Substantial proportions of Ir, Ni and Zn within the kerogen structure were probably contained in these substances arriving at the sedimentary site. It is proposed that these humics were probably transported by acid surface waters (induced by the KT asteroid impact) into the shallow marine basin of Stevns Klint. It is also suggested that local leaching/weathering of the asteroidal impact fallout on the land near these waters played an important role in providing Ir, Ni and Zn for these substances. Apparently, Ir, Ni and Zn of the kerogen were created by the chondritic component of the impact ejecta fallout.

scholarly journals The isotopic constitution and atomic weights of hafnium, thorium, rhodium, titanium, zirconium, calcium, gallium, silver, carbon, nickel, cadmium, iron and indium

1935 ◽  
Vol 149 (867) ◽  
pp. 396-405 ◽  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earths ◽  
Mass Spectra ◽  
Mass Number ◽  
Atomic Weight ◽  
Complete Data ◽  
Pure Sample ◽  
Titanium Zirconium ◽  
Similar Element

An account of experiments has already been given by which the analyses of the rare earth elements were completed with the aid of a particularly favourable arrangement of the anode ray apparatus. This paper contains a description of analyses of other elements made with the same setting and also of some others subsequently made to obtain more accurate and complete data on elements whose constitution had already been provisionally settled. Results (72) Hafnium —Many previous attempts to obtain the mass spectra of this element had failed. For the most similar element, zirconium, the only successful results had been obtained from the fluoride. A pure sample of hafnium fluoride had been kindly provided by Professor G. v. Hevesy, one of the discoverers of the element, and this was incorporated into the anode mixture. The first trial was a failure; but after the work on zirconium described below a second attempt was made, this time with resolved, so that only rough estimates of abundance could be obtained. These were as follows:— Mass numbers . . . . . 176 177 178 179 180 % abundance . . . . . . 5 19 28 18 30 These given a mean mass number 178·5. Applying the same correction as with the rare earths we get atomic weight of hafnium = 178·4 ± 0·2 in fair agreement with the International value 178·6.

scholarly journals Hydrothermal Synthesis of Rare-Earth Modified Titania: Influence on Phase Composition, Optical Properties, and Photocatalytic Activity

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 713 ◽  
Author(s):  
Nejc Rozman ◽  
David Tobaldi ◽  
Uroš Cvelbar ◽  
Harinarayanan Puliyalil ◽  
João Labrincha ◽  
...  
Keyword(s):  
Optical Properties ◽  
Photocatalytic Activity ◽  
Rare Earth ◽  
Hydrothermal Synthesis ◽  
Rare Earth Elements ◽  
Rare Earths ◽  
Light Absorption ◽  
Pure Tio2 ◽  
X Ray ◽  
Hydroxyl Oxygen

In order to expand the use of titania indoor as well as to increase its overall performance, narrowing the band gap is one of the possibilities to achieve this. Modifying with rare earths (REs) has been relatively unexplored, especially the modification of rutile with rare earth cations. The aim of this study was to find the influence of the modification of TiO2 with rare earths on its structural, optical, morphological, and photocatalytic properties. Titania was synthesized using TiOSO4 as the source of titanium via hydrothermal synthesis procedure at low temperature (200 °C) and modified with selected rare earth elements, namely, Ce, La, and Gd. Structural properties of samples were determined by X-ray powder diffraction (XRD), and the phase ratio was calculated using the Rietveld method. Optical properties were analyzed by ultraviolet and visible light (UV-Vis) spectroscopy. Field emission scanning electron microscope (FE-SEM) was used to determine the morphological properties of samples and to estimate the size of primary crystals. X-ray photoelectron spectroscopy (XPS) was used to determine the chemical bonding properties of samples. Photocatalytic activity of the prepared photocatalysts as well as the titania available on the market (P25) was measured in three different setups, assessing volatile organic compound (VOC) degradation, NOx abatement, and water purification. It was found out that modification with rare earth elements slows down the transformation of anatase and brookite to rutile. Whereas the unmodified sample was composed of only rutile, La- and Gd-modified samples contained anatase and rutile, and Ce-modified samples consisted of anatase, brookite, and rutile. Modification with rare earth metals has turned out to be detrimental to photocatalytic activity. In all cases, pure TiO2 outperformed the modified samples. Cerium-modified TiO2 was the least active sample, despite having a light absorption tail up to 585 nm wavelength. La- and Gd-modified samples did not show a significant shift in light absorption when compared to the pure TiO2 sample. The reason for the lower activity of modified samples was attributed to a greater Ti3+/Ti4+ ratio and a large amount of hydroxyl oxygen found in pure TiO2. All the modified samples had a smaller Ti3+/Ti4+ ratio and less hydroxyl oxygen.

Dynamic structure of humic substances: Rare earth elements as a fingerprint

2010 ◽  
Vol 345 (2) ◽  
pp. 206-213 ◽  
Author(s):  
Mathieu Pédrot ◽  
Aline Dia ◽  
Mélanie Davranche
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Humic Substances ◽  
Dynamic Structure

Effects of Spraying Rare Earths on Contents of Rare Earth Elements and Effective Components in Tea

2003 ◽  
Vol 51 (23) ◽  
pp. 6731-6735 ◽  
Author(s):  
Dongfeng Wang ◽  
Changhong Wang ◽  
Sheng Ye ◽  
Hongtao Qi ◽  
Guiwen Zhao
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earths ◽  
Effective Components

Recovery of rare earths from sludges containing rare-earth elements

2006 ◽  
Vol 425 (1-2) ◽  
pp. 145-147 ◽  
Author(s):  
Tetsuji Saito ◽  
Hironori Sato ◽  
Tetsuichi Motegi
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earths

Green chemistry and sustainable development: approaches to chemical footprint analysis

2018 ◽  
Vol 90 (1) ◽  
pp. 143-155 ◽  
Author(s):  
Natalia P. Tarasova ◽  
Anna S. Makarova ◽  
Stanislav F. Vinokurov ◽  
Vladimir A. Kuznetsov ◽  
Pavel I. Shlyakhov
Keyword(s):  
Heavy Metals ◽  
Sustainable Development ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Regional Scale ◽  
Small Water ◽  
Federal Districts ◽  
Footprint Analysis ◽  
Development Goals ◽  
The Impact

AbstractThe methods to monitor the distribution of chemicals in the biosphere and to estimate the impact of chemicals on the biosphere are necessary to reach Sustainable Development Goals (SDGs). The paper presents the examples of methods to measure the concentration of heavy metals (including rare earth elements) and to rank them by the level of hazard to human health on different scales. The megacity scale presents the investigation of the impact of heavy metals on the small water bodies using water contamination index (WCI); and the investigation of snow contamination to estimate the level of short-term seasonal emission of heavy metals and rare earth elements. The 2nd part of the paper presents approaches to mitigate the exposure to mercury on the regional scale: the estimation of the current concentrations of mercury in atmospheric air, natural soils, and fresh waters using UNEP/SETAC USEtox model, as well as the estimations of the variations in the concentrations of mercury for the year 2045 in the federal districts of the Russian Federation, based on representative concentration pathways (RCPs) scenario and Minamata Convention scenario.

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