Factors controlling growth of modern tufa: results of a field experiment - Tufas and Speleothems: Unravelling the Microbial and Physical Controls - page 160

Fig. 12. Calcified cyanobacterial filaments: (a) sub-vertically arranged filaments entombed in growing sparry crystals
comprising several needle-shaped subcrystals, openings of some filament moulds are arrowed, tufa formed at L ´ ˇ ky E
point on Cu tablet between August and November 2002, (b) sparry calcite crystals with entombed filaments, Karw ´ w
cascade point, tufa formed on Cu tablet exposed between August 2002 and October 2003; (c) cross-section of filament
openings differing in size, small openings (arrows) probably represent diatom stalks, crystal broken surface, the same
sample as in b; (d) fan of upward radiating filaments, tufa formed at Karw ´ w cascade point between March and June
2003; (e) detail from d; (f ) top view of the fan, scattered moulds of cyanobacteria and detritic quartz grains (arrows)
incorporated into fan are visible, tufa formed at Karw ´ w dam point on limestone tablet exposed between August 2002
and October 2003; a, c, f - SEM images, b, d, e - thin sections.

M ¨ller 1968; D ¨rrenfeldt 1978), Belgium (Symoens
1957; Janssen et al. 1999), France (Freytet & Plet
1996), Italy (Golubic et al. 1993) and Greece
(Andrews & Brasier 2005). They are particularly
abundant at the H ´ j study site, where they domi-
nated

(Fig. 17d). Such housings may be produced by
Trichoptera and Chironomidae larvae (see Wallner
1934a;D¨rrenfeldt 1978; Drysdale 1999). How-
ever, it is impossible to precisely ascertain their
producers in the studied case as a reconnaissance
examination carried out at the H ´ j site proved the tufa micromorphology in June 2003