Pactolus Bank or Burnham Bank was discovered at 56°36′S 74°20′W and a depth of 67 fathoms (123 m; 402 ft) by Captain W.D. Burnham on the American ship Pactolus on November 6, 1885.

Felix Riesenberg, who served under Burnham, postulated that Pactolus Bank was the sunken location of Elizabeth Island, discovered by Sir Francis Drake's ship the Golden Hinde in 1578. Leaving the Magellan Strait, Drake's ship was driven far to the west and south, before clawing its way back towards land. On 22 October the ship anchored off an island which Drake named "Elizabeth Island," where wood and water was collected and seals and penguins captured for food, along with "herbs of great virtue." According to Drake's Portuguese pilot, Nuño Da Silva, their position at the anchorage was 57°S. However, no island has been confirmed at that latitude, although a sinking volcanic island may have been sighted in that vicinity by the Danish ship Lutterfeld in December 1876.

The USS Wyandot investigated the area in 1956 and found no indication of a shoal, so Pactolus Bank may itself be a phantom island.