Geological Magazine


Growth rate observation from the moss-built Checa travertine terrace, central Spain

Ruud Weijermarsa1, Carla W. Mulder-Blankena2 and Jaap Wiegersa3

a1 Department of Mineralogy and Petrology, Institute of Geology, University of Uppsala, Box 555, S-75122 Uppsala, Sweden

a2 Geological Institute, University of Amsterdam, 130 Nieuwe Prinsengracht, NL-1018 VZ Amsterdam, The Netherlands

a3 Hugo de Vries-Laboratory, University of Amsterdam, 221 Sarphatistraat, NL-1018 BX Amsterdam, The Netherlands


In situ observations of fossil and living specimens of the calcicolous mosses Bryum pseudotriquetrum, Cratoneuron commutatum and Catoscopium nigritum revealed very fast calcite depositional rates. Rhythmic layering in the fossil mosses corresponding with the seasonal climatic cycle suggests that the moss curtain occupied by these three mosses maintains the deposition of spongeous travertine layers at a mean rate of 4 cm a−1. A mean depositional rate of 4.2 cm a−1 may be calculated from measurements of the loss of bicarbonate from the springwater after it percolated through the moss curtain. These rates suggest that the 8 m high travertine terrace of Checa with a surface area of 800 m2 did not exist two millennia ago.

Mosses could be put to man's use for creating natural overgrowths on artificial surfaces, an idea based on an allusion by Wallner. He observed that the thread-forming, blue-green algae Vaucheria builds travertine deposits at an annual rate of 0.7–1.4 cm. We observed that the mosses Cratoneuron commutatum and Bryum pseudotriquetrum may form spongeous travertine layers at respective maximum rates of 11 and 14 cm a−1. This would reduce the time required to build natural overgrowths on artificial objects to a practical period of months.

(Received April 17 1985)

(Revised September 23 1985)

(Accepted October 03 1985)