Some evolutionary patterns of palaeokarst developed in Pleistocene deposits (Ebro Basin, NE Spain): Improving geohazard awareness in present‐day karst

Abstract

Pleistocene detrital deposits in the central Ebro Basin frequently show deformation features due mainly to karstification in the underlying Neogene evaporites. In 123 cases, estimation of parameters of shape and minimum volume of materials involved was accomplished. Six of them were analysed in more detail to establish the main processes involved in their genesis and the succession of events. All the deformation features in the selected sites are synsedimentary. To achieve the objectives, intense fieldwork was made applying methods of sedimentology and structural geology. Usually, a complex evolutionary pattern was observed, with evidences of dissolution, sagging, collapse, gravity flow, suffosion, and plastic flow. In a schematic way, three main situations, independent of the age of the analysed deposits, can be distinguished: (a) slow subsidence, (b) collapse, and (c) temporal overlapping of both processes. In the first 2 scenarios, basins with smooth or abrupt borders, respectively, were generated on the land surface. In the third one, slow subsidence was followed by a collapse, located in the area of maximum flexure. These patterns are also observed in present-day dolines. Comparison of direct and indirect parameters between paleodolines and present-day dolines indicates a bigger size of the latter, probably caused by the different conditions of observation. This study helps to know the possibilities in the evolution of mantled karst features, to estimate the volume of material affected by karstification and to improve the knowledge of present-day dolines behaviour. Consequently, study of paleodolines must be considered to achieve a better urban planning in active karstic areas.

Deep Learning for Characterizing Paleokarst Collapse Features in 3‐D Seismic Images

“…Buried, collapsed paleokarst systems can form carbonate petroleum reservoirs including those explored in the Fort Worth Basin (FWB) (e.g., Dou et al, 2011; Kerans, 1988; Loucks & Anderson, 1985), the Lower Cretaceous Golden Lane field in eastern Mexico (Coogan et al, 1972; Viniegra & Castillo‐Tejero, 1970), the Tarim Basin in China (e.g., Desheng et al, 1996; Maoshan et al, 2011; Qi et al, 2014; Zeng et al, 2011), and other paleokarst‐related fields reported in previous works (e.g., Andre & Doulcet, 1970; Loucks, 1999; Mazzullo & Mazzullo, 1970; Zhai & Zha, 1982). In addition, collapsed paleokarst systems pose potential drilling hazards due to the weakness of the paleokarst zones (Qi et al, 2014; Soriano et al, 2019; Zhao et al, 2018). Therefore, delineating subsurface collapsed paleokarst systems is important for petroleum reservoir characterization and production.…”

Plio-Pleistocene Dust Traps on Paleokarst Surfaces: A Case Study From the Carpathian Basin

“…The rate and distance of eolian transportation strongly depend on grain ability and availability (grainsize and shape), terrain and wind strength (Evans and Reed, 2007;Varga et al, 2011;Kok et al, 2012;Vandenberghe, 2013;Újvári et al, 2016). Allochthonous karst depression, cave and fissurefill sediments are mostly believed to be originated from local sources (Pickford and Mein, 1988;Atalay, 1997;Evans and Reed, 2007;Peresani et al, 2008;Evans and Soreghan, 2015;Muttoni et al, 2017), and considered to be derived from the terrain directly overlying the fracture networks on carbonates (Bosch and White, 2007;Costantini et al, 2009;Mikulčić Pavlaković et al, 2011;Gil et al, 2013;Al-Farraj et al, 2014;Peng et al, 2019;Soriano et al, 2019). Only a few studies have recognized the link between cave and fissure sediments and windblown dust (Coude-Gaussen et al, 1984;Villa et al, 1995;Evans and Reed, 2007;Merino and Banerjee, 2008;Rellini et al, 2013;Evans and Soreghan, 2015;Andreucci et al, 2017;Kovács et al, 2017;Bosák and Zupan Hajna, 2018;Durn et al, 2018;Ge et al, 2020).…”

Hydrogeology of salt flats : the Salar de Atacama example

“…The zoning to quantify the recharge by rainfall was performed at two levels: (1) peripheral sub-basins and ( 2) the salt flat nucleus, mixing zone and alluvial fans. The first correspond to the most elevated areas located between 2,400 and 5,500 m a.s.l.…”

“…Nevertheless, 3D regional scale models are needed for the management of any hydrogeological system. In the case of coastal systems, this problem is solved in two ways: (1) 10…”

“…The objectives of this work are (1) to establish a methodology for the estimation of the evaporation discharge in salt flats and to evaluate its sensitivity to the accuracy of the water table depth data, ( 2) to quantify the spatio-temporal impacts of the brine pumping in the Salar de Atacama case of study and 3) to evaluate the best distribution of brine pumping wells to reduce the ecological impacts on salt flats.…”