Jon Mosar

Université de Fribourg · Department of Geosciences

In foreland fold-and-thrust belts, the distribution of deformation and of the associated stress field can notably be perturbated due to local-scale features such as tectonic structures or surface topography. In the frame of geothermal exploration in the Geneva Basin, constraining possible future deformation in the area and the associated state of s...

In this paper we explore the stress orientation and magnitudes of the Greater Geneva Basin in the detached Alpine Foreland in Switzerland and France. The interpretation is based on shallow earthquake focal mechanisms from strike-slip faults. The area of investigation comprises the westernmost Molasse Basin, the Vuache mountain range formed by the V...

The northern deformation front of the European Alps, i.e. the northern limit of Alpine thrusting, is characterized by structural variability along strike. It can be subdivided into four regions: the deformation front in (i) France and Switzerland, (ii) western Austria and Bavaria, (iii) eastern Bavaria, Salzburg and Upper Austria, and (iv) Lower Au...

The balancing technique, called 2D kinematic forward modelling, is a powerful tool to understand the kinematic evolution of fold-and-thrust belts. This study presents a new 2D kinematic forward model for the westernmost Internal Jura fold-and-thrust belt (FTB), situated immediately adjacent to the Geneva Basin. The technique used not only provides...

The paper presents the results of the U-Th-Pb isotope system study of the accessory zircon from the basalts of the Ghoithsk volcanic region (GVO) of the Western Caucasus. The sample for isotope dating was taken from basalt porphyrites of the Chataltapa volcanic complex, in the Tuapse River basin. It was shown by using of the ion microprobe isotope...

The arcuate Jura Mountains Fold-and-Thrust Belt (FTB) is situated in the NW Alpine Foreland and its formation is related to the Alpine orogeny. The western part of the Jura FTB, investigated here, is situated in France to the north of the Geneva Basin (Switzerland). The geothermal project "GEothermie2020" of the larger Geneva area allowed us to rea...

The Greater Caucasus doubly-vergent orogenic system has its origin in a Mesozoic-Early Cenozoic back-arc-type basin, floored by an extensively stretched and heavily intruded continental crust that has subsequently been inverted. Our field investigations along the Georgian Military Road in the eastern Central Greater Caucasus provide insights in its...

Lake Afdera is a hypersaline endorheic lake situated at 112 m below sea-level in the Danakil Depression. The Danakil Depression is located in the northern part of the Ethiopian Afar and features an advanced stage of continental rifting. The remoteness and inhospitable environment explain the limited scientific research and knowledge about this lake...

Pre-existing faults in the mechanical basement are believed to play an important role in controlling deformation of the thin-skinned Jura Mountains fold-and-thrust belt, which constitutes the northernmost extension of the European Alps. We use brittle-viscous analogue models to investigate the influence of frontal and oblique basement steps on the...

We present insights into the Cenozoic tectonic evolution of the region around the Pontarlier strike‐slip fault zone within the Jura fold‐and‐thrust belt by combined study of paleostress and geomorphic analyses. A preliminary separation of heterogeneous fault‐slip data and bedding‐tilt correction was performed before determining the paleostress axes...

Results from isotope dating of the Greater Caucasus crystalline basement in the Elbrus subzone of the Main Caucasus Range inside of the HT gneiss-migmatite area of the Gondaray Metamorphic Complex is discussed herein. The measurements of the zircons isotope composition were performed on the ion microprobe SHRIMP-II at the CIR VSEGEI (St. Petersburg...

Being a part of ongoing continental collision between the Arabian and Eurasian plates, the Caucasus region is a remarkable site of moderate to strong seismicity, where devastating earthquakes caused significant losses of lives and livelihood. In this article, we survey geology and geodynamics of the Caucasus and its surroundings; magmatism and heat...

This study focuses on a geological section in the Jura Mountains across the villages of Travers, La Brévine in Switzerland, and Morteau in France. Field mapping was conducted to complement and densify existing data. A kinematically and geometrically consistent forward model has been developed to understand and interpret the observed surface structu...

This work focuses particularly on the geomorphological evidence for the tectonic controls on the development of the present-day fluvial landscapes in the westernmost part of Switzerland. The tectonic deformation was evaluated on the basis of a combined analysis of several classical geomorphic indices (hypsometric curves and integrals, transverse to...

The Loki massif is located near the southern border of Georgia and is large anticline structure of E-W oriented extension. The most ancient formations of the massif are crystalline schists outcropping along western, northern and southern peripheries of the massif. Crystalline schists are penetrated by granites and divided in two age complexes, Pale...

Main features of geological structure and a new tectonic map of Georgia

Tectonics in the Greater Caucasus (Georgia – Russia): From an intracontinental rifted basin to a doubly verging fold-and-thrust belt

Tectonics of the Greater Caucasus: from rifting to collision

Alpine tectonics of the Greater Caucasus: a review

Main features of geological structure and a new tectonic map of Georgia

Plain Language Summary The southern slope of the Greater Caucasus mountains is the site of a former rift basin. In order to explain shortening deficits, plate deceleration, and the ~5 Ma reorganization of the Arabia‐Eurasia collision zone Cowgill et al. (2016) proposed that this basin closed ~5 Myrs ago. Within the western Greater Caucasus, at leas...

For this pilot study we used recorded seismic events from the SED permanent network and data from a dedicated SNS network to improve the seismotectonic understanding of very weak seismicity in the vicinity of the Mont Terri underground laboratory. We combined field data on faults with microseismic events and modelling of stress and focal mechanisms...

A revised compilation of thickness maps of the main décollement zone of the Alpine foreland beneath the Jura fold-and-thrust belt (FTB) and the Swiss-French Molasse Basin is discussed. The décollement zone is located in the Muschelkalk and Keuper units (Middle-Upper Triassic). Strain is partitioned between several décollement levels and the brittle...

Species of the genus Porosononion from Sarmatian deposits of Georgia and their stratigraphic significance

Continental Europe has a long history of deformation since Paleozoic times. Prominent witnesses are the Permo-Carboniferous grabens or the Eocene-Oligocene European Cenozoic Rift System (ECRIS) with the Bresse Graben (BG) and Upper Rhine Graben (URG) bordering the Jura Mountains. In conclusion, Europe was extensively pre-structured when the sedimen...

Seismic hazard assessment of slow active fault zones is challenging as usually only a few decades of sparse instrumental seismic monitoring is available to characterize seismic activity. Tectonic features linked to the observed seismicity can be mapped by seismic imaging techniques and/or geomorphological and structural evidences. In this study, we...

For this pilot study we used recorded seismic events from the SED permanent network and data from a dedicated SNS network to improve the seismotectonic understanding of very weak seismicity in the vicinity of the Mont Terri underground laboratory. We combined field data on faults with microseismic events and modelling of stress and focal mechanisms...

Structural inheritance of preexisting crustal discontinuities is widely accepted to have played a crucial role during the Cenozoic tectonic evolution of the northern Alpine foreland. It is recognised as a process that can strongly influence local fault kinematics and strain patterns. The case study presented herein is dedicated to the tectonic anal...

Obtaining robust event catalogs in regions of low seismicity can be timeconsuming, because quality events are less frequent and sensor coverage is generally sparse. Optimizing event detection and location in such regions is all the more crucial because these areas tend to host a higher density of sensitive infrastructures. The methodology proposed...

The Greater Caucasus (GC) results from the rotational convergence of the Arabian and Eurasian plates. It forms a doubly vergent orogen with a dominant thrust direction top-to-the south. Both, to the N and the S the orogen active foreland-fold-and-thrust belts propagate into their flexural foreland basins. The orogen extends from the Black Sea in th...

The SED (Swiss Seismological Service) recently reported 30 earthquakes close to the city of Biel. The seismic activity was clustered in periods of a few days – weeks in January 2014 and January-February 2015. Two events reaching local magnitudes above ML 3 were largely felt by the local population. With the aim to complete the catalog in the lower...

Abstract We report new observations in the Eastern Black Sea-Caucasus region that allow reconstructing the evolution of the Neotethys in the Cretaceous. At that time, the Neotethys oceanic plate was subducting northward below the continental Eurasia plate. Based on the analysis of the obducted ophiolites that crop out throughout Lesser Caucasus an...

Key dynamics influencing unstable slope mass movements can be investigated with the most precise timing by seismic monitoring, which brings a unique insight into the mechanisms driving the slope movement. Recently, a newly developed method named nanoseismic monitoring (Joswig, 2008) enabled the observation of various landslide induced seismic event...

Since April 2014, two mini-array seismographs (Seismic Navigating System / SNS) [Joswig, 2008] were installed in the Mont Terri underground rock laboratory to monitor seismic activity in the vicinity of the laboratory in St-Ursanne (JU). Two additional SNS were installed respectively on July and September 2015 at the surface near the area of the ro...

The samples from Gorastskali gorge section were investigated from a nannofloral viewpoint. To this date studies of the rock samples from this section have indicate the lacking of calcareous nannofossils. However, a new sampling and in depth investigation has documented a complex association of calcareous nannofossils including Crucirhabdus minutus...

Combining field observations, cross-section area balancing techniques and kinematic forward modelling , we present new insights into the evolution of the Jura fold-and-thrust belt in the Chasseral area between Lake Biel and the Vallon de St-Imier, in the Canton of Bern, Switzerland. Our results show that the structures of the Chasseral area and the...

The Fribourg Lineament (FL) is a 30 km long N-S cluster of weak seismic activity (ML < 4.3). It is located in the Western Swiss Molasse Basin, east of Fribourg. Three series of events, which took place in 1987, 1995 and 1999 were located in the sedimentary cover at a depth of 2 km but identified as related to deep reaching structures carrying in si...

The area of Bulle is located in the frontal part of the allochtonous Préalpes Klippen belt of western Switzerland, between SE-dipping imbricates of the Subalpine Molasse to the North and the overriding Préalpes Médianes to the South. The Bulle area is structured by two major tectonic elements: [i] a NE-SW trending, SE-dipping thrust system affectin...

We used nanoseismic monitoring (NM) techniques (Wust-Bloch & Joswig 2006, Joswig 2008) to characterize local microseismicity generated within the Fribourg area (Switzerland). NM takes advantages of mini-arrays and advanced signal processing techniques to optimize seismic event detection and location: (1) SNR conditions are maximized by deploying po...

An increased level of local microseismicity was recorded over the past decade within the Fribourg region (Kastrup et al., 2007). Since 2010, two portable sparse mini-arrays were deployed to enhance seismic monitoring capabilities in that area. The waveforms recorded by these arrays, together with those recorded by local stations of the Swiss Seismo...

The Swiss and German Molasse Basin is generally of high geo-economical interest as it is considered to host potential reservoirs for natural gas and geothermal energy production, as well as sites for radioactive waste disposal and CO2 storage. Its successful exploration and eventually exploitation requires detailed understanding of its deep undergr...

This study investigates low-magnitude seismicity generated within the Fribourg area (Western Molasse Basin – Switzerland (Fig 1)). It focuses on the Fribourg Lineament (FL), a North-South trending cluster of weak earthquakes that were generated East of the city of Fribourg and may be associated to the lineament described by Kastrup et al. (2007). V...

This analysis investigates low-magnitude seismicity generated within the Fribourg area (Western Molasse Basin (WMB) - Switzerland). It focuses on the Fribourg Lineament (FL), an alignment of weak seismicity that showed recent signs of increased activity (KASTRUP et al., 2007). The FL runs in a North-South direction east of the city Fribourg and is...

The Swiss Molasse Basin is located to the North of the Subalpine Molasse and the Prealpes Klippen belt, and is forming along its northern edge an erosive limit with the first fault-related folds of the Jura fold-and-thrust belt (JFTB). Originally the Molasse Basin extended farther north into the JFTB as documented by the numerous Molasse occurrence...

This study presents an analysis of microseismicity in the Fribourg area (Western Swiss Molasse Basin), a region that has recently displayed increased microseismicity (KASTRUP et al., 2007). Arrival time data of these earthquakes were used in a non-linear probabilistic earthquake relocation approach and to refine an existing three-dimensional (3-D)...

As part of two joint PhD projects, we study the low-magnitude seismicity in the Fribourg area (Switzerland) with special focus on the Fribourg Lineament (KASTRUP et al., 2007) (Figure 1). Since the beginning of 2010, the Fribourg Lineament has been monitored by two seismic navigating systems (SNS), consisting each of one central 3D sensor surrounde...

Diem M., Gruber M., Ibele T. & Mosar J., 2012. The Broye Graben System: a tectonically active graben in a compressional environment. Bulletin de la Société vaudoise des Sciences naturelles 93.1: 13-20. The identification of normal faults affecting deltaic sediments of Pleistocene age in a gravel pit near Granges-près-Marnand suggests a recent norma...

As part as two joint PhDs, we monitor and study the seismicity of the Fribourg Lineament. The Fribourg Lineament or Fribourg Zone is represented by an alignment of weak seismicity that seems to show recent signs of increased activity (KASTRUP, 2007). The lineament runs in a South-North direction west of the city of Fribourg - Switzerland, and is pa...

As part of two joint PhDs, we study the very small seismicity along the Fribourg Lineament and in the larger Fribourg area. The Fribourg Lineament or Fribourg Zone is represented by an alignment of weak seismic events that seems to show recent signs of increased activity (Kastrup 2007). The lineament runs in a South-North direction west of the cit...

We present a synoptic overview of the Miocene-present development of the northern Alpine foreland basin (Molasse Basin), with special attention to the pattern of surface erosion and sediment discharge in the Alps. Erosion of the Molasse Basin started at the same time that the rivers originating in the Central Alps were deflected toward the Bresse G...

Ce document présente une comparaison des logiciels de simulation de chutes de blocs RocFall, RockFall Analyst et PiR3D basée sur l'observation des réactions des logiciels aux variations des paramètres d'entrée qu'ils ont en commun, soit les coefficients de restitution et l'angle de frottement/coefficient de glissement des sols. Les réponses des log...

Located between the Jura mountains to the North and the Alps to the South the larger Fribourg region has been, possibly since Oligocene, and is still subjected to compressive stresses resulting from the alpine orogenic processes. The subsurface geology of the Fribourg area is basically a layer cake with 3 main levels: the Tertiary Molasse sediments...

In the Lesser Caucasus three main domains are distinguished from SW to NE: (1) the autochthonous South Armenian Block (SAB), a Gondwana-derived terrane; (2) the ophiolitic Sevan–Akera suture zone; and (3) the Eurasian plate. Based on our field work, new stratigraphical, petrological, geochemical and geochronological data combined with previous data...