As referred to earlier, airborne particles in smoke from forest fires include
pseudomorphs of CaOx in the form of CaC[O.sub.3] (Hoyas et al.
Muscovite
pseudomorphs after staurolite as a record of fluid infiltrating during prograde metamorphism.
In many cases the
pseudomorphs after feldspar are well noticed.
Some of these minerals represent
pseudomorphs after previous mafic minerals (Fig.
* Crystal
pseudomorphs. Evaporite crystal splays can produce radial structures (J.
Rarely, the district has also provided good specimens of hausmannite, pyrolusite,
pseudomorphs of hausmannite after manganite, and
pseudomorphs of pyrolusite after calcite--but it is almost entirely to its wonderful manganite specimens that Ilfeld owes its fame in the world of mineral collecting.
Chemical weathering of plagioclase, alkali feldspar, and biotite has formed kaolin which mostly occurs as an anisotropic matrix which
pseudomorphs primary minerals (Fig.
Donaldson, A., and Hilowle, M.A., 2002, Organic mats, evaporite
pseudomorphs and soft-sediment deformation in quartz arenites of the Cambro-Ordovician Nepean Formation: GAC-MAC, Saskatoon 2002, Program with Abstracts, [http://gac.esd.mun.ca/gac_2002/search_abs/ sub_program.asp?sess=98&form=10&abs_no=73]
Ink Release 43 Thick or diffuse clouds,
pseudomorphs, long ropes, short strings, diffuse puffs, or alternating with defecation 6.
The ratios among the remaining alkalies and alkaline earths, as well as their concentrations in the HO--Al(Mg, Fe)--O--Si--O newly formed precipitates and their total negative charge, are decisive in the resulting clay mineral assemblage within the individual
pseudomorphs. The microenvironment rich in [K.sup.+] prefers the crystallization of illite, while that rich in [Na.sup.+] or [Ca.sup.2+] or [Mg.sup.2+] prefers the crystallization of smectite or vermiculite.
Microscopic supporting evidence includes microcracks, intraformational micro-breccia/conglomerate, an abundance of dolomite, anhydrite/gypsum
pseudomorphs, and fenestrate structures lined with calcite, dolomite and tar.