Late Cretaceous stratigraphy, sediments and structure: Gems of the Dorset and East Devon Coast World Heritage Site (Jurassic Coast), England

被引:8
|
作者
Mortimore, Rory N. [1 ]
机构
[1] ChalkRock Ltd, 32 Prince Edwards Rd, Lewes Sussex BN7 1BE, England
关键词
Cretaceous; Devon and Dorset; Sea-level; Overstep; Marker beds; Inversion tectonics; Durdle Cove structures; A354 road cutting; Coniacian and Campanian fossils; Inoceramid bivalves; Echinocorys scutata; CARBON ISOTOPES; TURONIAN CHALK; SEA-LEVEL; OXYGEN; BRACHIOPODS; SEQUENCE; GENESIS;
D O I
10.1016/j.pgeola.2018.05.008
中图分类号
P5 [地质学];
学科分类号
0709 ; 081803 ;
摘要
Extraordinary, long-distance litho-marker beds such as the Lewes and Shoreham Tubular Flints and associated marl seams and fossils, recognised in cliff exposures and cliff-fall boulders, are keys to unlocking the stratigraphy and tectonic structures in the Late Cretaceous of the Dorset and East Devon Coast World Heritage Site (Jurassic Coast). Durdle Cove is a special gem exposing the Lewes and Seaford Chalk stratigraphy where new marker beds are identified and sediments and tectonic structures provide clues to timing of movements that produced a Late Cretaceous pericline which grew into a Miocene monocline along the line of the underlying Purbeck Reverse Fault. During 'inversion' along this fault some Late Cretaceous Chalk formations were in part or completely 'lost' (e.g. Middle Turonian New Pit Chalk Formation) and others were condensed (e.g. Late Santonian and Early Campanian Newhaven Chalk Formation). Excavation of the A354 road cutting at the Lower Bincombe Farm, has greatly added to the stratigraphical records of Late Cretaceous fossils in South Dorset, especially Coniacian and Early Campanian inoceramid bivalves and the various stratigraphically specific forms of the Late Santonian to Early Campanian echinoid fossil Echinocorys scutata spp. not recorded before in this coastline. The very large bivalve fossil Platyceramus sp. provides clues to chalk sea-floor environments. (C) 2018 The Geologists' Association. Published by Elsevier Ltd. All rights reserved.
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页码:406 / 450
页数:45
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