Multiple Scales in Rock Alteration and Ore Deposit Genesis

2021 ◽  
pp. 355-363
Author(s):  
H-B Muhlhaus ◽  
BE Hobbs ◽  
R Freij-Ayoub ◽  
JL Walshe ◽  
A Ord ◽  
...  
Keyword(s):  
Multiple Scales ◽  
Ore Deposit ◽  
Rock Alteration

Modelling Study on Uranium Migration in Rocks Under Weathering Condition

1994 ◽  
Vol 353 ◽  
Author(s):  
Toshihiko Ohnuki ◽  
Takashi Murakami ◽  
Hiroshi Isobe ◽  
Tsutomu Sato ◽  
Nobuyuki Yanase
Keyword(s):  
Uranium Concentration ◽  
The Other ◽  
Two Dimensional ◽  
Ore Deposit ◽  
Uranium Migration ◽  
Irreversible Sorption ◽  
Rock Alteration ◽  
Weathering Process ◽  
Good Agreement ◽  
Modelling Study

AbstractA modelling study has been completed to understand the effect of rock alteration on uranium migration at the Koongarra ore deposit, Australia. The model considers the weathering process, the mechanism and rate of chlorite alteration, a major mineral of the host rock, and assumes the presence of reversible sorption sites of chlorite and the presence of reversible and irreversible sorption sites of the weathering products. One- and two-dimensional, calculated uranium concentrations were compared with those observed. Good agreement between the calculated and observed uranium concentration profiles was obtained only when an appropriate fraction of uranium is fixed to the irreversible sorption sites of Fe-minerals produced during weathering of chlorite. On the other hand, the conventional Kd model failed to estimate an adequate uranium concentration profile. The results suggest that the fixation of uranium to Fe-minerals has dominated the migration of uranium in the vicinity of the Koongarra ore deposit.

Geological Characteristics and Prospecting Criteria of Sanbao Silver Polymetallic Ore Deposit in Malipo Cuntry of Yunnan Province

2013 ◽  
Vol 868 ◽  
pp. 88-91
Author(s):  
Jian She Wang ◽  
Yong Feng Yan ◽  
Dong Wang ◽  
Peng Yu Feng
Keyword(s):  
Low Temperature ◽  
Yunnan Province ◽  
Wall Rock ◽  
Ore Genesis ◽  
Ore Deposit ◽  
Geological Characteristics ◽  
Polymetallic Deposit ◽  
Wall Rock Alteration ◽  
Rock Alteration ◽  
Polymetallic Ore

Sanbao silver polymetallic deposit is overally located in the front of "North convex" in Laojun Mountain granite body, belonging to polymetallic deposit of stratabounded medium-low temperature hydrothermal reformation genesis. It has been found that six mineralized belt, having developed the wall-rock alteration. The prospecting criterion is determined by ore genesis and ore-controlling factor.

A Modelling Study on the Fractionation of Uranium Among Minerals During Rock Weathering

1992 ◽  
Vol 294 ◽  
Author(s):  
Toshihiko Ohnuki ◽  
Takashi Murakami ◽  
Nobuyuki Yanase
Keyword(s):  
Sequential Extraction ◽  
Rock Weathering ◽  
Ore Deposit ◽  
Secondary Minerals ◽  
Iron Minerals ◽  
Irreversible Sorption ◽  
Rock Alteration ◽  
Weathering Process ◽  
Good Agreement ◽  
Modelling Study

ABSTRACTA modelling study has been carried out to understand the effect of rock alteration on the fractionation of uranium among coexisting minerals (chlorite, vermiculite, kaolinite, amorphous and crystalline iron minerals) at the Koongarra ore deposit, Australia. The model considers the chlorite weathering process, its mechanism and rate, and assumes the presence of reversible and irreversible sorption sites in the secondary minerals. The calculated uranium concentrations at the two different sites in the minerals were compared with the results of sequential extraction experiments. Good agreement between the calculated and observed uranium concentrations was obtained only when an appropriate fraction of uranium is fixed to the irreversible sorption sites of the altered clay minerals. However, a conventional Kd model gave inconsistent uranium concentrations. The calculated results show that the crystalline iron minerals sorb uranium during all stages of weathering, and that the uranium fractionation among the minerals varies with time until the end of the weathering.

Ore Mineralogy of the Louvem Copper Deposit Val d'Or, Quebec

1972 ◽  
Vol 9 (12) ◽  
pp. 1596-1611 ◽  
Author(s):  
Jayanta Guha ◽  
Richard Darling
Keyword(s):  
Copper Deposit ◽  
Wall Rock ◽  
Textural Features ◽  
Ore Deposit ◽  
Ore Body ◽  
Ore Minerals ◽  
Wall Rock Alteration ◽  
Ore Mineralogy ◽  
Rock Alteration ◽  
Host Rocks

Microscopic study of samples from the Louvem copper deposit shows that the principal ore minerals are pyrite, chalcopyrite, and sphalerite and the accessory ore minerals are rutile, tetradymite, two unidentified tellurides, cobaltite, molybdenite, galena, and four optically distinct phases having compositions along the digenite–bornite tie line.The Louvem ore body is a pipe-shaped mass of mineralized rhyolitic tuff and agglomerate that is conformable with enclosing volcanic and pyroclastic rocks. The ore body is zoned, with a copper-rich core and pyrite-rich margins. Wall-rock alteration spatially related to the ore deposit suggests that it was formed by replacement of porous tuffaceous host rocks by a hydrothermal fluid. Textural features of the ore indicate that it was subjected to post-emplacement thermal metamorphism.

Environmental Studies and Ethnic Studies

2020 ◽  
Vol 43 (2) ◽  
pp. 9-16
Author(s):  
David N. Pellow
Keyword(s):  
Case Studies ◽  
Multiple Scales ◽  
Ethnic Studies ◽  
Environmental Studies ◽  
Potential Value

This article offers insights into conceptual, pedagogical, and programmatic crossings and conflicts between the fields of Environmental Studies and Ethnic Studies. It highlights both the important intersections between the two fields and their potential value, while also addressing the challenges posed in the development of programmatic collaborations. Utilizing case studies drawn from the author’s own experiences, the article’s focus is on harnessing the strengths and limitations of both fields to promote transformative knowledge and action at multiple scales.

The Role of Nonprofit Sector Networks as Mechanisms for Immigrant Political Participation

2012 ◽  
Vol 7 (1) ◽  
pp. 27-46 ◽  
Author(s):  
Luisa Veronis
Keyword(s):  
Political Participation ◽  
Nonprofit Organizations ◽  
Latin American ◽  
Social Action ◽  
Multiple Scales ◽  
Nonprofit Sector ◽  
Ethnographic Study ◽  
Immigrant Community ◽  
Immigrant Political Incorporation

Issues of immigrant political incorporation and transnational politics have drawn increased interest among migration scholars. This paper contributes to debates in this field by examining the role of networks, partnerships and collaborations of immigrant community organizations as mechanisms for immigrant political participation both locally and transnationally. These issues are addressed through an ethnographic study of the Hispanic Development Council, an umbrella advocacy organization representing settlement agencies serving Latin American immigrants in Toronto, Canada. Analysis of HDC’s three sets of networks (at the community, city and transnational levels) from a geographic and relational approach demonstrates the potentials and limits of nonprofit sector partnerships as mechanisms and concrete spaces for immigrant mobilization, empowerment, and social action in a context of neoliberal governance. It is argued that a combination of partnerships with a range of both state and non-state actors and at multiple scales can be significant in enabling nonprofit organizations to advance the interests of immigrant, minority and disadvantaged communities.

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