Photomicrographs of Detrital Grains

 Rock fragments (XPL)
 SS : very fine-grained sandstone fragment,
 A : argillite,
 QM : quartz-mica aggregate.

 Manhang Formation
 Danyang coalfield

 Photo courtesy of C. Lim

 Rock fragments (XPL)
 S : siltstone rock fragment,
 A : argillite.

 Manhang Formation
 Danyang coalfield

 Photo courtesy of C. Lim

 Chert grain (XPL)

 Manhang Formation
 Danyang coalfield

 Photo courtesy of C. Lim

 Limestone rock fragment (XPL)

 Manhang Formation
 Mungyeong coalfield

 Photo courtesy of C. Lim

 Slate fragment (OPL)

 Manhang Formation
 Danyang coalfield

 Photo courtesy of C. Lim

 Quartz-mica aggregate fragment  consisting  of quartz and muscovite (XPL)

 Manhang Formation
 Cheongseon coalfield

 Photo courtesy of C. Lim

 Quartz-mica tectonite fragment deformed  between competent grains by shear stress  (XPL)

 Manhang Formation
 Danyang coalfield

 Photo courtesy of C. Lim

 Spike-shaped overgrowth of tourmaline.  Host  tourmaline is subrounded (XPL)

 Manhang Formation
 Cheongseon coalfield

 Photo courtesy of C. Lim

 Rounded tourmaline (OPL)

 Manhang Formation
 Mungyeong coalfield

 Photo courtesy of C. Lim

 Plagioclase replaced by quartz (XPL)

 Manhang Formation
 Gangreung coalfield

 Photo courtesy of C. Lim