{"title":"The Isle of Wedmore relay ramp: how fault evolution created King Alfred's historic landmark","authors":"A.J. Newell , D.C.P. Peacock","doi":"10.1016/j.pgeola.2023.04.001","DOIUrl":null,"url":null,"abstract":"<div><p>The Isle of Wedmore covers an area of ~<!--> <!-->19 km<sup>2</sup>, rises up to ~<!--> <!-->65 m above the surrounding lowlands of the Somerset Levels, and was an island until the Middle Ages. The topography is interpreted as having been formed by a relay ramp between two right-stepping faults (the Weare Fault to the west and the Mudgley Fault to the east) which have tens of metres of downthrow to the south, and which are probably normal faults. The relay ramp has a dip of about 3° to the SW and is breached by the NW-striking Wedmore Fault, which has up to ~<!--> <!-->23 m downthrow to the NE. Several NE-trending faults occur in the relay ramp, which are interpreted as having formed when the relay ramp became a contractional step when the Weare and Mudgley faults underwent sinistral reactivation, or as N–S contraction occurred during the Cenozoic. Analogues for this behaviour are presented from the Liassic rocks on the coast between Lilstock and East Quantoxhead.</p></div>","PeriodicalId":49672,"journal":{"name":"Proceedings of the Geologists Association","volume":"134 3","pages":"Pages 314-321"},"PeriodicalIF":1.2000,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of the Geologists Association","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0016787823000330","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Earth and Planetary Sciences","Score":null,"Total":0}
引用次数: 0
Abstract
The Isle of Wedmore covers an area of ~ 19 km2, rises up to ~ 65 m above the surrounding lowlands of the Somerset Levels, and was an island until the Middle Ages. The topography is interpreted as having been formed by a relay ramp between two right-stepping faults (the Weare Fault to the west and the Mudgley Fault to the east) which have tens of metres of downthrow to the south, and which are probably normal faults. The relay ramp has a dip of about 3° to the SW and is breached by the NW-striking Wedmore Fault, which has up to ~ 23 m downthrow to the NE. Several NE-trending faults occur in the relay ramp, which are interpreted as having formed when the relay ramp became a contractional step when the Weare and Mudgley faults underwent sinistral reactivation, or as N–S contraction occurred during the Cenozoic. Analogues for this behaviour are presented from the Liassic rocks on the coast between Lilstock and East Quantoxhead.
期刊介绍:
The Proceedings of the Geologists'' Association is an international geoscience journal that was founded in 1859 and publishes research and review papers on all aspects of Earth Science. In particular, papers will focus on the geology of northwestern Europe and the Mediterranean, including both the onshore and offshore record. Following a long tradition, the PGA will focus on: i) a range of article types (see below) on topics of wide relevance to Earth Sciences ii) papers on aspects of Earth Science that have societal relevance including geoconservation and Earth management, iii) papers on palaeoenvironments and palaeontology of the Mesozoic and Cenozoic, iv) papers on aspects of Quaternary geology and climate change, and v) papers on the history of geology with particular reference to individuals that have shaped the subject. These topics will also steer the content of the themes of the Special Issues that are published in the PGA.