The plagioclase is commonly zoned, at places oscillatory, with much altered cores containing white mica
and zoisite granules, and ranges from sodic andesine to albite.
Topaz occurs in the form of irregular grains and/or anhedral aggregates, rimmed by a mixture of white mica
and clay minerals (dickite) (Fig.
The 40Ar/39Ar thermochronology reveals that the exposed rock in the Kumaun and Garwhal Lesser Himalaya underwent cooling below the closure temperature (Tc) for white mica
at different times in the late Tertiary.
Other topics of the 23 papers include the effects of transverse structural lineaments on the Neogen- Quaternary basin, Ar/Ar dating of detrital white mica
in China, the anatomy of a fluvial lowstand wedge in Argentina, and river morphologies of western Africa during humid climatic conditions.
The rock is penetratively foliated with the foliation mainly defined by oriented white mica
and elongated trails of epidote.
The samples used in this experiment are polypropylene [PP: J-900GP, molecular weight ([M.sub.w]) 35 X [10.sup.4], melting point 170[degrees]C, Idemitsu Petrochemical] and white mica
[mica: A-11, true and bulky specific gravities are 1.9-2.2 X [10.sup.3] kg/[m.sup.3] and 0.12 X [10.sup.3] kg/[m.sup.3], respectively, mica particle size is 0.3-15 [micro]m, Yamaguchi Mica].
"We believe that this special effect can have the same universal attractiveness as white mica
hues and extremely iridescent hues did in the past".
The framework grains of the Aghajari Formation sandstones are rich in quartz followed by lithic grains and depleted in feldspar and mica (predominantly white mica