The Neogene history of the Transylvanian basin in relation to its surrounding mountains

Abstract

Abstract. The structural and subsidence history of the Neogene Transylvanian basin is reviewed in order to analyse its relation to the tectonic and erosional history of the surrounding Carpathian mountains that has been defined by apatite fission track data from previous studies. The main processes studied are redistribution of mass by erosion, and tectonic loading. A mass balance is calculated between material eroded from the mountains and material deposited in the sedimentary basin. The mass balance fits to within 20% and confirms the restricted nature of the Transylvanian basin from Late Badenian to Pannonian, and directly links the mass transfer from the tectonically active mountains to the coevally subsiding basin. From Pliocene to recent both the basin and the now tectonically inactive mountains have been eroding leading to a change in the mass redistribution and isostatic uplift of the basin.Numerical flexural-isostatic 3-D modelling is used to study the effect of loading and subsequent unloading of the lithosphere as a consequence of the mass transfers by tectonic and erosional processes. From Badenian to Pannonian the combined load of the surrounding mountains and the basin fill lead to a minimum of 2 km of basin subsidence. During this period the Transylvanian basin can be regarded as a retro foreland basin of the Carpathian mountain belt. From Pliocene to recent the erosianal abrasion of both the mountains and the basin lead to a isostatic uplift of the basin surface between 300 and 500 m. The modelling results fit well with apatite fission track constraints, the subsidence history of the basin and field observations on structures and paleostress. The quantitative approach constrains the processes that dominated the formation of the Transylvanian basin since the Late Badenian and explain its present day enigmatic relative high altitude of 400 m above sealevel.

Fractal dimension estimations of drainage network in the Carpathian–Pannonian system

“…The growing orogen of the East Carpathians together with the high relief in the Apuseni Mts. prevented open gateways towards adjacent basins, which generated a mostly concordant series of molassetype sediments in the basin (Sanders et al, 2002). Most of the Late Miocene and post-Miocene faults described in the Transylvanian basin indicate strike-slip fault kinematics (Ciulavu et al, 2000(Ciulavu et al, , 2002.…”

“…In the aftermath of collision in the Carpathians, erosional unloading induced regional isostatic flexural rebound in the whole region. This resulted in a few hundred metres surface uplift and exposed the basin to erosion from Pliocene onwards (Sanders et al, 2002). In addition, documented regional compression suggests that lithospheric folding may also play a key role influencing the observed uplift pattern in the Transylvanian basin and Apuseni Mts.…”

“…Tilted and folded strata at the eastern and western flanks of the basin record pronounced compression. High sedimentation rates in the Sarmatian and Pontian is associated with the exhumation and erosion of the Eastern Carpathians, which provided sediment supply to the Transylvanian basin (Sanders et al, 2002). In the aftermath of collision in the Carpathians, erosional unloading induced regional isostatic flexural rebound in the whole region.…”

Generation of normal and adakite-like calc-alkaline magmas in a non-subductional environment: An Sr–O–H isotopic study of the Apuseni Mountains neogene magmatic province, Romania

“…show that an E-W to NW-SE compressive stress prevails, along with important isostatic uplift (Ratchbacher et al, 1993;Bojar et al, 1998;Ciulavu et al, 2000;Huismans et al, 2001;Sanders et al, 2002). …”

Landslide Spatial Distribution Analysis Using Gis. Case Study Secașelor Plateau

“…From a lithological perspective, one notices the presence of the friable rocks like marl, clay and poorly cemented sands etc., which are the result of sedimentation from the eroded materials of the Carpathian Mountains that delineate the Transylvanian Basin. (Sanders et al, 2002;Krezsek and Filipescu 2005;Krezsek and Bally, 2006). Also, we must highlight the fact that the anthropic factors played a decisive role in triggering the geomorphological processed, especially from the land use perspective.…”