气候变化领域集成服务门户(CCPortal): Differentiation of subglacial conditions on soft and hard bed settings and implications for ice sheet dynamics: a case study from north-central Poland

CCPortal

DOI	10.1007/s00531-020-01920-x
	Differentiation of subglacial conditions on soft and hard bed settings and implications for ice sheet dynamics: a case study from north-central Poland
	Sokołowski R.J.; Wysota W.
发表日期	2020
ISSN	14373254
起始页码	2699
结束页码	2717
卷号	109 期号:8
英文摘要	We reconstruct patterns of subglacial processes on a hard bedrock and a soft bed under the southern sector of Scandinavian Ice Sheet (SIS) occurring in the basal till of the Late Saalian Glaciation at the Wapienno, Barcin and Młodocin sites (north-central Poland). Based on detailed sedimentological studies, two phases of SIS transgression were recognised. In the initial phase of the transgression, the SIS advanced onto a frozen substrate (continuous permafrost). The low permeability of the substratum led to a high subglacial water pressure (SWP) and increased basal sliding. The local increase of SWP led to the development of different types of structures and sediments. On a hard bedrock, with low SWP, abrasion predominated and linear structures were developing, while in the case of high SWP, the ice was decoupled from the hard substrate, pressurised liquefied sediment flowed, and structures of the p-form and s-form type developed. On a soft bed, the ice-bed contact was of a mosaic type and the ice movement had an ice-stream character. The ice-stream developed towards the east in the marginal zone of the SIS and used a W-E oriented valley filled by the Wapienno Formation fluvial complex. During a later phase, the ice movement was slower and did not have a stream character. Its direction changed to SE. The deposition of the main part of the diamicton occurred mainly as a result of the lodgement process. © 2020, The Author(s).
英文关键词	Abrasional forms; Basal till; Boulder pavement; Late saalian glaciation; Palaeo-ice stream
语种	英语
scopus关键词	bedrock; boulder; glaciation; ice stream; Saalian; Scandinavian Ice Sheet; sedimentology; subglacial environment; till; Poland [Central Europe]
来源期刊	International Journal of Earth Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/147601
作者单位	Department of Geophysics, Institute of Oceanography, University of Gdańsk, Al. Piłsudskiego 46, Gdynia, 81-378, Poland; Department of Geology and Hydrogeology, Faculty of Earth Sciences and Geospatial Management, Nicolaus Copernicus University, Lwowska 1, Toruń, 87-100, Poland
推荐引用方式 GB/T 7714	Sokołowski R.J.,Wysota W.. Differentiation of subglacial conditions on soft and hard bed settings and implications for ice sheet dynamics: a case study from north-central Poland[J],2020,109(8).
APA	Sokołowski R.J.,&Wysota W..(2020).Differentiation of subglacial conditions on soft and hard bed settings and implications for ice sheet dynamics: a case study from north-central Poland.International Journal of Earth Sciences,109(8).
MLA	Sokołowski R.J.,et al."Differentiation of subglacial conditions on soft and hard bed settings and implications for ice sheet dynamics: a case study from north-central Poland".International Journal of Earth Sciences 109.8(2020).