scholarly journals The Use of the Heavy Mineral Fraction of Stream Alluvium: Application To Low - Energy Glaciated Environments in eastern Canada

1991 ◽  
Author(s):  
Y T Maurice
Keyword(s):  
Low Energy ◽  
Heavy Mineral ◽  
Eastern Canada ◽  
Mineral Fraction

scholarly journals Separation and identification of the silt-sized heavy-mineral fraction in sediments

Circular ◽  
1992 ◽  
Author(s):  
Judith A. Commeau ◽  
Lawrence J. Poppe ◽  
R.F. Commeau
Keyword(s):  
Heavy Mineral ◽  
Mineral Fraction

scholarly journals The Pliocene and Pleistocene fluvial evolution in the northern Upper Rhine Graben based on results of the research borehole at Viernheim (Hessen, Germany)

2009 ◽  
Vol 57 (3/4) ◽  
pp. 286-314 ◽  
Author(s):  
Christian Hoselmann
Keyword(s):  
Research Programme ◽  
Heavy Mineral ◽  
Characteristic Change ◽  
Upper Rhine Graben ◽  
Sedimentary Sequence ◽  
Sedimentary Sequences ◽  
Mineral Fraction ◽  
Rhine Graben ◽  
Minimum Disturbance ◽  
Upper Rhine

Abstract. The research borehole drilled in 2006 by the Hessian Agency for the Environment and Geology (HLUG) north of Viernheim (Hessisches Ried) reached a total depth of 350 m, and penetrated high resolution fluviatile and limnic-fluviatile sediments (0 to 225 m) of Pleistocene age, and partially highly pedogenically overprinted limnic-fluviatile sands, clays and silts of Pliocene age (225 to 350 m). The Pliocene sediments tend to be sourced locally. The sediments repeatedly show sourcing from the Odenwald which is characterised by a high percentage of green hornblende in the heavy mineral fraction. As part of the Heidelberg Basin research programme, one of the main purposes of this borehole was to analyse the Pleistocene “Normal Facies” of the northern Upper Rhine Graben, i.e. a sedimentary sequence subject to minimum disturbance, largely unaffected during the Pleistocene by material sourced from the graben margins or smaller tributaries. The Pleistocene sedimentary sequence consists of three units: a thin horizon with reworked Pliocene material is overlain by ten cycles each beginning erosively with gravely sandy sediments and ending with siltyargillaceous to in part peat-like sediments. Internal cycles can also be identified, amongst other features. A characteristic aspect is the green-grey, strongly calcareous, micaceous and well sorted, fi ne to medium sands of the Rhine. These are dominated by the Rhine Group (garnet, epidote, green hornblende and alterite) in the heavy mineral fraction. These sediments are classifi ed as the “Rhenish Facies”. The upper Pleistocene sedimentary sequences at the top of the Viernheim research borehole are dominated by several fi ning-upward and in part coarsening-upward sequences. The deposits in this part of the well are dominated by gravel deposited by the Neckar. The heavy mineral distribution of the sand fraction reveals, however, that there was mixing with Rhenish sediments. Weichselian to Holocene aeolian sands form the topmost part of the well section. The stratigraphic classifi cation of the Pleistocene sedimentary sequences is still uncertain in parts. The Pliocene-Pleistocene boundary is placed at 225 m because of the characteristic change in facies. Due to lithostratigraphic correlations with sediments within the Lower Rhine Embayment, a larger unconformity at the depth of 225 m must be accepted. Research carried out in the area around the well indicates that the youngest fine-clastic section penetrated by the well between 39.76 and 58.55 m is of Cromerian age.

Genesis of podzols on coastal dunes in southern Queensland. V. Chemistry and mineralogy of the non-opaque heavy mineral fraction

Soil Research ◽  
1998 ◽  
Vol 36 (4) ◽  
pp. 699 ◽  
Author(s):  
D. J. Chittleborough ◽  
M. S. Tejan-Kella ◽  
R. W. Fitzpatrick
Keyword(s):  
Coastal Dunes ◽  
Fine Sand ◽  
Parent Material ◽  
Mineral Weathering ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Sand Fraction ◽  
Mineral Fraction ◽  
Insignificant Difference ◽  
Proximate Source

Eight podzols on coastal dunes from the Cooloola chronosequence, and an associated pedon from North Stradbroke Island (Amity), were studied to establish (i) the degree of homogeneity of the parent material between and within profiles, (ii) the extent of heavy mineral weathering, and (iii) whether the parent sediments of each pedon had a common proximate source. The pedons are Quartzipsamments and Troporthods with ages ranging from Holocene to Pleistocene. On the basis of ratios zircon : rutile, zirconium : titanium, and non-magnetic : very magnetic heavy minerals in the fine sand fraction (53–125 µm), we concluded that the parent materials of the Cooloola pedons were mineralogically similar. By using zirconium in the non magnetic heavy mineral fraction as an index for zircon, it is evident that there has been considerable pedogenetic weathering of the heavy mineral fraction. There is a statistically insignificant difference in hafnium concentrations of zircons which implies that parent sediments of the soils at Cooloola and North Stradbroke Island were derived from a common immediate source.

Varietal heavy mineral analysis of sediment provenance, Lower Cretaceous Scotian Basin, eastern Canada

2011 ◽  
Vol 237 (3-4) ◽  
pp. 150-165 ◽  
Author(s):  
Basilios Tsikouras ◽  
Georgia Pe-Piper ◽  
David J.W. Piper ◽  
Michael Schaffer
Keyword(s):  
Lower Cretaceous ◽  
Heavy Mineral ◽  
Sediment Provenance ◽  
Mineral Analysis ◽  
Eastern Canada ◽  
Heavy Mineral Analysis

scholarly journals Indicator mineral and till geochemical signatures of the Broken Hammer Cu–Ni–PGE–Au deposit, North Range, Sudbury Structure, Ontario, Canada

2019 ◽  
Vol 20 (3) ◽  
pp. 337-356
Author(s):  
M. B. McClenaghan ◽  
D. E. Ames ◽  
L. J. Cabri
Keyword(s):  
Heavy Mineral ◽  
Laurentide Ice Sheet ◽  
Surface Zone ◽  
The North ◽  
Visual Identification ◽  
Mineral Fraction ◽  
Sudbury Structure ◽  
Platinum Group Minerals ◽  
Indicator Mineral ◽  
Liberation Analysis

The Broken Hammer Cu–Ni–PGE–Au footwall deposit in the North Range of the Sudbury Structure in Canada consists of a shallow surface zone of vein-hosted and vein stockwork-hosted mineralization within Sudbury breccia developed in the quartz monzonite Levack Gneiss Complex. The surface of the deposit consists of a 2–120 cm wide chalcopyrite vein and numerous smaller veins dominated by chalcopyrite–magnetite–millerite with trace gold, platinum group minerals, tellurides, bismuthides and selenides. The Laurentide Ice Sheet flowed southward across the region depositing a sandy till that contains abundant sperrylite (hundreds of grains), chalcopyrite, pyrite and gold in the heavy mineral fraction down-ice of mineralization. Mineral liberation analysis of the <0.25 mm heavy mineral fraction of metal-rich till identified a broader suite of PGM and sulfides than visual identification methods. The <0.063 mm fraction of till displays a strong geochemical signature of the mineralization for Pd, Pt, Au, Cu and Ag and, to a lesser extent, Bi, Te and Sn; however, geochemical signatures are not detectable as far down-ice as indicator minerals. Till sampling has not been used for exploration in the Sudbury region because of the abundant outcrop and the use of geophysical and prospecting techniques. This study demonstrates that indicator mineral and till geochemical methods are useful exploration tools for the region. The presence of sperrylite and chalcopyrite in oxidized till indicates that even thin (<1 m) highly weathered till is an effective sample medium here.

Dissociated Σ=27 boundaries in silicon

1988 ◽  
Vol 46 ◽  
pp. 624-625
Author(s):  
A. Garg ◽  
W.A.T. Clark ◽  
J.P. Hirth
Keyword(s):  
Electron Diffraction ◽  
Local Minimum ◽  
Boundary Energy ◽  
Coincidence Site Lattice ◽  
Boundary Plane ◽  
Low Energy ◽  
Theoretical Understanding ◽  
Site Lattice ◽  
Kikuchi Pattern ◽  
Analysis Techniques

In the last twenty years, a significant amount of work has been done in the theoretical understanding of grain boundaries. The various proposed grain boundary models suggest the existence of coincidence site lattice (CSL) boundaries at specific misorientations where a periodic structure representing a local minimum of energy exists between the two crystals. In general, the boundary energy depends not only upon the density of CSL sites but also upon the boundary plane, so that different facets of the same boundary have different energy. Here we describe TEM observations of the dissociation of a Σ=27 boundary in silicon in order to reduce its surface energy and attain a low energy configuration.The boundary was identified as near CSL Σ=27 {255} having a misorientation of (38.7±0.2)°/[011] by standard Kikuchi pattern, electron diffraction and trace analysis techniques. Although the boundary appeared planar, in the TEM it was found to be dissociated in some regions into a Σ=3 {111} and a Σ=9 {122} boundary, as shown in Fig. 1.

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