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Treatment of Microanalyses of Intimately Mixed Products of Mica Weathering
Chemical composition Electron microprobe Mica Statistical treatment Weathering
2012/1/4
Weathering of minerals often produces intimate mixtures of reactants and products in a smaller volume than that explored by an electron microprobe. As a result, many microanalyses are difficult to dec...
Weathering of Hornblende to Ferruginous Products by a Dissolution-Reprecipitation Mechanism: Petrography and Stoichiometry
Gibbsite Goethite Hornblende Iron Kaolinite Neoformation Petrography Scanning electron microscopy Weathering
2012/1/9
Hornblende of the Carrol Knob mafic complex (southern Blue Ridge Mountains, North Carolina) has weathered under humid, temperate conditions. Hornblende weathering appears to have been a dissolution-re...
Weathering of Iron-Bearing Minerals in Soils and Saprolite on the North Carolina Blue Ridge Front: II. Clay Mineralogy
Chlorite Goethite Hematite Iron Kaolinite Mossbauer spectroscopy Saprolite Soils Vermiculite Weathering
2011/11/30
Abstract: The mineralogy of the clay fraction was studied for soils and saprolite on two Blue Ridge Front mountain slopes. The clay fraction contained the weathering products of primary minerals in th...
Weathering of Iron-Bearing Minerals in Soils and Saprolite on the North Carolina Blue Ridge Front: I. Sand-Size Primary Minerals
Almandine Biotite Chlorite Iron Magnetite Saprolite Soils Weathering
2011/11/30
Abstract: The weathering products of primary biotite, chlorite, magnetite, and almandine in mica gneiss and schist in the North Carolina Blue Ridge Front were determined. Sand-size grains of biotite, ...
Apatite Replacement and Rare Earth Mobilization, Fractionation, and Fixation During Weathering
Apatite Florencite Granite Phosphorus Rare earth elements Rhabdophane Scanning electron microscopy Weathering
2012/1/5
During an electron microscope study of the weathering of granite from southern New South Wales, Australia, an assemblage of minerals including florencite and rhabdophane was discovered replacing apati...
Chemical Weathering of Crystalline Rocks in the Catchment Area of Acidic Ticino Lakes, Switzerland
Acid precipitation Aluminum hydroxide Gneiss Iron hydroxide Weathering
2012/1/10
Atmospheric acidic deposition introduces hydrogen ions to terrestrial and aquatic ecosystems, which become partially neutralized by chemical weathering. In the southern Alps of Switzerland, small catc...
Weathering Sequence and Alteration Products in the Genesis of the Graskop Manganese Residua, Republic of South Africa
Birnessite Dolomite Infrared spectroscopy Manganese Nsutite Petrography Wad Weathering X-ray powder diffraction
2012/1/10
Although numerous, small, manganese oxide deposits associated with dolomite in the Eastern Transvaal escarpment, Republic of South Africa, have been known for many years, their mineralogical make-up i...
Weathering of Chlorite and Vermiculite in Ultramafic Rocks of Cabo Ortegal, Northwestern Spain
Chlorite Hydroxy-Al Serpentinite Smectite Vermiculite Weathering X-ray powder diffraction
2012/1/9
Chloritic veins in serpentinite and their weathering products were analyzed by X-ray powder diffraction (XRD) and X-ray fluorescence spectrometry (XRF). Chlorite formed during the Hercynianage orogene...
Weathering of Basalt: Formation of Iddingsite
Goethite Iddingsite Iron Olivine Scanning electron microscopy Transmission electron microscopy Weathering
2012/1/11
The formation of iddingsite by the oxidative weathering of Fo80 olivine begins by solution of Mg from planar fissures, 20 Å wide and spaced 200 Å apart, parallel to (001). Oxidation of Fe ...
Weathering of Basalt: Changes in Rock Chemistry and Mineralogy
Basalt Core-stone Element mobilization Goethite Halloysite Smectite Weathering
2012/1/10
The weathering of eastern Australian basalts, sampled from the rounded, hard, core-stone to the rind of softer weathered material, has been examined by bulk chemical analyses, thin section petrography...
Hydroxy-Cu-Vermiculite Formed by the Weathering of Fe-Biotites at Salobo, Carajas, Brazil
Cation-exchange capacity Copper Intergrade Manganese oxide Supergene enrichment Vermiculite Weathering
2012/1/12
Weathering of a copper stratiform deposit (schist) at Salobo, Brazil, has produced two distinct Cu-bearing minerals from a biotite parent: vermiculite and a manganese oxide containing as much as 13% a...
Replacement of Quartz by Opaline Silica during Weathering of Petrified Wood
Opal-A Opal-CT Petrified wood Quartz Silica Weathering
2012/2/2
A mineralogical investigation by X-ray powder diffraction and optical, scanning, and transmission electron microscopy of partially weathered petrified wood in the Yegua Formation (Eocene) of east-cent...
Feldspar Weathering in Lateritic Saprolite
Feldspar Gibbsite Halloysite Kaolinite Noncrystalline material Weathering
2011/11/25
Abstract: Feldspars in granitic saprolite in southwestern Australia have altered to halloysite, kaolinite, and gibbsite with no evidence of noncrystalline material. The secondary minerals are commonly...
Weathering of Ilmenite in a Lateritic Pallid Zone
Anatase Halloysite Ilmenite Kaolinite Laterite Leucoxene Pseudorutile Rutile Weathering
2012/2/6
In a lateritic pallid zone ilmenite crystals alter via pseudorutile to porous leucoxene grains composed of randomly oriented aggregates of ∼0.06 µm anatase crystals. This style of alterati...
Mineralogical Transformations during Weathering of Lignite Overburden in East Texas
Lignite Oxidation Reclamation Smectite Soil Weathering
2011/11/25
Abstract: Mineralogical weathering sequences in sediments overlying lignite beds were investigated in a core (27 m deep) from Calvert, Robertson County, northeast Texas. Weathering trends were evaluat...