Coralline algal assemblages from the Sierra de Marmolance (Middle Miocene, SE Spain)

The Sierra de Marmolance is an NNE-SSW-trending ridge located about 4 km WNW of Huéscar, in the Granada province (SE Spain). The Marmolance succession consists of ~300 m thick limestone beds, gently dipping to the W-SW, which overlie and interfinger with pelagic marls. Based on planktonic foraminiferal assemblages, the succession ranges from the Burdigalian-Langhian transition (M5b biozone of Wade et al., 2011) in the lower part to the Langhian-Serravallian boundary (M7 biozone of Wade et al., 2011) in the top. The limestones consist of packstone-rudstone beds locally displaying crossbedding, with variable amounts of siliciclastics, generally increasing toward the top. Micropaleontological and lithofacies analyses were made in several stratigraphic sections. The major bioclastic components are coralline algae, larger and small benthic foraminifera, echinoids, bryozoans, corals, and bivalves, with minor serpulids and barnacles. Coralline algae are the most abundant components in all facies except in distal planktonic foraminifer packstones. They occur mostly as fragments or, less frequently, as rhodoliths. Hapalidiales is the dominant group, being Mesophyllum, represented by Mesophyllum roveretoi and Mesophyllum sp., the most abundant genus. Lithothamnion group corallioides, Lithothamnion ramossissimum, and other undifferentiated species of the genus are the second most abundant taxa. Sporolithon sp., Lithoporella minus, Subterraniphyllum thomasii and several geniculate species complete the coralline algal assemblages, which are similar to those found in other closely located Middle Miocene carbonates (Aguirre and Braga, 2022).