submillimeter scale zonation of δ18o in quartz and feldspar isle of skye scotland abstract laser probe analysis of oxygen isotope ratios in submillimeter domains of quartz and feldspar in hydrothermally altered granite reveals complex intragranular zonation that can be contoured within individual grains two samples collected within 10 m of each other in the maol na gainmhich epigranite mge isle of skye scotland are similar petrographically yet display very different 18o zonation patterns sk1 has isotopically zoned quartz 18 o 1 8 8 2 with intragranular gradients of 18o as great as 5 mm and individually homogeneous grains of k feldspar 0 2 which also display a large range of values 18 o 1 7 to 7 3 oxygen isotope gradients of more than 11 mm were measured in this sample in contrast sk4 has homogeneous quartz 18o 5 7 0 3 n 14 and a zoned k feldspar phenocryst 18 o 3 3 to 6 9 isotopic heterogeneity in quartz correlates with the degree of chlorite alteration in adjacent hornblende grains the isotopic heterogeneity revealed by the laser probe in single grains of quartz and feldspar is greater than the entire range of values displayed by bulk mineral analysis of samples collected throughout the mge pluton although the average values of 18o obtained by laser probe are identical to the average bulk values values in k feldspar suggest exchange at 400 c with infiltrating meteoric water 18 o 10 the marked differences in zonation profiles between samples on the outcrop scale suggest that permeability and isotope exchange during hydrothermal alteration was highly heterogeneous these microanalytical data for quartz and feldspar provide the first oxygen isotope evidence from pervasively altered granites that paleopermeability is caused at least in part by intracrystalline microfractures

development of single crystal σ shaped quartz porphyroclasts by dissolution precipitation creep in a calcite marble shear zone abstract within a greenschist facies calcite marble shear zone isolated quartz grains change shape across the shear zone profile whereas quartz grains have a spherical to elongated shape in the coarse grained marble protolith and protomylonite they are asymmetric shaped porphyroclasts with wedge shaped appendages wings in ultramylonites in all cases quartz grains are single crystals they are sometimes twinned but never recrystallized stress induced dissolution precipitation creep is the favourable shape controlling process during deformation providing a relatively undeformed core truncation of pre existing cathodoluminescence cl patterns and syntaxial precipitation of wings the necessary fluids may have been released from fluid inclusions during dynamic recrystallization of the calcite matrix the development of shape is not related to the crystallographic orientation of the quartz porphyroclasts crystallographic orientation analysis by electron backscatter diffraction ebsd and cl analyses exclude crystal plasticity as a shape controlling mechanism of quartz grains during mylonitisation however in ultramylonites quartz clasts have a strong crystallographic preferred orientation cpo with c axes sub parallel to the shear direction this fabric is uncommon for quartz under greenschist facies conditions it might be explained by a strengthening of a pre existing weak cpo during mylonitisation by rigid particle rotation of elongated quartz grains

anaerobic ammonium oxidation in deep sea sediments off the washington margin the significance of anaerobic ammonium oxidation anammox for nitrogen removal in deep continental margin sediments was studied with 15n amendments to suboxic sediments collected from 2800 3100 m water depth at eight sites in the cascadia basin eastern north pacific ocean consistent with earlier data from deep continental margin sediments pore water distributions of inorganic n indicated nh z removal from suboxic zone sediments likely due to reaction with nitrate anammox rates estimated from suboxic sediment incubations with 15n labled substrates ranged between 0 065 and 1 7 nmol n ml21 h21 wet sediment which suggested that anammox was responsible for the observed nh z removal anammox and denitrification rates derived from nh z and no pore water profiles were 32 82 mmol n m 22 d21 and 50 110 m mol nm 22 d21 respectively the average contribution of anammox to total n2 production was 40 15n amended sediment incubations to 42 flux from pore water inorganic n which does not support earlier reports that suggested that the relative importance of anammox increased with water depth and thereby should dominate over denitrification at depths greater than 1000 m

plagioclase mantles on sanidine in silicic lavas clear lake california implications for the origin of rapakivi texture at clear lake california mixed dacite lavas contain sanidine mantled by oligoclase that closely resemble rapakivi feldspars in granites resorption and mantling of sanidine by plagioclase is one of many disequilibrium textures in these lavas resulting from maficfelsic magma interaction mantling of sanidine by plagioclase may occur directly in mixed magmas due to shifts in composition and temperature or indirectly in crystal rich silicic magmas influenced by thermal under plating or mafic felsic hybridization in adjacent regions of the magmatic system other silicic laves containing mantled sanidine also show evidence for mafic felsic magma interaction textural and compositional similarities between rapakivi texture in extrusive and intrusive rocks suggest that they have a common origin moreover modification of early formed textures due to protracted crystallization subsolidus reactions and metasomatic hydrothermal alteration in the plutonic environment accounts for most of the observed differences between extrusive and intrusive examples the association of coeval mafic rocks and evidence for mafic felsic magma interaction in many plutons containing rapakivi exture confirm that magma mixing plays a key role in its formation in some intrusive texamples evidence for a compositional control and multiple episodes of mantle formation are also compatible with repeated cycles of recharge and mixing regardless of the exact cause of k feldspar instability textural evidence from volcanic rocks and experiments indicates that development of rapakivi texture is controlled by cation diffusion in a dissolution boundary layer developed on k feldspar mantles appear to form in a two stage process that involves initial epitaxial nucleation of plagioclase on sanidine followed by simultaneous dissolution of sanidine and inward growth of plagioclase

topographical changes revealed by high resolution airborne lidar data the 1999 tsaoling landslide induced by the chi chi earthquake abstract the 1999 chi chi earthquake triggered the catastrophic tsaoling landslide in central taiwan we mapped the landslide area and estimated the landslide volume using a high resolution digital elevation model from airborne lidar light detection and ranging aerial photographs and topographic maps the comparison between scar and deposit volumes about 0 126 km3 and 0 150 km3 respectively suggests a coseismic volume increase of 19 due to decompaction during landsliding in july 2003 the scar and deposit volumes were about 0 125 km3 and 0 110 km3 respectively these estimates suggest that 4 years after the event the volume of landslide debris removed by river erosion was nearly 0 040 km3 these determinations are confirmed by direct comparison between the most accurate topographic models of the post landslide period indicating a very high erosion rate at the local scale 0 01 km3 year for the deposit area of the landslide such a large value highlights the importance of landslide processes for erosion and long term denudation in the taiwan mountain belt

triggering and runaway processes of catastrophic tsaoling landslide induced by the 1999 taiwan chi chi earthquake as revealed by high velocity friction experiments pliocene sedimentary rocks of about 130 mm3 in volume slid along bedding planes dipping by 14 with an average speed of about 35 m s during the tsaoling landslide we conducted friction experiments to reproduce the initiation processes of this landslide by idealizing landslide movements during the earthquake as accelerating decelerating motion experiments were done on shale from the field at 3 mpa normal stress corresponding to the overburden pressure results indicate that the accelerating decelerating motion causes weakening and strengthening at each oscillation cycle and results in overall slip weakening which can be approximated as an exponential slip weakening behaviors during oscillatory slip are fairly similar to those during sliding at constant slip rates newmark analysis with measured frictional properties reveals that the landslide can be triggered with wet gouge properties but the landslide motion stops with parameters for dry shale gouge delayed initiation of the landslide is consistent with a survivor s witness

simulating the failure process of the xinmo landslide using discontinuous deformation analysis abstract the xinmo landslide slope in sichuan china was stable during the intensive wenchuan earthquake in 2008 but failed on june 24 2017 landslide debris buried xinmo village and blocked the songpinggou river at the slope toe this study aims to clarify the post failure behavior of the landslide using two dimensional discontinuous deformation analysis 2d dda the simulation results provide comprehensive information on the initiation and the evolution of the landslide the failure process determined by the dda correlates well with the seismic signal analysis results in addition the location of the calculated rock deposit is similar to that shown by the topographic map after the landslide the maximum rock velocity in the landslide is 65 4 m s therefore the impacts of the high velocity blocks and the buildings in xinmo village must be considered to simulate the burial of xinmo village by rocks and the transport of additional rocks across the songpinggou river this xinmo landslide study demonstrates that the dda accurately simulates the post failure behavior and determines the impact area of a landslide with complicated failure processes and topography

a melt inclusion study of the toba tuffs sumatra indonesia the toba caldera in northern sumatra indonesia is the site of earth s largest quaternary volcanic eruption this eruption dated at 74 ka produced the 2800 km3 youngest toba tuff ytt and ash fall quartz bearing silicic pumices ranging from 68 to 77 wt sio2 indicate that the ytt magma was zoned compositionally and mineralogically prior to the ytt eruption two other silicic quartz bearing tuffs known as the middle toba tuff mtt and the oldest toba tuff ott were erupted from toba at 0 501 ma and 0 840 ma respectively although the volatile contents of the toba magmas are poorly constrained aerosols generated by the ytt eruption are generally thought to have caused a global volcanic winter an evaluation of the pre eruptive dissolved gas contents of the ytt magma is fundamental to understanding the global effects of this eruption we used melt inclusions in quartz crystals to determine the dissolved h2o co2 s cl and f contents of the ytt mtt and ott magmas quartz crystals selected from pumice blocks and welded tuffs that spanned the compositional ranges of the three units were chosen for study major and trace element analyses of melt inclusions were also conducted to characterize melt evolution and provide context to the volatile data melt inclusions from the ytt mtt and ott are rhyolitic in composition 73 77 wt sio2 and have overlapping indistinguishable major element trends inclusions from the large eruptions ytt and ott have similar geochemical relationships where the most evolved melt inclusions occur in the least silicic bulk rock samples and are more evolved than their matrix glasses in contrast the least evolved melt inclusions occur in the most silicic samples and either overlap with or are less evolved than their matrix glasses these patterns can be explained if quartz crystals in the least silicic magmas were inherited from more evolved melt while those in the most silicic melt formed in situ several lines of evidence suggest that crystal settling of early formed quartz crystals in long lived magma bodies was an important process in the ytt and ott magmas trace element data from the ytt melt inclusions have wide ranges rb 250 830 ppm ba 10 485 ppm and mostly support these models however incompatible trace elements are enriched 2 3 over their matrix glass compositions in all samples in the smaller mtt melt inclusions overlapped with the compositional range of the bulk rock samples and are consistent with in situ crystallization ftir analyses indicate that the ytt mtt and ott melts contained about 4 0 5 5 2 0 5 5 and 2 0 5 5 wt h2o respectively co2 contents in all units are generally 100 ppm and cl is 2000 ppm water gradients occur in all 3 tuffs cl gradients are evident only in the ytt and the least silicic samples from all units had no detectable co2 sulfur contents in melt inclusions are low in all samples 32 ppm and overlap with matrix glass s contents applying broad degassing constraints about 1014 g of h2so4 aerosols were likely loaded into the atmosphere during the ytt eruption 2 orders of magnitude less than previous petrologic estimates considerably more cl and f about 1015 g of each may have been part of the ytt aerosol cloud

lead isotopes as a provenance tool for quartz examples from plutons and quartzite northeastern minnesota usa abstract the u pb isotope system in plutonic quartz samples approximates the crystallization age of the host granitoid and thus provides a useful provenance tool for detrital quartz grains we present lead isotopic data and u and pb concentrations of quartz from three late archean granitoids and from the early proterozoic pokegama quartzite all in northeastern minnesota lead in granitic quartz is considerably more radiogenic than in its associated whole rock host but it is similar or only slightly more thorogenic than its host pb pb ages obtained from quartz whole rock leached feldspar from the late archean granitic plutons are consistent with existing geochronology suggesting that the u pb system in quartz remained closed since crystallization u pb isotopic data for detrital clear quartz populations in the pokegama quartzite record late archean ages 2550 2650 consistent with a source from the superior province lead isotopic compositions of detrital k feldspar populations and lead and neodymium isotopic compositions of whole rocks samples from the pokegama quartzite also support a superior province source this study highlights the potential of the lead isotope system in detrital quartz k feldspar and whole rocks in provenance studies of sandstones

pseudostatic analysis of tsao ling rockslide caused by chi chi earthquake during the 1999 chi chi earthquake extensive slope failures were triggered by the earthquake in central taiwan among those a large scale dip slope slide in tsao ling occurred which involved the mass movement of 120 million cubic meters four catastrophic dip slope rockslide events in history in tsao ling are reported furthermore the stability analysis of the tsao ling landslide caused by the chi chi earthquake was conducted for the original and remaining slope results of pseudostatic analysis indicated that a reduction factor of 2 3 for both vertical and horizontal peak ground acceleration with 30 of material strength degradation were likely the case for inducing the tsao ling landslide and the effects of vertical acceleration were significant accordingly it was concluded that ground motion and degradation of material strength were the major factors for the inducement of the tsao ling landslide by the chi chi earthquake

using titanium in quartz geothermometry and geospeedometry to recover temperatures in the aureole of the ballachulish igneous complex nw scotland titanium in quartz geothermometry suggests quartzites could yield reliable temperature estimates we here apply four calibrations of the titanium in quartz geothermometer to contact metamorphosed quartzites surrounding the ballachulish igneous complex scotland two agree broadly with thermal modelling and pre existing geothermometry two give temperatures consistently too low as reported in earlier studies the technique suffers from difficulties in analysing low titanium ti levels with high spatial and analytical precision however this study finds that the critical problem is one of ti heterogeneity which poses difficulties in constraining the chemical activity of ti during quartz growth under metamorphic conditions scanning electron microscope cathodoluminescence sem cl textures support an interpretation of extensive ti disequilibrium despite the presence of rutile indicating dynamic interplay between grain boundary diffusion fluid melt percolation and grain growth the strong zonation suggests a possible geothermometer based on apparent volume diffusion of ti in quartz to derive grain growth histories analysis of rutile quartz interaction implies peak contact temperatures of 645 12 c precise but reliant on external estimates of cooling rate from thermal models our conclusions support caution in applying ti in quartz geothermometry in aureole settings however rutile quartz juxtaposition prior to heating to 600 c defines a ti diffusion couple employable as a thermometer if cooling rates are constrained by other means

the chemistry of quartz in granitic pegmatites of southern norway petrogenetic and economic implications trace element concentrations in quartz from 188 granitic pegmatites in the froland and evje iveland pegmatite fields southern norway have been determined to establish exploration targets for high purity quartz and to gain a better understanding of the genesis of pegmatites hosting these deposits both pegmatite fields were formed during the sveconorwegian grenvillian orogeny 1145 900 ma at the western margin of the fennoscandian shield in situ raster analyses within single quartz crystals were undertaken by laser ablation inductively coupled plasma mass spectrometry la icp ms spot size 75 m to assess levels of lattice bound impurities rather than mineral and fluid inclusions that are relatively easily removed during high purity quartz processing quartz in the froland pegmatites has relatively pure and homogeneous compositions containing 46 24 gg 1 al 8 3 gg 1 ti 1 4 0 8 gg 1 ge and 11 7 gg 1 li the ti in quartz geothermobarometer gives an average pegmatite crystallization temperature of 537 39 c temperature estimates are highest along the northwestern margin of the pegmatite field 550 c whereas the most differentiated pegmatites occur toward the northeast the area of greatest economic potential for high purity quartz lies just north of the central part of the field where individual pegmatites contain 1 million metric tons mt quartz with low average trace element contents of 67 11 gg 1 from mineral chemical criteria and a range of other geologic factors we propose that pegmatite melts in the froland field were generated by fluid present crustal melting at about 1060 ma in zones of localized high strain deformation during progressive thrusting along the porsgrunn kristiansand fault zone quartz in the evje iveland pegmatites has more variable compositions with 69 57 gg 1 al 19 11 gg 1 ti 2 3 1 8 gg 1 ge and 7 5 gg 1 li from its ti content it crystallized at temperatures of 613 70 c the regional spatial distribution of ti in quartz temperatures appears irregular mainly due to the scattered distributions of chemical evolved pegmatites with amazonite cleavelandite replacement zones which show crystallization temperatures down to 442 c quartz from the evje iveland pegmatites is unlikely to be of current economic interest due to its moderate to high trace element contents heterogeneous chemistry and low volume the evje iveland pegmatites show no apparent genetic link to a granite intrusion instead they probably formed as a result of partial melting at the depth of their amphibolite country rocks at around 910 ma this is related to a regional low pressure high temperature metamorphic event at about 930 to 920 ma

initiation movement and run out of the giant tsaoling landslide what can we learn from a simple rigid block model and a velocity displacement dependent friction law abstract tsaoling landslide is the largest and best documented landslide among several large landslides induced by the 1999 taiwan chi chi earthquake pliocene sedimentary rocks of about 125 mm 3 in volume slid along very flat bedding planes dipping by 14 with an average speed of 35 40 m s for about 1650 m before hitting the bank of the chinshui river during the landslide detailed analysis of dtms before and after the earthquake using a gis software leads to an accurate determination of the locations of the centroids of landslide mass revealing the horizontal and vertical displacements of the 2524 m and 524 m respectively those displacements and landslide mass give an apparent friction coefficient of 0 21 and the release of the potential energy of 1 6 10 15 j we conducted rotary shear high velocity friction experiments on fault gouge from bedding parallel faults under semi wet conditions and at 3 mpa normal stress corresponding to the overburden pressure of the landslide mass we also compiled reported data on the frictional properties on shale powders and fault gouge from the landslide site under both dry and wet conditions and proposed a velocity displacement dependent friction law that can describe most experimental data newmark analysis of landslide motion with six scenarios for different landslide materials and conditions assuming a simple rigid block sliding and using measured frictional parameters revealed that the landslide did not occur with dry frictional properties and that the landslide occurred at 38 39 s with accumulated displacements of 0 62 m 1 09 m and reached at the river bank at 82 87 s after the generation of chi chi earthquake at its epicenter those timings are consistent with high frequency signals at 32 40 s and at 76 s recorded at a nearby seismic station and with a survivor s witness that the landslide initiated 10 s after he felt strong ground motion possible s wave arrival at 25 2 s slip weakening is essential in initiating the landslide and low friction coefficient 0 08 0 1 allowed high speed of the landslide possible the landslide was caused by a few peaks of northeast oriented strong accelerations of the ground motion frictional work during the sliding of the landslide mass was estimated to be of about 23 of potential energy and the rest of the released energy is likely to have been consumed during the stopping phase of the landslide after hitting the river bank in complex processes such as fragmentation heat dissipation and spreading of the landslide deposits

cathodoluminescence of quartz from sandstones interpretation of the uv range by determination of trace element distributions and fluid inclusion p t x properties in authigenic quartz quartz overgrowths from keuper sandstones of the paris basin were examined using cathodoluminescence cl microscopy and spectroscopy coupled with a scanning electron microscope sem with the use of standard cold cl equipment it was observed that the emission of authigenic quartz is much less intense than that of detrital quartz grains but a reversal of intensity was observed with scanned cl in the 200 800 nm range the main cl emission band of diagenetic quartz is at 330 340 nm in the uv range with other bands in the visible range the determination of trace element distributions in authigenic quartz by in situ analyses and by sims imagery reveals the correlation of the 330 340 nm emission band with the highest al and li contents the cathodoluminescence emission of diagenetic quartz in the uv range appears to be influenced by the coupled substitution of al and li into the crystal two explanations are suggested 1 ai li or both serve as activators and 2 the incorporation of al and li causes lattice defects that lead to an enhancement of the intrinsic luminescence trace element analyses and fluid inclusion studies revealed that quartz overgrowths precipitated from a fluid that partially originated from an li enriched primary brine derived from eastern triassic evaporites of the paris basin the specific cl emission band in the uv range can be linked to the diagenetic environment the chemistry of the fluids appears to be the essential parameter whereas precipitation temperatures do not influence the occurrence of such emissions

quartz and feldspar zoning in the eastern erzgebirge volcano plutonic complex germany czech republic evidence of multiple magma mixing abstract zoned quartz and feldspar phenocrysts of the upper carboniferous eastern erzgebirge volcano plutonic complex were studied by cathodoluminescence and minor and trace element profiling the results verify the suitability of quartz and feldspar phenocrysts as recorders of differentiation trends magma mixing and recharge events and suggest that much heterogeneity in plutonic systems may be overlooked on a whole rock scale multiple resorption surfaces and zones element concentration steps in zoned quartz ti and feldspar phenocrysts anorthite content ba sr and plagioclase mantled k feldspars etc indicate mixing of silicic magma with a more mafic magma for several magmatic phases of the eastern erzgebirge volcano plutonic complex generally feldspar appears to be sensitive to the physicochemical changes of the melt whereas quartz phenocrysts are more stable and can survive a longer period of evolution and final effusion of silicic magmas the regional distribution of mixing compatible textures suggests that magma mingling and mixing was a major process in the evolution of these late variscan granites and associated volcanic rocks quartz phenocrysts from 14 magmatic phases of the eastern erzgebirge volcano plutonic complex provide information on the relative timing of different mixing processes storage and recharge allowing a model for the distribution of magma reservoirs in space and time at least two levels of magma storage are envisioned deep reservoirs between 24 and 17 km the crystallisation level of quartz phenocrysts and subvolcanic reservoirs between 13 and 6 km deflation of the shallow reservoirs during the extrusion of the teplice rhyolites triggered the formation of the altenberg teplice caldera above the eastern erzgebirge volcano plutonic complex the deep magma reservoir of the teplice rhyolite also has a genetic relationship to the younger mineralised a type granites as indicated by quartz phenocryst populations the pre caldera biotite granites and the rhyodacitic schonfeld volcanic rocks represent temporally and spatially separate magma sources however the deep magma reservoir of both is assumed to have been at a depth of 24 17 km the drastic chemical contrast between the pre caldera schonfeld westfalian b c and the syn caldera teplice westfalian c d volcanic rocks is related to the change from late orogenic geotectonic environment to post orogenic faulting and is considered an important chronostratigraphic marker

genetic significance of the trace element content in metamorphic and hydrothermal quartz a reconnaissance study abstract a reconnaissance study on trace elements in metamorphic and hydrothermal quartz was carried out using quartz samples from the tin district erzgebirge germany the gold mineralization at kasperske hory czech republic and the gold quartz vein deposits muruntau and myutenbai uzbekistan a new method of sample preparation has been developed to prepare pure quartz samples by combining conventional hand picking with microscopic and spectroscopic studies as well as acid wash etch procedures preparation of monomineralic samples was followed by sample dissolution and measurement by icp ms the metamorphic quartz has very low concentrations of li 0 4 ppm al 30 ppm k 35 ppm rb 50 ppb sr 0 3 ppm and y 15 ppb moreover it is characterized by light rare earth element enriched lanthanide distribution patterns lacking eu anomalies the low element concentrations in metamorphic quartz are interpreted to result from recrystallization metamorphic quartz from alteration halos enveloping tin and gold deposits has distinctly different trace element signatures these differences are related to the hydrothermal overprint of the pre existing metamorphic quartz by the mineralizing fluids hydrothermally altered metamorphic quartz from tin deposits has elevated concentrations of li 0 9 ppm al 50 ppm k 45 ppm rb 250 ppb and y 40 ppb whereas altered metamorphic quartz from gold deposits is characterized by elevated concentrations of sr 0 5 ppm the rare earth element distribution patterns of altered metamorphic quartz show variable enrichments of the heavy rare earth elements and frequently display positive eu anomalies hydrothermal vein quartz from the gold deposits usually has elevated al 50 ppm and sr 0 6 ppm contents the lanthanide distribution patterns exhibit variable enrichments of the heavy rare earth elements and commonly show positive eu anomalies the elevated sr concentrations in the quartz from gold deposits are best explained by sr release during feldspar alteration in the wall rocks this mechanism may also account for the relative enrichment of eu in the mineralizing fluids although other processes may not be unambiguously ruled out

experimental and theoretical study of the fault slip events of rock masses around underground tunnels induced by external disturbances abstract fault slip events of rock masses around underground tunnels such as irreversible displacements and slip type rock bursts can easily occur after external disturbances to investigate the mechanism and threshold conditions of fault slip events triggered by external disturbances a series of slip experiments using red sandstone blocks were performed with various horizontal pulling forces and vertical dynamic disturbances the experimental results show that the relative vertical displacements of the adjacent blocks were the main reasons for anomalously low friction phenomenon the initial stress state strongly affected the final residual horizontal displacements and the threshold conditions of fault slip events as the shear force ratio increased the stabilities of the rock blocks became increasingly sensitive to disturbance energies and the threshold disturbance energies for causing fault slip events decreased and when was close to 1 even a considerably small disturbance triggered a sustained slip failure based on energy analyses a theoretical model was developed and a dimensionless energy parameter i was introduced to quantifiably characterize the threshold conditions of different types of fault slip events the threshold condition for rock blocks to start slipping was that the i value should reach a threshold value while the threshold conditions of a sustained slip failure were that the i value should reach a larger threshold value and should simultaneously exceed a certain value the expression for the i value was given and can reflect the dependency relationships between the disturbance energies shear force ratios and rock parameters i e the yield strain the length to height ratio and the ratio of the elastic coefficients the experimental results and the threshold conditions derived from the theoretical model are essential when carrying out stability analyses and geohazard predictions in rock engineering

landslide reconstruction using seismic signal characteristics and numerical simulations case study of the 2017 6 24 xinmo landslide abstract landslide modeling based on seismic signal characteristics is an effective method to study landslide evolution the scientific challenge lies in how to systematically characterize and reconstruct the entire landslide evolution process using the recorded seismic data we selected the 2017 6 24 xinmo landslide as a case study empirical mode decomposition emd is used to analyze the seismic signals from 14 seismic stations near the landslide area numerical simulations using two dimensional discrete element methods dem are performed to simulate landslide dynamics using the calculated kinetic energy profile after analyzing the short time fourier transform stft and fast fourier transform fft characteristics of the signal the landslide process is reconstructed and compared with the dem simulation the landslide process is observed to consist of a stationary stage slipping stage transition stage entrainment transportation stage and a deposition stage this is the first study that uses seismic signals to identify a transition stage which is a feature that is difficult to constrain from field survey and analysis alone landslide development and movement in the transition stage are discussed considering the sedimentology of the study area this study provides improved theoretical guidance for the reconstruction and characterization of landslide processes by seismic signals

discrete element modeling of the mass movement and loose material supplying the gully process of a debris avalanche in the bayi gully southwest china abstract the dynamic process of a debris avalanche in mountainous areas is influenced by the landslide volume topographical conditions mass material composition mechanical properties and other factors a good understanding of the mass movement and loose material supplying the gully process is very important for understanding the dynamic properties of debris avalanches three dimensional particle flow code pfc3d was used to simulate a debris avalanche in quaternary deposits at the bayi gully southwest china fortran and autocad were used for the secondary development to display the mass movement process and to quantitatively describe the mass movement and loose material supplying the gully process the simulated results show that after the landslide is initiated the gravitational potential energy is converted into kinetic energy with a variation velocity for the sliding masses two stages exist for the average movement velocity the acceleration stage and the slowdown stage which are influenced by the topographical conditions for the loose materials supplying the gully process the cumulative volume of the sliding masses into the gully gradually increases over the time when the landslide volume is not large enough the increasing landslide volume does not obviously influence the movement process of the sliding masses the travel distance and movement velocity increase with the decreasing numerical parameters and the mass movement process is finished more quickly using low value parameters the deposition area of the sliding masses decreases with the increasing numerical parameters and the corresponding deposition thickness increases the mass movement of the debris avalanche is not only influenced by the mechanical parameters but is also controlled by the topographical conditions

seismicity associated with dome growth and collapse at the soufriere hills volcano montserrat varied seismicity has accompanied growth and collapse of the lava dome of the soufriere hills volcano montserrat earthquakes have been classified as either volcano tectonic long period or hybrid and daily variations in the numbers of events have mapped changes in the style of eruption repetitive hybrid earthquakes were common during the first months of dome growth in july 1996 the style of seismicity changed and regular short lived hybrid earthquake swarms became common this change was probably caused by an increase in the magma flux earthquake swarms have preceded almost all major dome collapses and have accompanied cyclical deformation thought to be due to a build up of pressure in the upper conduit which is later released by magma moving into the dome

an experimental study of hydroxyl in quartz using infrared spectroscopy and ion microprobe techniques we have measured the concentrations of hydroxyl deuterium al fe li na k and rb in a natural quartz crystal before and after hydrothermaltreatment at 1 5 gpa and 800 degree 1050 degree c we employed microbeam infraredspectroscopy and ion probe techniques to avoid impurities trapped in healedcracks and fluid inclusions that might bias a normal bulk analysis the ital f sub h sub 2 of our experiments were buffered to thehematite magnetite oh fluid nickel nickel oxide oh fluid oriron wustite oh fluid phase assemblages after hydrothermal treatment the samples contained local concentrations of hydrogen or deuterium ofseveral hundred atoms 10 sup 6 si the starting crystal contained 45 h 10 sup 6 si we did several experiments with al sub 2 o sub 3 or rbcl added to the sample chargeand found local al enrichment where the deuterium concentration was highbut no rb enrichment finally we measured trace elements and hydroxyl in aquartz sample after plastic deformation in a talc furnace assembly inregions of the sample containing basal and prismatic deformation lamellae but no visible healed microcracks at 400 times optical magnification hydroxyl had increased to similar to 200 oo 10 sup 6 si with no increase in al or fe samples enriched in hydroxyl but not al including the plastically strainedsample gave infrared spectra resembling natural amethyst crystals

implications of trace element zoning in deformed quartz from the santa catalina mylonite zone ion microprobe analyses of trace elements in quartz from the santa catalina mylonite zone southern arizona show a wide range in li contents and little or no variation in b na al k and fe one large quartz crystal is protected on three sides by a partially altered alkali feldspar crystal the fourth side grades into small recrystallized quartz grains perpendicular to the c axis a step scan parallel to the c axis shows an approximately bell shaped curve for the distribution of li the fluid accompanying mylonitic deformation appears to have partially leached the quartz of li given temperature estimates of mylonitization for this sample of 500c diffusion coefficients estimated from the observed concentration profiles appear to be at least 7 10 orders of magnitude smaller than experimentally determined coefficients suggesting that 1 alkali metal diffusion in quartz in nature takes place via a different diffusion mechanism than measured in the laboratory or 2 a hydrous fluid is required to in

tracking meteoric infiltration into a magmatic hydrothermal system a cathodoluminescence oxygen isotope and trace element study of quartz from mt leyshon australia the oxygen isotope and trace element composition of hydrothermal quartz has been integrated with scanning electron microscope cathodoluminescence sem cl images and fluid inclusion properties to track fluid sources and hydrothermal processes in the mt leyshon an deposit australia oxygen isotope and trace element data were collected on parallel traverses across the same quartz sections using secondary isotope mass spectrometry sims and laser ablation inductively coupled plasma mass spectrometry la icp ms respectively with sem cl images obtained before analysis for petrographic context over the 280 to 650 degrees c quartz precipitation range suggested by fluid inclusion microthermometry delta o 18 quartz varies from 0 0 to 14 4 o corresponding to a wide range of equilibrium delta o 18 fluid values from 6 1 to 10 2 o vs v smow the delta o 18 quartz signature varies systematically among distinct sem cl quartz generations both within and between samples and can be correlated with variations in temperature and fluid composition but is independent of intra generational oscillatory zoning in contrast al and li concentrations correlate broadly with cl intensity in oscillatory quartz whereas their concentration is unpredictable in sealed fractures and overgrowths concentrations of b mg na p cl k ti mn fe ge and sn are independent of al li and oscillatory cl features but ti correlates with quartz precipitation temperature although no systematic correlation between delta o 18 quartz and trace element concentrations was found complementary patterns exist in narrow overgrowths of low delta o 18 quartz similar to 0 o and high al g 10 000 ppma these quartz zones likely formed during the incursion of o 18 depleted meteoric water into the magmatically dominated mt leyshon hydrothermal system we interpret the highest al concentrations as the result of high quartz precipitation rates triggered by depressurisation of the hydrothermal cell the decoupling of oxygen isotope and trace element patterns in quartz leads to the suggestion that 1 under most circumstances temperature and fluid chemistry dominate delta o 18 quartz and 2 the trace element record and in particular al and li is influenced by the superimposed effects of quartz precipitation rate c 2007 elsevier b v all rights reserved

quantification of quartz cements using combined sem cl and image analysis quartz cement content is often difficult to quantify using conventional petrography developments in equipment and technique reported here show how excellent high contrast images of quartz cements can be produced using combined scanning electron microscopy and cathodoluminescence sem cl in most cases quartz cement can be differentiated readily from detrital quartz image analysis allows the percentage of authigenic quartz to be quantified advantages of this method are 1 it can be readily automated 2 backscatter electron bse and cl images can be compared directly and 3 images can be improved through acquiring and integrating multiple images comparison of results from conventional optical petrography with those from sem cl suggests that the percentages of quartz cement determined by conventional methods are overestimated where quartz cement is present in high proportions and are underestimated where quartz cement is less abundant by adopting a statistically rigorous approach to image collection the abundance of quartz cement can be determined by sem cl with a known accuracy

modified newmark model for seismic displacements of compliant slopes newmark sliding block analyses are widely used for estimation of permanent displacements of slopes in earthquakes the conventional newmark model however neglects the dynamic response of the material above a potential failure surface decoupled procedures have been developed to account for that response but they neglect the effects of permanent displacements on the response a modified newmark analysis that considers the dynamic response including the effects of permanent displacements of the material above the failure surface is presented the modified newmark analysis shows that the decoupled approach produces somewhat conservative estimates of permanent displacements for stiff and or shallow failure masses but that it may produce unconservative estimates for failure masses that are soft and or deep many slopes of large lined landfills may fall into this latter category the notion of a slope spectrum which illustrates the effect of the natural period of a potential failure mass on permanent slope displacement is also introduced

melt and fluid inclusions in hydrothermal veins the magmatic to hydrothermal evolution of the elatsite porphyry cu au deposit bulgaria the magmatic to hydrothermal transition in the late cretaceous elatsite porphyry cu au mo platinum group element deposit has been studied in a suite of samples with clear timing relations between porphyry dikes magmatic hydrothermal veins silicate melt inclusions in quartz veins fluid inclusion generations and ore minerals ore mineralization occurs late at temperatures 200 to 300 c below those of the early multistage interplay between magmatic and hydrothermal processes at near magmatic temperature pressure conditions crosscutting relations and petrography indicate that shortly after the intrusion of the earliest monzodioritic dikes fluids precipitated a first generation of granular quartz veins accompanied by potassic alteration the second vein generation with crystalline quartz textures and k feldspar alteration halos formed at the same time as the second granodioritic pulse of porphyry intrusions cathodoluminescence imaging of quartz growth textures reveals that the earliest fluid inclusions in the crystalline quartz veins are of intermediate density and 8 wt nacl equiv salinity probably trapped at near lithostatic pressures of 1 200 to 1 300 bars at near magmatic temperatures 730 c and implies a depth of 4 to 5 km depressurization led to phase separation indicated by a first generation of coexisting brine and vapor inclusions trapped at temperatures of 640 c and suprahydrostatic pressures of 920 bars a second quartz generation in crystalline quartz veins precipitated during progressive depressurization and hosts assemblages of coexisting brine vapor and silicate melt inclusions trapped at temperatures in excess of 600 c and suprahydrostatic pressures of 630 to 880 bars some open spaced quartz veins were filled with aplite during this stage field relations and geochemical evidence suggest that the aplites as well as the silicate melt inclusions in hydrothermal quartz veins represent volumetrically minor residual melts that evolved directly from granodiorite porphyries at the level of deposit formation and do not represent aliquots of metal supplying magma at depth fluid inclusions coexisting with the silicate melt inclusions are metal rich but these fluids predate sulfide precipitation and are therefore not the dominant fluids responsible for the cu au mineralization at elatsite melt fluid metal separation processes recorded in these co trapped silicate melt and fluid inclusions in vein quartz are small scale local phenomena and do not appear to be suited for understanding and quantifying metal segregation in the deeper source microthermometry data of fluid inclusions trapped during the later stages of the formation of the second quartz generation show further depressurization to 260 to 325 bars and cooling to 460 c representing a hot hydrostatic regime bornite chalcopyrite and magnetite seem to be slightly later precipitated at temperatures 460 c in separate veins or opened spaces of preexisting veins dissolution textures of the second quartz generation indicate a subsequent local redissolution of vein quartz most likely as a result of passing through a window of retrograde quartz solubility upon further cooling below 460 c the next economically most important chalcopyrite pyrite stage is largely devoid of quartz precipitation and is mostly expressed as paint veins due to the lack of fluid inclusions the temperature pressure conditions of formation of these veins could not be constrained the waning phase of hydrothermal activity is represented by a quartz carbonate zeolite stage formed at low temperature 145 c as indicated by microthermometry of fluid inclusions trapped in quartz from this stage laser ablation inductively coupled plasma mass spectrometry analyses of fluid inclusions show very high cu contents in early intermediate density fluid inclusions and in the first vapor inclusion generation followed by a drastic decrease in the second generation of vapor inclusions the decrease correlates with the appearance of anhydrite inclusions in the second quartz generation and may indicate that a lack of sulfur in these later vapor inclusions led to cu partitioning into the brine alternatively it is also possible that unlike early vapor inclusions the later vapor inclusions were not susceptible to postentrapment copper enrichment in accordance with recent experiments a progressive cu enrichment in the brine phase correlates well with depressurization prior to mineralization mass balance considerations based on analyzed fluid components and fluid phase relations indicate that brine was volumetrically minor and therefore likely stagnant but this may have prepared ore precipitation by accumulating cu stripped from ascending vapor

comparison of ladderane phospholipid and core lipids as indicators for anaerobic ammonium oxidation anammox in marine sediments abstract we investigated anaerobic ammonium oxidation anammox in continental shelf and slope sediments of the irish and celtic seas by using anammox specific ladderane biomarker lipids we used the presence of an intact ladderane phospholipid as a direct indicator for living anammox bacteria and compared it with the abundance of ladderane core lipids derived from both living and dead bacterial biomass all investigated sediments contained ladderane core lipids as well as the intact ladderane phospholipid in agreement with 15 n labeling experiments which revealed anammox activity at all sites ladderane core lipid and intact ladderane phospholipid concentrations were significantly correlated r 2 0 957 and 0 464 respectively with anammox activity over the transect of the continental shelf and slope sediments in the irish sea 50 100 m water depth highest abundances of the intact ladderane phospholipid were found in the upper 2 cm of the sediment indicating a zone of active anammox a sharp decline further down core suggested a strong decrease in anammox biomass and rapid degradation of the intact lipids in comparison ladderane core lipids were 1 2 orders of magnitude higher in concentration than the intact ladderane phospholipid and accumulated as dead cell remnants with depth in the slope sediments of the celtic sea both ladderane core lipids and the intact ladderane phospholipid were found in sediments at water depths ranging from 500 to 2000 m here anammox seemed to be active at greater depths of the sediment 2 cm mean abundances of both intact and core ladderane lipids in whole sediment cores increased downslope indicating an increasing importance of anammox in deeper slope sediments

intensity of quartz cathodoluminescence and trace element content in quartz from the porphyry copper deposit at butte montana textures of hydrothermal quartz revealed by cathodoluminescence using a scanning electron microscope sem cl refl ect the physical and chemical environment of quartz formation variations in intensity of sem cl can be used to distinguish among quartz from superimposed mineralization events in a single vein in this study we present a technique to quantify the cathodoluminescent intensity of quartz within individual and among multiple samples to relate luminescence intensity to specific mineralizing events this technique has been applied to plutonic quartz and three generations of hydrothermal veins at the porphyry copper deposit in butte montana analyzed veins include early quartz molybdenite veins with potassic alteration pyrite quartz veins with sericitic alteration and main stage veins with intense sericitic alteration cl intensity of quartz is diagnostic of each mineralizing event and can be used to fingerprint quartz and its fluid inclusions isotopes trace elements etc from specific mineralizing episodes furthermore cl intensity increases proportional to temperature of quartz formation such that plutonic quartz from the butte quartz monzonite bqm that crystallized at temperatures near 750 c luminesces with the highest intensity whereas quartz that precipitated at 250 c in main stage veins luminesces with the least intensity trace element analyses via electron microprobe and laser ablation icp ms indicate that plutonic quartz and each generation of hydrothermal quartz from butte is dominated by characteristic trace amounts of al p ti and fe thus in addition to cl intensity each generation of quartz can be distinguished based on its unique trace element content aluminum is generally the most abundant element in all generations of quartz typically between 50 and 200 ppm but low temperature main stage quartz containing 400 to 3600 ppm al is enriched by an order of magnitude relative to all other quartz generations phosphorous is present in abundances between 25 and 75 ppm and p concentrations in quartz show little variation among quartz generations iron is the least abundant of these elements in most quartz types and is slightly enriched in cl dark quartz in pyrite quartz veins with sericitic alteration titanium is directly correlated with both temperature of quartz precipitation and intensity of quartz luminescence such that bqm quartz contains hundreds of ppm ti whereas main stage quartz contains less than 10 ppm ti our results suggest that ti concentration in quartz is controlled by temperature of quartz precipitation and that increased ti concentrations in quartz may be responsible for increased cl intensities

production of nitrogen gas via anammox and denitrification in intact sediment cores along a continental shelf to slope transect in the north atlantic we measured the production of n2 gas from anammox and denitrification simultaneously in intact sediment cores at six sites along a transect of the continental shelf 50 m and deeper slope 2000 m in the north atlantic maximum rates of total n2 production were measured on the shelf and were largely due to denitrification with anammox contributing on average 33 of this production on the continental slope the production of n2 gas decreased but the proportion due to anammox reached a maximum of 65 this change in both amount and dominant pathway of n2 production could be explained largely by the concentration of organic carbon at each site with increasing carbon the total production of n2 increased rapidly while the response of anammox was not significant on the continental slope total n2 production fell below 2 mmol n m22 h21 and anammox was strongly related r 5 0 95 to denitrification but the relative magnitude of anammox to denitrification 1 65 1 suggested that anammox could not be fuelled by no from denitrification alone on the shelf however where total n2 production was predominantly greater than 2 mmol n m22 h21 no relationship between anammox and denitrification was found and anammox remained constant at 1 4 mmol n m22 h21 despite the constancy and greater availability of no and lower temperatures on the continental slope the significance of anammox to the

geological causes and geomorphological precursors of the tsaoling landslide triggered by the 1999 chi chi earthquake taiwan the tsaoling landslide one of the largest landslide areas in taiwan has been affected by catastrophic events triggered by rain or earthquakes six times since 1862 these landslides including that caused by the 1999 earthquake have essentially not been reactivated old slides but were sequential new ones that developed upslope retrogressively the landslide area is underlain by pliocene sandstone and shale to form a dip slope with a bedding plane dipping uniformly at 14 the slip surface of the 1999 landslide was smooth and planar parallel to the bedding plane with a slightly stepped profile it formed within thinly alternated beds of fine sandstone and shale with ripple lamination or in a shale bed the shale is weathered by slaking and probably by sulfuric acid which is inferred to be one of the major causes of the intermittent retrogressive development of the landslides the weathering was likely accelerated by the removal of overlying beds during earlier landslides in 1941 and 1942 the top margin of the 1999 landslide in plan view coincided with a v shaped scarplet which can be clearly recognized on aerial photographs taken before the landslide this geomorphological feature indicates that this landslide had already moved slightly before its 1999 occurrence providing precursory evidences

a sem cathodoluminescence study of quartz in mildly deformed granite from the region of the atotsugawa fault central japan abstract cathodoluminescence cl images of quartz in granite distributed around the atotsugawa fault in central japan were observed by scanning electron microscopy and compared to optical microscope observations of the same crystals narrow or wide dark bands or dots were commonly recognized in the cl images almost all dots or narrow bands correlate with isolated bubbles or semi planar bubble arrays along healed cracks respectively some wide bands correspond to cracks filled with other minerals chlorite calcite mica etc or can be distinguished as zones with an extinction differing from that of surrounding areas in quartz crushed zones composed of healed crack arrays other wide bands are healed cracks where quartz is precipitated in optical continuity the quartz cl images displayed overall textures composed of mineral filled cracks bubble arrays along healed cracks and crushed zones more clearly than normal optical images healed cracks containing quartz precipitated in optical continuity with the enclosing grains were distinctly revealed as dark bands in cl images the abundance of these minor deformation structures as revealed in cl images increases with proximity to the fault therefore cl textures of quartz are an important aid in examining brittle deformation textures and understanding the tectonic processes that produce them

ion microprobe analyses of trace elements in anorthoclase hedenbergite aenigmatite quartz apatite and glass in pantellerite evidence for high water contents in pantellerite melt

disequilibrium partitioning of oxygen isotopes associated with sector zoning in quartz fractionation of oxygen isotopes during crystal growth is commonly assumed to be an equilibrium process we present evidence here that large variations in delta 18 o values in a zoned vein quartz crystal are the result of disequilibrium partitioning between fluid and crystal within a single crystal vith well developed concentric and sector zoning delta 18 o values determined with laser extraction techniques on milligram to submilligram sized samples range from 4 7 parts per thousand to 7 3 parts per thousand core to rim variations within single growth sectors fluctuate by 2 6 parts per thousand whereas differences between adjacent sectors along the same growth zone can exceed 2 0 parts per thousand in contrast fluid inclusion homogenization temperatures and salinities are relatively constant and show no effect of grow th or sector zoning differences in delta 18 o values between sectors along the same growth zone cannot result from variations in the oxygen isotope composition of the fluid and strongly suggest disequilibrium partitioning of oxygen isotopes between fluid and the growing crystal the cause of this disequilibrium is believed to be due to differences in surface structure and or growth mechanisms between nonequivalent faces

time scales of porphyry cu deposit formation insights from titanium diffusion in quartz porphyry dikes and hydrothermal veins from the porphyry cu mo deposit at butte montana contain multiple generations of quartz that are distinct in scanning electron microscope cathodoluminescence sem cl images and in ti concentrations a comparison of microprobe trace element profiles and maps to sem cl images shows that the concentration of ti in quartz correlates positively with cl brightness but al k and fe do not after calibrating cl brightness in relation to ti concentration we use the brightness gradient between different quartz generations as a proxy for ti gradients that we model to determine time scales of quartz formation and cooling model results indicate that time scales of porphyry magma residence are 1 000s of years and time scales from porphyry quartz phenocryst rim formation to porphyry dike injection and cooling are 10s of years time scales for the formation and cooling of various generations of hydrothermal vein quartz range from 10s to 10 000s of years these time scales are considerably shorter than the 0 6 m y overall time frame for each porphyry style mineralization pulse determined from isotopic studies at butte montana simple heat conduction models provide a temporal reference point to compare chemical diffusion time scales and we find that they support short dike and vein formation time scales we interpret these relatively short time scales to indicate that the butte porphyry deposit formed by short lived episodes of hydrofracturing dike injection and vein formation each with discrete thermal pulses which repeated over the 3 m y generation of the deposit

the magma mixing origin of mantled feldspars the key to mantled feldspar genesis is epitaxial nucleation of plagioclase on k feldspar or k feldspar on plagioclase once this nucleation takes place there is a relatively straightforward process of crystal growth yielding rapakivi and antirapikivi textures the most common mantling is plagioclase on k feldspar which occurs in both volcanic and plutonic environments in the volcanic environment the morphology of the plagioclase overgrowth typically is dendritic though in subvolcanic and shallow plutonic environments dendritic growth is followed by a more or less continuous non cellular shell of plagioclase in the plutonic environment early stages of plagioclase overgrowth also tend to be dendritic although with coarser grained characteristics dendritic morphology is thus a common denominator in rapakivi genesis since growth of dendritic plagioclase is clearly related to marked undercooling in silicate melt systems its occurrence in many volcanic rocks is to be expected equivalent quenching in the plutonic environment requires a cooling mechanism independent of conductive heat transfer to wallrock and also independent of effective cooling related to sudden loss of volatile phases that could only occur late in the crystallization of most magmas and therefore after much dendritic plagioclase had already formed internal quenching of portions of magma systems must occur if mafic magma is abruptly mixed with felsic magma such magma mixing yields a heterogeneous system at first one that is in a drastic state of disequilibrium and tending to force nucleation of one feldspar type on the surface of another resulting in epitaxial crystallization of dendritic plagioclase on k feldspar mantling of one feldspar type by another during magma mixing is paralleled by dendritic growth zones in coexisting plagioclase crystals

seasonal evolution of the cold pool gyre in the western irish sea an extensive cruise program during 1994 1995 and 1996 provided observations that describe the seasonal evolution of the three dimensional density field in the western irish sea a cold dense pool flanked by strong nearbed density gradients was present from may until october in spring salinity had a dominant influence on the density structure but from june until october temperature controlled the density stratification the trajectories of 55 satellite tracked argos drifters demonstrated the existence of the cyclonic circulation pattern that constitutes the western irish sea gyre and defined the gyre s spatial extent several distinct recirculation paths were observed and the implications for planktonic organisms of the seasonal variability in the recirculation are discussed drifter speeds were in good agreement with geostrophic calculations based on the observed density field and with de tided acoustic doppler current profiler adcp measurements the dynamical significance of strong nearbed gradients bottom fronts is highlighted the location of the dynamically significant baroclinicity below the level of wind mixing explains the persistence of the cold pool and cyclonic circulation until late october the dataset described here is valuable for environmental management purposes and it facilitates testing of the prognostic capabilities of the present generation of density advecting numerical models

titaniq a titanium in quartz geothermometer titanium is one of many trace elements to substitute for silicon in the mineral quartz here we describe the temperature dependence of that substitution in the form of a new geothermometer to calibrate the titaniq thermometer we synthesized quartz in the presence of rutile and either aqueous fluid or hydrous silicate melt at temperatures ranging from 600 to 1 000 c at 1 0 gpa the ti contents of quartz in ppm by weight from 13 experiments increase exponentially with reciprocal t as described by text log left x text qtz text ti right 5 69 pm 0 02 frac 3765 pm 24 t k application of this thermometer is straightforward typically requiring analysis of only one phase quartz this can be accomplished either by epma for crystallization temperatures above 600 c or by sims for temperatures down to at least 400 resulting temperature estimates are very precise usually better than 5 c potentially allowing detailed characterization of thermal histories within individual quartz grains although calibrated for quartz crystallized in the presence of rutile the thermometer can also be applied to rutile absent systems if tio2 activity is constrained

landslide seismic signal recognition and mobility for an earthquake induced rockslide in tsaoling taiwan abstract landslide seismic signal processing and the newmark s sliding block analysis are used in this research to analyze the initiation time and mobility of the tsaoling rockslide triggered by the 1999 chi chi earthquake in central taiwan a new technique the time frequency spectrum analysis is employed to identify the rockslide initiation and landing times from four real time seismic records of strong ground motion stations the results suggest that higher frequencies ranging from 30 to 70 hz correspond to the rockslide initiation and sliding process which are opposed to the low signal frequency of earthquake the landslide began at 32 5 s the sliding block sped up at 37 5 s and impacted on the opposite riverbank at 76 s on the seismic time record the mobile scenario of tsaoling rockslide induced by chi chi earthquake is simulated using newmark s sliding block analysis the maximum sliding velocity reaches approximately 75 1 m s despite being a simple conceptual model the newmark s sliding block analysis provides consistent results with the real time seismic signal analysis and details of the rockslide kinematics

tip to midpoint observations on syntectonic veins ouachita orogen arkansas trading space for time abstract by examining a vein from its tip to center we have established the transition from a single filled fracture at the vein tip to typical crack seal textures observed in fibered laminated veins the vein is contained in the boudin neck of a sandstone layer within the lower ordovician mazarn formation benton uplift ouachita orogen the tip of the vein is composed of one or more isolated veinlets defined as quartz filled narrow 5 25 m fractures parallel to the larger vein s long dimension scanned sem based cathodoluminescence shows that quartz laminae of the same orientation and thickness are found throughout the vein wall normal fibers first appear in the vein where detrital grains are cut by multiple veinlets each veinlet mimicking the crystallographic orientation of the detrital grain whereas later veinlets reflect the established crystallographic orientation of the fiber fibers throughout the vein retain evidence of having been formed by repeated fracturing and filling of a pre existing grain at the vein walls or fiber however recrystallization later modified the fibers by obliterating some evidence of the veinlets and moving fiber walls boudin formation provided the extension site that localized fracturing and vein filling the vein grows by the repeated addition of veinlets in the neck region recrystallization altered the shape of previously formed fibers

application of cathodoluminescence to magmatic quartz in a tin granite case study from the schellerhau granite complex eastern erzgebirge germany a model of the cooling history of tin bearing granitic magma forming the schellerhau granites eastern erzgebirge germany is shown on the basis of quartz textures similar grain size similar grain habit and correlatable growth textures of phenocrysts in different granite varieties give proof of a common crystallization history before the melts of the schellerhau granite varieties were intruded four nucleation events occurred during crystallization in different crustal levels between about 20 and 1 km depth the parental melt of the schellerhau granites is interpreted to have contained 2 5 wt h2o originally the water content of the melt during the subvolcanic intrusion stage amounted to more than 5 wt and characterizes highly evolved residual melts that enable the formation of tin deposits this study contributes to a better understanding of the development and behaviour of fractionated tin bearing granitic melts and links quartz cathodoluminescence cl with microanalytical studies

an experimental study to characterize the initiation of the seismic induced tsaoling rock avalanche abstract the tsaoling rock avalanche which had a sliding volume of 120 million m3 and a maximum thickness of 170 m was triggered by the chi chi earthquake in 1999 however the initiation mechanism has not been well understood because different friction models have been proposed to describe the triggering process using the newmark sliding model and numerical simulations in this study a new dynamic ring shear test with a maximum normal stress higher than 3400 kpa is applied as an alternative approach to investigate the initiation of the seismic induced rock avalanche along the wet sliding surface at the interface of the cholan sandstone and consolidated remold shale experimental results verify that the seismic stresses at the wet sliding surface touch the failure surface and generate significant cumulative shear displacements additionally the shear surface should have non linear failure criteria rather than the well known linear mohr coulomb failure criteria with a constant friction angle furthermore the initiation time of the tsaoling rock avalanche obtained from the dynamic ring shear test is strongly correlated with the available seismic signal interpretations and the interviews of witnesses who travelled with the sliding mass this is the first experiment clarifying the co seismic behavior of the sliding surface and the initiation of the tsaoling landslide during the chi chi earthquake additionally from the development of the ring shear test the integrations of high normal stress the wet sandstone shale interface and the dynamic test with seismic loadings greatly extend the use of ring shear tests to rock avalanches

characteristics and runout behaviour of the disastrous 28 august 2017 rock avalanche in nayong guizhou china abstract on 28th august 2017 a disastrous rock avalanche occurred in nayong guizhou china this catastrophic event killed 35 people and destroyed 23 houses in this study the failure process of the avalanche was analyzed using uav video footage and seismic signal recordings obtained for the pre and post failure stages of the landslide to better understand the possible mechanism of the avalanche and its dynamic characteristics a numerical simulation was conducted using a dynamic model dan3d to simulate the runout behaviour of the displaced materials simulated results indicate that the failure process of the nayong rock avalanche lasted approximately 30 s the duration of the failure process is close to that from the uav video footage and seismic signal recordings 35 s the duration of movement during the landslide process is estimated to be approximately 90 s with a maximum velocity of 40 m s the combined frictional voellmy model delivered the most accurate results when simulating this event the selected models and parameters are expected to aid in clarifying the propagation processes of similar rock avalanches and thus improve the accuracy of hazard prediction in mountainous karst areas

kinetics of crystallization of igneous rocks the geochemistry of igneous rocks is discussed with the primary objectives of bringing together the theories underlying the kinetics of crystallization of igneous rocks and illustrating the use of these theories in understanding experimental and observational data the primary purpose of the chapter is to introduce current thinking about the kinetics of igneous rocks and to provide a basis for understanding other work a basic assumption made in the discussion is that the rate of any chemical reaction including the crystallization of igneous rocks is zero at equilibrium and proceeds at a finite rate only at a finite deviation from equilibrium as such an understanding of the processes operating in igneous rocks requires an understanding of how deviation from equilibrium affects the rates and mechanisms of the processes occurring during crystallization these processes are detailed with special emphasis given to nucleation and crystal growth jmt

regression models for estimating coseismic landslide displacement newmark s sliding block model is widely used to estimate coseismic slope performance early efforts to develop simple regression models to estimate newmark displacement were based on analysis of the small number of strong motion records then available the current availability of a much larger set of strong motion records dictates that these regression equations be updated regression equations were generated using data derived from a collection of 2270 strong motion records from 30 worldwide earthquakes the regression equations predict newmark displacement in terms of 1 critical acceleration ratio 2 critical acceleration ratio and earthquake magnitude 3 arias intensity and critical acceleration and 4 arias intensity and critical acceleration ratio these equations are well constrained and fit the data well 71 br 2 b88 but they have standard deviations of about 0 5 log units such that the range defined by the mean one standard deviation spans about an order of magnitude these regression models therefore are not recommended for use in site specific design but rather for regional scale seismic landslide hazard mapping or for rapid preliminary screening of sites 2007 elsevier b v all rights reserved

detrital quartz sources in the scotian basin eastern canada using hot cathode cathodoluminescence availability of coarse grained sand for reservoirs quartz is the principal framework mineral in clastic sediment reservoirs in a frontier basin with sparse wells the source of quartz in sandstones may be a predictor of the availability of medium to coarse grained quartz sand from plutonic sources likely to provide good reservoirs the scotian basin offshore eastern canada was used to test this hypothesis because of its well understood provenance history and geographic variability in known medium to coarse grained reservoir sandstones the sources of detrital quartz in fine grained sandstones were determined using hot cathode cathodoluminescence cl supplemented by other petrographic techniques the cl color shift for different quartz types was calibrated against the cl properties of representative source rocks in the hinterland because generalizations in the literature do not precisely match our basin specific observations grain size of sandstone exerts a strong control over quartz type with plutonic hypabyssal quartz and high grade metamorphic quartz more abundant in coarse grained sandstones and low grade metamorphic quartz more abundant in fine grained sandstones nevertheless the analysis of fine grained sandstones shows that plutonic hypabyssal quartz is more abundant in fine grained sandstones of the sable subbasin than in those of the abenaki subbasin the abundance of plutonic hypabyssal quartz correlates with the abundance of medium to coarse grained sandstone reservoirs in the sable subbasin this study suggests that in frontier basins the abundance of plutonic hypabyssal quartz in fine grained sandstones can be used as an indicator of available medium to coarse grained sandstone reservoir

crystallisation of magmatic topaz and implications for nb ta w mineralisation in f rich silicic melts the ary bulak ongonite massif textural mineralogical and geochemical data on f rich rhyolite ongonite from the ary bulak massif of eastern transbaikalia help constrain the formation of magmatic topaz in these rocks topaz occurs as phenocrysts thus providing compelling evidence for crystallisation at the orthomagmatic stage cathodoluminescence images of topaz and quartz reveal growth textures with multiple truncation events in single grains indicative of a dynamic system that shifted from saturated to undersaturated conditions with respect to topaz and quartz electron microprobe and raman analyses of topaz indicate near pure f composition al2sio4f2 with very limited oh replacement laser ablation icp ms traverses revealed the presence of a large number of trace elements present at sub ppm to hundreds of ppm levels the chemical zoning of topaz records trace element fluctuations in the coexisting melt concentrations of some trace elements li ga nb ta and w are correlated with cathodoluminescence intensity thus suggesting that some of these elements act as cl activators in topaz the study of melt inclusions indicates that melts with different f contents were trapped at different stages during formation of quartz and topaz phenocrysts respectively electron microprobe analyses of glass in subhedral quartz hosted melt inclusions indicate f 1 2 wt whereas irregular shaped melt inclusions hosted in both topaz and quartz have f 9 wt cryolithionite na3li3al2f12 coexists with glass in irregular inclusions implying high li contents in the melt the very high f contents would have increased the solubility of nb ta and w in the melt thus allowing progressive concentration of these elements during magma evolution crystallisation of nb ta w oxides w ixiolite and tantalite columbite may have been triggered by separation of cryolithionite which would have caused f and li depletion and consequent drop in the solubility of these elements

melt generation and fluid flow in the thermal aureole of the bushveld complex granite sheets emplaced into the migmatite zone of the eastern contact aureole of the bushveld complex resulted from fluid enhanced incongruent biotite melting of the underlying silverton formation shales during prograde metamorphism ba concentrations are extreme in both the sheets 1000 ppm and the hornfels 800 ppm into which they have been emplaced we conclude that a ba rich hydrothermal fluid induced melting in the aureole and that fluid transport of ba2 and to a lesser extent sr2 and eu2 persisted in the melt zones under subsolidus conditions sr isotope systematics from high ba localities define an errorchron of 2161 106 ma with an initial 87sr 86sr ratio of 0 705 0 001 metasedimentary rocks unaffected by fluid infiltration were homogenized at the same time but with an increased initial ratio suggesting that whereas isotope homogenization was achieved between outcrops permeated by fluids there is no evidence of regional homogenization oxygen isotope compositions of psammitic metasediments in the aureole are uncorrelated with distance from the contact suggesting the infiltrating fluid equilibrated isotopically with the metasediments their elevated 18o values 11 3 12 1 are consistent with a fluid source from devolatilization of the sedimentary lithologies textural analysis at both outcrop and thin section scale of arkose and psammites in the aureole lakenvalei and magaliesberg formations shows that the extent of melting was highly heterogeneous even on the grain scale and resulted from heterogeneously distributed infiltration of aqueous fluid on dilatant cracks and grain boundaries cathodoluminescence imaging of quartz shows a marked difference in the amount of fine structure with that in the melted rocks having uniform luminescence in contrast to that in rocks containing little or no melt which preserve textures inherited from the regionally metamorphosed protolith simple finite difference thermal modelling of the aureole suggests that the width of the melt zone 500 m is inconsistent with conductive heat transfer and hence that the thermal structure has been modified by fluid advection

cathodoluminescence and trace element zoning in quartz phenocrysts and xenocrysts quartz phenocrysts and xenocrysts are a common component of volcanic rocks but rarely contribute to our understanding of magmatic or eruptive processes due to an apparent internal chemical and structural homogeneity scanning electron microscopy cathodoluminescence imaging sem cl and secondary ion mass spectroscopy ion microprobe analysis sims are used here to demonstrate that quartz crystals in volcanic rocks show hitherto unrecognised internal structural and chemical zoning two contrasting crystal morphologies have been studied porphyritic euhedral bipyramidal quartz crystals in dacite from bonne nuit bay jersey uk show fine scale growth zoning in sem cl zones are narrow 1 40 m wide planar parallel to crystal faces and overgrow more broadly zoned rounded cores these crystals are interpreted to have formed at small degrees of undercooling by diffusion controlled growth quiescent magma conditions are indicated by the preservation of an al rich diffusive boundary layer which has not been removed by melt shearing during convection in contrast rounded and embayed porphyritic quartz grains in a quartz dacite from the esperanza mine e1 salvador northern chile show broad internal sem cl zones with irregular boundaries some of which are truncated by grain margins indicating dissolution crystal rounding may occur by dissolution or melting due to thermal or thermal chemical disequilibrium with surrounding melt and embayments by gas bubble enhanced convective dissolution are consistent with the development of incipient ocelli textures strings of amphibole inclusions adjacent to quartz rims several episodes of rounding can be recognised in some xenocrysts ion microprobe sims analysis of quartz from both samples shows that a1 contents are higher in areas of bright cl emission previous studies of cl in quartz have suggested that several factors control luminescence although a1 substitution for si in sio4 tetrahedra may be partly responsible for sem cl zoning recorded in volcanic quartz additional mechanisms including the effect of growth rate on defect density probably also play a major role

convective crystal dissolution the effect of free and forced convection on crystal dissolution is examined both theoretically and experimentally well established relationships for heat and mass transfer are applied to obtain approximate expressions for the dissolution velocity and the associated thickness of the compositional boundary layer these expressions are found to be in good agreement with experimental observations of the dissolution of quartz crystals in basalt and nacl crystal in water when applied to light felsic crystals in basaltic magmas the expressions predict that forced convection will produce a boundary layer thickness of about 100 m and a dissolution velocity of order 10 6 cm s 1 these velocities are too slow for xenocrysts to be dissolved significantly during magma ascent in dykes but are sufficient for cm size crystals to dissolve in the interior of a convecting magma chamber larger crystals are likely to accumulate at the chamber s roof where free convection is predicted to dissolve them at velocities of order 10 7 cm s 1 in an appendix the dissolution of the chamber s walls is also considered and a velocity of order 10 8cm s 1 is predicted

ground vibrations produced by rock motions and debris flows 1 in this study we compare ground vibrations generated by various rocks and debris flows at the same channel to explore the origin of ground vibrations caused by debris flows in field experiments we identified the ground vibrations caused by motions of individual rocks ground vibrations were detected by geophones and analyzed in the time frequency domains we found that ground vibrations caused by individual rocks were 10 150 hz and that larger stones generate ground vibrations with lower peak frequencies a sphere packing model of granular rocks was used to estimate the propagation speed of ground vibrations this was found to be underestimated when compared with our experimental data the signal decay rate was obtained under the assumption that ground vibrations propagate as exponentially attenuating cylindrical waves ground vibrations produced by a debris flow at ai yu zi creek nan tou taiwan on 2 july 2004 revealed that the debris flow forefront produced vibrations lower than 50 hz and ranged between 50 and 100 hz after the front had passed when the main front was closest to the sensor the frequency spectrum covered a wide range from 10 to 250 hz the mean velocity of the debris flow front was 13 3 m s frequencies of ground vibrations caused by individual rocks are within the frequency range of ground vibrations captured during the debris flow confirming that one of the main sources of ground vibration caused by debris flows is the interaction of rocks or boulders with the channel bed

a method for producing digital probabilistic seismic landslide hazard maps abstract the 1994 northridge california earthquake is the first earthquake for which we have all of the data sets needed to conduct a rigorous regional analysis of seismic slope instability these data sets include 1 a comprehensive inventory of triggered landslides 2 about 200 strong motion records of the mainshock 3 1 24 000 scale geologic mapping of the region 4 extensive data on engineering properties of geologic units and 5 high resolution digital elevation models of the topography all of these data sets have been digitized and rasterized at 10 m grid spacing using arc info gis software on a unix computer combining these data sets in a dynamic model based on newmark s permanent deformation sliding block analysis yields estimates of coseismic landslide displacement in each grid cell from the northridge earthquake the modeled displacements are then compared with the digital inventory of landslides triggered by the northridge earthquake to construct a probability curve relating predicted displacement to probability of failure this probability function can be applied to predict and map the spatial variability in failure probability in any ground shaking conditions of interest we anticipate that this mapping procedure will be used to construct seismic landslide hazard maps that will assist in emergency preparedness planning and in making rational decisions regarding development and construction in areas susceptible to seismic slope failure

simulation of tsaoling landslide taiwan based on saint venant equations over general topography the 1999 chi chi earthquake triggered the catastrophic tsaoling landslide in taiwan the geomorphological change measured from the data of the 1989 and 2000 aerial photos reveals that the scar and deposit volumes are about 0 126 km3 and 0 15 km3 respectively the debris material ran over a distance of 1 6 km with 500 m descent in elevation in this paper we use the continuum model of hydraulic flow shaltop2d based on the equations of bouchut and westdickenberg to simulate numerically the landslide dynamics when the mass is moving the flow is assumed hydrostatic with a basal coulomb friction the best fit is obtained using the basal friction angle equal to 6 the only parameter of the simulation uniformly applied in the calculation domain the landslide front reaches the chinshui river valley the foothill of the slope within only about 25 s after initiation and the motion settles in about 113 s the maximum speed is estimated 75 m s the spreading of the deposit agrees well with the field measurement

cathodoluminescence properties of quartz eyes from porphyry type deposits implications for the origin of quartz hyperspectral cathodoluminescence cl mapping combined with electron probe microanalysis epma and fourier transform infrared spectroscopy was used for the reconstruction ofcrystallization conditions of quartz from porphyry environments quartz eyes from the two porphyry deposits rio blanco chile and climax u s a were studied three peaks are found to be responsible for the total cl emission 1 93 2 05 and 2 72 ev the first two peaks are assigned to o m with m being an alkali ion and oxygen vacancies respectively the 2 72 ev peak shows a linear correlation with the ti concentration determined by epma point measurements in addition a negative correlation between the 1 93 ev emission and the al concentration was observed quartz grains often form clusters in which adjacent grains show identical cl patterns indicating that they crystallized attached to each other and were not disturbed later quartz cores display sector zoning and enrichment in li oh and sometimes al which points to rapid crystallization from an extremely evolved melt quartz rims show high ti and low li and oh contents indicating crystallization from a less evolved melt either at higher temperatures or at higher titanium activities the al and ti distribution patterns are frequently not correlated and both show uneven distribution indicating fast growth from inhomogeneous melts only ti displays sharp transitions and fine oscillatory zoning which can be explained by the higher mobility of al in the quartz lattice the quartz eyes crystallized after magma emplacement under non equilibrium conditions it is likely that the crystallization occurred from the melt enriched in al li and oh and probably other metals and or volatiles on the brink of fluid exsolution subsequent fluid exsolution brought about disequilibrium to the system resulting in dissolution of quartz and redistribution of elements between the melt and the fluid the oh li and other alkali metals and volatiles partitioned into the fluid whereas ti and al remained in the melt resorption of quartz caused by the fluid exsolution continued until equilibrium was reached again after which crystallization of quartz rims began from the water alkali and volatile poor melt with higher ti activity furthermore accumulation of al and ti in the residual melt led to crystallization of extremely al and ti rich quartz

stochastic seismic response of a slope based on large scale shaking table tests abstract slopes should be regarded as stochastic dynamic systems when investigating the uncertainty of ground motions in engineering this involves the propagation and spatial evolution of physical quantities e g acceleration that can be assessed with some probability more specifically stochastic stability and amplification effects are important issues under random seismic inputs in studying the above a large scale shaking table test is carried out to investigate the slope seismic response under random earthquake ground motions where 144 ground motion samples are generated using a time evolution power spectrum model in this test acceleration evolves in a way that its pdf changes with time and space in the time domain the pdf variability first increases and then decreases with the progression of the earthquake in the spatial domain the pdf variability increases upslope indicating that the mean and standard deviation of amplification factors increase with elevation moreover the stability of the upper part of the slope stochastic dynamic system is poor meanwhile the de amplification effect of the slope toe is identified under random seismic inputs finally we discuss different amplification factors and consider applications of the research results in slope engineering

integrated methodology for determining provenance of detrital quartz using optical petrographic microscopy and cathodoluminescence cl properties abstract the provenance of detrital quartz is a useful predictor in frontier basin sandstone reservoirs of the availability of coarse grained quartz grains of plutonic or high grade metamorphic origin the standard approach is to use scanning electron microscope sem panchromatic cathodoluminescence cl imagery and observations from an optical petrographic microscope we describe a work flow modified from previous literature proposals to determine quartz provenance in detrital grains using optical petrographic microscopy and cl properties from both a hot cathode cathodoluminescence microscope attachment hcma and panchromatic sem cl hcma analysis permits better discrimination of different types of metamorphic quartz this method is applied to a middle jurassic to lower cretaceous section in the bandol 1 wildcat well located in the laurentian sub basin south of newfoundland two types of high grade metamorphic quartz are distinguished one with low luminescence as described in previous literature and one with medium blue cl colour and a moderate colour shift that is also known from granulite in the hinterland three phases of detrital supply are identified suggesting progressive unroofing of higher grade metamorphic sources through the middle jurassic and major input of plutonic quartz in the early cretaceous

cathodoluminescence and micro structural evidence for crystallisation and deformation processes of granites in the eastern lachlan fold belt se australia trace elements al k ti fe growth and deformation pattern in quartz of the multiple deformed carcoar barry and sunset hills granites were investi gated by electron micro probe and cathodolumines cence zoned quartz phenocrysts with high ti concentrations 70 ppm that show blue cathodolu minescence originated from the early stage of magma crystallisation multiple deformation of quartz causes the redistribution of al and k in the quartz lattice which results in the accumulation of these elements in submicroscopic inclusions 0 5 lm of muscovite like composition in contrast structural ti in quartz is mostly kept in the lattice common halos of defect poor secondary quartz around fluid inclusions result from re equilibration of fluid inclusions because of differences between fluid pressure and lithostatic pressure e g duringuplift isothermal decompression and or a b transition of quartz duringhealing defect poor sec ondary quartz grows at the cost of the host quartz and releases or replaces defect centres the results of micro structural investigations combined with al in horn blende thermobarometry allow the reconstruction of regional processes carcoar and barry granodiorites and sunset hills granite were intruded in the late ordovi cian early silurian at depths of 4 8 6 and 10 12 km respectively in contrast to the continuous crystallisation of the granodiorite magmas the magma of the sunset hills granite ascended in a stepwise fashion causing multiple quartz nucleation the two granodiorites were multiple post magmatically deformed first during early devonian under more brittle conditions at temperatures of 350 400 c whereas the sunset hills granite experienced more ductile deformation at tem peratures of around 550 c

classification and sudden departure mechanism of high speed landslides caused by the 2008 wenchuan earthquake the sudden departure mechanism of high speed landslides has always constituted a popular yet difficult research topic therefore although a systematic classification of high speed landslides is necessary particularly since different types of landslides exhibit different mechanisms an associated methodology has yet to be established this paper investigates an easily overlooked phenomenon landslide quake which is defined as a local ground vibration triggered by the sudden rupture of the locked segment of a high speed landslide that occurs immediately prior to the departure of the landslide this new concept is employed as a foundation for a new classification the characteristics and formation conditions of landslide quake are discussed based upon which the high speed landslides that occurred following the 2008 wenchuan earthquake are classified into three different types subsequently the sudden departure mechanism of each type of landslide is analyzed thereby providing a new method for research on the sudden departure mechanism of high speed landslides

the tsaoling landslide triggered by the chi chi earthquake taiwan insights from a discrete element simulation article i nfo in the village of tsaoling in yunlin county taiwan a major landslide was triggered by the chi chi earthquake in 1999 with more than 125 10 6 m 3 of rock displaced the kinematic behaviour of this landslide is simulated using a 2d discrete element model pfc2d code our numerical model is composed of discs bonded together the initial boundary conditions are applied along the ball wall contacts by using derived velocities integrated from the strong motion data with a duration of 160 s including the peak acceleration near tsaoling the constraints are mainly issued from the final geometry of the landslide including its capacity to cross the river valley and reach a significant elevation on the opposite mountain flank they also result from a variety of geological and hydrological observations including the local levels of material disruption and the location of survivors our modelling thus indicates that a low friction coefficient about 0 15 and a medium strength are required to account for the actual landslide characteristics a self lubrication mechanism probably accounts for the low residual friction our model also suggests that the maximum velocity of sliding reached 50 m s a result that cannot be checked in the absence of actual measurements in addition to friction the strength of sliding block is of special importance because it controlled the possibility for the upper layer fragments to roll and get buried and hence the probability of survival

zoned quartz phenocrysts from the rhyolitic bishop tuff cathodoluminescence cl reveals growth zones in quartz phenocrysts from the rhyolitic bishop tuff melt inclusions occur in various zones and record the evolving melt composition during zonal growth the zones form an oscillatory pattern between bright and dark cl quartz there are three recognizable patterns of cl zoning in these crystals 1 weakly zoned cores and bright cl rims 2 weakly zoned cores and dark cl rims and 3 no cl intensity difference from core to rim dark cl quartz generally occurs at crystal edges contains most of the melt inclusions and is interpreted as fast growing zones that occur along recognizable crystal edges edge zones are thicker than the same zone on adjacent faces consistent with relatively fast growth of these zones in each successive zone these edge zones decrease in size toward the rim while the zones along the crystal faces increase some of the melt inclusions have bright cl quartz locally associated with them this is interpreted as the postentrapment crystallization of slow growing quartz in the melt inclusions many crystals display zone discordance from the weakly zoned interiors to the rims most of the discordant surfaces are rational and probably are primary growth features pumice clasts from the southern vents are largely compositionally and texturally distinct from those from the northern vents and this distinction is also evident in the quartz cl the crystals that have bright cl rims are all associated with the late erupted northern part of the bishop tuff melt inclusion compositions and cl zoning patterns suggest a common origin for early and middle erupted quartz and the interior zones of late erupted quartz however the bright cl rim on the late erupted quartz indicates an additional stage of crystallization in late erupted magma melt inclusions in individual early erupted crystals have small variations in ba whereas inclusions in late erupted crystals markedly increase in ba toward the rim which is opposite to the normal zoning of sequentially trapped melts expected during closed system crystallization differentiation the quartz zoning features are consistent with the hypothesis of crystal settling in evolving magma that erupted late from northern vents

provenance analysis by single quartz grain sem cl optical microscopy abstract the integration of panchromatic scanning electron microscopy cathodoluminescence sem cl with optical microscopy analysis on single quartz grains is a new technique to interpret provenance of quartz rich sediments the combination of information gained from sem cl on textural features and cl response with information from optical microscopy allows distinction of different quartz types much more easily then with conventional microscopy or color cl analysis features visible by sem cl include zoning microcracks deformation fractures and lamellae diagenetic crushing recrystallization and strength and texture of cl response features visible by optical microscopy include embayments open fractures extinction behavior and mono poly and microcrystallinity the key is to integrate cl and optical properties of the same quartz grains in order to reduce ambiguities inherent in both techniques used on their own our technique is well suited for distinguishing between plutonic volcanic and metamorphic quartz in coarse to medium grained sand or sandstone this simple and inexpensive approach can easily be combined with other provenance techniques in this paper we outline the combined sem cl optical microscopy technique and demonstrate its application with examples from the south island of new zealand

skeletal quartz and dendritic biotite witnesses of primary disequilibrium growth textures in an alkali feldspar granite abstract we describe a case of s type alkali feldspar granite quartz k feldspar plagioclase biotite garnet 30 35 20 13 2 vol showing skeletal and dendritic textures it consists of three nested units distinguishable by the size of biotite crystals a first emplaced unit characterized by small biotite flakes 0 4 9 mm a second unit with cm sized biotite platelets 0 3 28 mm outlining a syn magmatic foliation and a third unit formed of large biotite plates 0 7 850 mm showing dendritic and radial growth patterns quartz occurs mostly as rounded to euhedral grains but also shows complex shapes serrated outline re entrants etc cathodoluminescence imaging reveals that grains consist of both rounded and skeletal bluish cores quartz 1 rimmed by reddish overgrowths quartz 2 that lead locally to the coalescence of neighbouring grains and equilibrated texture biotite is poikilitic enclosing dominantly quartz grains but also in lesser amount plagioclase and garnet in the third unit biotite shows textures typical of dendritic growth bifurcating radiating or branching structures skeletal core plagioclase an 25 occurs as small euhedral to subhedral grains scattered in the matrix or forming glomerophyric aggregates k feldspar or74 100 mostly forms an almost equilibrated mosaic of anhedral perthitic crystals it also appears in association with albite as a secondary phase replacing plagioclase the crystallization sequence started with garnet then proceeded with quartz plagioclase biotite and k feldspar ended with cordierite and was followed by subsolidus reequilibration the variability in size and morphology of quartz and biotite is interpreted in terms of variable undercooling depending on temperature of the host rocks and on more or less intense degassing of magma batches with variable melt water content here rapid crystallization prevented significant textural reequilibration and allowed the initial crystallization textures of quartz to be preserved overall this study shows that behind the common coarse grained texture of quartz in granite subsist primary disequilibrium crystallization textures

mobility of large rock avalanches evidence from valles marineris mars measurements of h l height of drop length of runout vs volume for landslides in valles marineris on mars show a trend of decreasing h l with increasing volume this trend which is linear on a log log plot is parallel to but lies above the trend for terrestrial dry rock avalanches this result and estimates of 10 4 to 10 5 pa yield strength suggest that the landslides were not water saturated as suggested by previous workers the offset between the h l vs volume trends shows that a typical martian avalanche must be nearly two orders of magnitude more voluminous than a typical terrestrial avalanche in order to achieve the same mobility this offset might be explained by the effects of gravity on flows with high yield strengths these results should prove useful to future efforts to resolve the controversy over the mechan ics of long runout avalanches

identification of co seismic ground motion due to fracturing and impact of the tsaoling landslide taiwan abstract earthquakes can generate seismic disturbances that propagate vast distances and trigger landslides that can achieve high speeds it remains difficult to identify the co seismic ground motion of these landslides and their triggering earthquakes in this paper we report on the analysis of co seismic ground motions generated by the initiating fracture and deposition impact of the tsaoling landslide the landslide with a source volume of 125 10 6 m 3 was triggered by the 1999 chi chi earthquake in taiwan the ground motion was recorded by a strong ground motion station chy080 near the scar area the polarization of the seismic waves indicates that the peak acceleration was parallel to the dip direction modified ensemble empirical mode decomposition eemd with additional clustering analysis was applied to decompose the seismic signals two instances were found in the seismic records of a series of peculiar wave packets with the first being associated with the landslide initiation and the second the landslide impact on the deposit valley to confirm the first landslide breakage the decomposed signals were compared with the predictions of the analytic elastic wave model and newmark analysis the landslide impact was verified with a computational fluid dynamic simulation comparison between the eemd decomposed signals elastic wave theory newmark rigid body analysis and numerical simulation demonstrates the claimed landslide motion

advances in lithium analysis in solids by means of laser induced breakdown spectroscopy an exploratory study lithium is an important geochemical tracer for fluids or solids however because the electron microprobe cannot detect li variations of li abundance at the micrometric scale are most often estimated from bulk analyses in this study the li intense emission line at 670 706 nm in optical emission spectroscopy was used to perfect the analysis of li at the micrometric scale by means of laser induced breakdown spectroscopy libs to estimate lithium content for different geological materials libs calibration of the emission line at 670 706 nm was achieved by use of synthetic glasses and natural minerals the detection limit for this method is 5 ppm li three applications to geological materials show the potential of libs for lithium determination namely for li bearing minerals melt inclusions quartz and associated fluid inclusions for spodumene and petalite from granite pegmatite dikes portugal the li2o concentrations are 7 6 1 6 wt and 6 3 1 3 wt respectively by use of libs these values agree with ion microprobe analyses bulk analyses or both for eucryptite crystals the li concentrations are scattered because grain size is smaller than the libs spatial resolution 6 to 8 m lithium concentrations of melt inclusions from the streltsovka u deposit siberia are in the range of 2 to 6 2 wt li2o for li rich daughter minerals lithium estimations on silicate glasses display values between 90 and 400 ppm lithium was also analyzed as a trace element in quartz transverse profiles were performed in hydrothermal barren quartz veins from the spanish central system sierra de guadarrama the highest li concentrations 250 to 370 ppm were found in specific growth bands in conjunction with the observed variation in optical cathodoluminescence intensity considering the fluid inclusion analysis the source of fluid responsible to the li enrichment in quartz is probably high salinity fluids derived from sedimentary basins

illumination of vein quartz textures in a porphyry copper ore deposit using scanned cathodoluminescence grasberg igneous complex irian jaya indonesia vein quartz from the grasberg igneous complex in irian jaya indonesia displays a wide range of features when observed using scanned cathodoluminescence imaging on the electron microscope examination of seventeen samples revealed concentric growth zoning quartz filled microfractures dark luminescence near sulfides changes in crystal size and orientation from vein edges to vein centers turbid growth zoning and the truncation of concentric growth zoning individual features observed along two large photomosaic traverses from vein margins to vein centers coupled with trace element analyses from the electron microprobe allow determination of a detailed history of fracture infilling the two traverses indicate a simple two stage history of crystal growth into an open fracture followed by mechanical closing of the fracture with resulting microfractures electron microprobe trace element analyses show that the fe content of quartz reaches values of up to 4900 ppm in dark luminescent regions near sulfide crystals and decreases smoothly to 200 ppm along traverses away from the sulfides the solution to the diffusion equation coupled with existing experimental data about fe diffusion in sio2 indicate the duration of the diffusion was perhaps on the order of thousands of years

trace element composition of quartz from the variscan altenberg teplice caldera krusne hory erzgebirge mts czech republic germany insights into the volcano plutonic complex evolution abstract in this study the internal structures and appropriate trace element distributions within quartz grains were investigated using a laser ablation icp ms technique combined with a hot cathode and scanning cathodoluminescence analysis the studied variscan magmatic suite is located in the altenberg teplice caldera eastern krusne hory erzebirge along the czech republic germany border and composed of co magmatic volcanics peraluminous basal rhyolite and associated dacite overlying three units of subaluminous teplice rhyolite and granite porphyry and plutonic granites two intrusions of a type biotite and zinnwaldite granites the trace element distribution in the granite porphyry and rhyolite quartz demonstrates a distinct zoning in the cathodoluminescence images and chemical compositions the core is poor in ti the outer rim zones are enriched in ti and the trends recorded for al are opposite to those of ti the quartz from granites is either very weakly zoned or homogeneous based on the chemical composition of quartz and its zoning we assume that the quartz crystals began to crystallize gradually in the primary deep seated magma chamber with a p t condition of 10 kbar and 750 c and in an environment with an increasing concentration of al and decreasing concentration of ti the early stage was followed by the subsequent adiabatic ascent into a shallow magma chamber estimated by the ti in quartz thermobarometry at approximately 700 c 2 kbar during which crystal rims rich in ti formed and then extruded after the caldera collapse part of the magma intruded as granite and in the environment of the residual melt rich in water and flux agents late quartz grew in the form of snowball quartz with an increased al content and decreased ti content

trace element zoning of sulfides and quartz at sheba and fairview gold mines clues to mesoarchean mineralisation in the barberton greenstone belt south africa abstract the fairview and sheba mines are two of the major gold mines in the paleoarchean barberton greenstone belt of southern africa at these mines gold is associated with quartz carbonate rutile veins and occurs both as invisible gold finely dispersed in sulfides primarily pyrite and arsenopyrite and as visible electrum grains hosted in pyrite up to approximately 1000 ppm au are contained in pyrite and up to approximately 1700 ppm in arsenopyrite mapping of trace element distribution in sulfide minerals using electron microprobe and proton probe techniques revealed multiple events of ore formation and au mineralisation at fairview mine three stages of pyrite formation were identified the last of which is associated with arsenopyrite electrum and other sulfide minerals sphalerite chalcopyrite galena gersdorffite and sb sulfides at sheba mine pyrite was deposited in two stages and electrum is associated with the second stage at both mines the last stage of sulfide formation is the main stage of au deposition and is associated with mobilisation of au as sb cu zn and ni the host rock composition seems to have affected the composition of pyrite since higher ni and co concentrations up to 1 4 and 1 6 wt respectively have been measured in meta ultra mafic host rocks in comparison with chert and metagreywacke arsenopyrite is chemically zoned and has sb and s rich cores and as and ni rich rims this zoning indicates variations in fluid compositions decreasing sb and increasing ni and crystallisation conditions increasing as content for increasing temperature geothermometric estimates based on the as content of arsenopyrite as 32 at indicate temperatures up to 420 c for the crystal rims petrographic and cathodoluminescence observations of quartz associated with gold mineralisation show only local brittle deformation and no plastic deformation this supports the notion that the ore transporting veins were emplaced late in the deformation history variations of cathodoluminescence of quartz are correlated with changing al contents al 0 16 wt and can be related to fluctuations in the ph of the mineralising fluids

influence of surface normal ground acceleration on the initiation of the jih feng erh shan landslide during the 1999 chi chi taiwan earthquake the 1999 chi chi taiwan earthquake triggered numerous landslides throughout a large area in the central range to the east southeast and south of the fault rupture among them are two large rock avalanches at tsaoling and at jih feng erh shan at jih feng erh shan the entire thickness 30 50 m of the mio cene changhukeng shale over an area of 1 km 2 slid down its bedding plane for a distance of about 1 km initial movement of the landslide was nearly purely trans lational we investigate the effect of surface normal acceleration on the initiation of the jih feng erh shan landslide using a block slide model we show that this ac celeration currently not considered by dynamic slope stability analysis methods significantly influences the initiation of the landslide

behavior of trace elements in quartz from plutons of different geochemical signature a case study from the bohemian massif czech republic article i nfo in this study the trace element content in igneous quartz from granitoids of different geochemical types was investigated using the laser ablation icp ms technique the variscan granitoids in the bohemian massif pro vide an excellent opportunity to study the chemical composition of magmatic quartz from the following granite types 1 geochemically primitive i type tonalites and granodiorites 2 peraluminous s type two mica granites 3 moderately fractionated a type volcano plutonic complexes of the teplice caldera and 4 highly fractionated s and a type rare metal granites this diversity of granitoids permitted the study of the chemical composition of magmatic quartz as the result of i different magma protoliths and ii variable degrees of differentiation there were only small differences in the quartz trace element con tents ranging from weakly to moderately differentiated plutons of all geochemical types al mostly in the range between 20 and 250 ppm ti mostly 20 110 ppm b b13 ppm be b0 7 ppm ge b1 ppm li b30 ppm and rb b2 ppm only the s type granites from western erzgebirge contain al enriched quartz mostly 200 400 ppm al since the beginning of its evolution however quartz from the highly fractionated granites group 4 differs significantly this quartz is generally poor in ti b20 ppm ti and enriched in al up to 600 ppm in a type and up to 1000 ppm in s type granites be up to 3 2 ppm ge up to 5 7 ppm li up to 132 ppm particularly in the s type granites and rb up to 15 ppm the contents of the analyzed lithophile elements in the quartz from the highly fractionated granites are similar to the contents reported to be present in evolved complex pegmatites although the input of ti into quartz is controlled mainly by the temperature and pressure of quartz crystallization the entry of al into quartz increases as a function of the water and fluorine content of the residual melt the contents of ge and li increase significantly with the fractionation of parental melt the concentrations of these elements in quartz from highly fractionated granites are controlled by the order of crystallization of the major minerals comb quartz crystallizing before li mica is strongly li enriched whereas groundmass and snowball quartz crystallizing after mica is relatively enriched in ge