AUTHOR=Aguirre Julio , Braga Juan C. 

TITLE=Middle Miocene (Serravallian) rhodoliths and coralline algal debris in carbonate ramps (Betic Cordillera, S Spain)

JOURNAL=Frontiers in Earth Science

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2022.958148

DOI=10.3389/feart.2022.958148

ISSN=2296-6463

ABSTRACT=<p>Serravallian (middle Miocene) coralline algal assemblages at the southern margin of the Guadalquivir Basin (southern Spain) occur as rhodoliths preserved <italic>in situ</italic> or very close to their growth habitats (autochthonous–parautochthonous assemblages) and also as reworked remains (allochthonous assemblages). The former assemblages consist of spherical rhodoliths built up by encrusting to warty plants and also of large fragments of branches, whereas the latter are mostly unrecognizable small fragments occurring in channeled packstone–grainstone beds. In both cases, the most abundant components are members of the order Hapalidiales (<italic>Mesophyllum roveretoi</italic>, <italic>Mesophyllum</italic> sp., <italic>Lithothamnion ramosissimum</italic>, and less frequently <italic>Phymatolithon</italic> group <italic>calcareum</italic> and <italic>Lithothamnion</italic> group <italic>corallioides</italic>). Laminar growths of <italic>Lithoporella minus</italic> and branches of <italic>Spongites</italic> group <italic>fruticulosus</italic> and <italic>Sporolithon</italic> sp. occur very rarely. There are also anecdotal records of <italic>Subterraniphyllum thomasii</italic>, extending its upper stratigraphic range up to the Serravallian in the western Tethys. The autochthonous–parautochthonous coralline algal assemblages formed in a middle ramp, at several tens of meters of water depth, as suggested by the dominance of Hapalidiales. The allochthonous assemblages represent fragments of coralline algae derived from the middle ramp and redeposited in deeper settings, most likely the outer ramp, due to storm-generated currents.</p>