See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/257497385 New insights on the red alga Archaeolithophyllum and its preservation from the Pennsylvanian of the Cantabrian Zone (NW... Article in Facies · October 2013 DOI: 10.1007/s10347-012-0347-8 CITATIONS READS 3 36 3 authors: Diego Corrochano Daniel Vachard Universidad de Salamanca Université des Sciences et Technologies de Li… 12 PUBLICATIONS 54 CITATIONS 449 PUBLICATIONS 4,178 CITATIONS SEE PROFILE SEE PROFILE Ildefonso Armenteros Universidad de Salamanca 90 PUBLICATIONS 769 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Visean calcareous algae and foraminifera in the Kiyasar section, northern Iran View project Foraminiferal biostratigraphy of the Mississippian rocks of Alborz (Iran) View project All content following this page was uploaded by Diego Corrochano on 17 November 2015. The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. Facies (2013) 59:949–967 DOI 10.1007/s10347-012-0347-8 ORIGINAL ARTICLE New insights on the red alga Archaeolithophyllum and its preservation from the Pennsylvanian of the Cantabrian Zone (NW Spain) D. Corrochano • D. Vachard • I. Armenteros Received: 27 June 2012 / Accepted: 7 November 2012 / Published online: 29 November 2012 Ó Springer-Verlag Berlin Heidelberg 2012 Abstract The new species Archaeolithophyllum asym- formed micrite-rich bioherms with abundant shelter metricum nov. sp., from the Bachende Formation (Penn- porosities, which are filled up with radiaxial-fibrous calcite sylvanian, Cantabrian Zone, NW Spain), is described (originally high-Mg calcite) and subsequent blocky spar. herein using cathodoluminescence microscopy. Under They constructed a rigid framework that was basically a plane-polarized light, A. asymmetricum occurs as elongate combination of the foliaceous growth form, crust fusion and arcuate sheets preserved as calcitic mosaics of tiny and division, and synsedimentary marine cementation. anhedral to subhedral crystals. Cathodoluminescence has Paleontological and sedimentological evidence suggests revealed that skeletal walls are composed of dull-bright that A. asymmetricum thrived in an outer platform envi- (locally bright) luminescent calcite that contrasts sharply ronment with relative quiet conditions. The exceptional with the nonluminescent cements filling the intraskeletal preservation of these algae was favored by a rapid pores. Skeletal walls are currently composed of low-Mg cementation of the intraskeletal pores under oxidizing calcite (0.5–2 mol % MgCO3) with low Sr content (aver- conditions in a marine phreatic environment, protecting age 415 ppm). A. asymmetricum shows a strong asymmetry skeletons from early dissolution and recrystallization. of the thallus organization. The internal tissue is well dif- Although the resulting neomorphic microsparite fabric ferentiated into a thick medullar hypothallus and a thin suggests an aragonite precursor, the morphological simi- upper cortical perithallus, the latter being composed of larities (especially reproductive organs) between Archae- nearly rectangular cells arranged in rows perpendicular to olithophyllum and Recent calcitic corallinaceans, and the the external surface. Cell fusions commonly occur in the similar trace element composition of the algal thalli and the perithallial tissue whereas conceptacles exhibit a highly surrounding high-Mg radiaxial-fibrous cements, suggest arched geometry lacking any preserved aperture. A. asym- that originally, Archaeolithophyllum was probably com- metricum accumulations display a growth pattern similar to posed of high-Mg calcite. Based on the morphologic fea- that reported from Late Paleozoic ‘‘phylloid algae’’, and tures, framework strategies (crust fusion and division) and also resemble Miocene frameworks of the corallinacean growth modes, it is suggested that Archaeolithophyllum Mesophyllum. These accumulations of A. asymmetricum might be phylogenetically related to the modern coralline algae. & D. Corrochano ( ) Á I. Armenteros Keywords ‘‘Phylloid algae’’ Á Cathodoluminescence Á Facultad de Ciencias, Departamento de Geologı´a, Universidad de Salamanca, Plaza de los Caı´dos s/n, 37008 Salamanca, Spain Archaeolithophyllum Á Pennsylvanian Á Cantabrian Zone Á e-mail: [email protected] Spain I. Armenteros e-mail: [email protected] Introduction D. Vachard Universite´ Lille 1, UMR 8217 du CNRS, Ge´osyste`mes, 59655 Villeneuve d’Ascq Cedex, France The ‘‘phylloid alga’’ Archaeolithophyllum appeared in the e-mail: [email protected] Late Mississippian (for a review see Wray 1977a, b; 123 950 Facies (2013) 59:949–967 Vachard and Aretz 2004;Co´zar et al. 2005; Somerville Fig. 1 a Geological map of the Cantabrian Zone showing the c 2008), and is very abundantly represented in Late Penn- location of the Salamo´n Gold District, modified from Julivert (1971) and Pe´rez-Estau´n et al. (1988). b Stratigraphic correlation of the cores sylvanian and Early Permian shallow-water carbonate SS-14, SS-16, and SS-58 in the Salamo´n Gold District, showing the shelves and ramps worldwide. They played an important sample horizon of Archaeolithophyllum asymmetricum sp. nov.; Mr role in mound and reef build-up development, commonly marl, M mudstone, W wackestone, P packstone, G grainstone, forming accumulations with high porosity and gas and oil R rudstone/floatstone, B boundstone, Md mudrock, f, m, c, Vc fine, medium, coarse and very coarse grained sandstone, respectively, Cg reservoir quality (Wray 1964). conglomerate Pray and Wray (1963) defined the term ‘‘phylloid’’ to describe various types of membranous leaf-like calcareous algae, irrespective of taxonomic identity or growth habit, Such cellular structure can hardly be observed under planar found in Late Paleozoic rocks of the Paradox Basin, USA. polarized light microscopy and, thus, most of taxonomic The term ‘‘phylloid’’ is predominantly applied to strongly affinities of neomorphosed ‘‘phylloid algae’’ are uncertain. recrystallized algae, which display a wide spectrum of Based on cathodoluminescence microscopy, this paper growth forms, although cyathiform (cup-shaped) and leaf- documents very well preserved specimens of a new species like (undulating plates) dominate (Enpu et al. 2007a). As of Archaeolithophyllum (A. asymmetricum sp. nov.) and the preservation of their internal cellular structure is illustrates the cellular structure and thallus organization of commonly poor, it is often virtually impossible to distin- this alga. The phylogenetic position of Archaeolithophyl- guish one genus from another (Wray 1977a), and this lum, along with the paleoecology, preservation, and dia- artificial group of algae has been usually used as a ‘‘waste- genesis, is also discussed. paper basket’’ (Schlagintweit 2010), and subsequently considered as unnecessary (Granier 2012). ‘‘Phylloid algae’’ include both Rhodophyta and Chloro- Materials and methods phyta (e.g., Konishi and Wray 1961; Wray 1977a; James et al. 1988; Enpu et al. 2007a, b). The most typical ‘‘phyl- Specimens of Archaeolithophyllum asymmetricum were loid algae’’, or Anchicodiaceae (Shuysky in Chuvashov collected from three cores (SS-14, SS-16, and SS-58) from et al. 1987; Mamet 1991) are represented by Ivanovia the Bachende Formation (late Kashirian/early Myachko- Khvorova 1946, Eugonophyllum Konishi and Wray 1961, vian, Moscovian, Pennsylvanian) in the Salamo´n Gold Anchicodium Johnson 1946, and Neoanchicodium Endo in District (Lois-Ciguera sector, Central Asturian Coalfield, Endo and Kanuma 1954 (as well as many junior synonyms Cantabrian Zone, NW Spain; Fig. 1a, b); these cores are of these genera, such as Kansaphyllum Baars 1992; Calci- housed in the core-repository of Castilla y Leo´n, Salam- petra Torres et al. 1992; and Iranicodium Senowbari-Dar- anca, Spain. SS-14 is 295 m long, SS-16 is 207 m long, yan and Rashidi 2010). The status of Anchicodium is and SS-58 is 347 m long (uncorrected and apparent controversial. It is included in the ‘‘phylloid algae’’ by e.g., thickness). Description of color in hand samples follows Konishi and Wray (1961) and Senowbari-Daryan and the Rock-Color Chart (Geological Society of America Rashidi (2010), although Baars and Torres (1991) and 1995) terminology. Almost 100 thin-sections were pre- Torres and Baars (1992) suggested that the thallus of pared and studied for microfacies analysis by traditional Anchicodium is cylindrical and branching, and hence the petrographic techniques. Thin-sections and polished slabs organism is not literally a ‘‘phylloid alga’’. Two genera were stained with combined Alizarin red S and potassium previously assigned to the ‘‘phylloid algae’’ differ funda- ferricyanide for distinguishing between ferroan phases in mentally from the anchicodiacean algae, Calcifolium calcites and dolomites (Dickson 1966). Fourteen thin-sec- Maslov 1956 and Archaeolithophyllum Johnson 1956. tions of algal-rich facies were studied in detail, from which Calcifolium is an algospongia (see Co´zar and Vachard two selected thin-sections (SS-14-4CT and SS-16-33.5CT) 2004), a group of incertae sedis algae recently revised by were polished and examined uncovered with a Cold Vachard and Co´zar (2010). Archaeolithophyllum, the Cathode Luminescence 8,200 mk3 equipment microscope questionable Kasimophyllum Mamet and