Exceptionally well-preserved specimens of a new cypridid ostracod (Crustacea), Raepula ira sp. nov., are described from palaeolake sediments of the Middle Miocene Barstow Formation of the Mud Hills, southern California. This is only the second occurrence of exceptionally preserved ostracods from the Miocene. Based on ages obtained from associated volcanic tuffs the palaeolake sediments were deposited between 16.3 and 15.8 Ma. The ostracods form one element of a diverse lake community dominated by fairy shrimps, copepods, diatoms, larvae of diving beetles, flies and mosquitoes, and body fossils and ephippia of branchiopods and anomopods. The ostracods are preserved three-dimensionally with their soft anatomy replicated in microcrystalline silica. Sub-micron scale details such as sensory setae are preserved, surpassing the resolution of most other ostracodbearing lagerstätten and allowing their biology to be compared with extant taxa.

Sedimentological data acquired by thin section petrography is a rich source of information to better understand and interpret depositional environments that are dominated by fine-grained deposits. This study provides an evaluation of the sedimentological and geochemical changes recorded over Upper Viséan to Lower Namurian successions preserved in a core section from a well drilled in the southern part of the Netherlands.Facies analysis and the recognition of microfacies associations allow detailed interpretations of depositional environments. Interpretation of additional geochemical data acquired by portable X-ray fluorescence analyses has resulted in a chemostratigraphic zonation for the core section.The zonation reflects stratigraphic changes in the mineralogy of the sedimentary successions. Integration of the microfacies associations and the chemostratigraphic zonation has led to the identification of three so-called depositional zones, which show the development of depositional settings from Late Viséan to Early Namurian times. Depositional Zone 1 consists of fine-grained turbiditic limestones and mudstones deposited in a distal carbonate ramp setting during Latest Viséan times. The overlying Depositional Zone 2 corresponds to the Geverik Member (Lower Namurian) and is particularly heterogeneous in geochemical and lithological terms: the zone reflects a complex interplay between different parameters such as sediment source, transport mechanisms and oxygen content that are assumed to be governed by fluctuating sea levels and changing depositional environments (from basinal to shallow marine settings). Sandy lenticular mudstones are predominant in the lower part of Depositional Zone 2 and show that sedimentation was via erosive bedload, whilst the common fossiliferous mudstones present within the upper part of the same zone yield evidence for increased endobenthic activity in dysoxic conditions. The successions assigned to Depositional Zone 3 ( = Epen Formation -Namurian) are the products of cyclic sedimentation of a terrestrial sourced delta.

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The Namurian and Westphalian sequences from the onshore well Scaftworth-B2, located in the Gainsborough Trough, central England, have been analysed for whole-rock inorganic geochemical data via inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (MS). The changes within key elements, and elemental ratios, results in a chemostratigraphic zonation scheme consisting of eight chemostratigraphic sequences and 13 chemostratigraphic packages, providing the type zonation for the Bowland Shale and overlying formations. Mineralogical data are provided by whole rock X-ray diffraction (XRD) and are used to calibrate the mineral modelling in order to generate a modelled mineral log for the study well. Furthermore, the modelled mineralogy is then used to calculate a relative brittleness for the samples, which can then be collaborated with traditional rock properties data at a later date. Elemental data can also be used to model the relative abundance of detrital quartz and biogenic silica; while total silicon is detected by ICP, biogenic silica is not detected by XRD owing to its amorphous nature. Enrichment factors calculated from the inorganic elemental data suggest that the sediment was deposited in an unrestricted marine setting, which experienced periods of anoxia.

A prerequisite to understanding the evolution and resource potential of a basin is to establish a reliable stratigraphic framework that enables the correlation of rock units across multiple depocentres. Establishing a stratigraphic model for the Adavale Basin is challenging due to its structurally complexity, lack of well penetration and its lateral changes in facies. Biostratigraphy appears broad-scale, and despite providing chronostratigraphic control for the Lower Devonian Gumbardo Formation when combined with U/Pb zircon geochronology, the rest of the Devonian succession is hampered by a lack of microfossil assemblages and their poor preservation. The aim of this study is to establish an independent chemostratigraphic correlation across the Adavale Basin using whole rock inorganic geochemistry. Within this study, a total of 1489 cuttings samples from 10 study wells were analysed by Inductively Coupled Plasma – Optical Emission Spectrometry and Inductively Coupled Plasma – Mass Spectrometry for whole rock geochemistry, in order to establish an independent chemostratigraphic zonation scheme. Based on key elemental ratios selected to reflect changes in feldspars, clay minerals and provenance, the Devonian-aged stratigraphy is characterised into four chemostratigraphic mega-sequences that encompass the Gumbardo Formation (Mega-sequence 1); the Eastwood Formation, the Log Creek Formation and the Lissoy Sandstone (Mega-sequence 2); the Bury Limestone and the Boree Salt formations (Mega-sequence 3); and the Etonvale and the Buckabie formations (Mega-sequence 4). These mega-sequences have been further subdivided into a series of chemostratigraphic sequences that can be correlated across the study wells, establishing a regional correlation framework.