The felsic lavas of the Bamenda Mountains, in the main part of the Cameroon Volcanic Line, are mainly represented by trachytes, with subordinated benmoreites and alkaline to peralkaline rhyolites. New K–Ar geochronological data define two main volcanic episodes, the first one between 18 and 22Ma, and the second one from 12.5 to 13.5Ma. Geochemical data indicate that these felsic rocks

The largest Kuiseb River floods initiate at the basin's semi-arid headwater. Downstream, along the hyperarid Namib Desert, these floodwaters are feeding shallow alluvial aquifers, the only available water for human activity and for the natural ecology. Here, we characterize the largest floods and their changing frequency and magnitudes using palaeohydrological methods. Along 120 km of the rivers canyon 35 palaeoflood deposit sites were identified. At five of these sites we conducted stratigraphic and geochronological analyses and flood discharge estimations. The upper bound of the largest flood over the late Holocene is $1475 m 3 s À1 . Over the last 1300 years more than ten floods have exceeded 1250 m 3 s À1 . An additional 33 floods exceeded 400 m 3 s À1 . The last millennium was characterized by one large flood every 30-40 years during the periods 1250-1335, 1355-1565 and 1715 AD to the present. A slight increase in flood frequency (not magnitude) occurred during 1565-1715 AD (one large flood in $20 years) and during two short episodes, 1185-1205 and 1335-1355 AD (seven and four floods in 20 years, respectively). These episodes of increased flood frequency are associated with other proxy records of higher water availability in the Namib.

Coal fires typically have a variety of mineral and organic deposits associated with the venting emission gases. In addition to the tars typically found at the Ruth Mullins coal fire, Perry County, Kentucky, a sooty carbon, superficially similar to a carbon from a university-based stoker-fired power plant, was sampled in an August 2010 visit. Carbons in the soot include complex carbon particles, nanotubes encapsulating Hg, onionlike structures with polyhedral and quasi-spherical morphology with hollow centers, and metal-bearing multiwalled nanotubes. Mineral sublimates from the Ruth Mullins fire in abandoned underground and surface mines in the high volatile A bituminous Middle Pennsylvanian Hazard No. 7 coalbed, Perry County, Kentucky, were examined by optical mineralogy, X-ray diffraction (XRD), and high-resolution-transmission electron microscopy (HR-TEM). Optical examination revealed the presence of salammoniac and a fine, unidentified fibrous mineral. XRD also showed the presence of salammoniac, along with trace amounts of quartz, kaolinite, and, possibly, phengite. Both cubic and dendritic salammoniac forms were observed with HR-TEM. Gypsum, jarosite, with cubic pseudomorphs after pyrite, and Fe-minerals, including Cr-bearing hematite in association with jarosite, were observed with HR-TEM. Dehydration of jarosite can lead to the formation of less hydrous Fe-sulfates and hematite. Mineral and amorphous inorganic phases included glassy Al-Si spheres with associated Pb and Se; nanopyrite grains with trace As and Se; nanohematite with V 3+ ; salammoniac; quartz; Cr-and Pb-bearing jarosite; fibrous pickeringite with surficial natrojarosite; and Cd-, Co-, Mo-, Ni, V-, W-, and Zr-bearing nanospheres.

The Austral-Magallanes is an oil-producing basin located in southern Argentina and Chile, containing a siliciclastic stratigraphic record ranging from the Late Jurassic to Late Cenozoic. This short paper finalize the two special volumes of the Latin American Journal of Sedimentology and Basin Analysis dedicated to the basin, and aim to provide a comprehensive synthesis based on the current knowledge about the chronology of deposition, stratigraphy, and tectonic events that shaped this basin. During the breakup of Gondwana in the Jurassic, an extensional phase was responsible for the beginning of accumulation of volcaniclastic material within grabens, which subsequently were covered by widespread Lower Cretaceous shallow and deep marine deposits that conforms the main hydrocarbon system. From Late Cretaceous onward, the subduction-related compressive regime associated to Andean uplift and fold and thrust belt migration was responsible for the onset of the foreland stage. During the L...

Field and microstructural analyses of faults with millimeters to hundreds of meters of displacement within welded tuffs at Yucca Mountain, Nevada, has led us to identify four different fault zone architectures. We designate these fault zones as Classes A-D. We conclude that Classes A, C, and D are genetically related and that observed differences in their morphology and deformation mechanisms are related to differences in displacement magnitude and changes in the rheology of faulted rocks. We show that Class A, C, and D fault zones were formed by progressive cataclasis, leading to the development of a foliated gouge core and wide damage zone at the highest displacement magnitudes. By inference, displacement variations across individual high displacement faults are expected to produce significant lateral changes in fault zone architecture. The broad range of fault rock textures and architectures found on the Class A, C, and D continuum may produce important corresponding variability in hydrologic properties in ignimbrites.

Interrelationships between peat and water were studied using a hydropedological modelling approach for adjacent relatively intact and degraded peatland in Central Kalimantan, Indonesia. The easy to observe degree of peat humification provided good guidance for the assignment of more difficult to measure saturated hydraulic conductivities to the acrotelm-catotelm hydrological system. Ideally, to prevent subsidence and fire, groundwater levels should be maintained between 40 cm below and 100 cm above the peat surface. Calculated groundwater levels for different years and for different months within a single year showed that these levels can drop deeper than the critical threshold of 40 cm below the peat surface whilst flooding of more than 100 cm above the surface was also observed. In July 1997, a dry El Niño year, areas for which deep groundwater levels were calculated coincided with areas that were on fire as detected from radar images. The relatively intact peatland showed resilience towards disturbance of its hydrological integrity whereas the degraded peatland was susceptible to fire. Hydropedological modelling identified areas with good restoration potential based on predicted flooding depth and duration. Groundwater level prediction maps can be used in fire hazard warning systems as well as in land utilization and restoration planning. These maps are also attractive tools to move from the dominant uni-sectoral approach in peatland resource management toward a much more promising multi-sectoral approach involving various forestry, agriculture and environment agencies. It is demonstrated that the combination of hydrology and pedology is essential for wise use of valuable but threatened tropical peatland ecosystems.

Melt impregnated plagioclase lherzolites from the Nain mélange, central Iran, contain pyroxenes enriched and chemically zoned with Sr. Pyroxenes from the lherzolite and the clinopyroxenite seams, which have been precipitated from the impregnating melt, show similar trace element geochemical characteristics, including a similar Sr anomaly. The associated plagioclase, precipitated from the impregnating melt, has been selectively altered to isotropic saussurite. Strontium concentration increases in the pyroxenes from the core to the rim and toward crosscutting saussurite trails in orthopyroxene porphyroclast cores. The highest Sr content (up to 10.8 ppm in clinopyroxene and 3.8 ppm in orthopyroxene) is found in the finer pyroxenes surrounded by thicker saussurite layers. The Sr enrichment within pyroxenes is neither caused by metasomatism nor modified by fluids involved in hydrothermal alteration because pyroxenes are extremely depleted in fluid-mobile and light rare earth elements. Also, Sr enrichment cannot be related to the melt impregnation, since the Sr supply from the impregnating melt was consumed by plagioclase crystallization. The Sr enrichment in the pyroxene postdates the melt impregnation and is due to the relatively high-temperature (375°C-850°C) of saussuritization, that is, the breakdown of plagioclase. Plagioclase decomposition has released appreciable amounts of Sr to enrich adjacent pyroxenes. Saussurite shows significantly lower Sr contents than the plagioclase. Sr enrichment in peridotite pyroxenes, which is ascribed primarily to the metasomatism of slab-derived fluids, should be treated carefully, particularly when altered plagioclase is present.

Volcano monitoring aims at the recognition of changes in instrumentally observable parameters before hazardous activity in order to alert governmental authorities. Among these parameters seismic data in general and volcanic tremor in particular play a key role. Recent major explosive eruptions such as Okmok (Aleutians) and Chaitén (Chile) in 2008 and numerous smaller events at Mt Etna (Italy), have shown that the period of premonitory seismic activity can be short (only a few hours), which entails the necessity of effective automatic data processing near on-line. Here we present a synoptic pattern classification analysis based on Self Organizing Maps and Fuzzy Cluster Analysis which is applied to volcanic tremor data recorded during a series of paroxysmal eruptive episodes and a flank eruption at Etna in 2007-2008. In total, eight episodes were analyzed; in six of these significant changes in the dynamic regime of the volcano were detected up to 9 h prior to the onset of eruptive activity, and long before changes in volcanic tremor amplitude and spectral content became evident in classical analysis. In two cases, the state transition was b 1 h before the onset of eruptive activity, which we interpret as evidence for very rapid magma ascent through an open conduit. We further detected twenty failed paroxysms, that is episodes of volcanic unrest that did not culminate in eruptive activity, between March and April 2007. As the application of the software for this synoptic pattern classification is straightforward and requires only moderate computational resources, it was possible to exploit it in an on-line application, which was tested and now is in use at the Istituto Nazionale di Geofisica e Vulcanologia in Catania for the monitoring of Etna. We believe that the pattern classification presented here may become a powerful addition to the repertoire of volcano monitoring tools and early warning techniques worldwide.

The seismicity depth distribution in the central and southern East African Rift System (EARS) is investigated using available catalogs from local, regional and global networks. We select well-determined events and make a re-assessment of these catalogs, including a relocation of 40 events and, where necessary, a declustering. About 560 events are finally used for determining foci depth distribution within 6 areas of the EARS. Assuming that short-term deformation expressed by seismicity reflects the long-term mechanical properties of the lithosphere, we build yield strength envelopes from seismicity depth distribution. Using brittle and ductile laws, we predict the strength percentage spaced every 5 km (or sometimes 2 km) in the crust, for a given composition and a specific geotherm, and constrain it with the relative abundance of seismicity. Results of this modeling indicate significant local and regional variations of the thermomechanical properties of the lithosphere which are broadly consistent with previous studies based on independent modelings. In order to explain relatively deep earthquakes, a highly resistant, mafic lower crust is generally required. We also find evidence for changes in the strength magnitude and in the depth of the brittle-ductile transitions which are clearly correlated to tectonic provinces, characterized by contrasted thermal gradients and basement types. A clear N-S increase and deepening of the peak strength level is evidenced along the eastern branch of the EARS, following a consistent southward migration of rifting sincẽ 8 Ma. We also detect the presence of a decoupling layer in the Kenya rift, which suggests persisting influences of the deep crustal structures (Archaean and Proterozoic) on the behavior of the extending crust. More generally, our results suggest that seismicity peaks and cut-off depths may provide good proxies for bracketing the brittle-ductile transitions within the continental crust.

The Middle Awash paleontological study area, located in the Afar Rift of Ethiopia, has yielded fossils spanning the last six million years. The geology and geochronology of the Mio-Pliocene sites of the study area have been refined and a reliable chronostratigraphy has been established by 40 Ar/ 39 Ar radiometric dating. The latest Miocene Adu-Asa Formation is divided into four members distinguished from each other by silicic and basaltic tuff marker horizons, most of which are dated basaltic tuffs. Radiometric dating has constrained the age of the Adu-Asa Formation to between 5.2-5.8 Ma. These dates are also supported by paleomagnetic results and biochronology. More than 2,000 fossil specimens were collected from the Adu-Asa Formation between 1992 and 2000. These fossils document 64 mammalian species belonging to 32 genera, 23 families, and 8 orders. This assemblage includes a number of new taxa. Included in the assemblage are First and Last Appearance Datums (FADs and LADs) of some groups, including the earliest record of the hominid genus Ardipithecus. Most of the taxa indicate a predominance of mesic and wooded habitat during the deposition of the Adu-Asa Formation. In these deposits, colobines, viverrids, mustelids, bovines, boselaphines, and tragelaphines are abundant, whereas alcelaphines are absent. Quantitative analyses of biogeographic relationships of the Middle Awash Late Miocene (MALM) mammalian fauna indicate stronger relationships with other African sites than with faunas from Eurasian sites. The MALM deposits have generated a critical dataset for analytic work on past environments, biogeographic relationships, and African vertebrate evolution. Moreover, the geographic position of the Middle Awash, coupled with its precise calibration and chronological span, make it a key section for interpreting latest Miocene faunal interchanges between Africa and Eurasia.

Kurzfassung: Triassische Ichthyosaurier sind weit verbreitet und sehr vielgestaltig, aber die meisten Formen sind schlecht bekannt. Neue Funde, wie sie hier beschrieben werden, unterstreichen die erste Feststellung, lassen die zweite aber nur langsam ungtiltig werden. Das erste assoziierte Skelett des ungew6hnlichen durophagen Ichthyosauriers Omphalosaurus, O. wolfi aus der Mitteltrias (unterstes Ladin) der Salzburger Alpen, wird beschrieben und diskutiert. Die Wirbel haben die ftir Ichthyosaurier typische Morphologie und belegen damit eindeutig die Zugeh6rigkeit dieses Taxons zu den Ichthyosauriern. Ein runder Knochen aus dem fr~inkischen Muschelkalk wird als linker Humerus von Omphalosaurus sp. identifiziert. Diese beiden Funde weiten das Verbreitungsgebiet und das zeitliche Auftreten von Ornphalosaurus bedeutend aus, da die Gattung bis jetzt nur vom Westrand des nordamerikanischen Kratons und von Spitzbergen bekannt war. Die neuen Funde erlauben aul3erdem eine Differentialdiagnose der Gattung und eine Revision ihrer Arten, von denen Omphalosaurus nettarhynchus, O. nevadanus und O. wolfi als gtiltig erachtet werden, nicht aber O. nisseri. Im Zusammenhang mit diesen neuen Einsichten zur Verbreitung triassischer Ichthyosaurier ist es n6tig, die Gtiltigkeit schlecht bekannter Gattungen, z.B. des mitteltriassischen Pessosaurus, zu tiberprtifen. Pessosaurus ist kein valides Taxon, weil ihm diagnostische Merkmale fehlen.

Amfilochia Bay (Eastern Amvrakikos Gulf, Western Greece), a complex marine area affected by tectonism, was investigated for seabed seepage manifestations and for possible inter-relationships between shallow gas accumulations and hypoxia. For this purpose, an integrated research methodology that combined geophysical, geochemical, and hydrographic surveys was applied. Marine geophysical and bathymetric surveys led to the discovery of a gas-induced pockmark group in the study area. Oceanographic surveying confirmed that the bay is hypoxic/anoxic below a depth of 15 m (dissolved oxygen from ~4 to 60 μM). Very weak CH4 seepage was detected in correspondence to the pockmark group that seemed to slightly enhance the hypoxic environment locally and close to the seabed, with no effect in shallower waters and the oxycline. Methane isotopic analysis showed variable carbon isotopic composition (from −41‰ to −86‰) which could be either related to differential CH4 oxidation or mixing between micr...

The Timor-Tanimbar region constitutes part of the non-volcanic outer Banda Arc of Eastern Indonesia. Here, the world's youngest 'A'-type high-pressure metamorphic belt crops out with different stages of evolution. Whereas an advanced domal uplift stage is seen in Timor island, the high-pressure (HP) metamorphic belt is still in the first stage of tectonic extrusion on the eastern small islands of Kisar, Leti, Moa, Sermata and Laibobar. The metamorphic rocks on Leti are among the best exposed in the islands. They are tectonically juxtaposed against overlying ultramafic rocks and underlying unmetamorphosed continental shelf sediments, bound by normal and reverse faults, respectively. The Leti metapelites display four progressive metamorphic zones: chlorite-biotite, garnet, chloritoid-staurolite and kyanite zones, with increasing grade. Zonation in Leti metabasite unit is comparable, and progressively changes from blueschist-greenschist transition (BS/GS), through epidote-amphibolite (EA), to amphibolite (AM) facies, with increasing grade. The highest-grade metapelites and metabasites occupy structurally intermediate levels.

Ediacaran fronds are iconic members of the soft-bodied Ediacara biota, characterized by disparate morphologies and wide stratigraphic and environmental ranges. As is the case with nearly all Ediacaran forms, views of their phylogenetic position and ecology are equally diverse, with most frond species considered as sharing a similar ecological guild rather than life history. Experimental biomechanics can potentially constrain these interpretations and suggest new approaches to understanding frond life habits.

The Moenave Formation was deposited during latest Triassic to earliest Jurassic time in a mosaic of fluvial, lacustrine, and eolian subenvironments. Ephemeral streams that flowed north-northwest (relative to modern geographic position) deposited singleand multi-storeyed trough cross-bedded sands on an open floodplain. Sheet flow deposited mainly silt across broad interchannel flats. Perennial lakes, in which mud, silt and carbonate were deposited, formed on the terminal floodplain; these deposits experienced episodic desiccation. Winds that blew dominantly east to south-southeast formed migrating dunes and sand sheets that were covered by low-amplitude ripples.

Wang, Y., Shih, C., Szwedo, J. & Ren, D. iFirst article. New fossil palaeontinids (Hemiptera, Cicadomorpha, Palaeontinidae) from the Middle Jurassic of Daohugou, China. Alcheringa, 1–12. ISSN 0311-5518.A new genus and species assigned to the extinct family Palaeontinidae, Synapocossus sciacchitanoae Wang, Shih & Ren, is described from the Middle Jurassic of Daohugou in Inner Mongolia, China. This new genus is established based on well-preserved fossil specimens with body and complete forewings and hind wings. It differs from other described genera by the following characters: small body size, RP and M1 coalescing for an interval on the forewings and M3 + 4 without bifurcation on the hind wings. The RP coalescence with M1 in Synapocossus Wang, Shih & Ren previously reported only in Turgaiella Becker-Migdisova & Wootton, seems to be associated with strengthening of the anterior wing margin. The intra-specific and individual variations of Synapocossus and numerous other insect fossils of northeastern China probably indicate long-lasting ecological stresses and a competitive environment in the Middle Jurassic to Early Cretaceous ecosystems.Synapocossus sciacchitanoae Wang, Shih&Ren;Palaeontinidae:, RPM1, M3+4, Synapocossus Wang, Shih&RenRPM1Turgaiella Becher-Migdisova&Wootton, Synapocossus

Within the eastern Himalayan syntaxis, carbonatite-like dykes occur in granulite facies gneisses of the Greater Himalayan Crystallines. Most dykes are dolomitic and are associated with scapolite-bearing hornblendite and glimmerite, which are separated from the country rocks by a selvage of altered rocks containing minerals such as diopside, tremolite, K-feldspar, albite, and calcite. Only a few dykes are calcitic with alteration halos containing wollastonite, calcite, anorthite, diopside, and scapolite. Dolomitic dykes as wide as several tens of metres contain irregular xenoliths of granulitic gneiss.

The Mesozoic southern branch of the Neo-Tethys Ocean was located between the Arabian shield and the Sanandaj-Sirjan continental block of Iran. The Kermanshah ophiolitic complex crops out in the Main Zagros Thrust Zone in Iran and consists of several rock associations, which record the geodynamic evolution of this ocean. In particular, the ophiolitic rocks that record the early stage of this oceanic evolution are represented by mantle metalherzolites, metagabbros and crosscutting metabasaltic dykes, as well as by basaltic pillow lavas and dykes. Mineral chemistry and whole-rock geochemistry of the metalherzolites show that they represent portions of exhumed sub-continental mantle. Four groups of rock can be recognized within the metagabbro and volcanic/subvolcanic sequences, based on many geochemical indicators and Sr-Nd isotopic data. They are: (1) metagabbros and metadykes with a N-MORB signature; (2) alkaline basalts and trachybasalts with ocean-island basalt (OIB) affinity; (3) rocks showing plume-type MORB (P-MORB) affinity; and (4) rocks showing enriched-type MORB (E-MORB) affinity. Metagabbros and metadykes show either low or high Sm/Yb ratios, which point to a genesis from partial melting of a pure depleted MORB mantle (DMM) source or a DMM source bearing garnet-pyroxenite relics, respectively. All volcanic and subvolcanic rock-types have variable, but generally high La/Yb, Sm/Yb, Th/Yb, Ta/Yb and Zr/Y ratios, and low Zr/Nb ratios. These features coupled with relatively low 143 Nd/ 144 Nd ratios and high 87 Sr/ 86 Sr indicate that the alkaline rocks were generated from an enriched, OIB-type (plume-type?) mantle source, whereas P-and E-MORB rocks can be interpreted as the product of variable interaction between depleted MORB-type asthenosphere and OIB-type material. We propose a tectono-magmatic model that can explain the different rock associations cropping out in the Kermanshah ophiolites involving a type of rifted margin that is intermediate between the amagmatic Iberia/Ligurian Tethys type and the magmatic, plume-influenced East Greenland type. This model presupposes that the Sanandaj-Sirjan block was rifted from the northern margin of Arabia through passive extension, which led to the exhumation of the sub-continental mantle now represented by the metalherzolites. Meanwhile, the asthenosphere upwelling associated with the partial melting of a heterogeneous mantle source locally bearing garnet-pyroxenite relics allowed the formation of both low and high Sm/Yb N-MORB-type metagabbros and metadykes at the continent-ocean transition zone. This model is similar to the model proposed for the Ligurian Tethys. But, in contrast with the Ligurian Tethys model, extension was also associated with volcanism characterized by a marked influence of OIB-type components linked to the uprising of MORB-type, depleted asthenospheric mantle. If so, the Kermanshah ophiolites represent a particular type of continental margin ophiolite, comprising a combination of continental margin-and plume-type ophiolites.

In 1985 archaeological excavations at Stavanger Airport, Sola, south-western Norway, revealed evidence for five phases of human activity ranging in age from the Mesolithic to the Late Bronze Age. The two youngest phases, namely 4 and 5 which reflect agrarian activity, are considered in detail in this paper. The fourth phase, which dates to ca. 3500 B.P., contains the first evidence of animal husbandry at the site and, in the fifth phase, there is evidence for a mixed farming economy. Physical evidence of cultivation includes intersecting patterns of plough-marks and, at seven sites, pollen assemblages indicative of arable farming have been recorded. The arable fields, in which weed-rich crops of Hordeum and Triticum were grown, date to ca. 2550-2200 B.P. The fields were subsequently covered by a thick layer of aeolian sand.

The large mammal and micromammal assemblages from Paleolithic cave sites in northwestern Croatia (Veternica, Velika peć ina, and Vindija) suggest the presence of relatively temperate environments without dramatic oscillations in faunal composition during MIS 3, and possibly also including MIS 2 and 4. Species such as woolly rhinoceros, arctic fox, varying hare, and saiga antelope were not present, and the micromammal assemblages show that all taxa are indicators of a temperate, continental climate characterized by somewhat less forested conditions than those present today. Nonetheless, the region does not appear to have served as a refuge for mammals whose distribution today is north of Croatia. The region appears to have had a fairly diverse and productive mammal fauna, which in turn could have supported significant hominin populations. Faunal composition did not dramatically change across the Middle-Upper Paleolithic transition (ca. 40 000-30 000 BP). The apparent stability in mammalian faunas could be owing to several factors: A) a depositional/preservational bias for warmer phases, B) dampered climatic oscillations in the region, C) faunal communities buffered from climatic oscillations owing to microclimate, topography, etc. Resolution of these factors requires further research.

In the last few years an increase in the frequency and magnitude of floods was detected on the Tisza River, endangering large areas of Hungary. The causes of these record floods were complex, including both natural and human induced factors. This paper focuses on river management works and their effect on planimetric and cross-sectional parameters, with special attention to the flood conductivity changes to the river channel. During 19th century river regulation works, half of the total length of the Tisza River was altered by cut-offs, while in the 20th century mostly revetments and groynes were constructed. Subsequently, horizontal and vertical channel parameters have changed considerably due to semi-natural bed processes. In order to reveal changes, hydrological map series (1842, 1890, 1929, 1957, 1976 and 1999) and cross-sectional surveys from the same dates were analysed. Prior to the intensive human interventions (before 1890s) the river's course was highly sinuous with some very sharp bends. Due to cut-offs both the length and sinuosity of the Tisza River decreased by 35%, while the lengths of straight sections and the river's slope doubled. As a consequence the river incised by up to 3.8 m until the 1929 survey, resulting better flood conductivity, which improved flood safety. In the 1920s river management favoured bank stabilisation in order to stop the lateral migration of the channel. Despite these measures, meander development has continued, however, in a distorted manner. This is reflected by the opposing processes of lengthening centre-line on the one hand and gradually decreasing radius of curvature on the other. These processes can be explained by the continuous development of natural point-bars on the convex bank, and the lack of lateral retreat on the concave stabilised bank. The width of the river decreased by 17-45%, while its mean and maximum depth increased by 5-48%. The area of cross-sections influenced by revetments decreased by 6-19%, resulting in a 6-15% decline in flood conductivity. The nonstabilised sections were influenced by upstream revetments. Therefore, their parameters show similar changes, but with a smaller rate. At present, the flood conductivity of the channel is worse than it was in its natural state. In all, it was found that the ongoing process of crosssectional distortion is a significant factor in increasing flood stage and hazard, and high floods can be expected more frequently in the future partly due to this factor.

Network arch bridges are arch bridges where hangers intersect each other at least twice. Although these innovative bridges present several advantages in terms of cost and structural performance with respect to the conventional tied-arch bridges, they remain vulnerable under certain loading condition. Indeed, due to the large compressive force that may arise in steel arches of the bridge under service, they are prone to deflect out of his plane resulting in the degradation of the aesthetic aspect often praised of bridges of this type and later its service disablement. For this reason, the lateral behaviour of such kind of bridges should be investigated carefully. In this study, lateral structural response of network arch bridges against traffic loads has been analyzed through extensive non-linear analyses. Firstly, a calibration is useful to validate the numerical model. Then, initial geometric imperfections are assigned to the arch member before the analysis in order to take into consideration defects from the manufacturing process. Finally, non-linear analyses are performed on a full 3D numerical model to capture the behaviour of the arch bridge. The results showed that the lateral displacement of the arch member increase with the increase of the traffic loads up to a certain value. In addition, it is observed that the lateral arch's bracing changes the development of plastic hinges in the arch.

This study illustrates the classification of the rock mass and evaluation of rock squeezing, rock burst potential, deformation modulus along the proposed tunnel alignment of small hydropower in Swat Valley, Khyber Pakhtunkhwa (KP), Pakistan. The field and laboratory studies were conducted to classify the rock mass by using geomechanical classification systems i.e. Rock Mass Rating (RMR), tunneling quality index (Q), Rock Mass Index (RMi). The empirical relations classified the ground as non-squeezing and minor to non-squeezing conditions, respectively. Whereas, other methods depict minor to medium bursting potential along chainage 1+000 to 4+000 m, while results along chainage 2+400-2+800 m present medium to high bursting potential. Furthermore, numerical analyses were carried out by RS 3 for elastic and plastic conditions in order to assess the total displacement of each section in unsupported and supported conditions. The results gave maximum displacement along chainage 2+400-2+800 m (19.2 mm in unsupported and 16mm in supported condition) and minimum displacement along chainage 0+876-1+000 m (1.4 mm in unsupported and 1.3 mm in supported condition). Hence, the estimated support by empirical methods has been optimized by using numerical analyses for the stability of rock mass along the tunnel.

The porosityofyoung limestonesexperiencing meteoricdiagenesisin the vicinityof theirdeposition(eagenetic karst) is mainly a doubleporosityconsistingoftouching-vug channelsandpreferredpassagewayslacingthrougha matrixof interparticleporosity. Incontrast,the porosityoflimestonesexperiencingsubaerialerosionfollowingburialdiagenesisandupliftitelogenetic karst) ismainlya doubleporosityconsisting ofconduits within a network offractures. The stark contrast between these two kinds of karst is illustratedby their position on a graph showing thehydraulic characteristics ofanequivalentporousmediumconsistingofstraight,cylindricaltubes(II-Dspace,wheren isporosity,D isthediameter ofthe tubes, and log n is plotted against log D).

New age data on detrital zircons and micas are presented from key units within the Neoproterozoic Katanga Supergroup, which hosts the major stratiform Cu-Co deposits of the Central African Copperbelt. Detrital zircon ages indicate a mainly Palaeoproterozoic (between 2081 ± 28 and 1836 ± 26 Ma) provenance for the Katanga basin, derived from the Lufubu Metamorphic Complex of the Kafue Anticline and the Bangweulu Block to the north of the outcrop belt. Detrital zircons and clasts from the Grand Conglomerat glacial diamictite indicate a source from the Palaeoproterozoic metavolcanic porphyries and granitoids of Luina Dome region, which was a basement high during Nguba Group deposition. Minor zircons of Mesoproterozoic age may have been derived from the Kibaran belt. Finally, 40 Ar/ 39 Ar age data from detrital muscovites from Biano Group siltstones give a maximum age of sedimentation of 573 Ma, strongly supporting previous models that the Biano Group was deposited in a foreland basin of the Lufilian Orogen.

The absence of dunite (>90 vol% olivine) in the howardite, eucrite, and diogenite (HED) meteorite suite, when viewed with respect to spectroscopic and petrologic evidence for olivine on Vesta, is problematic. Herein, we present petrologic, geochemical, and isotopic evidence confirming that Miller Range (MIL) 03443, containing 91 vol% olivine, should be classified with the HED clan rather than with mesosiderites. Similarities in olivine and pyroxene FeO ⁄ MnO ratios, mineral compositions, and unusual mineral inclusions between MIL 03443 and the diogenites support their formation on a common parent body. This hypothesis is bolstered by oxygen isotopic and bulk geochemical data. Beyond evidence for its reclassification, we present observations and interpretations that MIL 03443 is probably a crustal cumulate rock like the diogenites, rather than a sample of the Vestan mantle.

Considerably long periods of time are required to measure soil-water characteristic curves using conventional equipment such as pressure plate apparatus or a Tempe cell. A commercially available, small-scale medical centrifuge with a swinging type rotor assembly was used to measure the soil-water characteristic curves on statically compacted, fine-grained soil specimens. A specimen holder was specially designed to obtain multiple sets of water content versus suction data for measuring the soil-water characteristic curve at a single speed of rotation of the centrifuge. The soil-water characteristic curves were measured for three different types of fine-grained soils. The three soils used in the study were processed silt (liquid limit, wL = 24%; plasticity index, Ip = 0; and clay = 7%), Indian Head till (wL = 35.5%, Ip = 17%, and clay = 30%), and Regina clay (wL = 75.5%, Ip = 21%, and clay = 70%). The soil-water characteristic curves for the above soils were measured in 0.5, 1, and 2 ...

Comparison of the structural relationships between five gold deposits in Ordovician rocks of the central Victorian slate belt reveals a similar history and structural control of gold mineralization. Large quartz veins, spatially associated with gold mineralization, such as the famous saddle reefs of Bendigo, formed during the second deformation, earlier than the gold mineralization itself. Where they were overprinted by the effects of the fourth deformation, they provided structural sites for gold deposition on their boundaries with country rock where brecciation, jostling and fracture were favoured. Access of fluids resulting from metamorphism and deformation to the brecciated, fractured and jostled blocks of country rock created conditions suitable for the precipitation of gold through a sequence of alteration, replacement and infill. The dominant structural relationships that resulted in the generation of these sites were (a), the high angle of the axial plane of the fourth deformation to earlier structures and (b), the presence, during mineralization of large, pre-existing quartz veins that acted as structural discontinuities on which brecciation could occur. These factors allow a predictive capacity for exploration in the region.

Abrupt climate change in the past is thought to have disrupted societies by accelerating environmental degradation, potentially leading to cultural collapse. Linking climate change directly to societal disruption is challenging because socioeconomic factors also play a large role, with climate being secondary or sometimes inconsequential. Combining paleolimnologic, historical, and archaeological methods provides for a more secure basis for interpreting the past impacts of climate on society. We present pollen, nonpollen palynomorph, geochemical, paleomagnetic and sedimentary data from a high-resolution 2700 yr lake sediment core from central Italy and compare these data with local historical documents and archeological surveys to reconstruct a record of environmental change in relation to socioeconomic history and climatic fluctuations. Here we document cases in which environmental change is strongly linked to changes in local land management practices in the absence of clear climatic change, as well as examples when climate change appears to have been a strong catalyst that resulted in significant environmental change that impacted local communities. During the Imperial Roman period, despite a long period of stable, mild climate, and a large urban population in nearby Rome, our site shows only limited evidence for environmental degradation. Warm and mild climate during the Medieval Warm period, on the other hand, led to widespread deforestation and erosion. The ability of the Romans to utilize imported resources through an extensive trade network may have allowed for preservation of the environment near the Roman capital, whereas during medieval time, the need to rely on local resources led to environmental degradation. Cool wet climate during the Little Ice Age led to a breakdown in local land use practices, widespread land abandonment and rapid reforestation. Our results present a highresolution regional case study that explores the effect of climate change on society for an underdocumented region of Europe.

Deposits from the Minoan Santorini (Thera) eruption in the eastern Mediterranean region constitute the most important regional stratigraphic marker in the chronological perplexity of the 2nd millennium BCE. Extensive tsunami depos- its were discovered in Crete at the Minoan archaeological site of Palaikastro, containing reworked volcanic Santorini ash. Hence, airborne deposition of volcanic ash, probably during the 1st (Plinian) eruption phase, preceded the tsunami, which was apparently generated during the 3rd or 4th phase of the eruption, based on evidence from Thera. Average radiocarbon dates (uncalibrated) of animal bones in the Palaikastro tsunami deposits along the coast (3350 ± 25 BP) and at the inland archaeo- logical site (3352 ± 23 BP) are astoundingly similar to the average 14C date for the Minoan Santorini eruption at Akrotiri on Thera (3350 ± 10 BP). The wiggle-matched 14C date of the eruption in calendar years is 1627-1600 cal BCE. Late Minoan IA pottery is the younges...

A new sea-level record derived from coastal deposits of the South Vietnam shelf covers the deglacial sea-level history between 13.0 and 9.0 ka BP. This record reveals a relatively constant rate of sea-level rise and matches well with model results based on the RSES-ANU global ice-sheet model. However, the sea-level observations reveal a significant discrepancy with model results based on the ICE-5G global ice-sheet model, which further questions the existence of Meltwater Pulse 1B The incised-valley deposits of the South Vietnam shelf also complete the deglacial coastal evolution of southern Vietnam. The regional sea-level records of the South Vietnam shelf, the Mekong Delta and the Cambodian lowlands reveal an offset of about 18 m between 9.0 and 8.2 ka BP. The shoreline retreat of more than 200 km related to this offset was mainly caused by the differential hydro-isostatic adjustment between the South Vietnam shelf and the Cambodian lowlands. However, the GIAmodel results cannot fully explain this fast relative sea-level rise due to the topographic changes and, possibly, alternative melt-water sources not accounted for in the current models.

Live (Rose Bengal stained) benthic foraminifera were investigated in surface sediment samples from the Okhotsk Sea to reveal the relationship between faunal characteristics and environmental parameters. Live benthic foraminifera were quantified in the size fraction N 125 µm in the upper 8 cm of replicate sediment cores, recovered with a multicorer at five stations along the Sakhalin margin, and at three stations on the southwestern Kamchatka slope. The stations are from water depths between 625 to 1752 m, located close or within the present Okhotsk Sea oxygen minimum zone, with oxygen levels between 0.3 and 1.5 ml l -1 . At the high-productivity and ice-free Kamchatka stations, live benthic foraminifera are characterized by maximal standing stocks (about 1700-3700 individuals per 50 cm 2 ), strong dominance of calcareous species (up to 87-91% of total live faunas), and maximal habitat depths (down to 5.2-6.7 cm depth). Vertical distributions of total faunal abundances exhibit a clear subsurface maximum in sediments. At the Sakhalin stations, which are seasonally ice-covered and less productive, live benthic foraminifera show lower standing stocks (about 200-1100 individuals per 50 cm 2 ), lower abundance of calcareous species (10-64% of total live faunas), and shallower habitat depths (down to 2.5-5.4 cm depth). Faunal vertical distributions are characterized by maximum in the uppermost surface sediments. It is suggested that 1) lower and strongly seasonal organic matter flux, caused by the seasonal sea ice cover and seasonal upwelling, 2) lower bottom water oxygenation (0.3-1.1 ml l -1 ), and 3) more pronounced influence of carbonate undersaturated bottom water along the Sakhalin margin are the main factors responsible for the observed faunal differences. According to species downcore distributions and average living depths, common calcareous species were identified as preferentially shallow, intermediate and deep infaunal. Foraminiferal microhabitat occupation correlates with the organic matter flux and the depth of the oxygenated layer in sediments.

An integrated study involving sedimentology, mineral chemistry and spectroscopy highlights a distinctive compositional evolution of Cretaceous glauconite within the Ukra Hill Member. Glauconite occurs at the top part of transgressive systems tract deposits built on a marine shelf. The concentration of glau-conite steadily increases towards the maximum flooding surface, maximizing around 50%, and sharply falls at the onset of progradation. Unlike most Phanerozoic examples, Ukra glauconite forms by the variable degree of replacement of quartz, feldspar and mica grains. XRD, FEG-SEM and spectroscopy of glauconite pellets indicate an 'evolved' stage of maturation. Mossbauer spectroscopy reflects a minor substitution of Al 3þ-Fe 3þ (total) in tetrahedral sites and significant substitution of the same in octahedral sites. A consistently high value of K 2 O as well as Fe 2 O 3 contradicts the two popular theories, 'layer lattice' and 'verdissement', and support replacement origin of glauconite in a high a Siþ and high a Kþ pore water environment. Incipiently formed glauconite records a marginal increase in K 2 O content accompanied by release of Al 2 O 3 and SiO 2 to form evolved glauconite pellets; those forming within quartz grains involve an addition of Fe 2 O 3 (total) content during maturation. The minimal increase in K 2 O content of incipiently formed glauconite, best exhibited by those formed within quartz grains is possibly related to stratigraphic condensation. Compositional evolution like this is exhibited by Precambrian glauconites involving abiotic substrates, but is unusual for the Phanerozoic. Original K 2 O and Fe 2 O 3 (total) content of glauconites is reduced around peripheries and fractures during diagenesis, adding to compositional variability.

was based on isolated teeth from the Maastrichtian phosphatic deposits of Morocco. The recent discovery of new material, including skull and mandibular remains, improves our knowledge of this species. M. beaugei shares the following synapomorphies with the genus Mosasaurus: large teeth bearing two prominent carinae and with asymmetrical labial and lingual surfaces, the labial one being flattened and strongly facetted and the lingual one being convex; premaxillae with a small pointed rostrum and dentary without rostrum; palatal elements closely united; coronoid with very large ventromedial process overlying the prearticular. M. beaugei is characterised by the following autapomorphies: 12-13 maxillary teeth; marginal teeth bearing 3-5 prisms on the labial surface and 8-9 on the lingual one; palatine with posterior border concave and perpendicular to the long axis of the skull; splenial visible laterally on half of the dentary ventral surface; coronoid with anterior wing well developed and bearing two notches. M. beaugei is only known to date in the Maastrichtian phosphates of Morocco.

The trip starts at the Beale Library parking lot at Truxtun and Q
Streets in Bakersfield, California. From the parking lot the tour
will proceed east onto Truxtun Avenue, south on Union Avenue, west
on State Highway 58 Freeway, south on State Highway 99, to Taft
Highway, Old River Road, State Highway 166, State Highway 33, Ojai,
State Highway 150, and ends at Carpinteria State Beach.
In order to present the maximum amount of information, most stops
are limited to 20 minutes, except for the lunchtime stop and the
optional side trip which will be longer. Participants are
encouraged to bring a sack lunch and beverages. All vehicles are
encouraged to bring a CB radio set.

Twenty years of continuous Earth observation by satellite SAR have resulted in numerous new insights into active volcanism, including a better understanding of subsurface magma storage and transport, deposition of volcanic materials on the surface, and the structure and development of volcanic edifices. This massive archive of data has resulted in fundamental leaps in our understanding of how volcanoes work - for example, identifying magma accumulation at supposedly quiescent volcanoes, even in remote areas or in the absence of ground-based data. In addition, global compilations of volcanic activity facilitate comparison of deformation behavior between different volcanic arcs and statistical evaluation of the strong link between deformation and eruption. SAR data are also increasingly used in timely hazard evaluation thanks to decreases in data latency and growth in processing and analysis techniques. The existing archive of SAR imagery is on the cusp of being enhanced by a new gene...