Geochemistry of phosphatic nodules as a tool for understanding depositional and taphonomical settings in a Palaeolithic cave site (San Teodoro, Sicily)

Interpreting depositional settings of cave sites is generally problematic, especially in absence of palaeontological/archaeological evidence. This is the case of some deposits at San Teodoro Cave (Sicily), a key site for the Mediterranean Palaeolithic. In a stratigraphic level interrupted by a carbonatic concretion, phosphatic nodules are present only in the part enclosed between the concretion and the cave wall. The discovery of these nodules combined with the punctual lack of fossils had initially suggested an erosion phenomenon and subsequent formation of nodules at a vadose level. Here we show the usefulness of an integrated, geochemical-palaeoecological approach in defining stratigraphy and palaeoenvironmental reconstructions. XRD, ICP-OES, ATR-FTIR and EDS analyses allowed the formulation of a new hypothesis regarding the origin of the nodules, the depositional dynamics, and the role played by the guano produced by an extensive colony of bats. The role of barium and rubidium in detecting taphonomical processes has been highlighted.

Using Spatial Analysis of Hydrocarbon Compositions to Better Understand the Petroleum Systems of the South Sumatra Basin, Indonesia

The South Sumatra Basin has been a focus for hydrocarbon exploration since the earliest oil discoveries in the late 1890s. Despite production of over 2500MMbbls of oil and 9.5TCF of gas our regional understanding of the basin’s petroleum systems is still evolving. Most discoveries occur along a series of Late Neogene NNW-SSE elongated anticlines. The most prolific reservoirs are fluvial – shallow marine sandstones of the Upper Oligocene – Lower Miocene Talang Akar Formation but hydrocarbons have also been discovered in numerous sandstone and carbonate reservoirs ranging in age from Middle – Late Miocene to Eocene. Pre-Tertiary fractured Basement reservoirs are also important gas producers. A geochemical database for produced, tested and seep oils and gases has been compiled from the analytical reports, produced by different service companies over a 40-year period, to understand the spatial distribution of hydrocarbon types and relate this to source type, source maturity and migration patterns. Integration with published palaeoenvironmental reconstructions for the time intervals associated with source rock deposition has enabled a better understanding of migration directions and migration limits. The database of over 100 oils and 40 gases has revealed a wider variation in geochemical character than previously thought, indicating the presence of numerous fluvio-deltaic and lacustrine types suggesting subtle variations in the character of the effective source rocks within the basin, related to both organic matter type and depositional environment. Seven major oil families, often with several sub-groups, have been identified, while the presence of both biogenic and thermogenic gases of varying maturities are also noted. Spatial analysis of these hydrocarbons, integrated with source rock indications, palaeoenvironmental reconstructions and structural maps have allowed definition of kitchen areas and drainage areas for these hydrocarbon accumulations and a better understanding of the charge risk and likely hydrocarbon type in undrilled areas.

First record of stable isotopes (δ13C, δ18O) and element ratios (Mg/Ca, Sr/Ca) of Middle to Late Jurassic belemnites from the Indian Himalayas and their potential for palaeoenvironmental reconstructions

Middle to Late Jurassic belemnites from the Spiti and Zanskar valleys in the Indian Himalayas were used for stable isotope (δ13C, δ18O) and element (Mg/Ca, Sr/Ca) analyses. Although the Himalayan orogeny deformed and altered a large portion of the collected fossils, cathodoluminescence and scanning electron microscopy in combination with analyses of iron and manganese contents allowed the identification of belemnites believed to still retain their original chemical composition. Results indicate a long-term temperature decrease from the Middle Callovian–Oxfordian to the Tithonian, which is proposed to have been caused by a concomitant drift of eastern Gondwana into higher palaeolatitudes. Reconstructed absolute temperatures depend on the used equation and assumed δ18O value of seawater, but most likely varied between 17.6 °C to 27.6 °C in the Kimmeridgian and Tithonian with average values between 22 °C to 24 °C. This way, temperatures were similar to slightly warmer than today at comparable latitudes. The reconstruction of absolute temperatures for the Middle Callovian–Oxfordian was hindered by a larger number of poorly preserved belemnites representing this time interval.

Caves as geoheritage resource in remote desert areas: a preliminary evaluation of Djara Cave in the Western Desert of Egypt

Caves are rare in northeast Africa and, thus, deserve attention as potential geoheritage objects (geosites). Assessment of Djara Cave and its vicinity (Western Desert, Egypt) has permitted to document unique features, such as the cave itself as a peculiar subsurface landform, speleothems providing data for palaeoenvironmental reconstructions, rock art demonstrating elements of past landscapes, siliceous nodules weathered from Eocene limestones and a network of dry drainage channels indicative of wetter palaeoenvironments. These features are assigned to geomorphological, sedimentological and palaeogeographical types of geoheritage. Djara Cave and its vicinity are proposed as a geosite of national rank; it is vulnerable to anthropogenic stress and needs geoconservation measures and instalment of interpretative signs. This geosite is already popular among tourists, and can be used for further tourism development. More generally, the presence of caves in Egyptian desert areas makes possible the recognition of national speleological heritage that requires special country-level strategies of management.

Why a new volume on Non-Pollen Palynomorphs?

Here we introduce SP511, Applications of Non-Pollen Palynomorphs: from Palaeoenvironmental Reconstructions to Biostratigraphy. The study of Non-pollen palynomorphs (NPPs) has a long and rich history that is interwoven with that of pollen-based studies. NPPs are among the oldest fossils on record, and are instrumental in determining the origin and evolution of life, as well as studying origination and extinction events prior to the origin of pollen-producing angiosperms. This new volume on NPPs provides an up-to-date and seminal overview of the subject, linking deep-time and Quaternary study of the subject for the first time.

UPPER BURDIGALIAN-MIDDLE SARMATIAN CALCAREOUS NANNOFOSSILS FROM TOTEA-VĂLENI AREA (GETIC DEPRESSION, ROMANIA)

This work presents the calcareous nannofossils identified in samples recovered from 7 boreholes drilled on the western side of the Olt River, in the Totea, Colibasi, Radinesti and Valeni areas, within the central-southern part of the Getic Depression. These boreholes crossed upper Burdigalian–middle Sarmatian sediments. The identified assemblages are typical for the following calcareous nannofossil biozones: upper part of NN 3 – lower part of NN 4, corresponding to the late Burdigalian time interval, upper part of NN 4, corresponding to the early Badenian, NN 5, spanning the middle Badenian, and, respectively, NN 6-NN 8, covering the late Badenian – middle Sarmatian interval. The diversity and abundance of the identified nannofossil assemblages allow palaeoenvironmental reconstructions

Comparative analysis of six common foraminiferal species of the genera <i>Cassidulina</i>, <i>Paracassidulina</i>, and <i>Islandiella</i> from the Arctic–North Atlantic domain

Morphologically similar benthic foraminiferal taxa can be difficult to separate. Aside from causing issues in taxonomy, incorrect identifications complicate our understanding of species-specific ecological preferences and result in flawed palaeoenvironmental reconstructions and geochemical results. Over the years, a number of studies have grouped together several key Arctic–North Atlantic species in various combinations, despite their distinct environmental preferences and/or stratigraphical differences, causing great confusion in the literature. These species include Cassidulina laevigata, Cassidulina neoteretis, Cassidulina teretis, Paracassidulina neocarinata, Islandiella helenae, and Islandiella norcrossi. Here, we provide for the first time a detailed comparison of these taxa. We present a compilation of the original species descriptions, along with clear, illustrated guidelines on how to separate these taxa to circumvent taxonomic confusion. We acknowledge that some features cannot easily be seen with a standard low-powered microscope, especially if specimens are not well preserved. In those cases, we recommend the following actions: (i) always strive to make a precise identification and at least differentiate between the three genera; (ii) where C. neoteretis and C. teretis cannot be separated, and where the stratigraphical context does not make the species identification obvious, specimens belonging to these taxa should be reported as C. teretis/C. neoteretis; and (iii) where specimens in a sample cannot be confidently assigned to a specific species of Islandiella or Cassidulina, specimens should be grouped as Islandiella spp. or Cassidulina spp., followed by naming the most dominant species in brackets. The improved identification of Cassidulina, Paracassidulina, and Islandiella specimens will ensure development of a better understanding of the ecological affinities of these key Arctic–North Atlantic taxa, consequently resulting in more accurate palaeoenvironmental reconstructions and geochemical data.