scholarly journals Geochemical Mass Balance and Elemental Transport during the Weathering of the Black Shale of Shuijingtuo Formation in Northeast Chongqing, China

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Sixiang Ling ◽  
Xiyong Wu ◽  
Siyuan Zhao ◽  
Xin Liao ◽  
Yong Ren ◽  
...  
Keyword(s):  
Mass Balance ◽  
Black Shale ◽  
Chemical Weathering ◽  
Principal Component ◽  
Major Elements ◽  
Mass Transportation ◽  
Weathering Profile ◽  
Ph Values ◽  
Mass Fluxes ◽  
Geochemical Mass Balance

An understanding of the processes that control the behavior of major elements with respect to weathering profile is essential to calculate the mobility, redistribution, and mass fluxes of elements. Hence, this study aims to determine the geochemical mass balance, strain, elemental correlation, and transport in weathering profiles. We constructed three weathering profiles for the black shale of Shujingtuo formation. As per the principal component analysis of major elements, density, and pH values, the first component represents the “elemental factor” and the second denotes the “external factor.” The “depletion” pattern is a mass transportation pattern, and Na, K, and Mg are depleted along transect relative to the composition of fresh rock. Fe is redeposited at the bottom half of the saprock zone, whereas Al is accumulated at the regolith zone. The Fe and Al patterns are attributed to the “depletion–addition” and “addition” patterns, respectively. The strain in profiles A and B demonstrates the expansion at the regolith zone and part of the saprock zone. In profile C, however, these zones collapsed at all depths. In chemical weathering, Na, K, Ca, Mg, and Si are depleted in the following order: valley (C) > near mountaintop (B) > ridge (A).

Rare earth elements geochemistry of groundwater from Shanmuganadhi, Tamilnadu, India: Chemical weathering implications using geochemical mass-balance calculations

Geochemistry ◽  
2020 ◽  
Vol 80 (4) ◽  
pp. 125668
Author(s):  
F. Vinnarasi ◽  
K. Srinivasamoorthy ◽  
K. Saravanan ◽  
S. Gopinath ◽  
R. Prakash ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Mass Balance ◽  
Chemical Weathering ◽  
Geochemical Mass Balance

scholarly journals Rock-Sourced Nitrogen in Semi-Arid, Shale-Derived California Soils

2021 ◽  
Vol 4 ◽  
Author(s):  
Nina L. Bingham ◽  
Eric W. Slessarev ◽  
Peter M. Homyak ◽  
Oliver A. Chadwick
Keyword(s):  
Mass Balance ◽  
Chemical Weathering ◽  
Field Studies ◽  
N Deposition ◽  
Mixing Model ◽  
N Fixation ◽  
Atmospheric N Deposition ◽  
Geochemical Mass Balance ◽  
Semi Arid ◽  
N Flux

Models suggest that rock-derived nitrogen (N) inputs are of global importance to ecosystem N budgets; however, field studies demonstrating the significance of rock N inputs are rare. We examined rock-derived N fluxes in soils derived from sedimentary rocks along a catena formed under a semi-arid climate. Our measurements demonstrate that there are distinct and traceable pools of N in the soil and bedrock and that the fraction of rock-derived N declines downslope along the catena. We used geochemical mass balance weathering flux measurements to estimate a rock-derived N flux of 0.145 to 0.896 kg ha–1 yr–1 at the ridgecrest. We also developed independent N flux estimates using a 15N-based isotope mixing model. While geochemical mass-balance-based estimates fell within the 95% confidence range derived from the isotope mixing model (−1.1 to 44.3 kg ha–1 yr–1), this range was large due to uncertainty in values for atmospheric 15N deposition. Along the catena, N isotopes suggest a diminishing effect of rock-derived N downslope. Overall, we found that despite relatively large N pools within the saprolite and bedrock, slow chemical weathering and landscape denudation limit the influence of rock-derived N, letting atmospheric N deposition (7.1 kg ha–1 yr–1) and N fixation (0.9–3.1 kg ha–1 yr–1) dominate N inputs to this grassland ecosystem.

scholarly journals The influence of water–rock interactions on household well water in an area of high prevalence chronic kidney disease of unknown aetiology (CKDu)

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Liza K. McDonough ◽  
Karina T. Meredith ◽  
Chandima Nikagolla ◽  
Richard B. Banati
Keyword(s):  
Water Quality ◽  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Water Chemistry ◽  
Mass Balance ◽  
Stable Carbon Isotopes ◽  
Environmental Isotopes ◽  
Well Water ◽  
High Prevalence ◽  
Geochemical Mass Balance

AbstractPoor drinking water quality in household wells is hypothesised as being a potential contributor to the high prevalence of chronic kidney disease of uncertain aetiology (CKDu) among the farming communities of the Medawachchiya area, Anuradhapura, Sri Lanka. One of the natural processes that can affect water quality is the dissolution of minerals contained within an aquifer by water–rock interactions (WRIs). Here we present a comprehensive assessment of WRIs and their influence on the water chemistry in household wells and spring waters in the Medawachchiya area by combining measurements of environmental isotopes, such as strontium, lithium and stable carbon isotopes and inorganic chemistry parameters, and modelling geochemical mass balance reactions between rainfall and groundwater samples. Our results reveal the presence of strontium, dissolved from both silicate and carbonate minerals, with high isotopic (87Sr/86Sr) ratios of up to 0.7316. Geochemical mass balance modelling and prior 87Sr/86Sr studies on the Wanni Complex bedrock suggest these strontium values may be the result of biotite dissolution. We also identify lithium and uranium contributed from the dissolution of silicates, albeit at concentrations too low to constitute a known health risk. In contrast, the levels of magnesium and calcium in our samples are high and demonstrate that, despite the felsic bedrock, well water chemistry in the Medawachchiya area is dominated by carbonate dissolution.

Recurrent events on a Quaternary fault recorded in the mineralogy and micromorphology of a weathering profile, Yangsan Fault System, Korea

2005 ◽  
Vol 64 (2) ◽  
pp. 221-233 ◽  
Author(s):  
Gi Young Jeong ◽  
Chang-Sik Cheong
Keyword(s):  
Korean Peninsula ◽  
Recurrent Events ◽  
Chemical Weathering ◽  
Late Quaternary ◽  
Fault System ◽  
Weathering Profile ◽  
Multi Stage ◽  
Yangsan Fault ◽  
Yangsan Fault System ◽  
Event Based

AbstractRecurrence characteristics of a Quaternary fault are generally investigated on the basis of field properties that are rapidly degraded by chemical weathering and erosion in warm humid climates. Here we show that in intense weathering environments, mineralogical and micromorphological investigations are valuable in paleoseismological reconstruction. A weathering profile developed in Late Quaternary marine terrace deposits along the southeastern coast of the Korean Peninsula was disturbed by tectonic movement that appears to be a simple one-time reverse faulting event based on field observations. A comparative analysis of the mineralogy, micromorphology, and chemistry of the weathering profile and fault gouge, however, reveals that both the microfissures in the deformed weathering profile and larger void spaces along the fault plane were filled with multi-stage accumulations of illuvial clay and silt minerals of detrital origin, suggesting a repetition of fissuring and subsequent sealing in the weathering profile as it underwent continuous mineralogical transformation and particle translocation. We reconstruct a sequence of multiple faulting events unrecognized in previous field surveys, which requires revision of the view that the Korean Peninsula was tectonically stable, during the Late Quaternary.

scholarly journals Complex principal component analysis of mass balance changes on the Qinghai–Tibetan Plateau

2017 ◽  
Vol 11 (3) ◽  
pp. 1487-1499 ◽  
Author(s):  
Jingang Zhan ◽  
Hongling Shi ◽  
Yong Wang ◽  
Yixin Yao
Keyword(s):  
Tibetan Plateau ◽  
Mass Balance ◽  
Correlation Coefficient ◽  
El Niño ◽  
El Nino ◽  
Principal Component ◽  
Mass Change ◽  
Eastern Himalayas ◽  
The Third ◽  
Northwestern India

Abstract. Climatic time series for Qinghai–Tibetan Plateau locations are rare. Although glacier shrinkage is well described, the relationship between mass balance and climatic variation is less clear. We studied the effect of climate changes on mass balance by analyzing the complex principal components of mass changes during 2003–2015 using Gravity Recovery and Climate Experiment satellite data. Mass change in the eastern Himalayas, Karakoram, Pamirs, and northwestern India was most sensitive to variation in the first principal component, which explained 54 % of the change. Correlation analysis showed that the first principal component is related to the Indian monsoon and the correlation coefficient is 0.83. Mass change on the eastern Qinghai plateau, eastern Himalayas–Qiangtang Plateau–Pamirs area and northwestern India was most sensitive to variation of the second major factor, which explained 16 % of the variation. The second major component is associated with El Niño; the correlation coefficient was 0.30 and this exceeded the 95 % confidence interval of 0.17. Mass change on the western and northwestern Qinghai–Tibetan Plateau was most sensitive to the variation of its third major component, responsible for 6 % of mass balance change. The third component may be associated with climate change from the westerlies and La Niña. The third component and El Niño have similar signals of 6.5 year periods and opposite phases. We conclude that El Niño now has the second largest effect on mass balance change of this region, which differs from the traditional view that the westerlies are the second largest factor.

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