Neoproterozoic microfossils from the Officer Basin,Western Australia

Microfossil assemblages are described from the early Neoproterozoic Madley and Browne Formations, western Officer Basin. One chert and eleven siliciclastic samples yielded microfossils. Myxococcoides cantabrigiensis occurs as pustular mats in the chert sample and Eomicrocystis malgica, Pterospermopsimorpha granulata, Skiagia sp. cf. S. pusilla, and undetermined species of Obruchevella, Heliconema, and Trachystrichosphaera are present in acid macerated samples. Leiosphaeridia spp. and Siphonophycus spp. are also found in fine-grained siliciclastic samples, with clusters of Synsphaeridium sp. in some samples. These findings enable a more substantial reconstruction of the palaeoenvironment of Supersequence 1 in the western Centralian Superbasin. The acanthomorph acritarchs are considered to be planktonic eucaryotes washed into environments which ranged from coastal sabkha through to tidal flats, which may be the source of the prokaryotic, benthic, matforming cyanobacteria.     

A rare,late Paleocene molluscan faunule from the Kings Park Formation,Perth Basin,Western Australia

A shallow marine faunule of eight taxa from the Kings Park Formation of the Perth Basin is the first described Paleocene molluscan assemblage from Western Australia. These species are part of a depauperate suite of macroinvertebrates (molluscs, echinoids and corals) derived from deep, onshore caissons in Perth and are inferred to be late Paleocene in age, based on planktonic foraminiferal biostratigraphy and associated age ranges of the molluscan fauna. Bivalves are Sarepta austranaxa sp. nov. (Sareptidae), Solemya kingsparki sp. nov. (Solemyidae), Periploma vivarirex sp. nov. (Periplomatidae), Parvamussium sp. nov.? (Propeamussiidae), Serripecten? sp. (Pectinidae) and Venericardia (Rotundicardia) petraea Darragh (Carditidae). Gastropods are Levifusus? sp. cf. L.? quadrifunifer Darragh (Buccinidae), and Columbarium rumatoides Darragh (Turbinellidae). Bivalves dominate the fauna in dark, glauconitic siltstone and sandstone facies; gastropods are of relatively poor preservation and low diversity.     

Miocene scleractinian corals from a mixed siliciclastic–carbonate system: Bakhtiari succession,Zagros Basin (central-western Iran)

Colonial scleractinian corals were sampled from three levels within a Miocene marine unit of the Bakhtiari succession, Zagros Basin, central-western Iran. The first two coral-bearing intervals, A and B, contain small-scale scattered colonies and show a poor coral diversity, whereas the third, consisting of a strongly lithified limestone package, reflects a well-developed biostromal framework with higher coral skeletal volume within the Bakhtiari succession. The Bakhtiari succession coral assemblages are characterized by Porites sp. cf. P. maigensis, Porites sp. cf. P. mancietensis, Porites sp. cf. P. collegniana, Tarbellastraea reussiana, Favia sp., Montastrea sp. cf. P. tchihatcheffi, Favites sp. cf. P. neugeboreni, Favites sp. cf. P. neuvillei, Agathiphyllia sp. and Acropora sp. Sedimentological and palaeontological data indicate that the depositional environment is consistent with a mixed carbonate–siliciclastic ramp that was gently deepening basinwards from the shoreline. The hemispherical and massive growth forms of colonies and sparse branching forms dominated the well-illuminated euphotic zone. Abundant domestone and dense pillarstone coral growth fabrics interdigitating with coarse-grained terrigenous sediments developed in the shallow inner ramp environment. Branching forms and meandroid branching colonies together with some massive forms mostly inhabited the low-energy conditions of the lower euphotic to oligophotic zones of the middle ramp. In the middle parts of the mixed carbonate–siliciclastic ramp, sparse pillarstone together with domestone comprises a mixstone coral growth fabric. Fluctuations in nutrient and clastic sediment input, salinity and the growth of red algae likely terminated coral growth.     

Relationship of brines in the Kinnarot Basin,Jordan‐Dead Sea Rift Valley

Element ratios and water stable isotopes reveal the presence of only two independent deep brines in the Kinnarot Basin, Israel: the evaporite dissolution brine of Zemah‐1 and the inferred Ha’on mother brine (HMB) with low and high Br/Cl ratios, respectively. HMB is considered to be a representative of the Late Pliocene evaporated Sedom Sea. The freshwater‐diluted evaporation brine emerges as Ha’on brine on the eastern shore of Lake Tiberias and is also identified in the pore water of lake sediments. HMB is converted into Tiberias mother brine (TMB) by dolomitization of limestones and alteration of abundant volcanic rocks occurring along the western side of the lake. The Ha’on and Tiberias brines, both characterized by high δD and δ¹⁸O values, are similar in Na/Cl and Br/Cl ratios but are dissimilar in Br/K ratios because these brines were subjected to different degrees of interactions with rocks and sediments. Excepting the brine from KIN 8, all brines from the Tabigha area including the nearby off‐shore Barbutim brine are related to the TMB. The brine KIN 8 and all brines from the Fuliya and Hammat Gader areas are related to the HMB. The brine encountered in wildcat borehole Zemah‐1 is generated by halite‐anhydrite/gypsum dissolution and is independent from the HMB system.     

Geodynamic processes in the NW Bohemian swarm earthquake region,Czech Republic,identified by continuous gas monitoring

The time series of two continuously operating gas monitoring stations at Oldřišská and Nový Kostel located along seismoactive faults in the epicentral area of the NW Bohemian swarm earthquakes (Czech Republic) are compared with water level fluctuations in two boreholes positioned along these faults and with gas flux variations of a mofette at the Soos mofette field at 9 km distance. The seasonal trend of the monitored CO₂ concentration with a maximum in November and a minimum in March/April is governed by groundwater temperatures, superimposed in spring by soil temperatures. CO₂ concentration variations identified at Oldřišská are also reflected in gas flux variations in the Soos mofette and/or water level fluctuations of two boreholes. Variations in the gas monitoring recordings of station at Nový Kostel are also linked with variations at Oldřišská. In all data sets, diurnal variations generated by earth tides occur, reflecting a daily stress – fault permeability cycle. Additional stress interferes with this cycle. Significant, abrupt changes are attributed to geodynamic processes linked with seismic events, as revealed by local seismicity or by the transient of waves of a strong remote earthquake. Simultaneous variations of the gas concentrations in the Nový Kostel area and in the gas flux in the Soos point to an interconnected hydraulic conductive fault systems present in the northern part of the Cheb Basin. Sharp falls in gas concentration, during or subsequent to, earthquake swarms may reflect fault compression associated with impeded gas migration. However, gas variations also occur in periods without seismic activity, indicating changes in fault permeability were caused by local aseismic fault movements, as revealed by events with opposite trends in the gas recordings at Oldřišská, Nový Kostel and the Soos. Therefore, a mathematical approach to establish a correlation between seismicity and gas geochemical variations is not possible.     

A new genus and species of Steninae from the late Eocene of France (Coleoptera,Staphylinidae)

Cai, C., Clarke, D.J., Huang, D. & Nel, A., 2014. A new genus and species of Steninae from the late Eocene of France (Coleoptera, Staphylinidae). Alcheringa 38, 557–562. ISSN 0311-5518.

A remarkable new genus and species of rove beetle, Eocenostenus fossilis gen. et sp. nov., is described and figured based on one well-preserved specimen from the late Eocene of Monteils (near Alès, Gard, France). Eocenostenus is definitively placed in the extant subfamily Steninae, based on the combination of dense and coarse body punctation, globular and protruding eyes, exposed and closely spaced antennal insertions on the vertex, and six visible abdominal terga. Eocenostenus differs from the two extant stenine genera Stenus and Dianous most notably in the structure of the prothorax, which is strongly transverse and with unusual anterolateral projections, and in the anteriorly placed antennal insertions. This new discovery highlights the palaeodiversity of a genus-poor subfamily and suggests that the early diversification of Steninae is probably complicated.

Chenyang Cai [caichenyang1988@163.com] and Diying Huang [dyhuang@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Rd., Nanjing 210008, PR China; Dave J Clarke [dclarke@fieldmuseum.org], Integrative Research Center, Field Museum of Natural History, 1400 S Lake Shore Drive, Chicago, IL 60605, USA; and André Nel [anel@mnhn.fr], Muséum National d’Histoire Naturelle, Institut de Systématique, Evolution, Biodiversité, ISYEB, UMR 7205 CNRS UPMC EPHE, CP50, 45 rue Buffon, F-75005 Paris, France. Received 23.1.2014; revised 2.5.2014; accepted 12.5.2014.     

Gracilitheca and Nephrotheca (Hyolitha,Orthothecida) in the Cambrian of the Barrandian area,Czech Republic

VALENT, M., FATKA, O. & MAREK, L., iFirst article. Gracilitheca and Nephrotheca (Hyolitha, Orthothecida) in the Cambrian of the Barrandian area, Czech Republic. Alcheringa, 1–10. ISSN 0311-5518.

Five orthothecid hyoliths, Gracilitheca mirabilis sp. nov., Gracilitheca triangularis sp. nov., Gracilitheca sp., Nephrotheca betula sp. nov. and Nephrotheca sp. are described from the ‘middle’ Cambrian Buchava Formation of the Skryje–Tý?ovice Basin in the Czech Republic. The new forms are based on about forty well-preserved external and internal moulds of conchs; opercula of all species remain unknown. Stratigraphic ranges and geographic distributions within the Skryje Tý?ovice Basin are established for all taxa.     

南宋乌江流域少数民族地方武力——以夔州路抗蒙（元）战争为视角的探讨

乌江流域地处西南边陲,境内少数民族众多,宋廷因地制宜,组建了多支少数民族军队。这些地方武力主要由御前屯驻大军和乡军组成,在南宋抗蒙（元）战争中贡献卓著,并与宋朝国祚相始终。此外,它在保卫边防、稳定当地秩序、开发边疆等方面也发挥了积极作用。     

干旱区内陆河流域城乡聚落体系空间结构及影响模式研究——以石羊河流域为例

本研究以石羊河流域为研究区,选取2000、2006、2010年三期遥感影像为数据源,采用成本加权距离和城乡聚落体系潜能指数对传统的场强模型进行改进,综合利用扩张强度指数、扩张速度指数等分析研究石羊河流域内部城乡聚落体系空间结构分异。在此基础上,基于GIS技术并结合道路等级和长度计算流域内城乡聚落体系间最短时间距离来分析城乡聚落体系空间联系与空间相互作用,据此分析石羊河流域城乡聚落体系空间结构变化及影响模式。     

Hydrothermal control on organic matter alteration and illite precipitation, Mt Isa Basin, Australia

Abundant illite precipitation in Proterozoic rocks from Northern Lawn Hill Platform, Mt Isa Basin, Australia, occurred in organic matter‐rich black shales rather than in sandstones, siltstones and organic matter‐poor shales. Sandstones and siltstones acted as impermeable rocks, as early diagenetic quartz and carbonate minerals reduced the porosity–permeability. Scanning and transmission electron microscopy (SEM and TEM) studies indicate a relation between creation of microporosity–permeability and organic matter alteration, suitable for subsequent mineral precipitation. K–Ar data indicate that organic matter alteration and the subsequent illite precipitation within the organic matter occurred during the regional hydrothermal event at 1172 ± 50 (2σ) Ma. Hot circulating fluids are considered to be responsible for organic matter alteration, migration and removal of volatile hydrocarbon, and consequently porosity–permeability creation. Those rocks lacking sufficient porosity–permeability, such as sandstones, siltstones and organic matter poor shales, may not have been affected by fluid movement. In hydrothermal systems, shales and mudstones may not be impermeable as usually assumed because of hydrocarbons being rapidly removed by fluid, even with relatively low total organic carbon.