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XXII. 
ON THE OCCURRENCE OF MANGANESE IN SOME 
GRAVEL BEDS UNDER BIGBERRY Woop, 
NEAR CAN TERBURY, 
BY 
CAPTAIN McDAKIN. 
READ 9TH FEBRUARY, 1888, 
Although the district of the Lower Tertiaries, the Upper and 
Lower Cretaceous, and Wealden formations, comprised between 
Ramsgate and Hastings may be considered rich in fossils, the 
minerals are few. 
Chalcedony and crystals of Quartz occur in cavities of flints 
and fossils. Calcite in dividing septa of Septaria, and rock 
fissures ; Selenite in the London and Gault clays; Pyrites in all 
the local formations, replacing vegetable remains in the London 
Clay, and as curious shaped nodules in the Lower Chalk. Also a 
variety of pyrites, called Markasite, in the same formation ; 
Allophane, near Woolwich ; Websterite, as a grey earthy alumi- 
nous mineral, probably formed by the decomposition of pyrites and 
clay; Heavy Spar, or sulphate of Barytes in the Weald and 
London Clay; Amber cast up on the coast at Pegwell Bay; and 
Jet, but recently brought to our notice by Mrs. Cole, having been 
found near Battle Abbey ; and lastly Glauconite, the green mineral, 
giving the distinctive colouring to the Green-sands, both of the 
Cretaceous and Eocene formations: these form a list of those 
minerals that occur in any quantity. In addition we have several 
iron ores ; the silicious ironstones of the Woolwich beds, and some 
very remarkable beds capping the escarpment of the North Downs, 
the clay ironstone of the Weald, and bog iron ores; and recently 
I have found Manganese in sufficient quantity to include it in the 
list of our minerals. Like iron, it is very generally present in 
small quantities. Its colouring power is so great that its presence 
may be detected when existing in a very minute quantity, either 
by the blowpipe or wet analysis. It is frequently associated with 
iron and phosphorus in the bog ores, and with a peculiar blue 
mineral Vivinanite, found coating stones and the sides of fissures 
in rocks, and even vegetable remains, in appearance reminding 
one of the bloom on the fruit of the Blackthorn or Sloe, 
The chemist Rulong found four per cent. of Manganese 
