Edge Of Basin Research Articles

Outburst floods of the Maly Yenisei. Part II – new age constraints from Darhad basin

ABSTRACTSome of the largest cataclysmic floods of the Quaternary followed multiple breaches of glaciers damming the headwaters of the Maly Yenisei river in southern Siberia. The shorelines of the impounded lake in Darhad basin suggest at least four depths of 290, 175, 145, and 65 m. Fossil evidence, together with previous 14C and luminescence dating, indicates the existence of a deep lake during MIS 3; the eroded character of the highest shoreline suggests that the deepest lake was older. 10Be dating of moraines in the surrounding mountains has documented major glacial advances during MIS 2, although no published direct dating has confirmed a highstand of the lake then. To address this problem, we extracted lake sediments from a 92.6 m deep borehole, sampled beach sands from the nearby basin edge, and dated them both using luminescence methods. We also dated, with 10Be, the eroded remnants of the end moraine deposited by the last glacier that dammed Darhad basin, as well as other moraines in the mountains surrounding the basin. These numerical ages confirm that a deep lake existed in Darhad basin at ~20 ka and that a large glacier crossed the Maly Yenisei and dammed Darhad basin at ~21 ka. The deep lake persisted episodically until ~14 ka. The 10Be dating in the surrounding mountains shows that the MIS 2 glaciers subsequently retreated but stalled or re-advanced at ~12, 10, and 1.5 ka. 10Be dating from the central massif of Mongolia is consistent with this chronology and confirms that MIS 3 equilibrium-line altitudes were slightly (~75 m) lower or approximately the same as those of the MIS 2. The temporal and spatial patterns of glacial advances in southern Siberia and central Mongolia coincided with those of glacial advances in similar climate conditions of the Altai mountains.

Unusual, basin-scale, fluid–rock interaction in the Palaeoproterozoic Onega basin from Fennoscandia: Preservation in calcite δ18O of an ancient high geothermal gradient

A variety of carbonates of different geneses, as indicated by petrography and geochemistry, are found throughout 400m of the volcano-sedimentary rocks of the Zaonega Formation of Palaeoproterozoic age in the Onega basin of Fennoscandia. Following intensive sampling and analysis of varied calcites from drillcore recovered during the ICDP FAR-DEEP program, we report a highly unusual depth distribution of calcite oxygen isotope values (δ18Ocal). Unprecedentedly for such rocks, the δ18Ocal values over the full depth interval of 400m are strongly linearly correlated with depth (r2=0.9015, n=178). We propose that this is the result of major oxygen isotope resetting through water–rock interaction with a fluid of relatively constant oxygen isotopic composition (δ18Ow). In this model, the observed linear δ18Ocal-depth relationship is then a consequence of the increase in temperature with depth because of the background geothermal gradient. Minor deviations from the overall linear trend are likely due to bed-scale geological factors including locally high impermeability, and oxygen isotope modification of δ18Ow by comparatively intense water–rock interaction.Were the observed δ18Ocal values to have been reset during the greenschist facies Svecofennian metamorphism which affected the rocks at c. 1800Ma, the implied geothermal gradient of ∼560°Ckm−1 is geologically unreasonable and, accordingly, this hypothesis is ruled out. Rather, the δ18Ocal variation of 5‰ over 400m implies a near-surface depth for the rocks during fluid interaction, and this is consistent with a surface-derived origin of the infiltrating fluid (δ18Ow ∼−13.6‰ for a surface temperature of 15°C and geothermal gradient of ∼52°Ckm−1). It is speculated that the fluid accessed the carbonates from the basin edge by bed-parallel rather than cross-formational flow.There is an intriguing distribution of Na in the sedimentary rocks of the Zaonega Formation. Sodium is relatively abundant in rocks below a certain depth (the lowermost dolostone at ∼258m), but rare in shallower sequences. It is argued that this distribution did not originate with the basin-scale fluid–rock interaction documented above, but may rather be the result of evaporite dissolution, and subsequent redistribution of soluble elements during fluid flow associated with the syndepositional emplacement of basin-wide igneous rocks.

New insights into lithology and hydrogeology of the northern Newark Rift Basin

AbstractThe marginal facies of the Triassic rift basins in the eastern United States are poorly documented, particularly on the hinge or hanging wall margins. This study presents a lithological description and multiscale petrophysical analysis of basement rocks, overlying marginal facies of the early synrift strata, and the basal contact of the Palisade Sill that were drilled and cored in the northeastern part of the Newark Basin, near its terminus. The expression of the Stockton Formation differs from that in the central basin in having thinner layers, with uncertain temporal relationship to the type area. The bottom 50 m is lithologically distinct with brick‐red to dark‐purple mudstones and sandstones, abundant gypsum‐filled fractures, and a thin zone with anomalously high uranium concentration, not associated with organic‐rich mudstones as other occurrences in the basin. The crystalline basement is apparently Fordham gneiss, overlain by a thin sandstone layer and a dark‐purple hydrophilic mudstone. Despite the abundance of coarse‐grained strata and multiple sets of tectonic fractures, hydraulically transmissive zones are sparse, and do not uniquely correlate to fracture and/or matrix characteristics. Enhanced transmissivity may exist along intrusion boundaries due to enhanced thermal fracturing, but more hydraulic data are needed to verify it. Comparison of petrophysical data in two boreholes ∼210 m apart shows no direct correlation of individual lithological units and their hydraulic properties, although the overall formation characteristics are similar. The results highlight challenges for outcrop correlation at the marginal edges of the rift basins and estimating reservoir properties of these heterogeneous formations.

Interaction of geometry and mechanical property of trapezoidal sedimentary basins with incident SH waves

This paper investigated the effects of basin geometry and material property on the response of 2D trapezoidal sediment-filled basin to incident plane SH waves. Ten basin configurations with different geometries were developed, and then their seismic responses to both Ricker wavelets and seismic records were simulated by using an explicit finite difference scheme. The definition of deep/shallow basin, the precondition for the observation of prominent surface waves and the influential area of edge effects of the shallow basin were discussed quantitatively in this study. The followings were concluded: in the common velocity contrast range (v s1/v s2 3.0 can be estimated approximately by 1D theory. The complexity of peak ground acceleration distribution pattern, the width of the most affected section as well as the amplitude of ground motion in the Edge Region increase with incident frequency. Prominent surface waves can only be observed when the incident wavelength is shorter than the critical wavelength λ c . The interaction between incident wave and basin dynamic property plays a dominant role on the peak ground acceleration amplitude while the interaction between incident wave and geometry plays a more significant role on the peak ground acceleration distribution. For very shallow basin, different areas along the basin width are affected to different extents. Only a limited area close to the basin edge is influenced significantly. It is more feasible to propose spectral aggravation factor for different surface zones respectively than a uniform constant as a tool to calibrate the 1D-based design spectrum so as to take the basin effects into account.

Performance evaluation of water collection systems for a hybrid dephlegmator

Trough and basin water collection systems are used in wet-cooling towers and evaporative air-cooled heat exchangers to collect cooling or deluge water below the fill or heat exchanger bundle at the air inlet. Trough systems typically collect water in overlapping parallel troughs while allowing air to pass upwards between the troughs, whereas basin systems collect the water in a basin and the air enters laterally above the basin edge. The novel hybrid (dry/wet) dephlegmator (HDWD) requires a deluge water collection system supported high above the ground. A trough system is therefore considered the best option for this application. Apart from patents, limited information is found on the design and air-side loss coefficients of such systems and how they compare to equivalent basin systems. An existing trough collection system is therefore investigated experimentally to determine its collection effectiveness and drainage capability and to measure pressure drop characteristics. Modifications are made that increase the collection effectiveness from 92% to 100%. Parametric CFD models are developed and used to determine the loss coefficients for the trough and various basin system designs and empirical relations are proposed. A comparison shows that the trough system generally has the lowest loss coefficient and pumping head requirements.

Spatio-temporal distribution pattern of vegetation coverage in Junggar Basin, Xinjiang

Vegetation coverage is an indicator used for exploring the growth of vegetation, which has attracted attention from ecologists owing to its significant role in ecological conservation and restoration. As an important component of the terrestrial ecosystem, changes in vegetation coverage reflect changes in the environment, especially with respect to arid areas. A change of vegetation coverage will trigger desertification, degradation of the eco-environment, and regional climate change. Hence, we studied the spatio-temporal distribution pattern of vegetation coverage and ephemerals in the Junggar Basin during the last few decades based on normalized difference vegetation index. The following conclusions were drawn. The vegetation coverage of the basin shows an overall upward trend, mainly because of the expansion of farmland. In particular, the southern rim has already formed an apparent continuous oasis belt, and the central part of the basin has low vegetation coverage due to a rugged environment but is relatively stable, whereas the northern part has a relatively small oasis distribution pattern. With respect to annual variation, the vegetation coverage of the basin reached the peak in July of every year, whereas the peak in the desert was in May or June; ephemeral plants clearly flourished during this phase. Ephemeral plants were distributed in the whole basin; the most prosperous region was the southern of the basin edge, and the plants decreased gradually from the edge to the center of the basin. The desert area of the central basin was the least prosperous area, but the southern and mid-eastern parts of the desert were prosperous. The expansion of the oasis has mainly had an impact on the 50-km range of the oasis edge, and the greatest impact is at the 5- to 20-km range of the oasis edge.

Approaching mud volcanoes on seafloor -for understanding of MV extruding at Kumano Basin Edge Fault Zone

Approaching mud volcanoes on seafloor -for understanding of MV extruding at Kumano Basin Edge Fault Zone

Source and age of upper Transvaal Supergroup, South Africa: Age-Hf isotope record of zircons in Magaliesberg quartzite and Dullstroom lava, and implications for Paleoproterozoic (2.5–2.0 Ga) continent reconstruction

The Magaliesberg Formation quartzite of the upper Transvaal Supergroup in north-central South Africa represents the biggest Paleoproterozoic arenite deposit on Earth, with a present-day lateral extent of more than 600km. It therefore has a great potential to provide detailed information about Archean to early Paleoproterozoic crust–mantle evolution in the hinterland of the Kaapvaal Craton and for global plate tectonic reconstruction. Detrital zircons in Magaliesberg Formation quartzites provide evidence for magmatic activities in the source region at 2080–2130Ma (11%), 2220Ma (35%), 2350–2450Ma (8%) and, following an age gap of ca. 200millionyear, at 2650–2780Ma (11%), 2820–2910Ma (25%), and at 3060–3100Ma (6%). Minor zircon formation took place during Bushveld Complex contact metamorphism at 2055Ma, and less than 3% underwent a post-Bushveld age reset. Detrital zircons in a sediment-rich Dullstroom lava yield similar ages between 2120±12Ma and 2865.2±1.7Ma, indicating that Magaliesberg and post-Magaliesberg/Dullstroom sediments were derived from the same sources, and deposited between 2080 and 2055Ma. Distinct age spectra among the investigated quartzites indicate that the sandstone detritus was derived from different sources and rapidly deposited without complete homogenization, in a regressive shore line, braid-delta environment.Combined Hf isotope-age data reveal two distinct groups of zircon. Zircons of group I have Archean ages (>2.65Ga), and define a crustal array that points to protracted crust reworking in the hinterland between 3.10 and 2.65Ga. Likely sources for these zircons are granitoids of the Pietersburg Block, which is located at the northern edge of the Transvaal basin. Zircons of group II have Paleoproterozoic ages between 2.45 and 2.08Ga. They are mostly subchondritic, and show highly variable εHft between +4 and −19. These large variations hint to their formation in a magmatic arc and/or collisional setting. As granitoids with ages between 2.65 and 2.06Ga are absent on the Kaapvaal Craton, detrital zircons of such ages must have been derived from sources outside of the present-day craton. One potential source could be the Ophthalmia orogenic belt, which became amalgamated to the joined Kaapvaal–Pilbara and perhaps Zimbabwe cratons (Zim)vaalbara at 2.22–2.14Ga, whereas coeval magmatic rocks in southern America (e.g., Minero Belt of the Sao Francisco Craton) or West Africa can be excluded, as they were mostly derived from depleted mantle sources in oceanic environments. Abundant occurrence of detrital zircons with ages of 2.5Ga in the lower Pretoria Group (Duitschland Formation), but their complete absence in the upper Pretoria Group (Magaliesberg Formation), hint that (Zim)vaalbara was attached to an early Paleoproterozoic orogenic belt, which disappeared completely between 2.3 and 2.08Ga, most likely by cratonic break up.

Weak dissipative effects on trajectories from the edge of basins of attraction

The purpose of this work is to present convergence properties of regular and chaotic conservative trajectories under small dissipation. It is known that when subjected to dissipation, stable periodic points become sinks attracting the surrounding trajectories which belong to rational/irrational tori, while chaotic trajectories converge to a chaotic attractor, if it exists. Using the standard map and a mixed plot we show that this simple scenario can be rather complicated and strongly depends on the dissipation intensity. For small dissipations the huge amount of attractors of the phase-space generates a complicated and intricate dynamics where trajectories are steered to their attractors based on the local (non)hyperbolicity, measured by the Lyapunov vectors. Dissipation creates holes (or attracting channels) on the torus from the conservative limit and allows trajectories to penetrate it. These holes are regions of large local hyperbolicity and are related to sticky channels reported recently. For stronger dissipation sinks tend to attract all trajectories, prevailing over the chaotic attractor.

Geodinámica de los márgenes conjugados del Atlántico Sur central: implicaciones para el potencial de hidrocarburos

Using a new margin restoration model for the central South Atlantic we highlight margin-opposed rift basin subsidence characteristics, reconcile important facies relationships and consider the associated processes responsible for contrasting basinward transitions to oceanic crust. We interpret these parameters as diagnostic of strain evolution during rifting. Pre-salt subsidence patterns and sequence isopachs of late syn-rift and early post-rift sequences are symptomatic of these complex extension behaviours. Inherited basement fault trends partition extensional strain during stretching with resultant rift-related structural styles recording the heterogeneity of the pre-rift crust. Correspondingly the seismic and gravity expression of the transition from continental crust to oceanic crust differs systematically along the length of the ‘conjugate’ basins. The presence of a conspicuous coast parallel positive linear gravity anomaly, referred to as the ‘terminal horst’, defines the basinward extent of attenuated continental crust in the more symmetrical Campos Basin and its interpreted conjugate. In the ‘asymmetrical’ Santos and Benguela Basins the ocean–continent transition at the present-day OCB (ocean–continent boundary) becomes equivocal with little gravity expression. Consequently the relationship of primary salt basin edges to the basinward extent of crustal extension appears more complex. Pre-existing crustal and lithospheric mantle scale heterogeneities are considered to impart a first-order control on whole crust deformation and ultimately ‘sag’ basin development. These structurally defined heterogeneities are believed to partition crustal strain and juxtapose endmember mechanisms of pure-shear and simple shear deformation styles as recorded by the complex distribution of syn-rift subsidence patterns within the pre-salt basins of the central South Atlantic. These conclusions challenge the necessity for invoking dominantly depth-dependent processes as a mechanism to explain apparent pre-salt, syn-rift subsidence anomalies. The complex interplay of structure and stratigraphy with an overlay of palaeoclimatic models provides important insights into hydrocarbon play fairways along the margin. In particular the impact on reservoir and source rock distribution and heat flow are discussed.

Dynamics inside the cancer cell attractor reveal cell heterogeneity, limits of stability, and escape

The observed intercellular heterogeneity within a clonal cell population can be mapped as dynamical states clustered around an attractor point in gene expression space, owing to a balance between homeostatic forces and stochastic fluctuations. These dynamics have led to the cancer cell attractor conceptual model, with implications for both carcinogenesis and new therapeutic concepts. Immortalized and malignant EBV-carrying B-cell lines were used to explore this model and characterize the detailed structure of cell attractors. Any subpopulation selected from a population of cells repopulated the whole original basin of attraction within days to weeks. Cells at the basin edges were unstable and prone to apoptosis. Cells continuously changed states within their own attractor, thus driving the repopulation, as shown by fluorescent dye tracing. Perturbations of key regulatory genes induced a jump to a nearby attractor. Using the Fokker-Planck equation, this cell population behavior could be described as two virtual, opposing influences on the cells: one attracting toward the center and the other promoting diffusion in state space (noise). Transcriptome analysis suggests that these forces result from high-dimensional dynamics of the gene regulatory network. We propose that they can be generalized to all cancer cell populations and represent intrinsic behaviors of tumors, offering a previously unidentified characteristic for studying cancer.

Numerical study on basin-edge effects in the seismic response of the Gubbio valley, Central Italy

The Gubbio basin in Central Italy is a intermountain basin of extensional tectonic origin, typical of Central and Southern Apennines, characterized by moderate seismicity. The strongest recorded event within the area is a magnitude 5.7 earthquake which occurred on 29 April 1984 along the Gubbio fault, bordering the eastern side of the basin. The main objective of this study is to analyze the features of earthquake ground motion as related to basin-edge effects, by performing physics-based numerical simulations of the 1984 earthquake through a high-performance spectral element code. The simulated ground motions are found in reasonable agreement with the recorded motions when using the kinematic source model developed by Ameri et al. (Bull Seismol Soc Am 99:647–663, 2009), with a rise-time equal to 1 s and a nucleation point located in the middle of the fault. Pronounced differences were noted between records from the basin and adjacent sites at outcropping bedrock, owing to both the strong impedance contrast between soft alluvial sites and bedrock formations (lithostratigraphic amplification), as well as lateral discontinuities related to the 2D/3D geometry of the basin (generation of surface waves). Since the fault was located beneath the basin, 1D amplification effects were found to be more relevant than those associated with the generation of surface waves from the basin edge. Finally, an envelope delay spectrum was computed for the simulated ground motions, showing that surface waves are excited in the frequency band of 0.2–0.8 Hz with a significant increase of ground motion duration within the basin.

Provenance of Pliocene clay deposits from the Iberian Atlantic Margin and compositional changes during recycling

The XRD mineralogy and geochemistry of recycled fine-grained deposits from the West Iberia Atlantic Margin are used to establish sediment provenance and evaluate the features that most closely reflect the nature of the source areas and the transformations during the last depositional cycle. A set of Pliocene sediment samples is organized according to grain size distribution, geochemistry, and mineralogy, and their chemical composition is compared with the composition of possible source rocks. Most deposits located to the north of the Mondego River were derived from the uplifted Precambrian metapelites of the basin edge, while to the south of the Mondego River they result mainly from recycling of Cretaceous and Cenozoic clastic units, which, in turn, were derived from Precambrian–Paleozoic granitoids and metasedimentary rocks. This differentiation is supported by several element ratios and biplots involving La, Sm, Gd, Sc, Th, U, Y, Yb, and Zr. For the specific grain size range of the deposits studied, which are mainly made up of silt and clay particles, composition is not substantially affected by the grain size distribution of the sediment. Multi-element diagrams designed to discriminate the tectonic setting and the nature of source rocks are of little use in the interpretation of provenance but help to trace geochemical and mineralogical transformations during the last depositional cycles. Despite the evidence of element leaching during the Pliocene depositional cycle, the geochemical and mineralogical indicators of weathering intensities are largely determined by the nature of the previous cycle units.

Effects of lateral variations in megaregolith thickness on predicted lunar seismic signals

AbstractWe use a modified phonon synthetic seismogram method to investigate the effects of laterally varying megaregolith thickness on the propagation of seismic energy and on the resulting seismic signals recorded at various epicentral distances from the source. We show that receivers located in large impact structures, with thin crust and thinner megaregolith, can record seismic signals that are less affected by high levels of scattering. In particular, receivers located away from the basin edge by a distance greater than or equal to the thickness of the surrounding megaregolith can record seismograms in which secondary arrivals containing important information about interior structure can be more readily identified. Seismic sources located beneath the near‐surface scattering layer, such as deep lunar quakes, are also advantageous because the resulting seismograms are less affected by high levels of scattering than those from sources within the scattering layer or surface impacts.

Directional dependence of site effects observed near a basin edge at Aegion, Greece

We study site effects using 520 weak motion earthquake records from a vertical array in Aegion, Greece. The array is inside a basin, has four stations in soil, and one in bedrock (178 m depth). The site is marked by high seismicity and complex surface geology. We first use the records to establish the downhole accelerometer orientations and their evolution with time. Then we estimate site effects using empirical spectral ratios with and without a reference site (standard and horizontal-to-vertical spectral ratio). We find significant site amplification which cannot be accounted for by 1D model predictions, along with a significant difference in the amplification level between the two horizontal components. These are indications of 2D effects, namely surface waves generated at the basin edge. The difference in amplification between the horizontal components is maximised when these are rotated with respect to the orientation of the basin edge. The strongest amplification takes place in the direction parallel to the basin edge (SH, or out-of-plane motion), and is up to 2 times higher than in the perpendicular direction (SV, or in-plane motion). This directional effect on the amplification is corroborated by numerical 2D modelling using incident SH and SV waves, with the former possibly generating strong Love waves. In the records, the directionality is clear for windows containing the largest amplitudes of the records (S waves and strong surface waves), while it tends to vanish for coda-wave windows. This directionality is also observed when using response spectral ratios rather than Fourier ratios. We compute soil-to-rock amplification factors for peak ground acceleration (PGA) and find it is significantly higher than what is predicted by current design codes. We attribute this difference to the basin edge amplification, linear soil behaviour, and to the inability of simple scalar values like PGA to describe complex amplification effects. Finally, we analyse the earthquake records at a surface station near the slope crest and do not observe significant topographic amplification.

Three-dimensional simulations of strong ground motion in the Shidian basin based upon the spectral-element method

The strong motion of a small long and narrow basin caused by a moderate scenario earthquake is simulated by using the spectral-element method and the parallel computing technique. A total of five different geometrical profiles within the basin are used to analyze the generation and propagation of surface waves and their relation to the basin structures in both the time and frequency domain. The amplification effects are analyzed by the distribution of peak ground velocity (PGV) and cumulative kinetic energy (Ek) in the basin. The results show that in the 3D basin, the excitation of the fundamental and higher surface wave modes are similar to that of the 2D model. Small bowls in the basin have great influence on the amplification and distribution of strong ground motion, due to their lateral resonances when the wavelengths of the lateral surface waves are comparable to the size of the bowls. Obvious basin edge effects can be seen at the basin edge closer to the source for constructive interference between direct body waves and the basin-induced surface waves. The Ek distribution maps show very large values in small bowls and some corners in the basin due to the interference of waves propagating in different directions. A high impedance contrast model can excite more surface wave modes, resulting in longer shaking durations as well as more complex seismograms and PGV and Ek distributions.

Fore-arc basin deformation in the Andaman-Nicobar segment of the Sumatra-Andaman subduction zone: Insight from high-resolution seismic reflection data

The Andaman-Nicobar region is the northernmost segment of the Sumatra-Andaman subduction zone and marks the western boundary of the Andaman Sea, which is a complex active back-arc extensional basin. We present the interpretation of a new set of deep seismic reflection data acquired across the Andaman-Nicobar fore-arc basin, from 8°N to 11°N, in order to better understand its structure and evolution, focusing on (1) how obliquity of convergence affects deformation in the fore arc, (2) the nature and role of the Diligent Fault (DF), and (3) the Eastern Margin Fault (EMF). Despite the obliquity of convergence, back thrusting and compression seem to dominate the Andaman-Nicobar fore-arc basin deformation. The DF is primarily a back thrust and corresponds to the Mentawai and West Andaman Fault systems farther in the south, along Sumatra. The DF is expressed in the fore-arc basin as a series of mostly landward verging folds and faults, deforming the early to late Miocene sediments. The DF seems to root from the boundary between the accretionary complex and the continental backstop, where it meets the EMF. The EMF marks the western boundary of the fore-arc basin; it is associated with subsidence and is expressed as a deep piggyback basin, containing recent Pliocene to Pleistocene sediments. The eastern edge of the fore-arc basin is the Invisible Bank (IB), which is thought to be tilted and uplifted continental crust. Subsidence along the EMF and uplift and tilting of the IB seem to be related to different opening phases in the Andaman Sea.

Calculation of Geodiversity from Landscape Units of the Cadeado Range Region in Paraná, Brazil

This work aims to carry out a quantitative evaluation of geodiversity in a unit of Cadeado Range, Parana state, Brazil, on the eastern edge of the Parana sedimentary basin. We identified and defined eight compartments or landscape units using an integrated analysis of the set of elements of their geoecological structure: geomorphological, geological, pedological, hydrologic, and socioeconomic features. We made a quantitative evaluation of the abiotic elements of the landscape, aiming to understand the spatial distribution of geodiversity. To this, we applied the calculation of geodiversity index proposed by Serrano and Ruiz-flano ((62):1–8, 2007), in order to determine the geodiversity richness index for each compartment, as well as the distribution or relative frequency of the elements. It was possible to demonstrate that compartments with a wider territorial area do not necessarily hold a greater richness index and that compartments with greater richness area do not necessarily shelter a better equability or relative frequency among elements. Therefore, areas with a higher geodiversity index are associated with a balance between element distribution in a given area and its richness. We believe that this method can inform future studies to compare rates of geodiversity and biodiversity in the territory with a nature conservation aim.

Active transform fault zone at the fringe of the Dead Sea Basin

The evolution of an asymmetric basin at the edge of a pull-apart structure is studied using geophysical observations and mechanical modeling. A new seismic analysis of the northern edge of the Dead Sea basin indicates recent subsidence, folding and oblique faulting along the Jericho strike-slip fault; a main segment of the Dead Sea Transform fault. The subvertical fault trace crosses the entire sedimentary sequence typically branching in the shallow subsurface. The seismic analysis reveals the three-dimensional structure of the area as an asymmetrical basin bordered on the east and on the west by long monoclinic folds. The thickness of the sedimentary fill varies from ~ 1.4 km near the present lake shores to a few hundreds of meters about 10 km northward. The subsidence is partitioned between a vertical component of slip along the Jericho Fault and the simultaneously active monoclines bordering the basin. We present a model and simulations that reconstruct the present basin structure in the uppermost part of the crust and demonstrates the generation of flexures along the basin margins without horizontal shortening. We show that the basin asymmetry and the association of folds and fault can be explained as a long-term ductile response of the sediments to local subsidence. The asymmetry along the basin is a consequence of a later vertical displacement component on a pre-existing strike-slip fault. Our analysis points to ongoing northward propagation of the Dead Sea basin and provides an explanation for the structural asymmetry of the basin margins.

Three Dimensional Deformation of Mining Area Detection by InSAR and Probability Integral Model

Abstract. A new solution algorithm that combined D-InSAR and probability integral method was proposed to generate the three dimensional deformation in mining area. The details are as follows: according to the geological and mining data, the control points set should be established, which contains correct phase unwrapping points in subsidence basin edge generated by D-InSAR and several GPS points; Using the modulus method to calculate the optimum parameters of probability integral prediction; Finally, generate the three dimensional deformation of mining work face by the parameters. Using this method, the land subsidence with big deformation gradients in mining area were correctly generated by example TerraSAR-X images. The results of the example show that this method can generate the correct mining subsidence basin with a few surface observations, and it is much better than the results of D-InSAR.