plymouth accommodation Home Page Your Room Breakfasts Prices Finding Us Plymouth Exploring Booking Links Contact Us accommodation plymouth, plymouth hoe, coastal path holiday, bed & breakfast, guest house vacation, guesthouse, business accomodation, short break acomodation, b&b acommodation, devon hotel To the north and north east of the city the granite mass of Dartmoor has had a profound impact on climate and economic activity. Granite has historically been exported around the world via Plymouth. Rocks around the edge of the Dartmoor granite mass were not only changed by the heat of the intrusion but were also heavily mineralised by fluids driven by the heat. This has given rise to ores containing tin, copper, tungsten, lead and other minerals in the Tamar Valley and other areas close to the moor, which have been exploited. After solidification and during the cooling of the intrusive granite mass, the decomposition of some of the material, particularly feldspar, took place to produce kaolin, or china clay. Locally this is found at Lee Moor and continues to be extracted today. The middle Devonian limestone belt in the south edge of Plymouth and in Plymstock has been quarried for many years. There is clear evidence of former activity at West Hoe, Cattedown and Radford. Currently quarrying takes place at two sites in Plymstock where the limestone has been worked over the last hundred years. Pomphlett Quarry has an estimated life of 25 years. Limestone and shale are extracted from separate parts of the complex. The limestone is crushed and then used with the shale for the production of cement. Moorcroft Quarry has a longer life expectancy and is continuing to extend eastwards. The limestone is processed on site to produce crushed aggregate, road stone, concrete blocks, ready mixed concrete and agricultural lime. An extensive complex of china clay workings at Lee Moor, on the southern edge of Dartmoor exploits the kaolinised granite. Existing for over 100 years the workings have expanded with the development of improved mining equipment. Some of the extracted clay is piped to Marsh Mills in Plymouth for drying. The china clay, which is put to a wide variety of uses, from the production of china and paper to cosmetics, is exported nationally and internationally. The large piles of mica sand resulting from this operation are excellent quality for use in concrete but the cost of transport has so far prohibited significant use. Tungsten A deposit of Tungsten was discovered in 1867 at Hemerdon, close to the Lee Moor complex, north of Plympton. Since then sporadic activity has taken place on site. In 1986 planning permission was given to develop a 200 metre deep pit, 850 metres by 540 metres. It was expected that the mine would have a life of about 20 years. However, although sufficient work has taken place to implement the permission, the price of tungsten on the world market has not warranted any further working of the deposit. There is evidence that tin was extracted from gravel in some streams below Hemerdon and near Plympton. Groundwater is the water held underground in rock formations. These supplies are generally referred to as aquifers and in many parts of the United Kingdom these are primary sources of drinking water. Ground waters are classified as controlled waters and it is an offence to cause or knowingly permit a discharge of poisonous, noxious or polluting matters, or solid waste matter, into any of these waters. All discharges to controlled waters require appropriate authorisation. There are no major aquifers in the southwest. Some minor aquifers are important for local supplies, as is the case in Plymouth. Aquifers are based on their resource viability in terms of water extraction. Minor aquifers will contain water but it is often difficult to extract. There are 12 licensed private groundwater abstractions within the Plymouth boundaries. These are for a variety of uses, such as agriculture, extraction, domestic and process water. Four of these are for private drinking supplies and are regularly monitored by the Local Authority. These are regarded as sensitive receptors and must be protected from contamination. |