Why is stromatactis so rare in Mesozoic carbonate mud mounds?

Abstract

The sedimentary–diagenetic structure stromatactis is widespread in Palaeozoic spiculitic carbonate mud mounds, but occurs only sporadically in Mesozoic sponge carbonate mud mounds. Comparative analysis of Palaeozoic and Mesozoic stromatactis limestones suggests that this variation results from the degree of siliceous sponge skeletal rigidity and the amount of internal sediment accumulation in the original cavity network. Partial to entire filling by internal sediment resulted in a continuum, from a small amount of internal sediment and large amount of cement (stromatactis, common in the Palaeozoic), to only internal sediments (aborted stromatactis, common in the Mesozoic). These observations match independent lines of evidence concerning the siliceous sponge evolution and sediment recycling (e.g. bioerosion) across the Palaeozoic to Mesozoic biotic revolution.

Microfacies associations of Middle and Upper Triassic slope and basin carbonates deposited along the Neo-Tethyan margin, NE Hungary

“…On the basis of co-occurrence of clotted micrite and stromatactis structures, it has been clearly established that these structures indicate presence of organic matter in increased amount e.g. decayed sponges or microbial activity (Aubrecht et al, 2002;Hladil, 2005;Neuweiler and Bernoulli, 2005). Sponge spicules and skeletons are rare elements in the analysed thin sections.…”

“…Neuweiler et al, 2001). On the basis of co-occurrence of clotted micrite and stromatactis structures, it has been clearly established that these structures indicate presence of organic matter in increased amount e.g.…”

Late Jurassic facies architecture of the Złoczew Graben: implications for evolution of the tectonic-controlled northern peri-Tethyan shelf (Upper Oxfordian–Lower Kimmeridgian, Poland)

“…The origin of the cavities here is related to remodeling of initial open spaces in an inhomogeneous, partly lithified sediment (cf. Matyszkiewicz 1997a; Neuweiler et al 2001;Olchowy 2011). Such open spaces might have formed at the contacts of loose particles (ooids, oncoids, bioclasts, or intraclasts) and partly lithified microbial crusts during sedimentation (cf.…”

A novel population of composite mounds: their initiation, growth and demise. San Emiliano Formation, Cantabrian Mountains, Spain

“…Monty 1995;Pratt 1995;Kaufmann et al 1996;Neuweiler et al 2001;Krause et al 2004;Hebbeln and Samankassou 2015). Riding (2002) reviewed the historical classification of organic reefs, in an attempt at the standardisation of what is a fraught nomenclature.…”