Rock & Mineral Analysis

2019 ◽  
pp. 7-47
1996 ◽  
Vol 33 (7) ◽  
pp. 245-248 ◽  
Author(s):  
Christopher Hall ◽  
Paul Barnes ◽  
Jeremy K. Cockcroft ◽  
Simon D. M. Jacques ◽  
Andrew C. Jupe ◽  
...  

Author(s):  
William F. Chambers ◽  
Arthur A. Chodos ◽  
Roland C. Hagan

TASK8 was designed as an electron microprobe control program with maximum flexibility and versatility, lending itself to a wide variety of applications. While using TASKS in the microprobe laboratory of the Los Alamos National Laboratory, we decided to incorporate the capability of using subroutines which perform specific end-member calculations for nearly any type of mineral phase that might be analyzed in the laboratory. This procedure minimizes the need for post-processing of the data to perform such calculations as element ratios or end-member or formula proportions. It also allows real time assessment of each data point.The use of unique “mineral codes” to specify the list of elements to be measured and the type of calculation to perform on the results was first used in the microprobe laboratory at the California Institute of Technology to optimize the analysis of mineral phases. This approach was used to create a series of subroutines in TASK8 which are called by a three letter code.


2021 ◽  
pp. 1-13
Author(s):  
Jasper Verhaegen ◽  
Hilmar von Eynatten ◽  
István Dunkl ◽  
Gert Jan Weltje

Abstract Heavy mineral analysis is a long-standing and valuable tool for sedimentary provenance analysis. Many studies have indicated that heavy mineral data can also be significantly affected by hydraulic sorting, weathering and reworking or recycling, leading to incomplete or erroneous provenance interpretations if they are used in isolation. By combining zircon U–Pb geochronology with heavy mineral data for the southern North Sea Basin, this study shows that the classic model of sediment mixing between a northern and a southern source throughout the Neogene is more complex. In contrast to the strongly variable heavy mineral composition, the zircon U–Pb age spectra are mostly constant for the studied samples. This provides a strong indication that most zircons had an initial similar northern source, yet the sediment has undergone intense chemical weathering on top of the Brabant Massif and Ardennes in the south. This weathered sediment was later recycled into the southern North Sea Basin through local rivers and the Meuse, leading to a weathered southern heavy mineral signature and a fresh northern heavy mineral signature, yet exhibiting a constant zircon U–Pb age signature. Thus, this study highlights the necessity of combining multiple provenance proxies to correctly account for weathering, reworking and recycling.


2009 ◽  
Vol 54 (No. 2) ◽  
pp. 41-46 ◽  
Author(s):  
G.A. Papadopoulos ◽  
D.G.D. Maes ◽  
G.P.J. Janssens

The present study investigated the effect of a moderate substitution of inorganic mineral sources with chelated mineral sources from four weeks prior to parturition throughout lactation on sow and litter performance. In addition, the aims were to determine whether the mineral source and litter performance affect mineral status and accretion in piglets at birth and at weaning. Forty gestating sows in a commercial pig herd were selected and randomly assigned to two experimental groups, with part of the Cu, Mn, Zn and Fe content of the feed added as either an inorganic mineral source or a chelated mineral source. From each sow, one piglet was randomly selected at birth and at weaning for total body mineral analysis. Neither the performance of the sows and the piglets nor the total body mineral concentrations of the piglets at birth and at weaning were significantly different between the two diet groups (<i>P</i> > 0.05). Fe, Na and P content of piglets at birth were inversely correlated with birth weight (<i>r</i> = –0.447, <i>P</i> = 0.004 for Fe; <i>r</i> = –0.431, <i>P</i> = 0.005 for Na; <i>r</i> = –0.340, <i>P</i> = 0.032 for P). Daily accretion rate of K and Ca of piglets was positively correlated with piglet growth performance during the entire lactation period (<i>r</i> = 0.469, <i>P</i> = 0.008 for K; <i>r</i> = 0.581, <i>P</i> < 0.001 for Ca), and negatively correlated with number of liveborn piglets (<i>r</i> = –0.424, <i>P</i> = 0.014 for K, and <i>r</i> = –0.405, <i>P</i> = 0.027 for Ca). In conclusion, the study documented that partial substitution of inorganic minerals with a chelated mineral source failed to exert significant effects on performance and total body mineral concentrations. The importance of the influence of sow milk production on mineral body stores in piglets warrants further investigation.


1984 ◽  
Vol 30 (104) ◽  
pp. 49-57 ◽  
Author(s):  
R. Raiswell

AbstractChemical models for the evolution of bulk melt waters can be constructed by assuming that rock mineral weathering and solute acquisition are controlled by carbonate equilibria. Different open- and closed- system models are defined by variations in the rates of weathering relative to the rate of hydrogen-ion supply by the dissolution and dissociation of CO2, and can be recognized by characteristic pH and ∑+relationships. The observed and inferred compositions of englacial and subglacial melt suggest that mixing is unlikely to be conservative and that closed-system conditions result where post-mixing weathering reactions occur. The final composition of bulk melt waters is determined by the mixing ratio between englacial and subglacial melt, the extent of post-mixing evolution, and opportunity for mixing with ground waters or re-equilibration with the atmosphere.


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