CONTEMPORANEOUS SLUMPING IN THE EMBSAY LIMESTONE SERIES OF THE SKIPTON ANTICLINE

Abstract

This paper furnishes a brief description of certain features demonstrating movement contemporaneous with deposition in the Embsay Limestone on the northern flank of the Skipton Anticline. The Embsay Limestone series was named and discussed by Hudson and Mitchell1 in 1937 but at that time it was not well exposed. In recent years complete sections through the series have become available in the quarry cuttings at Halton East and have been noted by Hudson2 who gives the following details :— | | | | | | | FEET | |:----------------------------------------------------------------------- | --- | --- | --- | --- | --- | ---- | | Upper limestone with shales in upper part | | | | | . . | 45 | | Middle limestones and shales with many slump conglomerates and breccias | | | | . . | . . | 95 | | Lower limestone, with inconstant boulder bed in middle | . . | . . | . . | . . | . . | 50 | | Basement boulder bed | | | . . | . . | . . | 2 | The quarry3 is worked largely for the lower limestone in beds dipping steeply northward so that the middle limestone and shales form the northern quarry face. Owing to the methods of working and debris disposal, the sections herein described either are rapidly deteriorating as a result of falls and surface creep, or are in process of being obscured. Throughout the middle division small scale effects of submarine disturbance may be detected; limestones, with apparently normal relationship to beds above and below, may be traced laterally into contorted or brecciated beds within the limits of the quarry, whilst overlying and subjacent beds remain subparallel and undisturbed. Often the upper limit of disturbance is an erosion surface; occasionally ...