Factors controlling growth of modern tufa: results of a field experiment - Tufas and Speleothems: Unravelling the Microbial and Physical Controls - page 167

Fig. 19. (a) Corroded sparry crystals below micrite (arrows), tufa formed on limestone tablet at Karw´w cascade point
between June and October 2003; (b, c) laminated hemisphere, tufa formed on limestone tablets at Karw´w dam point
between August 2002 and October 2003 (b) and Karw´w cascade point between March and June 2003 (c); (d) laminated
hemisphere surrounded by detritic quartz grains, Karw´w dam point, tufa on limestone tablet exposed between August
2002 and November 2003; (e) linked hemispheres constituting continuous tufa cover on limestone tablet exposed at
Karw´ w dam point between August 2002 and October 2003; (f ) isolated hemispheres, limestone tablet exposed at
Karw´ w cascade point between August and December 2002; a - d thin sections, arrows in e and f indicate direction of
water flow.

Another type of lamination is visible because of
changes in porosity within tufa of fibrous texture
(Fig. 24a - c). It is akin to lamination in algal
mats. This type of lamination is especially well
developed at the L ´ ˇ ky top and E points, in the
tufa with fibrous texture. More compact laminae
alternate with those being more porous. The dimen-
sions of crystals in compact laminae gradually grow

upwards (Fig. 24b). Both types of laminae are built
of moulds of filamentous algae, highly encrusted
with calcite. In the compact laminae, spacing
between particular algal filaments is small, so that
cement largely fills the gaps between the filaments
(Fig 24d). In the porous laminae the number of
algae is considerably smaller and the spaces
between them remain open. Thus, the lamination