This massive organic deposit later became heated and transformed under pressure into oil.

These massive deposits gave birth to a healthy mining industry that still extracts the grey, sea green, and red material.

The town is situated on massive deposits of salt, and salt has been extracted there since ancient times.

The Abitibi belt also has some of the largest massive sulfide deposits in the province.

Although the gold ore was lean, it was a massive deposit that remained as an active mine until 2002.

Thrifts in the Rust Belt held massive deposits for which they had no demand.

The deposited metal sulfides can become massive sulfide ore deposits in time.

And I found a massive deposit of calvinum.

Alteration not associated with the ore forming process may also be omnipresent both above and below the massive sulfide deposit.

A volcanogenic massive sulfide ore deposit within the mountain was mined after rail service became available.