CEMS-RI Weekly Seminar on July 14, 2021 by Prof. Piotr Migoń

PRESENTS AN​ ONLINE SEMINAR             

Geomorphological Evolution of Sedimentary Tablelands

Date      : Wednesday, July 14, 2021                                                                                                                           

Time     : 10:00 – 10:30 AM                                                                                                                                      

Location: Online Zoom Room - Join Meeting (Password: 630562)

Speaker:​ 

Abstract:

Flat-lying and slightly tilted sedimentary successions occupy large tracts of the land surface globally, giving rise to extensive plateaus and long escarpments as distinctive regional landforms. The presence of escarpments is lithologically controlled. The upper slope sections coincide with outcrops of stronger and more resistant rock layers, and therefore they are steeper than the mid- and lower slopes, often taking the form of a rock cliff. Although escarpment retreat was recognized as a dominant pathway of slope evolution in layered rocks long ago, recognizing the exact mechanisms, patterns and rates of retreat remains a challenge.

In this seminar, I will address the key issues relevant to the evolution of tablelands, especially in sandstone-dominated sedimentary successions: (1) terminology applied to the geomorphology of plateaus and escarpments; (2) processes involved in cliff retreat, mainly weathering, mass movements and subterranean erosion; (3) the role of spring erosion and fluvial processes, leading to fluvial dissection and development of canyons present in many tablelands; (4) evolution of residual hills in front of the retreating escarpments. I will also summarize major advances in our understanding of tableland evolution made of the last two-three decades such as the recognition of the key role of emerging groundwater in non-uniform escarpment retreat, of an important role of silica dissolution and underground removal of dissolved solids, increasing appreciation of rock properties in governing the patterns of escarpment retreat, and the proposal that cliffs do not necessarily retreat via catastrophic rock slope failures but may disintegrate in situ. Finally, geoheritage and geodiversity values of sedimentary tablelands will be briefly discussed.

All faculty, researchers and graduate students are invited to attend