bibliography - various topics

Varia / 12th May 2017

LAGROU D., COEN-AUBERT M. 2017. Update of the Devonian lithostratigraphic subdivision in the subsurface of the Campine Basin (northern Belgium). Geologica Belgica (2017) 20, 1/2, 13 pp.;; available online since 10 January 2017.
[keywords: Booischot Formation, Givetian, Frasnian, Famennian, lithostratigraphy, biostratigraphy]
The continental and mainly conglomeratic Booischot Formation is formally introduced for the strata intersected close to the base of the Booischot borehole from the Campine Basin. It is nearly 400 m thick and its upper part is Upper Givetian to Upper Frasnian in age whereas its lower part has not been dated so far. The Booischot borehole is overlain by the Upper Devonian marine Aisemont and Falisolle Formations which are capped by Famennian sandstones assigned to the Evieux Formation. These latter three lithostratigraphic units are also present in the Heibaart borehole, above a few metres of the Middle Frasnian Huccorgne Formation which rest directly on the Caledonian basement of the Brabant Massif, without any trace of the Booischot Formation. It appears that in the Campine Basin, the Devonian transgression arrived very late during the Frasnian. The Devonian succession at the northern margin of the Brabant Massif is very different from that of the north side of the Namur Basin and the Visť area characterized more particularly by the occurrence of Givetian marine deposits. Some rugose corals of this stage are figured for the first time from the Visť area. The conglomerates of the Booischot Formation are also compared to similar thick strata from the Givetian of NW Germany. [original abstract; listed corals are the Upper Frasnian Frechastraea limitata, Potyphyllum ananas and Thecostegites cf. dumoni from Aisemont Fm of Booischot borehole; illustrated are Givetian corals Columnaria intermedia and Temnophyllum wellinense from the Dalhem borehole; Wrzolek]

MORO A., HORVAT A., TOMIC V., SREMAC J., BERMANEC V. 2016. Facies development and paleoecology of rudists and corals: an example of Campanian transgressive sediments from northern Croatia, northeastern Slovenia, and northwestern Bosnia. Facies 62, 19: 1-25.
At six localities in northern Croatia (Donje Orešje, Gornje Orešje), Slovenia (Stranice, Slovenj Gradec), and Bosnia (Bešpelj and Kober), successions of shallow-water Campanian deposits transgressively covered a tectonically uplifted and eroded paleorelief. They constitute different lateral parts of a transgressive subtidal environment, where rudists and corals are typical macrofossils. At the investigated localities, two types of succession were distinguished: (a) clastic and (b) carbonate. Most localities are within the extended chronostratigraphic range of Calveziconus cf. lecalvezae (80.5-79.03 Ma), which comprises the upper part of the Vaccinites alpinus interval zone (for Stranice and Slovenj Gradec localities) and beginning of the Pironaea polystyla interval zone (for Bešpelj and Kober localities). In clastic successions, corals are the most abundant macrofossils, whereas rudists predominate within carbonate sections. The depositional setting of the investigated localities results from rapid relative sea-level rise with a tectonic overprint, which covered different types of paleo-relief. In cases when the paleorelief is gentle, a transgressive succession starts with clastic coral-rich sediments or carbonates with radiolitids. In areas of steeper paleorelief carbonate sediments were deposited with a mixed radiolitid-hippuritid community, and the rudists, as the major macrofossils, indicate higher sedimentation rates in comparison with the clastic situations. [original abstract; Löser]

ZAPALSKI M. K., WRZOLEK T., SKOMPSKI S., BERKOWSKI B. 2017. Deep in shadows, deep in time: the oldest mesophotic coral ecosystems from the Devonian of the Holy Cross Mountains (Poland). Coral Reefs (2017); doi:10.1007/s00338-017-1575-8.
[keywords: Platy corals; Devonian; Photosymbiosis; Mesophotic; Tabulate corals]
Recent mesophotic coral ecosystems (MCE) occur at depths between 30 and 150 m and are characterized by dominance of platy corals. Such morphology is an effect of specific adaptation to efficient light harvesting. Here, we describe and analyze platy coral assemblages from two Middle Devonian localities in the Holy Cross Mountains (Poland) that during this time were located on the southern shelf of Laurussia at tropical latitudes. The Eifelian argillaceous sediments of Skaly are dominated by platy and encrusting tabulate corals (Roseoporella, Platyaxum and Alveolites). Coeval faunas from the shallow-water parts of the Holy Cross Mountains basin display bulbous and branching morphology, thus indicating a Paleozoic coral zonation similar to that known in the Recent. Hence, the Skaly site seems to be the oldest known MCE (ca. 390 Ma). A Givetian biostrome from Laskowa Quarry is a second example dominated by platy corals, with abundant branching forms; this site can be recognized as another Devonian MCE. Frondescent Platyaxum, common at both sites, had a growth habit similar to that of Recent Leptoseris, Mycedium or Pavona. Platy morphology is photoadaptive and may evidence photosymbiosis in tabulate (Alveolites, Roseoporella, Platyaxum) and rugose corals (Phillipsastrea). Furthermore, it may serve as a tool for recognition of the lower euphotic zone in the fossil record. [original abstract; Wrzolek]