“…In recent years, one line of research on ancient sponge-rich carbonate mudmounds gained substantial momentum through the rediscovery of a modern, calcifying siliceous sponge (Wiedenmayer, 1978;Neuweiler and Burdige, 2005;Neuweiler et al, 2007Neuweiler et al, , 2009a. Highly reactive, freshly produced humic compounds (Ziechmann, 1994) originating from sponge tissue degradation-exudation contribute to a permineralizing interstitial fluid as a dissolved to colloidal phase.…”