gis based landslide susceptibility mapping using bivariate statistical analysis in devrek zonguldak turkey devrek town with increasing population is located in a hillslope area where some landslides exist therefore landslide susceptibility map of the area is required the purpose of this study was to generate a landslide susceptibility map using a bivariate statistical index and evaluate and compare the results of the statistical analysis conducted with three different approaches in seed cell concept resulting in different data sets in geographical information systems gis based landslide susceptibility mapping applied to the devrek region the data sets are created from the seed cells of a crowns and flanks b only crowns and c only flanks of the landslides by using ten different causative parameters of the study area to increase the data dependency of the analysis all parameter maps are classified into equal frequency classes based directly on the percentile divisions of each corresponding seed cell data set the resultant maps of the landslide susceptibility analysis indicate that all data sets produce fairly acceptable results in each data set analysis elevation lithology slope aspect and drainage density parameters are found to be the most contributing factors in landslide occurrences the results of the three data sets are compared using seed cell area indexes scai this comparison shows that the crown data set produces the most accurate and successful landslide susceptibility map of the study area

characterization of coarse soils derived from igneous rocks for rammed earth abstract rammed earth refers to a conventional construction method as well as a material comprising gravel sand and fine soil there has been an increasing interest due to it being a sustainable and environmentally friendly material the strength of rammed earth depends on the material and environment e g temperature and relative humidity while rammed earth is an established and accepted construction material in some countries e g australia and new zealand its use in south china is mostly related to historical structures of which the unesco tulou buildings in fujian province is an example in addition south china has a sub tropical climate with a distinctive rainy humid and hot season followed by a dry and cool season and soils are granular due to the underlying igneous geology with a coarse fraction sand and gravel in excess of 80 their appropriateness as earthen materials is at first sight debatable this paper aims to assess the pertinence of three representative soils from hong kong residual soil alluvium and completely decomposed granite for unstabilised rammed earth unconfined compressive strength tests and shrinkage measurements at different relative humidity as well as the organics content are determined to aid the interpretation of the strength and shrinkage data a fundamental characterization is conducted namely of the wettability and particle attributes size and shape by comparing the results to established guidelines for earthen construction the three soils are shown to achieve strengths in the range 0 2 1 4 mpa and shrinkage after equilibration for one week up to 4 with the residual soil outperforming the others moreover it was found the strength of the soils was influenced by the relative humidity and was strongly dependent on changes of dry density the wettability results confirmed the higher organics for the alluvium while the more rounded particle shape and greater content of potassium feldspar of the completely decomposed granite corroborated with its lower strength the results highlight the importance of conducting a fundamental characterization of natural soils for rammed earth via the particle attributes wettability and mineralogy

martin brasier s contribution to the palaeobiology of the ediacaran cambrian transition martin brasier s work spanned almost the entire geological column but the origin of animals and the nature of the cambrian explosion were areas of particular interest to him martin adopted a holistic approach to the study of these topics that considered the interplay between multiple geological and biological phenomena and he sought to interpret the fossil record within the broad context of geological biogeochemical and ecological changes in the earth system here we summarize martin s main contributions to this area of research and assess the impact of his findings on the development of this field karl popper would have said that palaeontology is not real science because you can t go out and sample it i think absolutely the opposite i think this is actually where science is it s trying to guess what lies over the hill and map terra incognita when people come in and colonize that s just technology martin brasier 2013 excerpt from a phone interview in moor 2016

assessing landslide potential using gis soil wetness modeling and topographic attributes payette river idaho this study utilizes gis modeling to determine if the location of 559 landslides in the 875 km2 catchment of the middle fork of the payette river idaho can be predicted based on topographic attributes and a wetness index generated by the dynwet model slope and elevation were significantly related to landslide occurrence at this landscape scale aspect was also retained as a variable for further analysis because despite a non significant chi square relation to landslide occurrence graphical analysis suggested a relation between aspect and mass wasting chi square analysis indicated that plan and profile curvature flow path length upslope contributing area and the dynwet based moisture index were not significantly related to landsliding a bayesian probability model based on combinations of elevation slope aspect and wetness indicates that elevation exhibits the closest relation to landsliding followed by slope but that neither aspect nor wetness index values help in prediction the bayesian probability model using elevation and slope generates a map of relative landslide risk that can be used to direct activities away from mass wasting prone areas the association between elevation and landslides is perplexing but is perhaps due to the location of logging road at specific elevations roads could not be included in the input data for analysis because they have not been adequately mapped the lack of explanation provided by the dynwet wetness index was also surprising and may be due to the 30 m digital elevation model dem and the soils data having resolutions too coarse to adequately portray local variations key to mass wasting we believe the inadequacy of data to drive the models is typical of the majority of catchment scale setting for now the ability of researchers to effectively model landscape scale landsliding is more limited by the type resolution and quality of available data than by the quality of the landslide models

the frequency and distribution of recent landslides in three montane tropical regions of puerto rico landslides are common in steep mountainous areas of puerto rico where mean annual rainfall and the frequency of intense storms are high each year landslides cause extensive damage to property and occasionally result in loss of life average population density is high 422 people km2 and is increasing this increase in population density is accompanied by growing stress on the natural environment and physical infrastructure as a result human populations are more vulnerable to landslide hazards the blanco cibuco and coamo study areas range in surface area from 276 to 350 km2 and represent the climatologic geographic and geologic conditions that typify puerto rico maps of recent landslides developed from 1 20 000 scale aerial photographs in combination with a computerized geographic information system were used to evaluate the frequency and distribution of shallow landslides in these areas several types of landslides were documented rainfall triggered debris flows shallow soil slips and slumps were most abundant hillslopes in the study area that have been anthropogenically modified exceed 12 in gradient are greater than 300 m in elevation and face the east northeast are most prone to landsliding a set of simplified matrices representing geographic conditions in the three study areas was developed and provides a basis for the estimation of the spatial controls on the frequency of landslides in puerto rico this approach is an example of an analysis of the frequency of landslides that is computationally simple and therefore may be easily transferable to other settings

modular construction of early ediacaran complex life forms newly discovered exceptionally preserved soft bodied fossils near spaniard9s bay in eastern newfoundland exhibit features not previously described from ediacaran terminal neoproterozoic fossils all of the spaniard9s bay taxa were composed of similar architectural elements centimeter scale frondlets exhibiting three orders of fracticality in branching frondlets were combined as modules atop semi rigid organic skeletons to form a wide array of larger constructions including frondose and plumose structures this architecture and construction define the rangeomorphs a biological clade that dominated the mistaken point assemblage 575 to 560 million years ago but does not appear to be ancestral to any phanerozoic or modern organisms

a procedure for landslide susceptibility zonation by the conditional analysis method numerous methods have been proposed for landslide probability zonation of the landscape by means of a geographic information system gis among the multivariate methods i e those methods which simultaneously take into account all the factors contributing to instability the conditional analysis method applied to a subdivision of the territory into unique condition units is particularly straightforward from a conceptual point of view and particularly suited to the use of a gis in fact working on the principle that future landslides are more likely to occur under those conditions which led to past instability landslide susceptibility is defined by computing the landslide density in correspondence with different combinations of instability factors the conceptual simplicity of this method however does not necessarily imply that it is simple to implement especially as it requires rather complex operations and a high number of gis commands moreover there is the possibility that in order to achieve satisfactory results the procedure has to be repeated a few times changing the factors or modifying the class subdivision to solve this problem we created a shell program which by combining the shell commands the gis geographical research analysis support system grass commands and the gawk language commands carries out the whole procedure automatically this makes the construction of a landslide susceptibility map easy and fast for large areas too and even when a high spatial resolution is adopted as shown by application of the procedure to the parma river basin in the italian northern apennines

smothering of microbial mats by macrobiota implications for the ediacara biota abstract recent advances in understanding the preservation of the soft bodied neoproterozoic ediacara biota have centred upon the role of microbes in casting the morphologies of static or dead macrobiota on the precambrian sea floor this experimental study explores the preservational effects brought about by the passive movement of dead macro organisms upon a pre established marine microbial mat under laboratory conditions this demonstrates the potential for making multiple impressions of body tissues on the surface of microbial mats by means of passive transport alone this throws doubt on the evidence for active feeding in ediacaran fossils such as dickinsonia and yorgia supplementary material methods are available at http www geolsoc org uk sup18375

review of close range three dimensional laser scanning of geological hand samples abstract the morphological study of geological hand samples has a wide variety of applications in the geosciences which is conventionally accomplished by measuring the distance between features of interest on the sample s surface close range three dimensional 3d laser scanners provide an opportunity to study the form and shape of geological samples in a digital environment and have been increasingly utilized in fields such as paleontology rock mechanics and sedimentology with some uptake in planetary sciences and structural geology for paleontological studies primary applications are in quantitative analysis of fossil morphology and integration into 3d animated models for understanding species movements in the field of rock mechanics typical uses of 3d digital geological hand sample models include quantifying joint roughness coefficient jrc determining the surface roughness of rock samples and assessing morphological changes over time due to processes such as weathering in the field of sedimentology such models are incorporated to characterize the shape of sediment particles and to calculate key parameters such as bulk density this paper aims to provide a comprehensive review of established literature that includes substantial use of digital geological hand samples acquired from 3d close range

a rich ediacaran assemblage from eastern avalonia evidence of early widespread diversity in the deep ocean the avalon assemblage ediacaran late neoproterozoic provides some of the oldest evidence of diverse macroscopic life and underpins current understanding of the early evolution of epibenthic communities however its overall diversity and provincial variability are poorly constrained and are based largely on biotas preserved in newfoundland canada we report coeval high diversity biotas from charnwood forest uk which share at least 60 of their genera in common with ones in newfoundland this indicates that substantial taxonomic exchange took place between different regions of avalonia probably facilitated by ocean currents and suggests that a diverse deepwater biota may already have been widespread at the time contrasts in the relative abundance of prostrate versus erect taxa likely record differential sensitivity to physical environmental parameters hydrodynamic regime substrate and highlight their significance in controlling community structure

comparison of bivariate and multivariate statistical approaches in landslide susceptibility mapping at a regional scale abstract landslide susceptibility assessment was undertaken for the waikato region new zealand landslide inventory data were extracted from a pre existing database that included few landslides in the region 1 4 of area and is limited in terms of completeness of record and location uncertainty this database is in contrast to those normally used for research which are derived for the research project and are complete and accurate but is representative of those that may exist within government bodies this paper applies statistical methods to derive a meaningful predictive map for planning purposes from such a relatively poorly defined database susceptibility maps for both logistic regression and weights of evidence were derived and evaluated using success prediction and roc curves both statistical methods gave models with fair predictive capacity for validation samples from the original database with areas under roc curves auc of 0 71 to 0 75 an independent set of landslide data compiled from observations made in google earth showed lower overall prediction quality with the logistic regression method giving the best prediction auc 0 71 for this regional assessment categorical data proved a major constraint on the application of logistic regression as the area considered has complex geology and geomorphology as a result the large number of categories required led to a complex and unwieldy statistical model whereas division into fewer categories meant that real variability in the area could not be adequately represented this limited the result to a model with two continuous variables slope and mean monthly rainfall the incomplete record in the database proved of little concern for the logistic regression method as the model was able to generalise landslide locations from the known sites well giving a similar auc value for the original and independent data the same was not true for the weights of evidence method which was not successful at predicting landslides outside those in the original data

understanding ancient life how martin brasier changed the way we think about the fossil record crucial to our understanding of life on earth is the ability to judge the validity of claims of very ancient fossils martin brasier s most important contribution to this debate was to establish a framework within which to discuss claims of the oldest life in particular he made it clear that the burden of proof must fall on those making the claim of ancient life not those refuting it this led to his formulation of the concept of the continuum of morphologies produced by life and non life and the considerable challenges of differentiating biogenesis from abiogenesis martin brasier developed a set of criteria for distinguishing life from non life and extended the use of many new high resolution analytical techniques to palaeontological research he was also renowned for his work on the cambrian explosion and the origin of animals although he had spent much of his early career working on the geological context of these events it was not until he returned to studying the ediacaran and cambrian periods in his later years that he began to apply this null hypothesis way of thinking to these other major transitions in the history of life this led to him becoming involved in the development of a series of nested null hypotheses his cone of contention to analyse enigmatic fossils more generally in short martin brasier taught us how to formulate biological hypotheses in deep time established the rules for how those hypotheses should be tested and championed a host of novel analytical techniques to gather the data required as a consequence future discussions of enigmatic specimens and very old fossils will be greatly enriched by his contributions

evolutionary relationships within the avalonian ediacara biota new insights from laser analysis abstract we report new high resolution laser scanning of the type material for the earliest complex ediacaran genera charnia bradgatia charniodiscus and ivesheadia from charnwood uk and compare these with beothukis mistakensis gen et sp nov and the recently described taxa charnia wardi charnia antecedens and fractofusus spp from broadly coeval strata in newfoundland we use the laser and other techniques to map the similarities and differences in morphology between these ediacaran rangeomorphs key features are suggested to include the number of growth axes the number and placement of growth tips the presence of radiating or subparallel axes for the first and higher order branches the extent of displayed or undisplayed leaf like rangeomorph9 architecture and the extent of furling of the margins of these leaf like elements these features are then used to propose suggested homologies between these taxa leading to a preliminary phylogenetic hypothesis for the evolution of the avalonian ediacara biota

use of an artificial neural network for analysis of the susceptibility to landslides at boun korea the purpose of this study was to develop landslide susceptibility analysis techniques using artificial neural networks and to apply the resulting techniques to the study area of boun in korea landslide locations were identified in the study area from interpretation of aerial photographs and field survey data a spatial database of the topography soil type timber cover geology and land cover was constructed and the landslide related factors were extracted from the spatial database using these factors the susceptibility to landslides was analyzed by artificial neural network methods the results of the landslide susceptibility maps were compared and verified using known landslide locations at another area yongin in korea a geographic information system gis was used to analyze efficiently the vast amount of data and an artificial neural network turned out to be an effective tool to analyze the landslide susceptibility

wrinkle structures microbially mediated sedimentary structures common in subtidal siliciclastic settings at the proterozoic phanerozoic transition sedimentary structures produced by microbial activity are well known from ancient carbonate facies but little is known about equivalent microbial structures in ancient siliciclastic facies wrinkle marks and kinneyia ripples are closely related sedimentary structures that are commonly found in ancient siliciclastics and they may represent microbial activity to evaluate this possibility these structures were studied in vendian cambrian strata of north america and compared to structures formed by modern microbial mat communities in redfish bay texas striking similarities in sedimentologic petrographic and morphologic characteristics of modern and ancient occurrences suggest that the enigmatic but widespread ancient structures could have been formed by microbial processes the relative abundance of these structures in siliciclastic facies of this interval further suggests that prior to the onset of relatively intense bioturbation in the ordovician microbial mats could have played a significant role in the evolution and diversification of early life in a broad variety of sea floor environments

slope vulnerability to earthquakes at subregional scale using probabilistic techniques and geographic information systems abstract the susceptibility of slopes to failure during earthquakes is calculated in terms of critical horizontal acceleration on a subregional scale for the upper part of the serchio river basin tuscany italy according to the working scale 1 10 000 and to the availability and accuracy of the input data the infinite slope analysis was judged to be the most appropriate method but particular attention was devoted to the error evaluation due to spatial variability of the geotechnic geometric and hydrologic parameters a geologic geomorphologic and hydrologic survey of the area was therefore performed and the geotechnic parameters were collected at local administrations all the data were stored in a gis used as a tool to build the spatial and attribute data base and to prepare the input data layers for the stability analysis in order to assess the variability of geotechnic parameters a statistical analysis was performed to assign the best fitting probability distribution to cohesion angle of internal friction and unit weight of the soil as hydrogeologic data were not available for the area only surface hydrology information could be used a map of probability of spring occurrences was derived by a bayesian method the weight of evidence modelling and was used as groundwater indicator a monte carlo procedure and a first order second moment method were applied and compared as error estimators in assessing the slope susceptibility to failure the differences between the two methods are discussed and two maps showing respectively the critical horizontal acceleration and the probability of failure associated with each slope are presented together with the curve plotting the reliability index against the probability of failure

ediacaran epifaunal tiering epifaunal tiering the subdivision of vertical space within a community is a fundamental attribute of phanerozoic suspension feeding communities this paper documents tiering including the presence of meter tall organisms in neoproterozoic ediacaran communities ediacaran tiering was studied from three exceptionally preserved deep water communities at mistaken point newfoundland which contain in situ census populations of hundreds to thousands of organisms tiering consists of overlapping populations of dominant organisms and is characterized by gradational rather than abrupt tier boundaries at least three tiers are apparent a lower level 0 8 cm above the seafloor an intermediate level between 8 22 cm above the seafloor and an upper level that extends as high as 120 cm tier boundaries are relatively consistent between communities but the constituent organisms in each level are variable suggesting that some ediacaran taxa could fill different tiers interchangeably development of a tiered epifaunal structure is consistent with suspension feeding or absorbing dissolved nutrients directly from seawater despite the common occurrence of tall organisms all communities share a similar population structure in which biomass is concentrated in the basal 10 cm above the seafloor comparison with shallow water ediacaran localities suggests that the observed tiering structure is typical of ediacaran communities ediacaran tierers also show the fundamental subdivision between organisms and or colonies that fed along their entire length and those that developed a specialized feeding apparatus implying that the features of phanerozoic tiered skeletal ecosystems were first initiated in soft bodied communities in the late neoproterozoic

analytic network process model for landslide hazard zonation various controlling factors such as lithology slope angle slope aspect landuse channel proximity etc are generally considered for the landslide hazard assessment although outer dependence of these parameters to a landslide is inevitably taken into account inter dependence among the factors is seldom addressed analytic network process anp is the multi criteria decision making mcdm tool which takes into account such a complex relationship among parameters in this research an anp model for landslide susceptibility is proposed priority weights for each parameter controlling the landslide were determined and a hazard map was prepared of an area in a fragile mountainous terrain in the eastern part of nepal the data used in the example were derived from published sources aerial photographs and a topographic map however the procedures developed can readily incorporate additional information from more detailed investigations

vendobionta and psammocorallia lost constructions of precambrian evolution the non availability of biomineralized skeletons and low levels of predation led vendian evolution along strange avenues the ediacara type vendobionta appear to represent a kingdom in which foliate shapes large sizes and the necessary compartmentalization were achieved by quilting of the skin rather than by multicellularity psammocorallia in contrast are interpreted as coelenterates that constructed an internal sand skeleton both were immobile soft bottom dwellers that had high population densities and both became preserved by obrutional accidents thus they render fossil snap shots in which the original distributional patterns age structures and standing biomasses of populations are accurately recorded

volcanosedimentary paleoenvironments of ediacaran fossils in newfoundland a new perspective on paleoenvironments of ediacaran fossils of the upper conception group newfoundland comes from geochemical and sedimentological study of volcanic tuffs and sedimentary rocks tuffs in the conception group have major and trace element compositions and u pb ages comparable with those of source volcanics on the nearby burin and bonavista peninsulas and the islands of st pierre and miquelon loss of silica and alkalies in some ashes indicates weathering on land not marine diagenesis volcanic crystal and lapilli tuffs fail to show grading and have lapilli and highly vesicular scoria scattered in a fine grained matrix and so they were deposited on land not in water these as well as block and ash flows volcanic spindle bombs and degassing features are evidence of eruptions from nearby subaerial volcanic edifices the fossiliferous conception group accumulated within a forearc basin formed on continental crust inboard of the holyrood horst and uplifted as part of an ancient subduction complex or accreted terrane like analogous forearc basins in oregon washington southern chile and japan the conception group includes not only marine bay turbidites but also a variety of intertidal and terrestrial tsunamites seismites tempestites and paleosols traditional marine turbidite models explain deposition of the mall bay lower drook and lower briscal formations of the conception group but the gaskiers upper drook upper briscal and mistaken point formations were deposited in coastal plains and intertidal zones paleoenvironments of vendobiont fossils preserved in life position in newfoundland were terrestrial to marginal marine not deep sea

an objective method to rank the importance of the factors predisposing to landslides with the gis methodology application to an area of the apennines valnerina perugia italy the present work aims at contributing to further our knowledge on the predisposing factors to landslides as well as proposing a method that allows us to weigh up as objectively as possible the influence that the various factors have on landslides in order to construct a realistic map of potential landslide hazards in order to assess the differential incidence of very predisposing factor to landslides maps of the various factors considered were drawn up with the aid of idrisi software 1997 the factors were as follows the distance from faults parallelism between the fractures and the landslide scarps land use lithology distance from the streams orientation and steepness of slopes orientation of layers compared to the slope the global analysis of the different incidence of the factors analyzed on the landslides present in the study area was carried out by comparing the respective maps with that of the scarps in this way the number of pixels forming the scarps which fell into the various classes of the maps was calculated the result thus obtained can form the basis of an objective assignation of the different ratings to be attributed to the various factors under consideration in fact the analysis carried out in this study has shown that the factors act differently and for every factor only some of the classes considered have marked importance

cross application used to validate landslide susceptibility maps using a probabilistic model from korea a study of landslides in youngin janghung and boeun korea using the geographic information system gis validates a spatial probabilistic model for landslide susceptibility analysis locations were identified from aerial photographs satellite images and field surveys topography soil type forest cover and land cover maps were constructed from spatial data sets landslide occurrence is influenced by 13 factors evidence for which was extracted from the database with the frequency ratio of each factor computed landslide susceptibility maps use frequency ratios derived not only from data for each area but also ratios one from the probabilistic model calculated from the other two areas nine maps in all as a cross check of method validity for validation analytical results were compared in each study area with actual landslide locations boeun based on its frequency ratio showed the best accuracy 82 49 whereas janghung based on the boeun frequency ratio showed the worst 69 53

explaining the exceptional preservation of ediacaran rangeomorphs from spaniard s bay newfoundland a hydraulic model exceptional 3 d preservation of ediacaran rangeomorph fossils is found on a single bedding plane at upper island cove spaniard s bay newfoundland this high quality preservation has previously been explained by entrainment of organisms within the td e mudstone division of a distal turbidite followed by encasement within concretions our sedimentological and taphonomic analysis reveals a clear association between these fossils and evidence for erosive unidirectional flows including scours marks tool marks ridge and groove marks parting lineations and current crescents we suggest an alternative sequence of events that runs broadly as follows i rangeomorph discs were anchored to the seafloor during deposition of planar laminated silts our unit 2 10 mm thick td now bearing pyrite framboids and pyritized organic matter ii rangeomorph fronds were then felled and entrained by high velocity unidirectional currents to lie within their own erosional scours at the top of unit 2 or to form tool marks iii this topography was then draped and cast by soft weathering sand unit 3 tc associated with the growth of early diagenetic pyrite around sand grains pyrite grains also appear to have replaced clumps of organic matter fossil impressions have since been exposed by differential weathering of the ferruginous sands with respect to the silts this new context now provides a parsimonious explanation for a range of hitherto paradoxical structures features previously regarded as microbial mats bubble trains that formed in the lee of sinuous ripples on the top of unit 2 may be explained as load casts or by localised gas escape within areas of lowered hydraulic pressure rangeomorph fronds remarkably preserved in positive rather than the more usual negative epirelief are explained by means of sediment casting of branches that became ruptured in the high velocity current paradoxical structures previously thought to be enclosing biological sheaths around rangeomorph fronds are reinterpreted as scour marks whereas imbricate overlaps of first order branches in beothukis trepassia and avalofractus are explained by hydraulic shear driven by overlying currents across ruptured and deflated fronds we find that rangeomorph bodies could be deflated imbricated folded over inverted and infilled with fine sediment our hydraulic model provides a null hypothesis against which future observations of rangeomorph fronds can now be tested it removes some significant anomalies in our understanding of rangeomorph architecture and provides a better understanding of the physical properties of their body tissues permitting the possibility of a reasoned consideration of their puzzling biological affinities

landslide hazard evaluation a review of current techniques and their application in a multi scale study central italy in recent years growing population and expansion of settlements and life lines over hazardous areas have largely increased the impact of natural disasters both in industrialized and developing countries third world countries have difficulty meeting the high costs of controlling natural hazards through major engineering works and rational land use planning industrialized societies are increasingly reluctant to invest money in structural measures that can reduce natural risks hence the new issue is to implement warning systems and land utilization regulations aimed at minimizing the loss of lives and property without investing in long term costly projects of ground stabilization government and research institutions worldwide have long attempted to assess landslide hazard and risks and to portray its spatial distribution in maps several different methods for assessing landslide hazard were proposed or implemented the reliability of these maps and the criteria behind these hazard evaluations are ill formalized or poorly documented geomorphological information remains largely descriptive and subjective it is hence somewhat unsuitable to engineers policy makers or developers when planning land resources and mitigating the effects of geological hazards in the umbria and marche regions of central italy attempts at testing the proficiency and limitations of multivariate statistical techniques and of different methodologies for dividing the territory into suitable areas for landslide hazard assessment have been completed or are in progress at various scales these experiments showed that despite the operational and conceptual limitations landslide hazard assessment may indeed constitute a suitable cost effective aid to land use planning within this framework engineering geomorphology may play a renewed role in assessing areas at high landslide hazard and helping mitigate the associated risk

the problems and potential of using animal fossils and trace fossils in terminal proterozoic biostratigraphy abstract despite the discovery of soft bodied megascopic fossils of late neoproterozoic age at numerous localities world wide there has been slow acceptance of their potential for intercontinental correlation the stratigraphic thickness of sediments separating individual occurrences of such fossils from the base of the cambrian is very varied basic questions have also been posed as to the classification of the organisms represented and hence their likely time significance recent geochronological studies support notions of a narrow time distribution well studied neoproterozoic sequences in eurasia eastern and western north america and southern australia show strikingly similar patterns of increase in the numbers and diversity of trace fossils and soft bodied megascopic remains up section though strata immediately preceding the cambrian are relatively barren other than for a sparse palynoflora and compressions of primitive plants trace fossils from australian sections relating to an early part of the ediacaran apparently overlap a time of abundance of large process bearing acritarchs and big leiosphaerids this overlap of early animal traces and distinctive acritarchs may prove to be of significant biostratigraphic importance rare discoveries of forms resembling rangea gurich in the flinders ranges of south australia precede the classical ediacara assemblage and may provide a possible correlation with occurrences of this genus in namibia the distinctive remains and trace fossils at this level constituting the rangeid hiemalora assemblage zone resemble a biota from the podolia region of the ukraine and show a similarity to finds in parts of the windermere supergroup of the northwest territories canada similarly the offshore frondose assemblage of newfoundland is comparable with the biota of charnwood forest england the type ediacara assemblage of the flinders ranges characterizing the dickinsonia costata assemblage zone is a climax biota with diverse taxa and large individual species as well as some 20 ichnogenera it closely correlates with a late redkinian or early kotlinian assemblage in the upper part of the section on the zimny gory coast of the white sea northern russia the trace fossils of these levels show that significant diversification began before the cambrian

probabilistic landslide susceptibility and factor effect analysis the susceptibility of landslides and the effect of landslide related factors at penang in malaysia using the geographic information system gis and remote sensing data have been evaluated landslide locations were identified in the study area from interpretation of aerial photographs and from field surveys topographical and geological data and satellite images were collected processed and constructed into a spatial database using gis and image processing the factors chosen that influence landslide occurrence were topographic slope topographic aspect topographic curvature and distance from drainage all from the topographic database lithology and distance from lineament taken from the geologic database land use from landsat thermatic mapper tm satellite images and the vegetation index value from spot hrv high resolution visible satellite images landslide hazardous areas were analyzed and mapped using the landslide occurrence factors employing the probability frequency ratio method using the all factors to assess the effect of these factors each factor was excluded from the analysis and its effect verified using the landslide location data as a result all factors had relatively positive effects except lithology on the landslide susceptibility maps in the study area

landslide susceptibility analysis and verification using the bayesian probability model the bayesian probability model using the weight of evidence method was applied to the task of evaluating landslide susceptibility using gis data the location chosen for the study was the janghung area in korea which suffered substantial landslide damage following heavy rain in 1998 using the location of the landslides as well as topographic factors such as soil forest and land use the weight of evidence method was used to calculate each factor s rating tests of conditional independence were performed for the selection of the factors allowing the large number of combinations of factors to be analyzed for each factor rating the contrast values w and w were overlaid for landslide susceptibility mapping the results of the analysis were verified using the observed landslide locations and among the combinations the slope aspect curvature soil material and wood types show the best results

first evidence for locomotion in the ediacara biota from the 565 ma mistaken point formation newfoundland evidence for locomotion in the precambrian fossil record is scant reliable ediacaran trace fossils are all younger than 560 ma and consist of relatively simple horizontal burrows and trails from shallow water deposits here we describe an assemblage of macroscopic locomotory traces from deep water environments at mistaken point southeastern newfoundland canada dated to ca 565 ma these trails extend the record of complex trace fossils back into the earliest avalonian biota our new evidence for large motile organisms on the seafloor at this time suggests that at least some of these early ediacaran organisms whose biological affinities are widely debated could have been muscular and of metazoan grade

landslide susceptibility mapping using frequency ratio analytic hierarchy process logistic regression and artificial neural network methods at the inje area korea every year the republic of korea experiences numerous landslides resulting in property damage and casualties this study compared the abilities of frequency ratio fr analytic hierarchy process ahp logistic regression lr and artificial neural network ann models to produce landslide susceptibility index lsi maps for use in predicting possible landslide occurrence and limiting damage the areas under the relative operating characteristic roc curves for the fr ahp lr and ann lsi maps were 0 794 0 789 0 794 and 0 806 respectively thus the lsi maps developed by all the models had similar accuracy a cross tabulation analysis of landslide occurrence against non occurrence areas showed generally similar overall accuracies of 65 27 64 35 65 51 and 68 47 for the fr ahp lr and ann models respectively a correlation analysis between the models demonstrated that the lr and ann models had the highest correlation 0 829 whereas the fr and ahp models had the lowest correlation 0 619

a new ecological model for the 565 ma ediacaran biota of mistaken point newfoundland abstract ediacaran macrofossils immediately precede the first animal ecosystems of the cambrian period and have excited much attention for potentially containing ancestors of the modern animal phyla ediacaran fossil surfaces have been variously interpreted as vertically tiered census populations comparable to animal ecosystems or as osmotrophic ecosystems exploiting turbulent flow regimes these hypotheses are highly dependent upon the taphonomic interpretation of mistaken point newfoundland as a consensus population representing the associations of the organisms in life reanalyses of these surfaces however indicate that this taphonomic model is inconsistent with the range of preservation states seen in each taxon we present a new taphonomic model for mistaken point surfaces in newfoundland canada and describe it using an index of decay this reveals a complex history of life death and decay at these sites data gathered from large scale casting projects in newfoundland show that only 15 40 of individuals were killed by ash flows rather than the whole population as previously interpreted this shows that ediacaran organisms at mistaken point newfoundland had a diverse range of ecological relationships with the microbial mat system frondose organisms are engaged in chemical exchange with the sediment and the water column with the stem penetrating through the microbial mat reclining forms such as fractofusus lived exclusively above the microbial mat and drew nutrients from the dead organisms on which they typically grew the ecology is based on organism interaction with the sediment water interface quite unlike that of modern vertically tiered metazoan communities that have developed since the start of the cambrian period

spindle shaped ediacara fossils from the mistaken point assemblage avalon zone newfoundland the mistaken point assemblage of the ediacara fossils is dominated by rangeomorphs with homologous fractal branching elements the most distinctive are the fusiform fossils herein named fractofusus misrai n gen and n sp and fractofusus andersoni n gen and n sp although endemic to the newfoundland portion of the avalonia terrane they dominated deep sea floor communities below the photic zone in the mid ediacaran period ca 575 560 ma their biological affinities remain uncertain but their architecture suggests a phylogenetic position near the base of the metazoa

charnia and sea pens are poles apart c harnia from the ediacara biota is here examined in terms of its growth and development the ediacara biota comes from the critical period of evolution just before the cambrian explosion and is key to our understanding of the origin of animal life we show that charnia cannot be related to the modern cnidarian group the sea pens pennatulacea with which it has for so long been compared as generative zones cannot be homologized between these forms

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

landslide susceptibility assessment in the izmir west anatolia turkey city center and its near vicinity by the logistic regression method a landslide susceptibility assessment for izmir city western turkey which is the third biggest city of turkey was performed by a logistic regression method a database of landslide characteristics was prepared using detailed field surveys the major landslides in the study area are generally observed in the field dominated by weathered volcanics and 39 63 of the total landslide area is in this unit the parameters of lithology slope gradient slope aspect distance to drainage distance to roads and distance to fault lines were used as variables in the logistic regression analysis the effect of each parameter on landslide occurrence was assessed from the corresponding coefficients that appear in the logistic regression function on the basis of the obtained coefficients lithology plays the most important role in determining landslide occurrence and distribution slope gradient has a more significant effect than the other geomorphological parameters such as slope aspect and distance to drainage using a predicted map of probability the study area was classified into five categories of landslide susceptibility very low low moderate high and very high whereas 49 65 of the total study area has very low susceptibility very high susceptibility zones make up 11 69 of the area

validation of an artificial neural network model for landslide susceptibility mapping the aim of this study was to validate an artificial neural network model at youngin janghung and boeun korea using the geographic information system gis the factors that influence landslide occurrence such as the slope aspect curvature and geomorphology of topography the type material drainage and effective thickness of soil the type diameter age and density of forest distance from lineament and land cover were either calculated or extracted from the spatial database and landsat tm satellite images landslide susceptibility was analyzed using the landslide occurrence factors provided by the artificial neural network model the landslide susceptibility analysis results were validated and cross validated using the landslide locations as study areas for this purpose weights for each study area were calculated by the artificial neural network model among the nine cases the best accuracy 81 36 was obtained in the case of the boeun based janghung weight whereas the janghung based youngin weight showed the worst accuracy 71 72

assessment of landslide susceptibility on the natural terrain of lantau island hong kong steep terrain and the high frequency of tropical rainstorms make landslide occurrence on natural terrain a common phenomenon in hong kong for example more than 800 slope failures were triggered by a rainstorm in november 1993 on lantau island hong kong maps of recent landslides interpreted from aerial photographs in combination with a geographical information system were used to evaluate the frequency and distribution of landslides with particular reference to such physical parameters as lithology slope gradient slope aspect elevation vegetation cover and proximity to drainage line all of which are considered to be influential in the occurrence of landslides a stepwise logistic regression model was obtained between landslide susceptibility and the above mentioned physical parameters the study area has been classified into five classes of relative landslide susceptibility namely very low low moderate high and very high based on this methodology

ediacaran body and trace fossils in miette group windermere supergroup near salient mountain british columbia canadarevision of the paper was carried out by dr guy narbonne following the passing away of both hans hofmann deceased may 19 2010 and eric mountjoy deceased june 18 2010 after manuscript submission siliciclastic beds in the upper part of the miette group in southeastern british columbia have yielded an assemblage of late ediacaran soft bodied macrofossils and trace fossils the macrofossils comprise aspidella bradgatia and miettia salientensis gen et sp nov the ichnofossils include archaeonassa cochlichnus didymaulichnus gordia halopoa helminthoidichnites helminthopsis planolites and a large unnamed crawling trace in addition two types of unidentified problematica are recorded representing either tubular vendotaenia like body fossils or trace fossils the bradgatia constitutes the youngest occurrence of this type of fossil and is the first to be recorded from laurentia having previously been noted only in avalonia with cloudina and namacalathus in associated shallow water platform carbonates the miette biota in the study area contains a combination of namibian type and avalonian type elements

verification of landslide susceptibility mapping a case study a methodology is proposed for mapping susceptibility to landsliding and validating the results heavy rains in late 1996 and early 1997 led to a large number of landslids in the rute sector cordoba southern spain where landslide susceptibility mapping had previously been carried out using a matrix method developed with a geographical information system gis analysis of the distribution of the new landslides or reactivated earlier ones enabled the methodology to be validated by calculating association coefficients and determining the closeness of the match between subsequent field evidence and the previously defined susceptibility levels from the data obtained it can be concluded that the susceptibility mapping effectively explained the spatial distribution of landslides thus providing valuable information on stability conditions over a widespread area copyright 1999 john wiley sons ltd

a back propagation network for the assessment of susceptibility to rock slope failure in the eastern portion of the southern cross island highway in taiwan an assessment of the susceptibility to rock slope failure by means of a back propagation network is proposed for the eastern portion of the southern cross island highway in taiwan the model was developed on the basis of six influence parameters of rock slope instability which include the rock type slope aspect slope angle joint set number joint spacing and bedding slope relationship the values of these influence parameters were used as inputs for the network and were classified as nominal scales in terms of binary numbers while the state of failure non failure of a given slope was assumed to be the output variable data on a total of 170 slopes along the highway was fed into the network for learning according to the outputs of the network the susceptibility to rock slope failure is categorized into four levels namely low medium low medium and high which are mapped along the highway three highly susceptible regions are found which can be viewed as hazardous sections requiring cautionary measures moreover the proposed model can be used as a tool for determining the possible state of an unfamiliar rock slope in the context of devising management strategies to be applied to the investigated portion of the highway

post fossilization processes and their implications for understanding ediacaran macrofossil assemblages fossil assemblages from newfoundland s avalon peninsula preserve diverse examples of the enigmatic ediacaran macrobiota offering some of the earliest evidence for large and complex multicellular life these fossils are exposed on extensive coastal bedding planes in extraordinary abundances permitting palaeoecological studies based on census data from spatially extensive palaeocommunities such studies have been used to constrain the reproductive strategy and phylogenetic placement of ediacaran organisms geological mapping and stratigraphic correlation in the mistaken point ecological reserve reveal that some fossil bearing surfaces can be tracked over distances of several kilometres these laterally extensive surfaces reveal that the modern processes by which the sediment overlying a fossil surface is removed may impose important controls on the observed composition of fossil assemblages weathering and erosion along with factors associated with tectonics metamorphism and discovery are here grouped as post fossilization processes and introduce biases that are often not explicitly accounted for in palaeoecological studies specifically post fossilization processes may differentially influence the preservational fidelity of individual specimens on a given surface and generate features that could be mistaken for original morphological characters we therefore recommend that post fossilization processes must be considered when undertaking palaeoecological studies in ediacaran successions in newfoundland and potentially elsewhere

probabilistic landslide susceptibility mapping in the lai chau province of vietnam focus on the relationship between tectonic fractures and landslides this study evaluates the susceptibility of landslides in the lai chau province of vietnam using geographic information system gis and remote sensing data to focus on the relationship between tectonic fractures and landslides landslide locations were identified from aerial photographs and field surveys topographic geological data and satellite images were collected processed and constructed into a spatial database using gis data and image processing techniques a scheme of the tectonic fracturing of crust in the lai chau region was established lai chau was identified as a region with many crustal fractures where the grade of tectonic fracture is closely related to landslide occurrence the influencing factors of landslide occurrence were distance from a tectonic fracture slope aspect curvature soil and vegetative land cover landslide prone areas were analyzed and mapped using the landslide occurrence factors employing the probability frequency ratio model the results of the analysis were verified using landslide location data and showed 83 47 prediction accuracy that emphasized a strong relationship between the susceptibility map and the existing landslide location data the results of this study can form a basis stable development and land use planning for the region

gyrolithes from the ediacaran cambrian boundary section in fortune head newfoundland canada exploring the onset of complex burrowing abstract the beginning of the cambrian explosion is characterized by the onset of infaunalization and the appearance of systematic patterns of burrowing the trace fossil gyrolithes is common in the ediacaran cambrian global stratotype section and point where it shows a higher diversity and burrow depth than previously reported from any cambrian spiral vertical burrows two ichnospecies are present g scintillus isp nov exhibits a small burrow radius to whorl radius ratio whereas g gyratus hofmann exhibits an exceptionally large ratio that formerly led to its identification as an aberrant ichnospecies of skolithos the helical morphology of these cambrian gyrolithes is interpreted as having served two purposes as an anchor in a relatively high energy environment and as an optimal shape for maximizing surface area for bacterial gardening these shallow marine gardening burrows share a similar feeding strategy as graphoglyptids suggesting that shallow early cambrian sediments may have been relatively poor in organics and thus further supporting the model for onshore offshore migration of gardening burrows

phylogenetic relationships among the rangeomorpha the importance of outgroup selection and implications for their diversification the rangeomorpha are the oldest most diverse and most disparate clade of ediacaran macrofossils easily identifiable by their self similar branching pattern they occupied epibenthic niche space ranging from the lowest tiered and recumbent taxa up to metre long upright fronds a phylogenetic analysis using the largest and most complete character set known for this group scored for 14 separate taxa was undertaken to resolve their internal relationships and test previous hypotheses of their evolutionary and ecological history owing to the lack of consensus on the relationship amongst ediacaran clades several permutations with different potential outgroup taxa were performed across these analyses there is a strong signal for an upright frondose ancestral state for this clade likely displaying primary branches that were double sided nonrotated with the lower tiered and recumbent forms being derived members of a single subclade this has implications on the life history reconstruction as well as taxon

landslide susceptibility mapping by correlation between topography and geological structure the janghung area korea the purpose of this study is to develop and apply the technique for landslide susceptibility analysis using geological structure in a geographic information system gis in the study area the janghung area of korea landslide locations were detected from indian remote sensing irs satellite images by change detection where the geological structure of foliation was surveyed and analysed the landslide occurrence factors location of landslide geological structure and topography were constructed into a spatial database then strike and dip of the foliation and the aspect and slope of the topography were compared and the results which were verified using landslide location data show that foliation of gneiss has a geometrical relation to the joint or fault that leads to a landslide using the geometrical relations the landslide susceptibility was assessed and verified the verification results showed satisfactory agreement between the susceptibility map and the landslide location data

statistical analysis of landslide susceptibility at yongin korea the aim of this study is to evaluate the susceptibility of landslides at yongin korea using a geographic information system gis landslide locations were identified in the yongin area from interpretation of aerial photographs field surveys and maps of the topography soil type timber cover and geology these data were collected and constructed into a spatial database using gis the factors that influence landslide occurrence such as slope aspect and curvature of topography were calculated from the topographic database texture material drainage and effective soil thickness were extracted from the soil database and type age diameter and density of timber were extracted from the forest database lithology was extracted from the geological database and land use was classified from the landsat tm satellite image landslide susceptibility was analyzed using the landslide occurrence factors by probability and logistic regression methods the results of the analysis were verified using the landslide location data the validation results showed satisfactory agreement between the susceptibility map and the existing data on landslide location the gis was used to analyze the vast amount of data efficiently and statistical programs were used to maintain specificity and accuracy the results can be used to reduce associated hazards and to plan land use and construction

discontinuity controlled probabilistic slope failure risk maps of the altindag settlement region in turkey the evaluation of potential rock slope problems using stereographic projection techniques known as kinematic analysis is one of the most important parts of a slope stability investigation to be carried out in jointed rock media in conventional stereoprojection techniques for the assessment of possible rock slope failures the peak orientations of joints together with the slope geometry and the friction angle of the weakness planes are used other possible joint orientations which may be encountered in the rock media are ignored although they belong to the group of joint peak orientations in this study nearly vertical jointed andesites cropped out at the altindag settlement region in ankara were studied in order to evaluate the relevance of this ignored discontinuity orientation data on slope stability as a result probabilistic risk maps for planar toppling and wedge failures were produced using the kinematic rules and digital elevation model of the study area the comparison of the distribution of the actual failures in the area and the probabilistic risk maps prepared for the study area revealed that all of the identified failures are found to be located in the higher risk zones on the probabilistic risk maps

landslide susceptibility assessment in the hoa binh province of vietnam a comparison of the levenberg marquardt and bayesian regularized neural networks abstract this study investigates the potential application of artificial neural networks in landslide susceptibility mapping in the hoa binh province of vietnam a landslide inventory map of the study area was prepared by combining landslide locations investigated through three projects during the last 10 years some recent landslide locations were identified based on spot satellite images field surveys and existing literature the images have a spatial resolution of 2 5 m ten landslide conditioning factors were utilized in the multilayer feed forward neural network analysis slope aspect relief amplitude lithology land use soil type rainfall distance to roads distance to rivers and distance to faults two back propagation training algorithms levenberg marquardt and bayesian regularization were utilized to determine synoptic weights using a training dataset relative importance of each landslide conditioning factor was assessed using the above mentioned synoptic weights the final connection weights obtained in the training phase were applied to the entire study area to produce landslide susceptibility indexes the results were then imported to a gis and landslide susceptibility maps were constructed landslide locations not used in the training phase were used to verify and compare the results of the landslide susceptibility maps finally the two landslide susceptibility maps were validated using the prediction rate method subsequently areas under the prediction curves were assessed the prediction accuracy of landslide susceptibility maps produced by the bayesian regularization neural network and the levenberg marquardt neural network were 90 3 and 86 1 respectively these results indicate that the two models seem to have good predictive capability the bayesian regularization network model appears more robust and efficient than the levenberg marquardt network model for landslide susceptibility mapping

landslide characteristics and slope instability modeling using gis lantau island hong kong steep terrain and high a frequency of tropical rainstorms make landslide occurrence on natural terrain a common phenomenon in hong kong this paper reports on the use of a geographical information systems gis database compiled primarily from existing digital maps and aerial photographs to describe the physical characteristics of landslides and the statistical relations of landslide frequency with the physical parameters contributing to the initiation of landslides on lantau island in hong kong the horizontal travel length and the angle of reach defined as the angle of the line connecting the head of the landslide source to the distal margin of the displaced mass are used to describe runout behavior of landslide mass for all landslides studied the horizontal travel length of landslide mass ranges from 5 to 785 m with a mean value of 43 m and the average angle of reach is 27 7 this gis database is then used to obtain a logistic multiple regression model for predicting slope instability it is indicated that slope gradient lithology elevation slope aspect and land use are statistically significant in predicting slope instability while slope morphology and proximity to drainage lines are not important and thus excluded from the model this model is then imported back into the gis to produce a map of predicted slope instability the results of this study demonstrate that slope instability can be effectively modeled by using gis technology and logistic multiple regression analysis