Geološki anali Balkanskoga poluostrva

The Bulog Formation in the type area (Sarajevo) and related Middle and Late Triassic open-marine sedimentary successions in the Dinarides of Bosnia and Herzegovina

2025-07-15T09:29:18+00:00

The type area of the Bulog Formation in the area of Sarajevo is revisited in order to solve the still open question of the palaeogeographic provenance of the type-section of the late Pelsonian-Illyrian Bulog Formation and other related Middle Triassic and also Late Triassic open-marine sedimentary sequences. We revisited the type-section and re-evaluated existing data from several known Middle Triassic Bulog Limestone-bearing successions and the Late Triassic Hallstatt Limestones around Sarajevo. Besides their uniform underlying, that are the Middle Anisian (Pelsonian) shallow-water limestones of the Ravni Carbonate Ramp we studied especially their overlying sedimentary sequences and compared these sequences with other related Middle-Late Triassic sedimentary successions in Bosnia and Herzegovina. In addition, we studied some new sections in the area of Sarajevo resp. Bosnia and Herzegovina to compare the type area in an over-regional scale. The result shows a parautochthonous position of the type-locality in the palaeogeographic realm of the later East Bosnian-Durmitor megaunit like several other related successions not only in Bosnia and Herzegovina, also in Serbia and Montenegro. The type-section of the Bulog Formation is overlain by limestones of the prograding Wetterstein Carbonate Platform that means the Bulog Formation was deposited in a central shelf area where later the Early Carnian Wetterstein Carbonate Platform and the Norian-Rhaetian Dachstein Carbonate Platform evolved. Other sections of the Bulog Formation in the area of Sarajevo belong to the dismembered Hallstatt Limestone succession that means they were transported from the outer shelf to their actual position during the Middle-Late Jurassic orogenesis. On the basis of these results and the end of a more than hundred years lasting controversial discussion the way is now open for 1) a stable lithostratigraphic nomenclature for the entire Triassic of the Inner Dinarides to at least the East Bosnian-Durmitor megaunit, and for 2) a reliable time-space reconstruction of the Middle Triassic opening history of the Neo-Tethys Ocean, and 3) a palaeogeographic restauration of the Dinaridic segment of the Triassic western passive continental margin of the Neo-Tethys. In addition, the ?latest Illyrian to latest Longobardian Grabovik Formation, deposited above the Bulog Formation and below the evolving Early Carnian Wetterstein Carbonate Platform, is emended and formalized. Furthermore, we demonstrate, that the dismembered Hallstatt Limestone succession derive from the outer shelf and is part of the allochthonous and far-travelled Zlatar (Hallstatt) Mélange overlain by an ophiolitic mélange, described here for the first time from the Sarajevo area.

Stratigraphy and structural position of the type locality of Phasoula Formation (Upper Triassic, southwestern Cyprus)

2025-07-15T09:29:19+00:00

The Upper Triassic Phasoula Formation in its type locality in Dhiarizos River valley is interpreted as a large tectonic block incorporated in the Upper Cretaceous Mamonia Mélange. Volcanics of the Phasoula Formation are dated as Upper Triassic based on radiolarian assemblages from chert intercalations within these volcanics, while the clayey matrix of the mélange yields small blocks of red radiolarian cherts which are dated by radiolarians as Cenomanian. According to biostratigraphic and structural data all major localities of the Phasoula Formation (Petra tou Romiou, Akamas, Ayia Varvara, Phasoula) represent large blocks within the Mamonia Mélange.

Depth geological relations in the Timok Krajina, between Kladovo and Zaječar (eastern Serbia): based on surface, borehole and geophysical data

2025-07-15T09:29:20+00:00

The titled topic refers to the area from the great meander of the Danube River in the north, to Zagrađe, south of Zaječar and, to the west, it main-ly along the length of the mountain edge of the Carpathians, additionally with the intramountain trough of Borska Slatina. To the east of the state border, segments of the transborder area of Romania and Bulgaria are included. The total area of the amoeboid contour is about 2,500 km2, within the orthogonally wider framed map. In geological sense, it includes the westernmost margin of the Dacian Neogene Basin, unconformably formed above the crease belt of the Krajina Pre-Carpathians which was affected by Laramyian-Pyrenean defor-mations; in the trough of Borska Slatina above the Intra-Carpathian mag- matic-volcanic formation, and from the curved route east of the Peri-Carpa-thian contact as the whole cover of consolidated and block-shaped the Moesian Platform. A part of the abundant content of surface, field and cabinet paleontological-stratigraphic, primarily Neogene studies, resulting from the long-term research of recognized authors is displayed in an appropriate manner. Besides, individual representation and intervals from the sites of shallower drilling of different purposes were added. For the first time, the data related to the Neogene and older geological units from the deep boreholes are highlighted, and by well log interpretation and correlation positioned on the attached tables and illustrated with figures. For the first time, the geometry of indented base of the Cenozoic of the entire territory is presented, that is compatible with the geophysical primarily harmonized gravimetric and reflective-seismic indicators. In the Negotin - Zaječar area, we publish the first complex interpretation of the discontinuity of foothills formed as a result of the Alpine orogeny, by depth, above the paleomorphologically formed the Paleozoic Caledonian-Hercynian basement. The greatest thickness of Cenozoic deposits near Velika Vrbica, in the meander of the Danube River, has been interpreted up to 2,300 m, proved near Mala Vrbica (borehole Vb-1, 1,990 m) and, terminates in the Upper Cretaceus of the Carpathian foothills at a depth of 2,497.7 m . The oldest well-defined stratigraphic unit is the Ordovician in the Bukovče-1 borehole near Negotin, with a bottom of 1,982 m on the Krajina part of the Pre-Carboniferous to Sub-Jurassic interval of platform. The deepest borehole in the studied area is 55 Chilia 7, completed in the late Silurian of the Moesian Platform at a depth of 3,203.5 m.

The Purpri Fault: A Newly Identified Active Fault in East Kolaka, Indonesia, Based on HypoDD and DInSAR

2025-07-15T09:29:21+00:00

The Purpri Fault, a newly identified active fault in East Kolaka, Indonesia, has been analyzed using an integrated geophysical approach, combining HypoDD earthquake relocation and DInSAR ground deformation analysis. The relocation of 233 seismic events from January 24 to February 7, 2025, revealed a fault structure distinct from the Middle Kolaka and North Kolaka Faults, characterized by an oblique-normal faulting mechanism with a left-lateral component. The focal mechanism solution confirms significant vertical displacement, indicating a fault that accommodates both extensional and shear deformation. DInSAR analysis using Sentinel-1A SAR imagery detected subsidence and uplift patterns that align with the relocated seismicity, confirming ongoing crustal deformation along the Purpri Fault. The western block of the fault exhibits a subsidence of approximately –13 cm, while the eastern block shows uplift of +11 cm, consistent with the seismic activity. The integration of seismic relocation and deformation mapping interpretation confirms that the Purpri Fault is an independent and active fault system. The shallow depth of seismicity (<10 km) and evidence of ongoing deformation indicate a potential seismic hazard that is not currently accounted for in regional seismic hazard models. Given its capacity to generate moderate to strong earthquakes, incorporating the Purpri Fault into updated seismic risk assessments is essential for improving earthquake preparedness and hazard mitigation strategies in East Kolaka.

Depositional environmental, provenance and climatic signatures of textural characteristics and heavy mineral distribution of the Vaigai river channel bed sediments, Southern India

2025-07-15T09:29:21+00:00

Surface sediments of the river channels provide a proxy to understand contemporary-paleoconditions of sedimentary environments, climate, pro-venance, etc. Systematic field mapping, and delineation of geological and geomorphic features was conducted, followed by collection of surface sediments from river channels. Laboratory analyses included granulometry, textural statistical parameters, and heavy mineral analysis of 53 sediment samples collected from the entire reach of the Vaigai River from upstream to downstream, the majority of them were coarse sand, moderately sorted, finely skewed and platykurtic. Barring a few aberrations, a gradual increase in roundness of the grains from the headwaters to the basin outlet is recorded in the present study. The transportation of sediments is characterized by suspension with rolling. Discriminant plots of environmental and energy conditions affiliate the studied sediments to the riverine environment and unidirectional flow except few. Recycling of valley-fill sediments and negligible-noticeable sorting, weak transport characteristics during normal flow and effective exhumation-erosion-deposition during significant flow conditions were interpreted. Among the heavy minerals, the ubiquitous occurrence of hornblende followed by garnet, magnetite, epidote, rutile, zircon, and monazite in the decreasing proportion is documented. Elemental abundances in the heavy minerals of samples from the upper part of the basin show no significant/noticeable enrichment/depletion characteristics, whereas the samples of the lower part of the basin show uniformly abundant Si. These data and interpretations suggests that the channel bed sediments are mostly reworked and recycled, probably influenced by the river’s flow on an antecedent valley and valley-fill. Within this general nature, aberrations are introduced by land use and other anthropogenic factors-imposed changes in sediment size, shape, sorting and heavy mineral occurrence and relative proportions.

Characterization of hydrogeological units and hydrodynamics of a section of the aquifer system in the city of Cartago, Costa Rica

2025-07-15T09:29:22+00:00

The study focuses on the hydrogeological characterization of the aquifer system in the central sector of Cartago, Costa Rica. This area was selected due to its significant urbanization and agricultural activities, both of which heavily depend on groundwater resources. The conceptual hydrogeological model was developed using well records, field hydrogeological observations along rivers and material extraction pits, macroscopic sample collection for thin‐section analysis, spring and well inventories, and piezometric level analysis. A series of hydrogeological profiles were modeled to visualize the subsurface configuration of hydrogeological units and their relationships with existing geological materials. In areas with sufficient well density and adequate geographic distribution, the groundwater flow dynamics within the hydrogeological units were also analyzed. The results revealed that the aquifer system consists of a variety of materials, predominantly alluvial and laharic deposits, which function as aquifer hydrogeological units. These materials contain interspersed clay lenses, fine sands, and coarse sands, which collectively
influence the formation of saturated zones, aquitards, and aquicludes. Additionally, these characteristics determine the degree of confinement of the aquifer units. In some sectors, this confinement results in water upwelling, creating artesian conditions. Flow directions were predominantly oriented from north to south, following the surface gradient, although variations in flow direction highlighted the complexity and interconnectivity of the units. For the first time, the hydrogeological model of the Cartago aquifer system was defined. It comprises the Taras, La Chinchilla, Cartago, El Bosque, Tejar, and Dulce Nombre hydrogeological units. Each of these units corresponds to a specific portion of the study area within the central sector of Cartago, which lies atop the Cartago aquifer system.

GIS based Site Suitability Analysis for delineation of Wastewater Treatment Plant potential zones in Upper Ponnaiyar Watershed, South India

2025-07-15T09:29:23+00:00

The management of water resources is a major challenge for mostof the dry land areas, as the demand for water are increasing and the qualityare being compromised due to a number of natural and economic factors. Rural, periurban and urban should focus in future for decentralised wastewater treatment systems. The cluster of decentralised treatment system provide best management of wastewater in summer and winter seasons. The investment, operation and maintenance of decentralised treatment plants will provide a higher level of environment. In the selected study area Upper Ponnaiyar, water pollution issue has gotten worse recently, in order to solve the water pollution issue, building a wastewater treatment plant is a good way to treat polluted water. If the proper location for the treatment plant is not selected, then it may lead to soil degradation and groundwater pollution. This study was conducted by using GIS techniques for selecting suitable wastewater treatment plant zonation. There are seven parameters considered in the analysis consists of land use/land cover, elevation, road proximity, a slope of the ground, drainage density, geology, and soil. The weighted index overlay analyses of the final map with final weighted factor map were integrated and produced the final suitable wastewater treatment plant site map using ArcGIS Spatial Analyst tools. As a result, 73.88 km² (6.90%), 359.55 km² (33.59%), 441.08 km² (41.21%), 180.71 km² (16.88%), 15.05 km² (1.41%) of the total study area was found to be unsuitable, low suitable, moderate suitable, high suitable and very high suitable respectively. The area of very high suitable is preferable for wastewater treatment plant sites, because of their minimum effect on the environment, public health and cost effective than other parts of the study area. Therefore, the study will help the concerned authorities to formulate their development strategies according to the selected suitable wastewater treatment plant site available to the area.