Laboratory examination of anisotropy in the foliation plane of metamorphic rocks

2001 ◽  
Vol 61 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Bahman Bohloli ◽  
Bo Ronge ◽  
Gunnar Gustafson
Keyword(s):  
Metamorphic Rocks ◽  
Laboratory Examination ◽  
Foliation Plane

scholarly journals State of elements of the environment in the broader area of former uranium mines in the catchment of the Trgoviski Timok

2013 ◽  
pp. 163-174
Author(s):  
Zoran Nikic ◽  
Ljubomir Letic ◽  
Jovan Kovacevic ◽  
Vesna Nikolic
Keyword(s):  
Surface Waters ◽  
Metamorphic Rocks ◽  
Radioactive Elements ◽  
Laboratory Examination ◽  
Alluvial Sediment ◽  
Long Run ◽  
Partial Degradation ◽  
The Village ◽  
Existing Data ◽  
Geochemical Assessment

Mineral field ?Janja? extends over the Southwest slope of Stara Planina Mt., eastward from the village of Kalna in the belt of beech-fir forests. Exploitation of uranium used to be performed in three mines within this area, i.e. ?Mezdreja?, ?Gabrovnica?, and ?Srneci Do?, which are now closed down. One of the consequences of mining around these mines is partial degradation of natural balance. The greatest part of the terrain consists of granite, whereas metamorphic rocks are at the periphery. A geological survey with respect to the concentration of natural radioactive elements in the soil within the area of aforementioned mines has been conducted once so far. Alluvial sediment, ground and surface waters, as well as disposal were also examined. During the field study, radioactivity was measured and the methods of emanation and hydro-geochemical assessment were used, which was followed by collecting of samples for laboratory examination. The state of elements of the environment within the surveyed area is presented hereinafter on the basis of the existing data, having in mind that exploitation of uranium may disrupt natural balance in the long run.

TEM/AEM characterization of fine-grained clay minerals in very-low-grade rocks: Evaluation of contamination by empa involving celadonite family minerals

1996 ◽  
Vol 54 ◽  
pp. 694-695
Author(s):  
Gejing Li ◽  
D. R. Peacor ◽  
D. S. Coombs ◽  
Y. Kawachi
Keyword(s):  
Electron Microscopy ◽  
Volcanic Rocks ◽  
Analytical Electron Microscopy ◽  
Metamorphic Rocks ◽  
New Mineral ◽  
Chemical Compositions ◽  
Low Grade ◽  
Fine Grained ◽  
Depth Analysis ◽  
Mineral Aggregates

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.

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