Thus the mountains are riddled with old mines and exploratory shafts, but only a few of the miners struck paydirt.
An attack tunnel is dug in response, and the Australians successfully destroy the exploratory shaft with minutes to spare.
An exploratory shaft was drilled in the 1950s but was not worked, and the shafts and adit were partly or totally sealed in 1972 and 1989.
Dry washing of low grade ores continued intermittently for 100 years, along with many exploratory shafts.
The Upper Level of the city represents less than five percent of our construction and exploratory shafts.
From November 1989 until the end of 1992 exploratory shafts and galleries were dug, tunnelling proper lasted from July 1993 until early 1995.
Some specialised engines were also built with drums for winding in mine shafts, especially when exploratory shafts were being sunk.
The law requires that public hearings be held on the plan before the department can begin construction of exploratory shafts.
The drillers were once again brought out to the property and another exploratory shaft was sunk into the ground.
In anticipation of the school reconstruction project, workers dug exploratory shafts in December 2007.