Caspian Holdings, the oil and metals explorer, headed north on news of quick progress at its tungsten mining site in the Extremadura region of southwest Spain.Caspian claims the La Parrilla project contains "one of the largest tungsten deposits in the western world".Over the last three years the price of tungsten has more than doubled.The company has now begun a 1,500 metre drilling campaign to assess the mine. During the four month programme a total of 5 holes will be drilled targeting higher grade intersections at the edge of the ore body.As well as the deposits available from the mine itself, Caspian also has access to 2.5 million tons of "tailings" or residue from previous mining activity. It expects to extract tungsten from those tailings within the next 18 months.Over the past year Caspian shares have dropped 38%, but rose by 0.02p on the tungsten mine update to 0.3p.BS