abstract low molecular weight carboxylic acids (lmw) play an important role in improving the bioavailability of soil nutrients. nonexchangeable soil k, trapped between the interlayers of clay minerals, is an important source of k for plants in many soils. the objectives of this study were to determine the effect of selected lmw organic acids on the release of k from micaceous minerals and to in...

This paper presents a mineralogical and chemical investigation of shale deposits from the U.S. Gulf coast in order to document the mechanisms and reactions involved in the diagenetic conversion of smectite into illite. Cuttings from the 1,250 to 5,500 m stratigraphic interval of a well were sorted by grain size and analzyed by x-ray diffraction to assess chemical and mineralogical trends with d...

Interactions between injected CO2, brine, and rock during CO2 sequestration in deep saline aquifers alter their natural hydro-mechanical properties, affecting the safety, and efficiency of the sequestration process. This study aims to identify such interaction-induced mineralogical changes in aquifers, and in particular their impact on the reservoir rock's flow characteristics. Sandstone sample...

Twenty nine samples of silica sinter, ranging in age from modern to Miocene, record temporal changes in both mineralogy and texture. When ®rst deposited, sinters consist largely of noncrystalline spheres (<1±8 lm diameter) of opal-A exhibiting varying degrees of closepacking. Particle densities range from 1.5 to 2.1 g cm, total water 4±10 wt%, and porosities 35±60%. Changes over 10,000 years fo...

Tile crystal structures of sjogrenite and pyroaurite, two stacking modifications of approximate composition Mg.Fe.(OH),.(CO.).4H.O, have been determined by X-ray diffraction using three-dimensional methods. Sjogrenite is hexagonal, with a 3,13, C 15.66 A, space group P6.!mmc, Z = !; pyroaurite is rhombohedral, with aH 3,13, CH 23.49 A, space group R3m or R3m, Z = i. Both structures are based on...

of the International Mineralogical Association, 16th general meeting (1994), p. 40. 17. W. P. Grif® th, `̀ Raman Spectroscopy of Minerals’ ’ , in The Infrared Spectra of Minerals, V. C. Farmer, Ed. (Mineralogical Society, Lon-

This work studies mineralogical data from X-Ray Diffraction Techniques (XRD) and geochemical data analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) of fine fraction from samples collected along the Ocean Margin Exchange Project (OMEX) core KSGX 24. This core was recovered in the external sector of Ria de Vigo, N Spain. Radiocarbon ages allowed the estimation of an age about 3 ka...