Silver Valley Mine (New Phoenix Mine; Wheal Cheesewring), Craddock Moor, St Cleer, Cornwall, England, UKi

Regional Level Types
Silver Valley Mine (New Phoenix Mine; Wheal Cheesewring)	Mine
Craddock Moor	Moor
St Cleer	Civil Parish
Cornwall	County
England	Constituent Country
UK	Country

An old tin mine on eastern Craddock Moor, immediately west of the South Phoenix Mine. The sett is bounded to the north and south by the West Phoenix and Craddock Moor mines, respectively, and was earlier known as New Phoenix Mine. According to A.K. Hamilton Jenkin, the mine was also known as Wheal Cheesewring.

The sett includes two SE-trending lodes, which are believed to be the western extensions of the lodes worked at South Phoenix Mine, Grace Dieu Lode in the north and Prosper Lode in the south. Their strikes are marked at surface by two lines of shallow pits that remain of older workings. The underground workings are of a limited extent; they consist of a crosscut adit which starts on the slope to the south and extends 160 ft north where it meets Prosper Lode at 25 ft below surface, and of a level driven 120 ft west and 20 ft east of the junction along the strike of the lode. The grid reference marks the ruin of the engine house, which is located a little south of the entrance to the adit. There are no records of output.

In 1937, the property was prospected again and samples taken at irregular intervals from the old surface workings and from the level on Prosper Lode showed promising results of up to 30 lb of black tin per ton. A shaft was sunk between the lodes, but the project was abandoned soon after. During the second world war, the mine was tried again in hope of quick returns. The shaft was continued to a depth of 120 ft and crosscuts driven north and south from its bottom. The southern crosscut intersected a NE-trending caunter lode about half way between the shaft and Prosper Lode. The assays of systematic sampling however showed that, except for a few high isolated values, the average grades were barely 10 lb of black tin per ton in Grace Dieu Lode and even poorer in the other lodes, and in 1943, the mine was closed with no production.

Geochronology

Geologic Time				Rocks, Minerals and Events
Phanerozoic
	Paleozoic
		Permian
			Guadalupian	ⓘ Major polymetallic mineralization ~270 Ma Cornwall, England, UK
			Cisuralian	ⓘ Porphyry dikes intruded (latest age) ~275 Ma Cornwall, England, UK ⓘ Greisenization (latest age) ~280 Ma Cornwall, England, UK ⓘ Porphyry dikes intruded (earliest age) ~280 Ma Cornwall, England, UK ⓘ Formation of metallized pegmatites ~285 Ma Cornwall, England, UK ⓘ Greisenization (earliest age) ~285 Ma Cornwall, England, UK ⓘ Emplacement of major plutons ~295 Ma Cornwall, England, UK

Other Regions, Features and Areas containing this locality

References