Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1016/j.sedgeo.2007.05.006 |
Possible climate variability in the Lower Old Red Sandstone Conigar Pit Sandstone Member (early Devonian), South Wales, UK | |
Hillier, Robert D.1; Marriott, Susan B.2; Williams, Brian P. J.; Wright, V. Paul4 | |
通讯作者 | Hillier, Robert D. |
来源期刊 | SEDIMENTARY GEOLOGY |
ISSN | 0037-0738 |
出版年 | 2007 |
卷号 | 202期号:1-2页码:35-57 |
英文摘要 | The Early Devonian Conigar Pit Sandstone Member (CPSM) of the Freshwater West Formation (Lower Old Red Sandstone, Lochkovian age) at Freshwater West in south Wales comprises a heterolithic, predominantly alluvial suite (mudstones, fine to coarse-grained sandstones, conglomerates) with varying depositional architecture. A number of discrete facies associations are observed. The fine-grained, inclined- and non-inclined heterolithic association is dominant within the CPSM. It represents dryland sinuous channelized flow (IHS bedsets) and unconfined flow (non-inclined bedsets) at terminal and intermediate floodouts deposited under semi-arid conditions. Mudstones were deposited in two distinct environments associated with this semi-arid river system. Laminated and burrowed, reddish brown mudstones were deposited in shallow semi-permanent lakes or pools on the floodplain. Massive mudstones were deposited as within-channel muddy braid-bars, with sedimentary structures being lost during subsequent compaction. The mudstones exhibit Vertisol pedogenesis reflecting the seasonal wetting and drying associated with the semi-arid climate. Periods of intense desiccation are indicated by deep desiccation cracks and associated rubbly surfaces. Possible, though unproven tidal conditions influenced a small percentage of the heterolithic channels at Freshwater West. The extent of these channels is uncertain. The coarser-grained multi-storey sandstone association was deposited by low-sinuosity rivers with a fluctuating, but perennial discharge. Associated with these laterally extensive sandbodies was a high water table with surface ponding (wetlands) that enabled the preservation of plant detritus. During high discharge events, flow expanded over the contemporaneous floodplain depositing the sheet sandstone association within splay complexes. The interpretation that perennial discharge may have been triggered by basin-wide climate change challenges the long-held view that the Lower ORS climate was continuously semi-arid in nature. The spatial/temporal extent of this climate change is uncertain, as it is possible that the multi-storey sandbodies were deposited by allogenic rivers draining a distant, possibly uplifted source area. A decrease in the observed frequency and maturity of Vertisol profiles, and a corresponding increase in multi-storey sandbodies upward through the succession may reflect a long-term, episodic pattern of climate change. (c) 2007 Elsevier B.V. All rights reserved. |
英文关键词 | Devonian fluvial dryland climate change anglo-welsh basin Old Red Sandstone |
类型 | Review |
语种 | 英语 |
国家 | Wales ; England ; Scotland |
收录类别 | SCI-E |
WOS记录号 | WOS:000251601500003 |
WOS关键词 | ANGLO-WELSH BASIN ; ARID CENTRAL AUSTRALIA ; ACID SULFATE SOILS ; SAND BRAID-BAR ; FLUVIATILE SEDIMENTATION ; COOPER-CREEK ; DEPOSITIONAL ENVIRONMENT ; SEQUENCE-BOUNDARY ; BEDLOAD TRANSPORT ; EASTERN AUSTRALIA |
WOS类目 | Geology |
WOS研究方向 | Geology |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/155987 |
作者单位 | 1.Natl Museum & Galleries Wales, Dept Geol, Cardiff CF10 3NP, S Glam, Wales; 2.Univ W England, Sch Geog & Environm Management, Bristol BS16 1QY, Avon, England; 3.Univ Aberdeen, Dept Geol & Petr Geol, Aberdeen AB24 3UE, Scotland; 4.Univ Wales Coll Cardiff, Sch Earth Ocean & Planetary Sci, Cardiff CF10 3YE, S Glam, Wales |
推荐引用方式 GB/T 7714 | Hillier, Robert D.,Marriott, Susan B.,Williams, Brian P. J.,et al. Possible climate variability in the Lower Old Red Sandstone Conigar Pit Sandstone Member (early Devonian), South Wales, UK[J],2007,202(1-2):35-57. |
APA | Hillier, Robert D.,Marriott, Susan B.,Williams, Brian P. J.,&Wright, V. Paul.(2007).Possible climate variability in the Lower Old Red Sandstone Conigar Pit Sandstone Member (early Devonian), South Wales, UK.SEDIMENTARY GEOLOGY,202(1-2),35-57. |
MLA | Hillier, Robert D.,et al."Possible climate variability in the Lower Old Red Sandstone Conigar Pit Sandstone Member (early Devonian), South Wales, UK".SEDIMENTARY GEOLOGY 202.1-2(2007):35-57. |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。