Difference between revisions of "Geology of the Andover area: Exposed strata - Upper Greensand Formation"

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Revision as of 11:23, 28 August 2013

EXPOSED STRATA

Upper Greensand Formation (UGS)

This formation consists of pale, yellow-brown, grey and greenish grey, bioturbated siltstone and silty, very fine-grained sandstone, with variable amounts of mica and glauconite. In places the formation is indurated to form a ‘malmstone’ and there are common occurrences of grey and brown colloidal silica chert within the higher part of the succession.

During the recent survey of the Andover district the component members of the formation recognisable in other districts could not be identified consistently and as a result the Upper Greensand Formation is shown as a single unit.

The unit thickens from about 34 to 40 m in the north of the district and about 45 m in the south to over 70 m in the centre of the region.

In the Andover district, the Upper Greensand Formation forms the oldest unit at outcrop. It is present in the north-eastern and north-western corners of the district within the core of the Kingsclere Anticline and in the closure of the Pewsey Vale Anticline respectively.

Geology of the Andover area - contents

Introduction

Geological setting

Geological description

Concealed strata
Ordovician to Devonian
Carboniferous
Permian
Triassic
Jurassic
Cretaceous
Exposed Strata
Upper Greensand Formation (UGS)
Chalk Group
Palaeogene
Quaternary
Artificial ground

Applied geology

Hydrogeology
Bulk minerals
Geotechnical considerations and hazards

Information resources

References

Geological map