USS Milwaukee (CL-5) While steaming north of Hispaniola and Puerto Rico on 14 February 1939, "Milwaukee" discovered the deepest place in the Atlantic Ocean. The spot—which has a depth of —is now known as the "Milwaukee Deep". By January 1941, the ship had returned to Cruiser Division 2 which was now assigned to the Caribbean Patrol, commanded by Rear Admiral Jonas H. Ingram, part of the Neutrality Patrol established after the war began. Cruiser Division 2 was ordered to patrol the Atlantic between Trinidad, the Cape Verde Islands and the eastern bulge of Brazil in April, although "Milwaukee" was not immediately available. The
Canfield ocean during the Great Oxygenation Event. The presence of oxygen in the deep ocean made the formation of BIF impossible, which is seen in ocean sediment records. Conversely, the Canfield Ocean theory postulates that deep ocean water remained anoxic long after the Great Oxidation Event, and he argued that the euxinic conditions in the deep ocean ceased the deposition of BIF in ocean sediments. Euxinic describes anoxic conditions in the presence of hydrogen sulfide. Euxinic ocean conditions, a term describing restricted hydrologic circulation that lead to stagnant or anaerobic conditions, are the likely factor leading to sulfidic oceans. Canfield ocean The