Multi-origin of soft-sediment deformation structures A brief review on 7 papers from the special issue of “ The environmental significance of soft-sediment deformation ” of the Sedimentary Geology 344 (2016)

摘要

From the viewpoint of origins of soft-sediment deformation structures (SSDS), 7 papers (Ito et?al. , 2016; Jiang et?al. , 2016; Lunina and Gladkov, 2016; Moretti et?al. , 2016; Rana et?al. , 2016; Rodríguez-Pascua et?al. , 2016; Wheatley et?al. , 2016) selected from the special issue of “ The environmental significance of soft-sediment deformation ” of the Sedimentary Geology 344 (2016) were reviewed. (1) The first paper (according to the published order) by Moretti et?al. is a general review and introduction of this special issue. This special issue has made an important contribution to the study of sedimentary environments. (2) The fourth paper by Rodríguez-Pascua et?al. is an excellent case study. All evidence of earthquake in this paper is reliable. The old Roman City (adjacent to Madrid, the capital of Spain) was definitely destroyed by an earthquake. This paper solved the problem that the archaeologists have not solved yet. (3) The 19th paper by Rana et?al. is another excellent case study. It demonstrated that SSDS in the youngest modern sediments in the seismically active area, i.e. , the Alaknanda Valley, Garhwal Himalaya, India, are of non-seismic origin, but with typically sedimentary origin. All evidence of sedimentary origin of SSDS in the study area is reliable. (4) The second paper by Lunina and Gladkov stated that SSDS (mainly clastic dikes) in epicentral areas of the recent earthquakes in southern Siberia were originated by earthquakes and that the clastic dikes are the most reliable indicators in the epicentral areas of earthquakes. This conclusion is right. However, it is not accurate to consider all clastic injections as “ in-situ earthquake structures” in anywhere, because the clastic injections are with multiple origins. (5) The third paper by Wheatley et?al. comprehensively stated the clastic pipes of the Jurassic in the Colorado Plateau, USA. However, the principal origin of the clastic pipes (columns) was possibly not originated by “palaeoseismic controls”, but by “tectonic controls” or “tectonic uplifts”. (6) The 10th paper by Jiang et?al. proposed that 6 types of SSDS of the Lixian Section in eastern Tibetan Plateau, i.e. , in a tectonically and seismically active area, were originated by earthquakes. However, the evidence of seismic origin is not sufficient. Therefore, the origins of SSDS in the Lixian Section are worthy to be further discussed. (7) The “injectites” and “extrudites” in a Late Pliocene basin on the Boso Peninsula, Japan, from the 24th paper by Ito et?al. , are non-SSDS and their origin is unreliable.The above viewpoints may be inappropriate. Criticisms and corrections are welcome.This paper is not only the author's brief review on 7 papers selected from the special issue of the Sedimentary Geology 344 (2016), but also an invitation to geologists worldwide to write papers for a new special issue of “ The origins of SSDS ” of the Journal of Palaeogeography which is planned to be published in 2018.