Excursion to Upnor. Saturday, May 8th, 1880 - Geologists' Association excursion: Difference between revisions

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'''Director: W. Whitaker, F.R.S. (report by--The Director.) (Proc. Vol. vi. p. 336).'''
'''Director: W. Whitaker, F.R.S. (report by--The Director.) (Proc. Vol. vi. p. 336).'''
'''Note:''' [The Neighbourhood of Rochester. Of the details of the first visit of the Association to Rochester in 1866 no record exists. In 1880 an excursion to Upnor was made, details of which are given below.]


On leaving the railway at Strood, the party took the footpath up Frindsbury Hill, where a halt was made and the features of the district were explained, including the dip-slope of the Lower Greensand (seen through the gap in the Chalk ridge made by the Medway) and the tendency of the Chalk to have a small second escarpment, of which the standpoint was an example.
On leaving the railway at Strood, the party took the footpath up Frindsbury Hill, where a halt was made and the features of the district were explained, including the dip-slope of the Lower Greensand (seen through the gap in the Chalk ridge made by the Medway) and the tendency of the Chalk to have a small second escarpment, of which the standpoint was an example.

Revision as of 19:26, 5 February 2022

From: A record of excursions made between 1860 and 1890. Edited by Thomas Vincent Holmes , F.G.S. and C. Davies Sherborn, F.G.S. London: Edward Stanford [For the Geologists’ Association], 1891. Source: Cornell University copy on the Internet Archive (Public domain work)
Figure 29 Diagram section along the left bank of the Medway Near Upnor, 1⅓ miles (vertical scale exaggerated), by W. Whitaker, F.R.S.


Director: W. Whitaker, F.R.S. (report by--The Director.) (Proc. Vol. vi. p. 336).

Note: [The Neighbourhood of Rochester. Of the details of the first visit of the Association to Rochester in 1866 no record exists. In 1880 an excursion to Upnor was made, details of which are given below.]

On leaving the railway at Strood, the party took the footpath up Frindsbury Hill, where a halt was made and the features of the district were explained, including the dip-slope of the Lower Greensand (seen through the gap in the Chalk ridge made by the Medway) and the tendency of the Chalk to have a small second escarpment, of which the standpoint was an example.

The large chalk-quarries by the river side, on the south-east, were then visited. Here some well-marked layers of flint were noted, and also some pipey masses of irregular gravel on the Chalk, apparently the remains of a high terrace of Medway Gravel.

The walk having been continued northward, the party came to the most southerly of the Upnor sections, a disused pit at the south of Tower Hill, showing the junction of the Thanet Sand and the Chalk with the usual greenish bed and its green-coated flints.

Proceeding by the side of the Medway until, just before reaching the village of Upnor, a new section was seen in the River Drift, which here cuts across the low hill. It showed some feet .of brick-earth, with gravelly layers, over gravel. Attention was then drawn to the spot, on the opposite side of the river, where the largest fossil in the world (a Dutch war-ship) had been found in the alluvium during the works of the new Chatham Extension Dockyard.

The party straggled somewhat through the village, presumably to investigate the water-supply, but was soon re-united in the first of the great Tertiary sections. In this pit the junction of the sand of the Woolwich Beds with the Thanet Sand was seen; but the .Clay Shell-beds of the former and the overlying Oldhaven Beds and London Clay could only be got at with, difficulty. From the north-east dip, however, these higher beds are brought down in the next pit, at the hack of the cement-works.

Here the frequent occurrence of selenite was noticed, not only in the London Clay, but also in the underlying beds. In the London Clay here it often occurs in thin sheets along joint-fissures, as well as in detached crystals or masses' of crystals. In the estuarine shelly clays of the Woolwich Beds masses of crystals also occur, whilst in the intermediate Oldhaven Sand a peculiar variety is found, consisting of masses in which the fine grains of sand have been caught up between the plates of the crystals, forming, indeed, a sort of sandstone, which sometimes makes casts of the shells, and sometimes occurs in layers some feet long. This variety of the mineral has been found only in two chief Kentish sections of the Oldhaven Sand, those of the Upnor pits, and of Reculver cliffs. A number of fossils were obtained from the Oldhaven Beds; but the estuarine shells in the midst of the Woolwich Beds were mostly hidden by talus.

In the furthest pit the London Clay, with its septaria, was well seen, whilst the shelly clays of the Woolwich Beds could be worked at the floor.

A return was then made to Rochester, and the visit was brought to an end by a stroll to the Norman keep of Rochester Castle, from the top of which a fine view was obtained.

[For details of the sections seen the reader is referred to Whitaker, Geology of the London Basin, Geol. Survey (1872), pp. 28, 73, 143-145, 360.]

References

Maps

Ordnance Survey. Geological. Sheets 1, S.E. 3s. 6, 8s. 6d.

New Ordnance Survey. Sheet 272. 1s.