a study of metal bearing nanoparticles from the kangjiawan pb zn deposit and their prospecting significance abstract over the years using novel methods to find deep seated ore resources has always been a hot research topic in this paper we present a new method to investigate deep seated orebodies by characterizing metal bearing nanoparticles e g morphological features and chemical compositions in various media deep shallow groundwater ascending gas flow and soil via transmission electron microscopy tem from the kangjiawan pb zn deposit the study area the metal bearing nanoparticles collected from different media contain similar contents of ore forming elements e g cu zn pb fe and s and are strongly related to the presence of deep seated orebodies these ore related nanoparticles are grouped into four main categories i amorphous ii single crystal iii poly crystal and iv complex poly crystal in particular many amorphous nanoparticles in different media can transfer ore forming elements and provide mineralization information we propose that the ore forming elements exist and migrate in the form of these four types of nanoparticles the results can explain the geochemical anomalies and provide insights on the role of nanoparticles in post mineralization ore related elemental dispersion and could be useful in exploration for concealed orebodies

study of particles in the ascending gas of ruptures caused by the 2008 wenchuan earthquake abstract ascending gas is a global phenomenon it can move upwards along faults or fissures from the interior of the earth to the surface of the earth seismically active regions near continental plate boundaries are active regions of ascending gas based on the results of previous research abnormal concentrations of so 2 co 2 rn he h 2 o 2 ar n 2 and ch 4 in ascending gas may be applied to earthquake prediction in our study particles carried by ascending gas in ruptures caused by the wenchuan earthquake have been discovered using a transmission electron microscope it can be seen that there are far more particles in the ascending gas of ruptures caused by the 2008 earthquake than there are in the ascending gas of the non seismic fengguanshan fault or the ascending gas of the soil in wufeng town of jintang county or yuhe village of pengshan county which represent background areas the abnormal characteristics of the particles carried by the ascending gas of ruptures also include cu hg and os enriched particles the typical elemental associations are fe mn ni cr and pb cr sio 2 particles contain abnormally high contents of impure elements in the form of particles that have been encapsulated by sio 2 this is the first study to report the presence of particles carried by ascending gas in earthquake ruptures this study represents a new method of earthquake prediction these particles can provide us with abundant and direct information about earthquake activity which can be applied to earthquake prediction characteristics of the particles in the ascending gas combined with the concentrations of hg so 2 co 2 rn he h 2 o 2 ar n 2 and ch 4 can be used to develop a more efficient method of earthquake prediction

studies of colloids and suspended particles cigar lake uranium deposit saskatchewan canada abstract the cigar lake u deposit is located in northern saskatchewan in the eastern part of the athabasca sandstone basin and consists of a high grade ore body up to 55 u located at a depth of 430 m as part of a study to evaluate the analog features of this deposit with respect to a disposal vault for waste nuclear fuel colloids 1 450 nm and suspended particles 450nm in groundwater have been investigated to evaluate their effect on element transport through the u deposit tangential flow ultrafiltration was used to concentrate particles from 501 groundwater samples in order to characterize the size distribution concentration composition and natural radionuclide content of particles in representative parts of the u deposit although cigar lake groundwaters contain particles in all sizes ranging from 10 nm to slightly larger than 20 m most samples contained a relatively high concentration of colloids in the 100 400 nm size range particle compositions are similar to the composition of minerals in the sandstones and ore body suggesting that particles in groundwater are generated by the erosion of fracture lining minerals as a result particle concentrations in groundwater are affected by the integrity of the host rock in some piezometers the high initial concentrations of suspended particles which may have been drilling artifacts decreased during the collection of the first 350 1 although colloid concentrations fluctuated during sampling there are no indications that these concentrations will be permanently reduced by continued groundwater pumping the observed colloid and suspended particle concentrations in the deep groundwaters are too low to have a significant impact on radionuclide migration provided that radionuclide sorption is reversible if radionuclides are irreversibly sorbed to particles they cannot sorb to the host rock and their migration can only be evaluated with an understanding of particle mobility the data for dissolved and particulate u th and ra were used to calculate field derived distribution ratios rd between particles and groundwater the wide range of observed rd values indicates that these radionuclides in particulate form are not in equilibrium with groundwater u series isotope data indicated that most of the u and ra on particles was derived from groundwater some particles could have retained their u for as long as 8000 a the u and ra contents of particles in the ore and surrounding clay zones are significantly higher than in particles from sandstone suggesting that the clay has been an effective barrier to particle migration

chemical diagenesis in near surface zone above oil fields in geochemical exploration abstract hydrocarbon microseepages result in chemical and mineralogical changes in the near surface zone above oil reservoirs the results of geochemical research within the three oil fields of the west siberian basin demonstrate that chemical diagenetic processes lead to an increased inhomogeneity in chemical element distribution in soils subsoil atmosphere and snow pulse cathodoluminescence pcl study of soils and transmission electron microscopy tem study of micro and nanoparticles collected from the subsoil atmosphere showed that geochemical conditions over oil reservoirs were favorable for the enrichment of silicate and aluminosilicate minerals by chemical impurities chemical composition of micro and nanoparticles of metal compounds collected from within the vertical projection of the oil field outline suggested that these compounds were formed under intense reductive conditions that are not characteristic for the hypergene zone

transport of radon in flowing boreholes at stripa sweden granitic rock in an underground experimental waste storage site at stripa sweden is unusually high in natural radioelements 40 ppm uranium with higher concentrations occurring locally in thin chloritic zones and fractures consequently groundwater seeping through fractures into open boreholes is highly anomalous in its radon content with activity as high as 1 ci 1 when total count gamma ray logs are run in boreholes where groundwater inflow is appreciable the result is quite unusual the radon daughter activity in the water adds considerably to the gamma contribution from the rock and in fact often dominates the log the total gamma activity increases where radon charged groundwater enters a borehole and decays as the water flows along the hole in response to the hydraulic gradient as a consequence the gamma log serves as a flow profile locating zones of water entry or loss by an increase or decrease in the total gamma activity if mixing within the borehole does not occur the activity decreases exponentially along the hole away from the entry point because of the steady decay of radon and its daughter products as they migrate with the flow in the water column this spatial decay rate can be converted to a linear flow rate since the 3 8 day half life of radon governs the response time for example if the volumetric flow rate in a 76 mm hole falls within the range 0 5 50 liters per day and if observations are available from a 10 m length of hole then the flow rate can be measured quantitatively proportionately higher rates can be measured if longer hole lengths are available for observation a model for flow through a thin crack emanating radon at a rate e shows that the radon concentration of water entering a hole is e h where is the radon decay rate and h the crack aperture assuming that the flow rate and crack source area are such that an element of water resides within the source area for several radon half lives or more using this simple relationship independent measurements of emanation and concentration produce reasonable estimates of fracture aperture although uranium concentration values at stripa are unusually high neither the emanation coefficients nor the fracture properties appear to be unusual for granitic rock it therefore seems likely that many granitic sites must exist where the radon content in groundwater is higher than in other geological terranes although perhaps not as high as the microcurie per liter concentrations found at the stripa site

factors affecting exhalation of radon from a gravelly sandy loam measurements of radon exhalation from a gravely sandy loam have been made in a semi arid climate by using a combination of closed accumulation flow through accumulation and 222rn and 210pb soil profiles the meteorological factors that most affected the instantaneous value of exhalation of 222rn were atmospheric pressure and rain effects due to other parameters such as wind or temperature were either comparatively small or undetectable no evidence was seen for migration of radon from distant 10m sources or for an effect on exhalation due to limited nearby seismic activity measurements for 220rn indicated its exhalation was also sensitive to pressure variation but to a lesser extent than for 222rn while instantaneous exhalation of 222rn could easily vary by a factor of 2 or more time averaged exhalation was found to be close to that expected for pure diffusion there is thus some indication that the time averaged effect of cyclic environmental variables is small for this soil comparison with transport equations indicates that it is difficult to explain the observed variation in surface flux density solely in terms of the radon concentration gradient in the top few decimeters of soil a contribution to transport from direct flow perhaps through inhomogeneities such as cracks or channels is one possible explanation

application of 222rn technique to locate subsurface coal heatings in australian coal mines abstract subsurface coal heating poses a significant problem in many coal mines the identification of the exact location of the heatings that occur in often inaccessible locations several hundred meters deep in goaf areas is a key to allowing effective control measures to be taken detailed investigations were carried out to apply the surface based 222 rn technique to locate subsurface coal heatings in australia the results of two field trials indicated that subsurface coal heatings at depths up to 450 m lead to isolated 222 rn anomalies on the surface vertically above the heating zones the geogas microbubble model for 222 rn transport through strata appears to be most in accord with the results of the field trials

exhalation of radon and thoron the question of the effect of thermal gradients in soil abstract experimental measurements show no evidence for diurnal variation in exhalation of radon and thoron from soil due to convection induced by thermal gradients in the top few decimeters of soil as suggested by several authors estimates based on convective calculations indicate that even in the unlikely event of either vertical temperature gradients large enough to cause vertical instability or horizontal gradients sufficient to cause significant convection any effect would be too small to be detected these same calculations suggest that it is difficult to conceive of cases involving typical thermal gradients in unfractured porous media such as soil where thermally induced convection would play an important role in transport of radon or thoron

high resolution conceptual hydrogeological model of complex basaltic volcanic islands a mayotte comoros case study we present a high resolution conceptual hydrogeological model for complex basaltic volcanic islands based on mayotte island in the comoros its geological structure and hydrogeological functioning are deduced from a large dataset geological mapping geophysics some forty new boreholes piezometric data hydraulic conductivity hydrochemical data etc we describe previously unknown deep cut and fill palaeovalleys the resulting conceptual geological and hydrogeological model of the island is very different from the hawaiian model in that it lacks a low elevation basal aquifer and dyke impounded high level aquifers it is closer to the canary islands model which has however not yet been described at a high resolution scale it does not have a continuous aquifer but rather a discontinuous succession of perched aquifers separated by aquicludes and aquitards this results more from the complex geological structure of the island which has experienced several phases of volcanism erosion and weathering than from its age but is also a result of the high resolution scale of the model high resolution conceptual modelling is now necessary to solve problems of applied geology and hydrogeology

soil gas radon emanometry a tool for delineation of fractures for groundwater in granitic terrains in several arid and semi arid hard rock areas of the world overexploitation of groundwater has caused de saturation of the phreatic weathered zone attempts are now underway to draw supplies from deeper fracture zones but random drilling often fails to encounter such productive zones further currently available hydrogeological and geophysical methods are of limited applicability alternative geochemical methods employing soil gas 222radon rn and helium 4he have been explored but not investigated sufficiently this paper reports the results of a systematic survey of 222rn concentration in soil gas at a depth of 60 and 160 cm in a watershed located in a semi arid granitic area in india we were able to demarcate three high 222rn anomalies which were supplemented by 4he measurements drilling was carried out on the sites of these high 222rn anomalies as well as on low 222rn anomalies the bore wells drilled at the site of high 222rn concentration were found to be quite productive and those drilled on low 222rn concentration sites were dry those sites of the intermediate 222rn concentrations had intermediate yields these preliminary results suggest that 222rn emanometry method may turn out to be useful the method still needs to be investigated in detail and its usefulness in various settings still needs to be established on a statistical basis we have made an attempt to understand the process that may cause such 222rn anomalies our observations of 222rn concentration in the soil gas and of 222rn emanation rates from the soil and uranium concentrations in the soil indicate that fracturing of the rock rather than advection of 222rn from deeper strata may be responsible for such 222rn anomalies

nitrogen as the carrier gas for helium emission along an active fault in nw taiwan variations of he gas concentration are widely applied in studies devoted to the location of faults and to monitor seismic activities up to now its migration mechanism in soil is not fully understood a systematic soil gas survey across an active fault in nw taiwan provides the opportunity to closely examine the mechanism of he migration in the fault zone significant spatial and temporal correlations observed between soil n2 and he gas support the hypothesis that n2 is the probable carrier gas for he emission in the studied area based on n2 ar ratios and n2 isotopic results the excess soil n2 in this study is considered to be largely derived from ancient atmospheric air which was dissolved in groundwater furthermore observations rule out the possibility of co2 being the dominant carrier gas for he in the studied area based on the c and he isotopic compositions and the relationship between concentrations of these gases at least two soil gas sources a and b can be identified in the studied area source a is an abiogenic gas source characterized by excess n2 and he and very low o2 and co2 content source b on the other hand is a mixture of biogenic gas and atmospheric air the development of the fault system is an important factor affecting the degree of mixture between sources a and b therefore variations of soil gas composition in particular those derived from source a could be a useful proxy for tracing faults in the area

radon 222 emanometry a relevant methodology for water well siting in hard rock aquifers to improve the understanding of soil gas emanations with the aim of groundwater prospecting in fractured substrates radon anomalies were mapped in a tropical region french guyana where the structural features of a potential gas source are masked owing to the thick regolith cover two anomalies were located two probes were then installed one bl on the border of the north anomaly and the second b2 at the center of the south anomaly as well as a meteorological station and monitoring was carried out for 6 months extending from the dry to the rainy season signal processing of radon signal atmospheric pressure time series allowed us to determine the physical processes causing migration of the gases in the soil and the subsoil the radon anomalies are very probably associated with the presence in the hard rock substratum of a permeable structure that permits the transit of deep origin gas to the surface this transport by advection disturbs the radon diffusion profile from the first meters of soil into the atmosphere the radon thus behaves as a marker of deeper gases percolating through the regolith cover indeed in such a context with low permeability weathered formations because of its short half life 3 8 days the radon measured in the first decimeters of the soil displays an exclusively superficial origin hence the measurement of the radon content in soil at an identical depth from one sampling site to another helps locate the zones affected by advective gas transfers which explains why the radon anomalies in soil gases identified at the scale of a hydrogeological prospecting site located in a hard rock context usually coincide vertically in hydraulically active fracture zones this fully justifies the use of this method to site water wells provided some precautions are observed particularly pertaining to the spatial and temporal variability of the signal associated with different types of soils and changes in the meteorological parameters and soil moisture contents the methodology is simple since only robust equipment is required the estimation of gas transport parameters also helped identify the extent of advection areas during the dry season they are characterized by low gas velocity these zones shrink with the early rains and the advection area is confined vertically up the fault where a channeling effect occurs soil gas preferably follows the less constricted pores and the increased pressure gradient offsets the decrease in permeability

helium 4 and radon 222 concentrations in groundwater and soil gas as indicators of zones of fracture concentration in unexposed rock the presence of zones of fracture concentration in unexposed rock may be partially assessed by measuring the concentrations of sup 4 he and sup 222 rn in groundwater and soil gas helium 4 in groundwater and soil gas and sup 222 rn in groundwater were measured in the vicinity of two intersecting linements in lehigh county pennsylvania the limeaments are thought to mark deep fracture systems which provide conduits for the migration of sup 4 he and sup 222 rn high groundwater sup 4 he concentrations revealed the presence of the two lineaments low groundwater sup 222 rn activities are found near the lineaments and qualitatively support a numerical model which relates low sup 222 rn activity to high fracture transmissivity radon 222 activity correlates most strongly with the presence of h sub 2 s in groundwater implying that geochemical controls or groundwater circulation patterns strongly influence radon concentration soil gas concentrations of sup 4 he barely exceeded background levels and did not reliably indicate the lineament zones the data show that groundwater sup 4 he concentrations may be used to identify fracture zones in unexposed bedrock copyright american geophysical union 1988

identification of a hidden thermal fissure in a volcanic terrain using a combination of hydrothermal convection indicators and soil atmosphere analysis abstract mapping and characterizing fracturing in a volcanic terrain is facilitated by the analysis of physical and chemical properties of soils the parameters analyzed include the temperature at shallow depth the spontaneous potential sp and the 4 he 44 co 2 and 222 rn contents of soil gases as measured in situ by mass spectrometry and counter this analysis allowed a distinction of deep fissures not accompanied by thermal loss characterized by a negative sp anomaly and high he levels and of a hidden fissure with thermal loss characterized by a positive sp anomaly and high he rn and co 2 levels this fissure has no visible surface manifestations this method of analysing the convective thermal transfer is useful when analysing fracturing in volcanic structures to estimate their eruptive potential

a review of metal transfer mechanisms through transported cover with emphasis on the vadose zone within the australian regolith abstract there is a growing trend to try to make surface geochemistry effective for exploring areas of transported cover using sensitive techniques such as partial extractions of soil and gas analysis however these techniques have had mixed success in delineating buried ore bodies because the particular mechanisms and their effectiveness in transferring ore related metals upwards through transported cover are poorly understood this precludes discriminating null results a potentially ineffective technique from negative results no mineralization a review of mechanisms capable of transferring metals through barren transported cover to the surface identified those well documented and others not well studied but nonetheless promising the mechanisms are classified according to two main processes phreatic process involving groundwater flow convection dilatancy bubbles diffusion and electromigration and vadose processes involving capillary migration gaseous transport and biological transfer microbial metabolism affects the kinetics of many hydrochemical processes especially sulfide oxidation and other redox transfers and also impacts negatively and positively on the generation of gases throughout the entire cover sequence phreatic mechanisms require groundwater to transfer solutes and are most effective these have the most predictive capability where there are shallow water tables in the australian landscape groundwater occurs commonly more than 5 m below surface except in lower discharge landform sites and therefore other mechanisms biological capillary gaseous are necessary to transfer metals up from the water table thus much of the emphasis in this paper is on vadose processes an integrated approach is necessary combining different mechanisms with the nature and evolution of the transported cover and climatic settings regions and landforms of highly weathered transported cover with current or past water tables residing within the cover and long standing vegetation will favor combined mechanisms such as electrochemical plant uptake capillarity and bioturbation fresh relatively unweathered and thick 30 m transported cover may prove the most unlikely to develop surface geochemical anomalies gas e g co 2 h 2 s mechanisms may work provided that sufficient gases are generated from the oxidation of ore to produce a surface signature

radon 222 and its parent radionuclides in groundwater from two study areas in new jersey and maryland u s a abstract a study of groundwater chemistry and radionuclide mobility in new jersey and maryland was conducted to investigate natural processes that control the mobility of radionuclides in the water rock system groundwater was sampled from two geological units in new jersey and from six in maryland the water sampled was from aquifiers in fractured metamorphic rocks of varying composition and metamorphic grade in both areas groundwater chemistry was affected most by aquifier mineralogy and lithology concentrations of total dissolved u 226ra and 222rn were similarly affected in evey sample for which measurements were made dissolved utotal and 226ra were present in much lower concentrations than 222rn when expressed in terms of their radioactivity on the other hand the total amount of 222rn that could be produced in these rocks given their u contents is much higher than the concentrations observed in groundwater thus the emanating efficiencies of the aquifer rocks studied must be near 10 or less such low emanating efficiencies require that a fraction of the 226ra in the rock be located close to the water rock interface so that 222rn when produced can be rapidly and efficiently transferred to the aqueous phase this condition is established when a similar fraction of the u is in a readily leachable position no known u or ra solids were supersaturated in any of the samples thus adsorption processes probably play a role in limiting mobilities of utotal and 226ra concentrations of utotal and 226ra found in the water samples are comparable to those found in experimental studies of adsorption onto mineral surfaces

segmentation of the longmen mountains thrust belt western sichuan foreland basin sw china abstract many complex structures have developed in the longmen mountains thrust belt sw china over the course of polyphase tectonic movements in the region based on field investigations and interpretations of seismic sections we divided the belt into the following three segments and two transfer zones from northeast to southwest the northern segment anxian transfer zone ta central segment guanxian transfer zone tg and southern segment the northern segment located north of anxian county consists of the jiaoziding nappe comprising a triassic jurassic fold belt and a plastically deformed silurian belt the northern segment can be further divided into four sub segments the guangyuan chaotianyi sub segment n1 baitianba guangyuan sub segment n2 wenxingchang baitianba sub segment n3 and wuzhong mountain tangwangzhai nappe sub segment n4 the anxian transfer zone ta located between yuanmenba town and hanwangchang town consists of numerous thrust faults and strike slip faults at shallow levels with duplexes and detachment structures at deeper levels the central segment which consists of the jiudingshan nappe and numerous klippes and thrust faults is located between hanwangchang town and guanxian county this segment can be divided into two sub segments the mianzhu mianyang sub segment c1 and the dayuanbao sub segment c2 the guanxian transfer zone which is characterized by numerous thrust faults strike slip faults and duplexes is located between guanxian county and huaiyuan county the southern segment which consists of the baoxing nappe and contains arcuate thrust faults is located south of huaiyuan county the southern segment is divided into three sub segments the huaiyuan xinchang sub segment s1 xinchang lushan sub segment s2 and southern arcuate sub segment s3

large scale washover sedimentation in a freshwater lagoon from the southeast australian coast sea level change tsunami or exceptionally large storm a distinct lens of marine sand up to 90 cm thick confined vertically by peat is found in the upper fill of a closed freshwater back barrier lagoon on the southeast australian coast coring of the deposit suggests it extends continuously up to 600 m inland and tapers landward rising to 1 6 m above principle datum in places the sand is overlain by accumulations of organic rich silt that contain charophytes indicating re estab lishment of lagoon conditions hypotheses considered for the deposition of the sandsheet are higher holocene sea level storms and tsunami ground penetrating radar transects of the seaward dune system suggest a penecontemporaneous erosional contact between a series of truncated pre event dunes and several small over lying post event dunes dating the sandsheet was problematic but it is confined to the last 800 years the young age combined with a lack of associated beach deposits and evidence of wave scouring suggest that a higher sea level hypothesis is unlikely this sand lens is attributed to a large scale washover event from the southeast based on comparisons with modern storm deposits from the same coast and sedimentological diagnostic crite ria derived from studies of modern storm and tsunami deposited sandsheets it is concluded that this sand deposit is the product of a short lived large scale overwash event attributed to a late holocene tsunami

the effect of stress on radon emanation from rock a uranium bearing granitic rock of known radon emanation was deformed to failure under uniaxial stress radon emanation and microcrack activity were recorded continuously during the test radon concentration in the closed system was measured by an alpha detector a decrease in emanation was observed during the initial loading of the sample and is interpreted as associated with the closure of pre existing cracks within the rock at a uniaxial stress equal to approximately one half the ultimate strength a temporary increase 50 in the radon emanation was observed that correlated with an increase in microcracking within the sample when the stress was removed for several hours the original emanation was restored however once the specimen failed a temporary emanation increase of 120 was observed the emanation then decreased to a level nearly 5 greater than the prefailure specimen emanation

evidence for nondiffusive transport of 86rn in the ground and a new physical model for the transport concentration of radon has been measured in the soil near the ground surface with solid state nuclear track detectors with the inverted cup technique measurements were made in the overburden at depth intervals 0 1 0 7 m at 0 1 6 m and at a constant depth of 0 2 m in a narrow rectangular matrix the results disagree with the hypothesis that radon concentration only depends upon local production and migration by diffusion with a diffusion length of about 1 m a transport length of 0 1 0 2 m is observed near the ground surface and the transport is dominated by a flow component radon measurements in the ground surface over the laisvall lead mine have given evidence of radon transport through rock exceeding a distance of 100 m which is possible only if the migration is a flow transport with a characteristic transport length larger than about 10 m day to explain the radon transport in the overburden and through the rock with a common transport system the existence of a general upward flow of geo gas is

a synthesis and review of the geological evidence for palaeotsunamis along the coast of southeast australia the evidence issues and potential ways forward abstract in recent years the role of extreme events such as tsunamis and storms in shaping coastal evolution and change has been increasingly appreciated around the world tsunami geologists are increasingly recognising the signatures of palaeotsunamis almost everywhere they look and in many cases base their interpretations on similar evidence for quaternary tsunamis first identified in australia geological research suggests that the coast of south east australia and others worldwide may have been impacted by palaeotsunamis many times larger than the catastrophic 2004 indian ocean and 2011 t hoku events in australia the debate centres on the hypothesis that the coast of south east australia preserves evidence for repeated large magnitude quaternary tsunamis if independently validated this hypothesis has profound implications for risk despite the potential importance of this hypothesis no synthesis or comprehensive review of the proposed geological evidence and chronology exists as a result it is difficult to assess the evidence and to draw conclusions about the nature of the hazard and risk along the coast this synthesis details the spatial distribution of reported palaeotsunami deposits along the coast of new south wales south east australia and summarises the distribution of different types of sedimentary and erosional evidence the age range of reported palaeotsunami deposits is identified and mapped before discussing same age chronologically correlated deposits these data are then used to draw broad conclusions about the evidence and identify future research questions to aid in the testing of the hypothesis for repeated tsunami inundation we show that 60 sites are purported to contain evidence of tsunami inundation over 650 km of the south east australian coast with a spatial concentration south of sydney geomorphic evidence distinctly different to that used elsewhere in global palaeotsunami studies is reported at 54 sites with erosional features described as the most frequent indication of inundation proposed tsunami deposits are evident at 44 sites with the dominant deposit type being imbricated boulder stacks radiocarbon dating at 39 of the sites led to a proposition of nine events during the quaternary eight of which occurred during the holocene interestingly 18 sites have no chronological data associated with them alternative interpretations are offered at six type field sites purported to contain palaeotsunami evidence attention is drawn to the disjunct between historical and geological scales of tsunami inundation in the region in addition to the contrast between the scale of reported palaeotsunamis and the robust evidence of smaller events a synthesis of research into the nature of the evidence is offered including critiques of evidence type and mechanisms a critical review of the chronological data is also presented in addition to the recalibration and analysis of published radiocarbon data the paper concludes with an outline of research questions for further work on proposed palaeotsunami sites in australia as well as a statement about likely risk in south east australia it also advocates the need for caution when interpreting evidence for palaeotsunamis elsewhere around the world when those interpretations are based on signatures originally reported in south east australia

geometric and radiometric correction of tm data of mountainous forested areas methodologies to improve landsat tm thematic mapper forest classifications of alpine regions through the removal of some radiometric and geometric distortions are tested besides correcting for sensor and system induced errors geometric errors are corrected using a digital elevation model then scene related effects such as differences in illumination as well as the height dependent atmospheric influence and adjacency effects are corrected the improvement of the accuracy of a forest classification is demonstrated by comparison with ground truth data

ground variation of radon 222 for location of hidden structural features example of the south of france alpes maritimes we report two examples from the south of the french alps showing that radon emanation monitored by alpha sensitive film may be used to locate certain discrete structural features revealed in data collected by remote sensing from a satellite the variations observed in our data over a period of several months are in accordance with atmospheric changes and might correlate with local seismic activity when the detectors are located directly above structural fractures and the magnitude of the seismic event is greater than 2

evaluating the impacts of huge waves on rocky shorelines an essay review of the book tsunami the underrated hazard abstract tsunami the underrated hazard draws together and summarizes a wealth of information about the nature impacts and causes of tsunamis written from a natural hazards perspective the book stresses that large tsunamis can affect even protected coasts that have not experienced large tsunamis historically many deposits and erosional features described and discussed as tsunami signatures have yet to be linked specifically with tsunamis cited references in the book do not necessarily support a tsunami origin for these features because accepted scientific citation practices have not been followed although rocky shorelines in southeastern australia the hawaiian islands and elsewhere generate and preserve a variety of boulder and block deposits and erosional features their sediment dynamics and geomorphology are poorly studied and unequivocal criteria for distinguishing between deposits of storms and tsunamis have yet to be developed despite its shortcomings this book should be on the library shelves of all marine geoscientists who study modern and ancient shorelines however it should be used with great circumspection because the process product relationships it assumes are equivocal

gas geochemistry applied to earthquake prediction an overview terrestrial gases in groundwater and soil air have been extensively studied in recent years in seismically active areas especially in ussr china japan and united states in search of premonitory changes that might be useful for earthquake prediction concentrations of radon helium hydrogen mercury carbon dioxide and several other volatiles have been found generally to be anomalously high along active faults suggesting that the faults may be paths of least resistance for the terrestrial gases generated or stored in the earth to escape to the atmosphere temporal gas concentration changes with durations of a few hours to many months have been observed before many large earthquakes at a relatively small number of favorably situated stations at epicentral distances of up to several hundreds of kilometers these sensitive stations are generally located along active faults especially at intersections or bends of faults or some other structurally weak zones possibly because of tectonic strain concentration at such places however gas concentrations especially those measured at or near the ground surface may also be significantly affected by meteorological hydrological and other nontectonic changes in the environment the nontectonically induced variations must be carefully eliminated or recognized in the search of true earthquake related anomalies

geoelectrochemical anomaly prospecting for uranium deposits in southeastern china abstract most volcanogenic uranium deposits are deeply buried and very hard to locate a prospecting method using geoelectrochemical probes has been proven in practice to be an effective way of pinpointing the locations of these hidden deep uranium deposits the efficacy of the method has been verified through analyses of two carefully selected known uranium deposits the xiangshan and shenyuan uranium deposits in southeastern china analyses of geoelectrochemical probe samples presented in transections crossing the ore bodies revealed distinct anomalies of u and mo distribution the average anomaly contrast values the ratio of element concentration in the geoelectrochemical probe between potential areas and background areas ranging from 1 5 to 2 3 corresponded perfectly with the locations of the known ore bodies in the deposit anomalies of th pb zn and ag were also detected confirming the viability and effectiveness of using the geoelectrochemical probe method to locate buried deposits the geoelectrochemical anomaly detection was corroborated by detection of u bearing mineral nanoparticles scavenged in the probe foams a flotation mechanism using geogenic gas was suggested as the major driving force for the enrichment of the nanoparticles in the soil surface geogenic gas generated from fault belts and ore body differentiation oxidation reduction and weathering is an as yet neglected but potentially important mechanism for the formation of the anomalies

structural analysis and thermal remote sensing of the los humeros volcanic complex implications for volcano structure and geothermal exploration abstract the los humeros volcanic complex lhvc is an important geothermal target in the trans mexican volcanic belt understanding the structure of the lhvc and its influence on the occurrence of thermal anomalies and hydrothermal fluids is important to get insights into the interplay between the volcano tectonic setting and the characteristics of the geothermal resources in the area in this study we present a structural analysis of the lhvc focused on quaternary tectonic and volcano tectonic features including the areal distribution of monogenetic volcanic centers morphostructural analysis and structural field mapping revealed the geometry kinematics and dynamics of the structural features in the study area also thermal infrared remote sensing analysis has been applied to the lhvc for the first time to map the main endogenous thermal anomalies these data are integrated with newly proposed unconformity bounded stratigraphic units to evaluate the implications for the structural behavior of the caldera complex and geothermal field the lhvc is characterized by a multistage formation with at least two major episodes of caldera collapse los humeros caldera 460 ka and los potreros caldera 100 ka the study suggests that the geometry of the first collapse recalls a trap door structure and impinges on a thick volcanic succession 10 5 1 55 ma now hosting the geothermal reservoir the main ring faults of the two calderas are buried and sealed by the widespread post calderas volcanic products and for this reason they probably do not have enough permeability to be the main conveyers of the hydrothermal fluid circulation an active previously unrecognized fault system of volcano tectonic origin has been identified inside the los potreros caldera this fault system is the main geothermal target probably originated by active resurgence of the caldera floor the active fault system defines three distinct structural sectors in the caldera floor where the occurrence of hydrothermal fluids is controlled by fault induced secondary permeability the resurgence of the caldera floor could be induced by an inferred magmatic intrusion representing the heat source of the geothermal system and feeding the simultaneous monogenetic volcanic activity around the deforming area the operation of the geothermal field and the plans for further exploration should focus on both the active resurgence fault system and the new endogenous thermal anomalies mapped outside the known boundaries of the geothermal field

geochemistry of the maroni river french guiana during the low water stage implications for water rock interaction and groundwater characteristics abstract the maroni river draining a basin of 60 000 km 2 and flowing down to the atlantic ocean between french guiana and surinam was studied during a low flow period using the chemical and isotopic composition of its dissolved load the dissolved concentrations of major ions cl so 4 no 3 hco 3 ca na mg k trace elements rb and sr stable isotopes o and d and strontium isotopes 87 sr 86 sr were determined on samples from the main stream of the river and its tributaries and from groundwaters collected in wells and two boreholes the total dissolved solid tds and the sum of cations agree with those summarised for the major guyanan rivers the orinoco and amazon on a tds vs na na ca diagram all the data from the maroni catchment plot in the precipitation dominance field close to the plots of the tefe and negro rivers the groundwaters collected from wells largely mimic the surface waters and may represent alluvial groundwater along the maroni terraces whereas the groundwaters collected from the boreholes show clearly higher values and reflect an increase in water rock interaction the river and groundwaters of the maroni catchment have been isotopically enriched 18 o vs 2 h through evaporation and the 18 o and 2 h can be used as mixing tracers of river waters within the catchment after corrections for rainwater addition were computed for selected elements and for 87 sr 86 sr ratios using chloride as an atmospheric input reference the water rock interaction along the maroni catchment was investigated for cations and sr isotopes

thermal infrared remote sensing detection of thermal information associated with faults a case study in western sichuan basin china abstract using enhanced land surface temperatures lsts image retrieved from landsat etm this article shows that thermal information associated with faults have been detected these anomalies may be provided by geothermal natural convection through faults and partially influence the ground surface thermal environment the study area in southern segment of longmen mountains thrust belt of western sichuan basin contains complex faults and folds with recent earthquake activity in order to study the faults for future oil exploration we use lst data retrieved from landsat thermal infrared band to detect the thermal information associated with faults the lsts are enhanced by filtering out anthropogenic activity and influence land cover classes and interpolating to contour map the spatial patterns of the enhanced images revealed the spatial correspondence between the thermal information and the dip planes of faults when compared with the explanation profiles and geologic features obtained from the 3d seismic geophysical data the thermal affected ranges calculated and the statistically significant of regression model also indicate the result that the thermal information located near the faults are consistent with the faults dip planes

detection of geothermal anomalies using advanced spaceborne thermal emission and reflection radiometer aster thermal infrared images at bradys hot springs nevada usa abstract surface temperature anomalies associated with geothermal activity at bradys hot springs churchill county nevada were mapped using advanced spaceborne thermal emission and reflection radiometer aster thermal infrared tir image data in order to highlight subsurface contributions of geothermal heat the aster images were processed to minimize temperature variations caused by the diurnal heating effects of the sun surface temperature variations caused by changes in albedo were corrected with visible and near infrared aster bands and a 10 meter smoothed digital elevation model dem was used to correct for topographic slope effects field measurements of ground surface temperatures made over 24 hour periods were used to design a thermal inertia correction incorporating day and night thermal infrared images in the resulting processed image background temperature variations were reduced 30 50 without reducing the intensity of geothermal anomalies thus making it easier to distinguish geothermal activity from false anomalies caused by non thermal springs topographic effects and variable rock soil and vegetation compositions

geochemical challenges of diverse regolith covered terrains for mineral exploration in china abstract in recent years mineral exploration has concentrated on concealed deposits in regolith covered terrains in china the regolith covered landscapes mainly include desert windblown sand basins desert peneplains semi arid grassland loess plateaus forestry land alluvial plains and laterite terrains these diverse regolith covered areas represent geochemical challenges for mineral exploration in china this paper provides an overview of recent progress on mechanisms of metal dispersion from the buried ore deposits through the transported cover to the surface and penetrating geochemical methods to detect the anomalies case studies show that in arid and semi arid desert sand covered terrains sampling of fine fraction 120 mesh

soil gas radon emissions and volcanic activity at el hierro canary islands the 2011 2012 submarine eruption 1 soil gas radon 222rn and thoron 220rn activities have been continuously measured during the period of the recent volcanic unrest that occurred at el hierro canary islands at two different monitoring stations namely hie02 and hie03 significant increases in soil 222rn activity and 222rn 220rn ratio from the soil were observed at both stations prior to the 2011 2012 submarine eruption off the coast of el hierro showing the highest increases before the eruption onset and before the occurrence of the strongest seismic event m 4 6 statistical analysis showed that the long term temporal trend of filtered radon data matched closely that of seismic energy release during the volcanic unrest the observed increases of 222rn are related to the rock fracturing processes seismic activity and the magmatic co2 outflow increase as observed in hie03 station

earthquake forerunners in a selected area of northern italy recent developments in automatic geochemical monitoring abstract this article describes the monitoring of certain mud volcanoes in the northern apennines of italy this monitoring was carried out from a geochemical point of view and its aim was to verify the seismic precursory nature of the mud volcano fluids the operational strategy began by determining the regional character of the main physical and chemical precursors and a multidisciplinary approach to the historical research was used to achieve this the utility of such an approach in monitoring strategy has been confirmed a series of experiments was carried out to identify the physical model the main geochemical characteristics and the origin of the seismic precursory phenomena with particular reference to radon 222 the technological apparatus necessary for a reliable automatic continuous monitoring system of the geochemical parameters of mud volcanoes were then extensively tried out the first results of this monitoring system refer to dec 1988 jan 1989 in this period there were some seismic events which were preceded by certain phenomena we can call precursory an interpretative model has been created from all the information collected so that similar situations can be better understood from a physical and chemical point of view

soil gas emanations as precursory indicators of volcanic eruptions field measurements conducted on several active volcanoes in italy the lesser antilles and indonesia demonstrate the common occurrence of diffuse soil gas emanations from the volcanic piles at distances from active craters or fumarolic zones these emanations consist essentially of carbon dioxide and rare gases and their genetic link with crater fumaroles and or magma degassing at depth can be verified both chemically and isotopically we emphasize here the potential use of these fluids for continuous volcano monitoring and eruption forecasting

nanoparticles in groundwater of the qujia deposit eastern china prospecting significance for deep seated ore resources abstract the characterization of nanoparticles in groundwater is recognized as an important tool that can be applied to mineral exploration in this paper we investigate the concealed orebodies of the qujia gold deposit in the jiaojia orefield of eastern china by analyzing ore related nanoparticles in groundwater using transmission electron microscopy the nanoparticles contain variable amounts of ore related elements e g ag cu zn la ce pb pt and s some of these elements are rarely found in natural settings unrelated to orebodies or mineral extraction but are strongly linked to concealed orebodies in the study area these nanoparticles which are diverse in their shapes aggregated features and degrees of crystallinity can be grouped in terms of composition as i native metal nanoparticles ii metal based nanoparticles and iii carrier nanoparticles associated with trace elements we propose that these three main types of nanoparticles enable the efficient transport of ore forming elements in groundwater the results of this study provide insights into the migratory behaviour of ore related nanoparticles in groundwater and our methods could be applied for detecting deep seated mineral deposits

geothermal anomaly mapping using landsat etm data in ilan plain northeastern taiwan geothermal energy is an increasingly important component of green energy in the globe a prerequisite for geothermal energy development is to acquire the local and regional geothermal prospects existing geophysical methods of estimating the geothermal potential are usually limited to the scope of prospecting because of the operation cost and site reachability in the field thus explorations in a large scale area such as the surface temperature and the thermal anomaly primarily rely on satellite thermal infrared imagery this study aims to apply and integrate thermal infrared tir remote sensing technology with existing geophysical methods for the geothermal exploration in taiwan landsat 7 l7 enhanced thematic mapper plus etm imagery is used to retrieve the land surface temperature lst in ilan plain accuracy assessment of satellite derived lst is conducted by comparing with the air temperature data from 11 permanent meteorological stations the correlation coefficient of linear regression between air temperature and lst retrieval is 0 76 the modis lst product is used for the cross validation of landsat derived lsts furthermore landsat etm multi temporal brightness temperature imagery for the verification of the lst anomaly results were performed lst results indicate that thermal anomaly areas appear correlating with the development of faulted structure selected geothermal anomaly areas are validated in detail by field investigation of hot springs and geothermal drillings it implies that occurrences of hot springs and geothermal drillings are in good spatial agreement with anomaly areas in addition the significant low resistivity zones observed in the resistivity sections are echoed with the lst profiles when compared with in the chingshui geothermal field despite limited to detecting the surficial and the shallow buried geothermal resources this work suggests that tir remote sensing is a valuable tool by providing an effective way of mapping and quantifying surface features to facilitate the exploration and assessment of geothermal resources in taiwan