Rhodolith‐bearing limestones as transgressive marker beds: fossil and modern examples from North Island, New Zealand

Abstract

249 physiography contribute to determine the relationship between rhodolithbearing deposits and transgressive settings.

Deep-water rhodolith bed from central Brazilian continental shelf, Campos Basin: coralline algal and faunal taxonomic composition

“…Variations in biotic composition as well as differences in coralline algal mor phology can be used to assess the paleoecological settings of fossil rhodolith beds (e.g., Basso and Tomaselli 1994;Braga and Aguirre 2001;Nebelsick et al 2005;Nalin et al 2008;Bassi et al 2012a). Little is known about deep water rhodolith communities.…”

Origin and resedimentation of rhodoliths in the Late Paleocene flysch of the Polish Outer Carpathians

“…The rhodoliths of deeper water or low hydrodynamicenergy environments show large constructional void spaces, may lack an identifiable nucleus, and are composed of thin, irregular, encrusting thalli (e.g., Braga and Martín 1988;Barattolo et al 2007;Bassi 1998Bassi , 2005Nalin et al 2008;Bassi et al 2006Bassi et al , 2009. The predominantly asymmetrical and loosely packed inner structure of the studied rhodoliths in the present case indicates occasional overturning in an environment with moderate water turbulence.…”

“…According to Nalin et al (2008), the deposition of Cenozoic rhodolith-bearing sediments occurred commonly during marine transgressions, particularly (though not uniquely) in non-tropical areas. At the advanced stage of transgression, these rhodolith-bearing deposits would be covered by fine-grained subneritic facies (Nalin et al 2008) or buried by shoreline progradation during normal regression (Catuneanu 2006).…”

“…Rhodoliths are free-living nodules composed predominantly of non-geniculate coralline red algae with an admixture of other encrusting organisms (peyssonneliacean algae, encrusting foraminifera, serpulids, bryozoans; e.g., Bosence 1983a;Marrack 1999;Bassi et al 2009Bassi et al , 2011. Their development is controlled by an array of environmental factors, and hence rhodoliths are a valuable indicator of paleoenvironmental conditions (e.g., Bosence 1983b; Nalin et al 2008;Bassi et al 2009. The dominance of Sporolithon and melobesioids in the analyzed rhodoliths suggests a low light-intensity setting.…”

“…10a), when the accommodation space of the shelf zone increased, erosion declined, and sediment accumulation prevailed. Significant production of biogenic carbonates would occur in shallow-water areas with a suitable hydraulic energy and limited sediment supply (e.g., Monstad 2000;Philip 2003;Nalin et al 2008). This stage would probably persist until at least the early highstand (Sarg 1988;Tucker and Wright 1990;Leinfelder 1993;Brachert et al 2003), whereas erosion of the inner shelf might have commenced with the fall of relative sea level and persisted until the lowstand phase (Fig.…”