FischerLab: An Application for Generating Fischer Plots and Dynamic Fischer Plots from Wireline Well-Logs and Stratigraphic Data

Fischer plots are a technique that is used to graph changes in accommodation in cyclic carbonate successions. They typically depict the cumulative departure from the average cycle thickness as a function of the cycle number or stratigraphic depth. Many applications of Fischer plots focus on their construction from exposed cyclic carbonate successions. No published programs allow the direct construction of Fischer plots from digital wireline well-logs or dynamic presentations of Fischer plots. Here, we introduce a program known as FischerLab, which facilitates the generation and analysis of Fischer plots. In addition to accepting interpreted stratigraphic data input, FischerLab facilitates the interpretation of digital wireline logs for the generation of Fischer plots in cycle and depth domains, as well as in a dynamic evolving cycle and relative depth domain from an easy-to-use interface. The dynamic construction facilitates the correlation of specific stratigraphic packages to parts of the accommodation cycle while simultaneously tracking the locus of the mean subsidence vector. We demonstrate the use of FischerLab on data derived from the carbonate succession outcrops of the Al-Athrun Formation, Libya, and the Glen Rose Formation, Central Texas, USA, as well as on wireline well-log data from the Western Great Bahama Bank, the Bahamas.

Early Cretaceous cyclostome bryozoans from the early to middle Albian of the Glen Rose and Walnut formations of Texas, USA

The Glen Rose and Walnut formations of southcentral and northcentral Texas comprise shallow-water carbonates deposited during the late Aptian to middle Albian on a carbonate platform. The formations are famous for their rich fossil faunas. Although bryozoans are absent in late Aptian sediments, they are frequently found encrusting bivalve shells from the early to middle Albian parts of these formations. Here, we describe the cyclostome bryozoan fauna, which includes six species;Stomatoporasp.,Oncousoecia khirarn. sp.,Reptomultisparsa mclemoreaen. sp.,Hyporosopora keeran. sp.,Mesonopora bernardwalterin. sp., and ?Unicaveasp. Most cyclostomes are found encrusting rudist shells from Unit 2 of the Lower Member of the Glen Rose Formation and units 3 and 6 of the Upper Member of the Glen Rose Formation.UUID:http://zoobank.org/4380dcb5-63b2-4aa9-959c-09eb6b03831f

The first South American sandownid turtle from the Lower Cretaceous of Colombia

Sandownids are a group of Early Cretaceous-Paleocene turtles that for several decades have been only known by cranial and very fragmentary postcranial elements. Here I report and describe the most complete sandownid turtle known so far, including articulated skull, lower jaw and postcranial elements, from the Early Cretaceous (upper Barremian-lower Aptian, >120 Ma), Paja Formation, Villa de Leyva town, Colombia. The new Colombian sandownid is defined here asLeyvachelys cipadinew genus, new species and because of its almost identical skull morphology with a previously reported turtle from the Glen Rose Formation, Texas, USA, both are grouped in a single and officially (ICNZ rules) defined taxon. Phylogenetic analysis includingL. cipadisupports once again the monophyly of Sandownidae, as belonging to the large and recently redefined Pan-Chelonioidea clade. The morphology ofL. cipadiindicates that sandownids were not open marine turtles, but instead littoral to shallow marine durophagous dwellers.Leyvachelys cipadinot only constitutes the first record of sandowinds in South America, but also the earliest global record for the group.