The application of a limestone weathering index at churchyards in central Oxford, UK

2013 ◽  
Vol 42 ◽  
pp. 157-164 ◽  
Author(s):  
M.J. Thornbush ◽  
S.E. Thornbush
2010 ◽  
Vol 161 (12) ◽  
pp. 517-523
Author(s):  
Reto Giulio Meuli ◽  
Peter Schwab

The national soil monitoring network (Nabo) consists of 105 sites across Switzerland, 28 of which are located in forests. After 25 years already seven forest sites (25%) were more or less damaged by storms. Two of them had to be abandoned for a decade to recover. Concerning precautionary soil protection the legal guide value is exceeded at three forest sites for cadmium and at one site also for chromium. These sites are all based on Jurassic limestone, and it is well known that residuals of limestone weathering can be rich in cadmium. Hence, the enrichment is supposed to be of geogenic origin. In the Canton Ticino the top soil at Novaggio site exceeds the guide value for lead. Here, anthropogenic origin is very likely. The analysis of the organic pollutants PAH and PCB in the third sampling campaign revealed moderate concentrations with a maximum lower than or equal to ⅔ of the corresponding guide value. Based on the results of the first four sampling campaigns it can be concluded that only small changes in the measured heavy metal concentrations in the top soils at the 28 Nabo sites were found. The most dynamic element is lead. Most of the concentrations are far below the guide values, the same holds for the organic pollutants PAH and PCB.


2019 ◽  
Vol 527 ◽  
pp. 118774 ◽  
Author(s):  
Xiaoli Dong ◽  
Matthew J. Cohen ◽  
Jonathan B. Martin ◽  
Daniel L. McLaughlin ◽  
A. Brad Murray ◽  
...  

2019 ◽  
Vol 19 (3) ◽  
pp. 77-94
Author(s):  
Lara Ferreira Neves ◽  
Alessandro Batezelli

Geochemistry of major and trace elements has been used as an important tool for the study of provenance and tectonic and climatic evolution of sedimentary basins. The São Carlos Formation is an Upper Cretaceous unit that lies on the eastern border of the Bauru Basin. Despite the paleontological and paleodepositional studies performed in this unit in the last years, little is known about the correspondence between tectonic and climatic conditions acting during the first stages of sedimentation. The hypothesis of this paper is to evaluate São Carlos and Araçatuba formations and understand the evolution of the eastern border of the basin. Thus, were conducted geochemical studies using X-ray fluorescence on sandstones, siltstones, and shales from the São Carlos Formation. According to the chemical weathering index, which presented values ranging from 57.12 to 71.58%, the oxides of major elements indicate that moderate weathering processes affected the source area, possibly associated with the arid-semiarid climate. Alkaline rocks, granites, gneisses, and metasediments were the main lithotypes of the source area. Ternary diagrams show that the tectonic environment was equivalent to the passive continental margin, coinciding with the Serra do Mar and, secondarily, Alto Paranaíba Uplift regions. Based on major and trace elements, their ratios, and published data on the basin, was elaborated a paleogeographic model of the eastern border of the Bauru Basin, concluding that the source area of the sediments was constituted by intermediate and felsic rocks, sometimes recycled by sedimentary processes.


2010 ◽  
Vol 34 (5) ◽  
pp. 1543-1551 ◽  
Author(s):  
Marihus Altoé Baldotto ◽  
Maria Cristina Canela ◽  
Luciano Pasqualoto Canellas ◽  
Leonardo Barros Dobbs ◽  
Ary Carlos Xavier Velloso

As an alternative to the relatively complex and expensive spectroscopic methods, the redox properties of humic acids, determined by potentiometric titrations, have been used to evaluate the stability of soil organic C. The objective of the present study was to establish a Redox Index of C Stability (RICS) and to correlate it with some properties of the humic acids extracted from different modal soils in Brazil (distinct weathering stages or management) to facilitate system comparison. The RICS was efficient for soil comparison and variations were comparable to those of the chemical and spectroscopic methods used for humic acid characterization. The values of soil pH, point of zero salt effect, sum of bases, exchangeable Ca content, weathering index, as well as the humic acid O/C ratio, quinone and semiquinone free radical contents, aromatic C and fluorescence intensity were closely related with the RICS. The RICS was higher in less weathered soils, with more active clays and higher fertility. The RICS values of soils under long-term sugarcane management were ranked in decreasing order: unburned, burned with vinasse, burned without vinasse.


2002 ◽  
Vol 205 (1) ◽  
pp. 217-239 ◽  
Author(s):  
Bernd Fitzner ◽  
Kurt Heinrichs ◽  
Dennis La Bouchardiere

1993 ◽  
Vol 30 (9) ◽  
pp. 1853-1860 ◽  
Author(s):  
Pierre Bédard

Geochemical data from mineral exploration surveys are used to assess postglacial and pre-last-glacial weathering on the high plateaus of central Gaspésie by comparing the distribution of 30 elements in the B and C horizons of a thin soil developed on glacial deposits. Under postglacial weathering, Fe2O3, TiO2, P2O5, Cr, Li, U, and V are immobile relative to Al2O3, whereas the other elements are mobile and have been depleted to various degrees from the B horizon. Loss-on-ignition value is the only parameter showing a significant enrichment from the C to the B horizons. The apparently high degree of geochemical weathering of the glacial deposits in respect to their source bedrock lithologies suggests that the deposits also contain previously weathered material. The spatial distribution of the geochemical weathering index values calculated for the C horizon shows no clear relation to the underlying bedrock formations. The high values are located on topographic highs, with maxima over deeply weathered bedrock occurrences, and the low values are located in glacial valleys. The spatial distribution of this weathering index in the glacial deposits shows the geochemical signature of a pre-last-glacial weathered mantle.


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