Initially there were enough readily accessible surface deposits to make a good living without using machinery as the Chinese did.

Szymanksi thought the source of the surface deposits was clearly warm water bubbling up from below.

However, as easy-to-reach surface deposits played out, miners increasingly turned to hard rock mining.

There were rich surface deposits but they did not continue far into the ground.

Though it looks to me like a surface deposit of sulphide.

Recent research indicates that surface deposits of diatomaceous earth play an important role.

The dashed line indicated that the fault was covered by surface deposits at this location.

Abrading is the process in which surface deposits are removed using abrasives.

In fact no fossils are known from surface deposits older than the Eocene.

He was involved in the move to deep level mining when the surface deposits had run out.