Angular Blocks Research Articles

Study of clay degradation in an earthslide combining OBIA and roughness analysis of UAV‐based optical images

AbstractFlow‐like landslides in clay slopes pose major threats to people and infrastructure, which has led to numerous studies in recent decades. However, the mechanisms leading to the solid–fluid transition in clay are still poorly understood, despite numerous studies on its rheological evolution. The aim of this study is to contribute to quantify the degradation of clay at the surface of the Harmalière landslide (French Alps) from the analysis of a series of three unmanned aerial vehicle (UAV) acquisitions. Two approaches were combined to process the acquired optical images. First, image classification was performed applying object‐based image analysis (OBIA) to the red, green and blue (RGB) and surface roughness layers. Second, deeper analysis of the surface roughness allows to describe the morphology evolution and to interpret the degradation scheme from undegraded clay to degraded clay.The study shows that the applied methodology is appropriate to perform a thorough analysis of the material degradation pattern on the surface of a landslide. The temporal analysis shows an average degradation rate leading to the complete degradation of a block in about 2 years. Meanwhile, a spatial analysis shows that non‐degraded clays degrade faster in the lower part of the study area, reactivated 30 years ago, than in the upper part, reactivated only a few years ago. In addition, roughness analyses enabled to highlight the evolution of the morphology during the degradation process of the clay blocks, from angular blocks to mounds.

ON THE UNDERSTANDING OF AEOLIAN SEQUENCE STRATIGRAPHY: AN EXAMPLE FROM MIOCENE-PLIOCENE DEPOSITS IN PATAGONIA, ARGENTINA

Upper Tertiary aeolian strata (Río Negro Formation) outcrop in extensive sea cliffs at the Northeast of Patagonia. These outcrops show deposits corresponding to a complete suite of aeolian and aeolian related sub-environments, and also provide excellent exposures to analyse the sedimentology and internal architecture from a sequence stratigraphic point of view. Field studies, supplemented withline-drawings of oblique photographs, allowed the recognition of seven aeolian depositional sequences within the succession, each one bounded by regional super surfaces (or deflation surfaces). Internally these aeolian sequences display a cyclic recurrence in facies, that yields a tentative genetic model for their evolution. As documented from field examples, each basic aeolian depositional sequence was deposited during a single aggradational period, and is bounded by unconformities related to degradational periods. Degradational periods are regional deflationary events, that resulted in deep-scoured to flat surfaces, characterised by erosion / non deposition in which the only recognised accumulation is isolated and large angular blocks of fine-grained aggregates, interpreted as residual remnants of deposits of the previous sequence. Aggradational periods are characterised by a near- continuous accumulations responsible for the sequence building. Differences in the aeolian sediment budget to the area and the rising rate of water table control the related facies types, and allow to discriminateearly and late aggradational sub-periods. Early aggradational sub-periods form under conditions of relatively fast rising water tables associated with moderate aeolian sediment budget, thus resulting in the development of extended wet interduneslaterally associated with aeolian dunes and dry interdunes. During late aggradational sub-periods, the depositional surface outdistanced the water table, and aeolian dunes and dry interdunes tend to predominate. This sub-period is also characterised by an upward tendency to stabilisation, evidenced by the common occurrence of palaeosols in upper levels. Although the preserved thickness of each aeolian sequence is closely related to the average subsidence rate, the internal facies evolution suggests an overall climatic control for their origin.

High Speed Maneuvering Platform Squint TOPS SAR Imaging Based on Local Polar Coordinate and Angular Division

This paper proposes an imaging algorithm for synthetic aperture radar (SAR) mounted on a high-speed maneuvering platform with squint terrain observation by progressive scan mode. To overcome the mismatch between range model and the signal after range walk correction, the range history is calculated in local polar format. The Doppler ambiguity is resolved by nonlinear derotation and zero-padding. The recovered signal is divided into several blocks in Doppler according to the angular division. Keystone transform is used to remove the space-variant range cell migration (RCM) components. Thus, the residual RCM terms can be compensated by a unified phase function. Frequency domain perturbation terms are introduced to correct the space-variant Doppler chirp rate term. The focusing parameters are calculated according to the scene center of each angular block and the signal of each block can be processed in parallel. The image of each block is focused in range-Doppler domain. After the geometric correction, the final focused image can be obtained by directly combined the images of all angular blocks. Simulated SAR data has verified the effectiveness of the proposed algorithm.

Late Cretaceous Syn-depositional mass transport deposits in the turbidites of Zagros Orogenic belt: examples in the Maastrichtian Tanjero formation, Kurdistan region, NE-Iraq

In the northeast Iraq, the Maastrichtian turbidite deposits, as a Tanjero Formation, consist of very thick succession of sandstones, conglomerates, and calcareous shales. It deposited in a deep and coastal areas of the Early Zagros Foreland basin which is generated after the radiolarites and limestone obductions during Maastrichtian. The foreland basin was bounded from northeast by newly uplifted and highly elevated active terrestrial land from which voluminous amount of the siliciclastic sediments and carbonates transported to the different parts of the foreland basin. In the studied area, two types of lenticular bodies of synsedimentary mass transport deposits (MTDs) are recorded in the turbidite succession and studied in three outcrop sections about 70 km far from each other. The first type is deposits of coarse grain debris flow, characterized by bad sorting, mud supporting, chaotic internal structures, and bearing angular blocks of olistoliths which reveal instable tectonic setting of the basin. The second is Maastrichtian slump debris within sandstone bedsets (succession) which are extremely deformed, wildly fragmented to blocks of olistoliths and boulders. These deformed bedsets are squeezed between intact and unreformed strata of the lower part of the Tanjero Formation. The slump deposits contain folded sandstone beds and their attitudes indicate, on the stereonet, the southwest transport of the slump deposits. This direction is detected from trends of four fold axes included in the slump debris. The fold axes are extending northeast-southeast which indicate the gravitation stress was in the southwest direction. This study includes a first record of the catastrophic submarine coarse grain debris flow, slumping, and olistolith deposition in the Zagros orogenic belt that uncovers important tectonic setting processes and paleogeographic configuration of the Zagros Collisional Belt during Maastrichtian.

A calculation model of the normal coefficient of restitution based on multi-factor interaction experiments

As a key input parameter for simulating the moving trail of a rockfall, the magnitude of the normal coefficient of restitution (Rn) directly affects the prediction accuracy. However, few comprehensive and accurate calculation models are available for reference, owing to the fact that Rn is jointly controlled by multiple factors with the influence mechanisms being complex. Considering the interactive effects of influencing factors and the non-linear relationships between some influencing factors and Rn, the combined effects of the seven influencing factors on Rn were first investigated in this study by the response surface methodology–central composite design (RSM–CCD) method. The effects of the seven main factors on Rn were all significant; the results of the regression and variance analysis indicate that for non-angular blocks, the degree of influence of these factors is given by the following sequence: shape factor (η) > Schmidt hardness of the block (SHV1) > impact angle (θ) > rotational speed (ω) > Schmidt hardness of the slope surface (SHV2) > incident velocity (V) > block size (d). However, for angular blocks, the sequence is θ > SHV1 > ω > η > V > SHV2 > d. There are also many interaction parameters that had significant effects on the Rn of the test blocks (for non-angular blocks: η–θ > d–η > η–ω > V–d > SHV1–η > SHV1–θ; for angular blocks, d–θ > SHV1–d > V–η > SHV1–ω > d–η > η–ω > SHV1–η), the effects of which were examined via contour and three-dimensional surface plots. Based on the conclusions of these experiments (the determined significant influence parameters of Rn) and the previous single-factor experiments, the SPSS19.0 software was used to perform multivariate non-linear regression on the test results. Consequently, two Rn value calculation models of both non-angular and angular blocks were established. Through a contrastive analysis of the measured values of field tests and the predicted values of various models, the prediction ability of models “a” of the two types of blocks closely approached the measured values, with average deviations of only 3.4% and 9.8%; thus, these models can basically be used to achieve an accurate prediction of Rn values under various conditions. The models obtained in this study consider the comprehensive influences of various factors, which include not only the effects of all the main controlling factors, but also those of the interactions between them. Thus, these models can more accurately reflect the energy loss in the process of rockfall impact, which is helpful to improve the prediction accuracy of rockfall motion paths and is capable of providing a more reliable reference for the prevention and control of rockfall disasters.

APPLICABILITY OF THE GEOLOGICAL STRENGTH INDEX (GSI) CLASSIFICATION FOR THE TRUSMADI FORMATION AT SABAH, MALAYSIA

During the feasibility and preliminary design stages of a project, when very little detailed information on the rock mass and its geomechanic characteristics is not available, the use of a Rock Mass Classification Scheme (RMCS) can be of considerable benefit. Various parameters were used in order to identify the RMCS. The parameter comprised of Rock Quality Designation (RQD), Rock Mass Rating (RMR), Rock Structure Rating (RSR), Geological Strength Index (GSI), Slope Mass Rating (SMR), etc. In this paper, we present the results of the applicability of the Geological Strength Index (GSI) classification for the Trusmadi Formation in Sabah, Malaysia. The GSI classification system is based on the assumption that the rock mass contains a sufficient number of “randomly” oriented discontinuities such that it behaves as a homogeneous isotropic mass. In this study, the GSI relates the properties of the intact rock elements/blocks to those of the overall rock mass. It is based on an assessment of the lithology, structure and condition of discontinuity surfaces in the rock mass and is estimated from visual examination of the rock mass exposed in outcrops or surface excavations. A total of ten (10) locations were selected on the basis of exposures of the lithology and slope condition of the Trusmadi Formation. The Trusmadi Formation regionally experienced of two major structural orientations NW-SE and NE-SW. It consists mostly of dark grey shale with thin bedded sandstones, typical of a turbidite deposit. This unit has been subjected to low grade of metamorphism, producing slates, phyllites and meta-sediments and intense tectonic deformation producing disrupted or brecciated beds. Quartz vein are quite widespread within the joints on sandstone beds. The shale is dark grey when fresh but changes light grey to brownish when weathered. The results are classified as “Poor Rock” to “Fair Rock” in term of GSI. The poor categories (TR2 and TR7) represent slickensided, highly weathered surfaces with compact coatings or fillings or angular fragments. It is also characterized as blocky/ disturbed/seamy, which folded with angular blocks formed by many intersecting discontinuity sets. The fair categories can be divided into two (2) types; type 1 (TR1, TR6 and TR8) which represent as smooth, moderately weathered and have altered surfaces. It is also characterised as very blocky rock, which indicates interlocked, partially disturbed ass with multi-faceted angular blocks formed by 4 or more joint sets. Type 2 (TR3, TR4, TR5, TR9 and TR10) which represent as smooth, moderately weathered and have altered surfaces but characterized as blocky/disturbed/seamy, which folded with angular blocks formed by many intersecting discontinuity sets. It also has persistence of bedding planes or schistosity.

Seismic characterization of a blocky mass-transport deposit in the Trealla Limestone Formation, North Carnarvon Basin, Australia

The deepwater Cenozoic strata in the North Carnarvon Basin, Australia, represent an interval of interest for stratigraphic studies in passive margins settings of mixed siliciclastic-carbonate environments. We have explored the geomorphological characteristics of a mass-transport deposit (MTD) within the Trealla Limestone Formation to describe in detail the differences among the blocks. To characterize the individual geometry and structural configuration of the blocks within the MTD, we used geometric seismic attributes such as coherence, curvature, dip azimuth, and dip magnitude using horizon slices and vertical profiles. The evaluation finds two types of blocks: remnant and glide (or rafted) blocks. Remnant blocks are in situ and stratigraphically continuous fragments with the underlying strata. This type of block is frequently fault-bounded and displays low deformation evidence. Glide blocks are part of the transported material detached from a paleoslope. These blocks are deformed and occasionally appear as “floating” fragments embedded within a chaotic matrix in the MTD. Glide blocks are used as kinematic indicators of the direction of deposition of MTDs. We evaluate these elements in a modern continental analog that resembles a similar setting for a better understanding of the slide occurrence. Geological feature: Glide blocks, North Carnarvon Basin, Australia Seismic appearance: Discrete angular blocks with internal reflectors Alternative interpretations: Differential dissolution in a mixed siliciclastic-carbonate environment Features with a similar appearance: Carbonate buildups, differential dissolution blocks Formation: Trealla Limestone Formation, North Carnarvon Basin Age: Early-Middle Miocene Location: Offshore Northwest Australia, North Carnarvon Basin Seismic data: Obtained from Western Australian Petroleum and Geothermal Information Management System, Draeck 3D seismic data set Analysis tools: Visualization software (Petrel 2019) and attribute performance software (AASPI 6.0)

Mass wasting on Alpha Ridge in the Arctic Ocean: new insights from multibeam bathymetry and sub-bottom profiler data

Abstract Marine geological and geophysical data from Alpha Ridge in the Arctic Ocean are sparse because of thick perennial sea-ice cover, which prevents access by most surface vessels. Rare seismic data in this area, acquired largely from drifting ice-camps, had shown the hemipelagic drape that covers most of the ridge is highly disrupted within a large (>90 000 km 2 ) south central region. Here, evidence of pronounced seafloor erosion and debris flows infilling seafloor lows was previously interpreted to be the result of a possible bolide impact. In recent years, several icebreaker expeditions have successfully acquired multibeam bathymetry and sub-bottom profiler data in the western segment of this region. Analysis of these data reveals a complex seafloor morphology characterized by ridges and troughs, angular blocks and escarpments as well as seismic facies characterized by hyperbolic seafloor reflections, and convoluted to incoherent and transparent sub-bottom reflectivity. These features are interpreted as evidence of sediment mass movement with varying degrees of lateral transport deformation. At least two episodes of failure are interpreted based on the presence of both buried and surficial mass-transport features. As multiple events are interpreted, seismicity is the most plausible trigger mechanism rather than bolide impact.

Evidencias macromorfológicas y micromorfológicas de paleosuelos en el desierto de La Tatacoa y su variación sincrónica

Se estudiaron los conjuntos de capas rojas del desierto de La Tatacoa, Huila, Colombia, con el fin de comprobar la presencia de paleosuelos en ellas y de establecer sus propiedades y variabilidad espacial, así como las condiciones ambientales bajo las cuales se formaron. Se comprobó la existencia de paleosuelos alcalinos en las capas rojas inferiores y en las ferruginosas con las siguientes características: horizontes iluviales Bt de color rojo, con estructuraen bloques angulares, bajo contenido de materia orgánica, cútanes y espejos de falla (slickensides), que mostraban translocación de óxidos de hierro y manganeso y de carbonatos de calcio. Además, se observó una gran variabilidad espacial en el espesor y la posición de los paleosuelos con respecto a los lechos líticos. Los procesos pedogenéticos responsables de la evolución de los paleosuelos fueron la iluviación y la lixiviación de arcilla, la mineralización de la materia orgánica, la solodización, la rubefacción, la fersialitización, la carbonatación, el adensamiento y la erosión hídrica. Estos procesos indican que la pedogénesis se llevó a cabo en un clima estacional contrastado en humedad, con una época muy seca seguida de otra muy lluviosa. La presencia de paleosuelos intercalados con capas líticas de granulometría variable sin pedogénesis implica que en la región se presentó una inestabilidad importante en las condiciones climáticas y geomorfológicas durante la época en que se formaron los conjuntos de capas rojas en el desierto. Se concluyó que la liberación de hierro a partir de los minerales primarios y su difusión dentro de la matriz del material geológico, con su posterior oxidación, fue el mecanismo responsable del color dominante tanto de las capas rojas como de los paleosuelos del desierto de La Tatacoa. © 2018. Acad. Colomb. Cienc. Ex. Fis. Nat.

Submarine Deposition of a Subaerial Landslide in Taan Fiord, Alaska

AbstractA large subaerial landslide entered Taan Fiord, Alaska, on 17 October 2015 producing a tsunami with runup to 193 m. We use LiDAR data to show the slide volume to be 76 + 3/−4 million cubic meters and that 51,000,000 m3 entered Taan Fiord. In 2016, we mapped the fjord with multibeam bathymetry and high‐resolution seismic data. Landslide and postlandslide deposits extend 6 km downfjord, are up to 70 ± 11 m thick, and have a total volume of ~147,000,000 m3. Seismic data image a blocky landslide unit and two units deposited immediately after the landslide. The blocky landslide unit is ~65,000,000 m3. We infer it consists dominantly of subaerially derived material and secondarily of fjord floor sediment. The overlying units are likely megaturbidites presumably deposited within minutes to days after the landslide. We infer that these deposits dominantly consist of fjord floor material mobilized and suspended as the slide entered and traveled downfjord. The lower postlandslide unit is up to 35 ± 6 m thick, and the upper unit is up to 12 ± 3 m thick. These deposits are distinctive and will leave a lasting record of the event. This subaerial‐to‐submarine landslide deposit is distinct from other submarine landslide deposits studied in Alaskan fjords because it has a much greater thickness, larger and more angular blocks, distinctive postlandslide megaturbidites, and a higher‐amplitude acoustic signature of the blocky deposit. The tight constraints on the landslide source and deposit volumes, topography, bathymetry, and tsunami runup heights and flow directions should make this a benchmark site for landslide‐tsunami models.

Hominin raw material procurement in the Oldowan-Acheulean transition at Olduvai Gorge

The lithic assemblages at the Oldowan-Acheulean transition in Bed II of Olduvai Gorge, Tanzania, represent a wide variety of raw materials reflecting both the diversity of volcanic, metamorphic, and sedimentary source materials available in the Olduvai basin and surroundings and the preferences of the tool-makers. A geochemical and petrographic systematic analysis of lava-derived archaeological stone tools, combined with textural and mineralogical characterization of quartzite, chert, and other metamorphic and sedimentary raw materials from two Middle and Upper Bed II sites, has enabled us to produce a comprehensive dataset and characterization of the rocks employed by Olduvai hominins, which is used here to establish a referential framework for future studies on Early Stone Age raw material provenancing. The use of rounded blanks for most lava-derived artifacts demonstrates that hominins were accessing lava in local stream channels. Most quartzite artifacts appear to derive from angular blocks, likely acquired at the source (predominantly Naibor Soit hill), though some do appear to be manufactured from stream-transported quartzite blanks. Raw material composition of the EF-HR assemblage indicates that Acheulean hominins selected high-quality lavas for the production of Large Cutting Tools. On the other hand, the HWK EE lithic assemblage suggests that raw material selectivity was not entirely based on rock texture, and other factors, such as blank shape and availability of natural angles suitable for flaking, played a major role in Oldowan reduction sequences.

How to Trace out Impact-Triggered Effects Globally Scattered around Formation Boundaries: Case Uhry, North Germany (Eocene/Oligocene Boundary)

By focusing on impact-triggered phenomena having occurred synchronously with or shortly prior to formation boundaries, two glass sand pits (Upper Maastrichtian) located near Uhry, North Germany have been studied in regard to the K/T boundary throughout the last 40 years during progressive exploitation of glass sand. However, a clastic sequence of sand, mass flow and pelite deposited in a deep channel of about 10 - 12 m in depth, eroded into the glass sand, surprisingly shows an Upper Eocene/Lower Oligocene age, well defined by a Dinocyst assemblage (Chiripteridium c. galea, Enneado cysta arcuata, Areoligera tauloma = D 12na - D 14na) from a 0.5 meter thick pelite that marks the Rupelian transgression within an estuarian system running northwest/southeastward. The section exposes a high energy mass flow and formerly solid frozen angular glass sand blocks of up to a meter-size embedded in fluvial sand of the channel base. Furthermore, erratic clastics of up to 0.4 meter in diameter appear at the pelite base. The “unusual” Dinocyst assemblage is of autochthonous origin and comprises the fresh water alga Pediastrum Kawraiskyias indicator for cold climate, hitherto only known from Quaternary. Missing pollen indicate a vegetation-less hinterland. Thus, there cannot be any doubt that around the E/O b. at least one “rare event” has happened as verified by short tremendous flooding and significant temperature fall (“cosmic winter”). According to the attitude of the global impact scientific community, these phenomena belong to the spectrum of “indirect effects” of major impacts. Radiometric ages of relevant major impact events underline that both impact craters of Popigai, Russia (100 Kilometer in diameter, 35.7 Ma) and Chesabreake, USA (85 Kilometer in diameter, 35.5 Ma) happened shortly before the E/O b.(33.75 Ma). In addition, a tektite strewn field along the eastern coast of the USA and micro-tektites (Gulf of Mexico, Caribbean Sea, Barbados) yield an age of ~34.4 Ma, close to the E/O b. Consequently, there does exist an extremely high probability that Uhry site hosts impact-triggered products at the E/O b. It should be stressed that the Upper Eocene Epoch comprises an amazingly high number of impact events during the time-span 34.2 - 37.0 Ma.

Quartz-Amethyst Hosted Hydrocarbon-Bearing Fluid Inclusions from the Green Ridge Breccia in the Snoqualmie Granite, North Cascades, WA, USA

The Green Ridge Breccia cuts the composite Miocene Snoqualmie Batholith in King County, WA, USA. The granite was emplaced at ~5 km depth between ~17 and 20 Ma and the crosscutting NW trending breccia contains large angular blocks of the host granite (<1 m in longest dimension). The brecciated granite blocks are cemented by quartz-amethyst euhedra (<10 cm in longest dimension) bearing vugs. A notable feature is the presence of centimetric scale amber coloured oil inclusions within the quartz-amethyst crystals. Fluid inclusion studies using Transmitted Light Petrography, UV Microscopy, Microthermometry, Laser Raman Microspectroscopy and Gas Chromatography-Mass Spectrometry record the presence and the fluid composition of three fluid inclusion types hosted by the euhedra: primary Type 1 (liquid rich two-phase (L + V) aqueous inclusions) and secondary Type 2 bituminous two-phase (S + L) inclusions and Type 3 amber coloured oil bearing two-phase immiscible liquid inclusions. The Green Ridge Breccia was the locus for convective hydrothermal fluid flow that formed the quartz-amethyst vugs formed at T~390 °C assuming a trapping pressure of ~1.65 kb. Later, hydrocarbon fluids migrated downwards from the roof source rock (e.g., the Guye Sedimentary Member) and were trapped in the euhedra. This was followed by unroofing of the batholith and exposure of the Green Ridge Breccia. This study highlights the potential for other oil migrations into the Snoqualmie Batholith in areas where it forms the basement capped by the Guye Sedimentary Member.

Occurrence of Unusual Unarmored, Unlithified Fossil Mud Balls in Plio-Pleistocene Lacustrine Sediments, Kashmir, India

AbstractDespite documentation of fossil armored mud balls in the geological record, no fossil unarmored mud balls have been previously reported. Here, we report for the first time the occurrence of fossil unarmored mud balls at two locations from 2.6 Ma lacustrine sediments in the Kashmir basin, India. The two locations are stratigraphically equivalent. At location A, brown mud balls of various shapes and sizes occur with large rounded and angular blocks of brown and gray mud in a random manner, indicating that they were formed quickly by short transport and by the slumping of lake beach cliff, triggered by an earthquake. This conclusion is supported by the presence of slump folds within this mud ball unit. The external morphology and internal structure of these mud balls suggest their growth by rolling over the muddy lake beach in a unidirectional transport by strong tidal waves. The mud balls at location B are gray in color and smaller in size than those at location A. Location B mud balls show high sph...

Multi-granularity geometrically robust video hashing for tampering detection

The wide-spread video editing tools make it much easier to tamper a video, which raises a huge need for authentication techniques that can prove the originality of video content and locate the tampered regions on the video sequences. In this paper, a multi-granularity geometrically robust video hashing method is proposed for tampering detection and localization. In order to balance the robustness and sensitiveness, we describe a video from three levels of granularity: frame sequence level, block level and pixel level, and then hashes are generated at these three levels. Polar Complex Exponential Transform (PCET) moments are calculated on the low-pass sub-band of 3D Discrete Wavelet Transform (3D–DWT) on frame sequence to extract geometric invariant spatio-temporal hash, which is used for video authentication. Local PCET moments are calculated on annular and angular blocks, which are used for geometric correction and coarse tampering localization. Position information of salient objects is obtained from saliency map for fine tampering localization. Experimental results show that the proposed method is robust against temporal de-synchronization and geometrical transformation, and has high tampering localization accuracy even when the video is rotated. Compared with state-of-the-art methods, it is more robust against content-preserving operations and more sensitive to malicious manipulations.

VÝVOJ LEDOVCOVÝCH SEDIMENTŮ NA KONTAKTU S ŽULOVSKÝM MASIVEM VE ŠTACHLOVICÍCH U VIDNAVY

The Žulová Upland is composed of granitoids of the Žulová batholith with relicts of Pleistocene (Elsterian) continental glaciation sediments. The investigated outcrop represents development of glacigenic sediments on rugged topography of the Žulová Upland. Investigated locality is situated on a hill located on the northern margin of the Žulová Upland. It is located near Štachlovice, local part of the Vidnava town. The exposed part of the hilltop reveals a preglacial basement covered by glacigenic sediments. The facies analysis and gravel petrology analysis of clasts with fraction 16–64 mm in b-axis were undertaken on the walls of the outcrop. The Georadar (GPR, Ground penetrating radar) was used to investigate the sedimentary landform and its relation to the basement. The granitoid basement is in places formed by elevations covered by glacigenic sediments. The height of elevation reaches 350 cmin outcrop, or ca ~400 cm according to the GPR survey. The glacitectonite, formed on the gentle side of elevation, is composed of angular blocks of granitoids of the Žulová batholith, diamicton, sand, gravel and deformed glacifluvial sand. The glacitectonite was deposited during the advancement of the continental glacier. The original subglacial cavity is enclosed by a steep side of the elevation. This cavity is filled by foreset body composed of stratified sand and gravel and nonstratified gravelly sand, gravel and diamicton. The cavity was filled by high-density turbidity currents and debris flow in subaqueous-subaerial environment. The infill of the cavity reaches ~400 cm in thickness according to the GPR survey. The cavity was filled during deglaciation in subglacial environment. The glacitectonite underlies the diamicton (supraglacial till) that was deposited as a debris flow during the retreat of the continental glacier. Unsorted gravel overlaps with erosional base the infill of the cavity, this gravel has a huge extent according to the GPR survey. This sediment represents the environment of terminoglacial stream. Gravel material of all types of glacigenic sediments is mainly composed of rocks from the Rychleby Mts. (amphibolites, Gierałtow orthogneiss, other diverse gneisses, quartzites, mica schist),quartz, and Nordic and Polish rocks. Subglacial sediments contain clasts of amphibolites (~40 %), on the other hand supraglacial and terminoglacial sediments are more polymict. Dominant subrounded shape (~60–70 %) of clasts and composition of this material indicates its origin in preglacial fluvial sediments. These fluvial sediments were deposited by river flowing from the Rychleby Mts. towards their northern foreland. The locality represents preglacial elevation of bedrock, which was glacitectonically deformed during the glaciation. Lots of different types of sediments (sub-, supra-, and terminoglacial) were deposited around the elevation during deglaciation period. The elevation was completely buried by these sediments. Deposition of these sediments was related with morphology of the elevation of bedrock. Formation of these sediments took place in environment analogous to environment of part bedrock/part till drumlin (Stokes et al. 2011).

Development of Synthetic Rock Mass Bonded Block Models to Simulate the Behaviour of Intact Veined Rock

Synthetic rock mass (SRM) modelling, based on bonded particle models (BPM), has been successfully used to model jointed and veined rock. BPM models, however, have significant limitations in simulating some key elements of the behaviour of intact rock. In particular, BPMs have difficulties in reproducing the compressive to tensile strength ratio and determining the angle of internal friction characteristic of typical hard rock specimens. Use of bonded block models (BBM), where angular blocks are used in place of spherical particles in BPM, demonstrated improvements in modelling the behaviour of intact rock. However, SRM-style models using BBM have been only used on a limited basis to model foliated and veined rock. In previous applications the BBM based models lacked use of discrete fracture networks which are key in SRM simulations. This paper reports on an original application of bonded block SRM for modelling of intact veined rock and presents the developed methodology for SRM modelling of intact veined rock based on BBM. It has been demonstrated that that BBM models of intact rock are an improvement over modelling of intact rock using BPM. Finally, this paper presents the results of BBM SRM numerical simulations of compressive experiments on intact veined rock under a series of confining pressures.

Multiple subglacial till deposition: A modern exemplar for Quaternary palaeoglaciology

The sedimentology of a vertical succession of alternating beds of massive and fissile diamictons on a þorisjökull plateau icefield outlet foreland is employed to assess the evolution of subglacial traction tills at the margins of active temperate glaciers with deformable substrates, where tills appear to form sub-marginal incrementally thickened wedges that display multiple till emplacement events, potentially of annual scale. Lodged boulders display strong A-axes and surface striae alignments which parallel surface flutings, indicating that fluting construction and till emplacement were related to moulding by consistent glacier flow from the SSW during the Little Ice Age. In contrast, clast macrofabrics at the sub-boulder size, not unlike those reported from other Icelandic tills, are not as strong as would be expected in a subglacially sheared medium, indicating shear strains too low for a steady state strain signature. This separation of fabric data has isolated the strain signatures of the lodgement and deformation components of subglacial traction till, whereby the orientations of the largest, lodged clasts record high cumulative shear strains and those of the sub-boulder sized clasts record greater susceptibility to deformation of their enclosing matrix. This is likely due to the effect of clast collisions in clast rich till and the perturbations set up by the numerous large boulders, consistent with observations on till fabrics in flutings and around lodged clasts. A/B plane macrofabric data display unusually high degrees of isotropy, reflective of the more variable orientations of A/B planes, which are thought to reflect A/B plane susceptibility to dip parallel or anastomosing shear planes. A wide range of clast angularity values reflects the localized input of freshly plucked and hence relatively highly angular blocks to the deforming layer, a characteristic of stepped bedrock profiles beneath the snouts of mountain glaciers. Finally, we hypothesize that the massive and fissile units may represent A and B horizons of subglacial deforming layer couplets, and that each couplet could record seasonal emplacement and partial inter-couplet modification near the ice margin. If the latter is the case, then less than 1 m of subglacial till is advected to the glacier margin per (annual?) deformation event.

Geological Review of the Rafflesia Trail, Near Kampung Jedip, Lojing Highlands: Inputs for a Nature-Based Tourism Site in Kelantan, Malaysia

A geological review was performed in the Rafflesia Trail, near Kampung Jedip, in Lojing Highlands, Kelantan, Malaysia. This area is famous for its Rafflesia and has become one of tourism attractions in the state of Kelantan. However, the recent rampant agricultural activities have significant effects to the area. The objective of this study is to give substantial geological inputs in terms of geomorphology, lithology, structural features, and geohazard potentials in the study area. Desk study was conducted by reviewing some literatures related to the topic and the study area. Field work was organized during a scientific expedition in January 2014 to collect data, samples, and photographs. Geomorphologically, the study area is mountainous area which mostly consists of mountain ridges and mountain valleys. Some fluvial features occur in the study area, such as waterfalls, cascades, rapids, runs, pools, potholes, lateral bars, and point bars. This area is composed of granitic rocks, mostly porphyritic granite, and covered by superficial Quaternary deposits. The geological structure that is commonly found in the study area is joints, where they divide the rock body into large, roughly angular blocks, which is called as brecciation. The potential geohazard in the study area is landslides, where some of them are composed of soil only and some others are mixtures of rock and soil. This study recommends this area should be supported as a sustainable nature-based tourism site in Lojing Highlands, Kelantan.

Contribution of soil properties to the assessment of a seawater irrigation programme as a management strategy for abandoned solar saltworks

The installation of desalination plants close to ecosystems of interest may have environmental impacts that make corrective measures necessary. Especially, wetlands (which are water-dependent ecosystems) are prone to degradation. This is the case for the Agua Amarga salt marsh (SE Spain), that includes an abandoned solar saltworks and surrounding, topographically higher zones, in which the groundwater withdrawal to supply two desalination plants has led to a drop of the piezometric levels and the desiccation of the ecosystem. To overcome these problems, a programme to irrigate the marsh with seawater was established. This paper reports some soil characteristics of the marsh in relation to the different types of vegetation/environment identified and the seawater irrigation programme, with the objective being to propose some guidelines to improve the management of the site. Surface and subsurface samples were taken from 63 plots and the depth of the water level and the soil redox potential (Eh), moisture, electrical conductivity (EC), CaCO3, organic carbon, nitrogen and bulk density were determined. Also, the soil texture, structure, consistence, accumulation of salt crystals and redoximorphic features – indicative of reduction-oxidation processes – were described. The poor structure (weak, granular, subangular and angular blocks, very fine and fine) showed that the soils were hardly developed. The periphery (mainly colonised by Suaeda vera, Lygeum spartum and Limonium spp.) was less saline (EC 1:5 in the upper layers ~0.4 to ~4dSm−1) and drier (water level>−1.5m depth) than the abandoned saline ponds (EC 1:5 in the upper layers ~2 to ~9dSm−1 and water level between −1m depth and +0.2m above the soil surface), mainly colonised by Sarcocornia fruticosa, Arthrocnemum macrostachyum, Salicornia patula, Phragmites australis and Ruppia maritima in the flooded ponds. The soils of the periphery were always oxic (Eh>+500mV), but most of the abandoned saline ponds had suboxic (~+100mV<Eh<~+350mV) and even anoxic conditions (Eh<~+100mV), as shown by the existence of gley colours and redoximorphic features. The soil bulk density of the surface and subsurface layers showed that the most impermeable ponds were located in the centre of the marsh, where it is possible to maintain a surface water sheet during prolonged periods, suitable for the development of submerged plant species such as R. maritima and for waterbirds. Part of the seawater poured into more permeable ponds, such as those located in the southern and northern zones of the marsh, is lost by infiltration due to the lower bulk density of these soils. The latter facilitates the recovery of the piezometric levels and the growth of terrestrial plant species. Monitoring of redoximorphic features in the upper soil layers, in combination with symptoms of damage in the plants, could be used as a visual indicator of oxygen limitation due to excessive soil moisture. This would permit the regulation of the irrigation programme, hence optimising the energy and economic resources applied to maintain the ecosystem.