Summary

The Thames Barrier, now being built across the Thames between Silvertown and Woolwich, to prevent tidal flooding in London will consist of a series of rotatable gates built across the river and supported by massive concrete piers, the majority of which are founded in the chalk bedrock.

As part of the site investigation in early 1972 a micropalaeontological investigation of the chalk was undertaken to determine an accurate stratigraphic correlation of the chalk across the site, the position and nature of any faults which affected the site, and the distribution of in situ, soliflucted and frost-shattered chalk. As a part of the work various biostratigraphic techniques were employed and these are described in detail.

Following this investigation it was shown that that chalk had been gently flexed prior to pre-Thanetian erosion. Two sets of weak folds were detected, trending SE-NW and NE-SW. Five faults were recognized near the site. One trends slightly north of east, with the remaining four being en echelon along the navigation channel. Although some of these faults cut the pier sites their throws were considered too small to produce any significant difference in engineering properties across them.

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