Middle Miocene evolution and structural style of the Diapir Fold Zone, Eastern Carpathian Bend Zone, Romania: insights from scaled analogue modelling
Published:April 14, 2020
Dan M. Tămaș, Zsolt Schléder, Alexandra Tămaș, Csaba Krézsek, Bianca Copoț, Sorin Filipescu, 2020. "Middle Miocene evolution and structural style of the Diapir Fold Zone, Eastern Carpathian Bend Zone, Romania: insights from scaled analogue modelling", Fold and Thrust Belts: Structural Style, Evolution and Exploration, J. A. Hammerstein, R. Di Cuia, M. A. Cottam, G. Zamora, R. W. H. Butler
Download citation file:
The Diapir Fold Zone of the Carpathians is the most prolific onshore hydrocarbon area in Romania. Structural complexity, mainly due to the presence of salt, combined with poor seismic quality near and below the salt lead to contrasting structural models in the area. To gain insights into the mid-Miocene tectonic evolution, structural geometries and the effects of penetrative strain, we ran dual décollement scaled sandbox models with layered brittle and ductile materials. Results of two analogue models (20 and 33% shortening) revealed that the onset of the deformation sequence was mainly characterized by layer-parallel shortening. As shortening continued, a foreland-verging sequence of supra-salt detachment folds and sub-salt duplexes evolved. The sub-salt duplexes are located directly below the crests of the detachment folds, as the development of these large wavelength anticlines was related to sub-salt deformation. Salt flow was another controlling factor of the deformation style, as salt accumulated in the anticlinal cores and increased the coupling in the supra-salt synclinal axis. Our results offer insights into the effects of salt on the kinematic evolution of this area, help to predict geometries in areas of poor seismic quality, and highlight the important contribution of penetrative strain on deformation and reservoir quality.
Figures & Tables
Fold and Thrust Belts: Structural Style, Evolution and Exploration
CONTAINS OPEN ACCESS
The outer parts of collision mountain belts are commonly represented by fold and thrust belts. Major advances in understanding these tectonic settings have arisen from regional studies that integrate diverse geological information in quests to find and produce hydrocarbons. Drilling has provided tests of subsurface forecasts, challenging interpretation strategies and structural models. This volume contains 19 papers that illustrate a diversity of methods and approaches together with case studies from Europe, the Middle East and the Asia-Pacific region. Collectively they show that appreciating diversity is key for developing better interpretations of complex geological structures in the subsurface – endeavours that span applications beyond the development of hydrocarbons.