well as fire clay. The coalfields of the Ramgarh district lie in the Damodar Valley. The important geological formation of the district is the Gondwana System and the rocks of the Damuda Group of Lower Gondwana age comprises the most important coal seams. The district's coal deposits are mainly found in South Karanpura, West Bokaro and Ramgarh coalfields. Coal mines Central Coalfields Limited is a subsidiary of Coal India Ltd. The coalfield is divided into the following areas: South Karanpura coalfields Barka Sayal Area: Saunda D (formerly known as Bird Saunda) underground mines Saunda D open cast mines (not in operation) Central Saunda underground mines Saunda underground mines Sayal D underground mines Urimari underground mines Bhurkunda open cast mines Argada Area: Sirka open cast mines Sirka underground mines Argada underground mines Ramgarh coalfields Rajrappa Area: Rajrappa Project (formerly known as Ramgarh Project) open cast mines. CCL Coal Washery: RajrappaWashery West Bokaro coalfields Kuju Area : Sarubera open cast mines Sarubera underground mines Ara open cast mines Kuiu underground mines Topa open cast mines Topa underground mines Pindra open cast mines Pindra underground mines Pundi open cast mines Karma open cast mines Hazaribag Area: Kedla underground mines Kedla open cast mines Jharkhand open cast mines Laiyo underground mines Parej East open cast mines Tapin North, open cast mines Tapin South, mixed (open cast and underground). CCL Coal Washery: Kedla Washery Tata Steel: West Bokaro (Ghato) open cast mines Tata Steel established the country's first coal washery at West Bokaro (Ghato) in 1951. Mines Rescue Station (CCL): Naisarai, Ramgarh. Rescue Room (CCL): Kedla Captive coal mining blocks Captive coal blocks allocated to different companies by the Ministry of Coal, Government of India in the district are the following: Sugia: Jharkhand State Mineral Development Corporation Rauta: Jharkhand State Mineral Development Corporation Burakhap: Jharkhand State Mineral Development Corporation Kotre–Basantpur: TISCO (Tata steel) Patratu: Jharkhand State Mineral Development Corporation Coal-bed methane Coal-bed methane (CBM), is an eco-friendly natural gas, stored in coal seams, generated during the process of the coalification. ONGC is doing exploration work in South Karanpura Coalfields for CBM. Underground coal gasification Coal India Limited has identified two sites for developing UCG with Joint Venture Partners. Kaitha Block in Ramgarh coalfield under CCL command area is one of them. Ramgarh district marked a substantial increase in collection of mining revenue on fiscal year 2014-15 as revenue collected till 30 March 2015 while mining