While I am not a geologist, I do enjoy the rocks, particularly the onces that have economic value.
Given the fact that Zone's deposit is in close proximity to Adriana and NML it is fair to assume that the deposit is of a similar variiety / grade as encountered there.
What we will likely be dealing with is TACONITE. Please see further explanation hereunder. I trust this helps.
From Wikipedia, the free encyclopedia
Taconite is a variety of iron formation, an iron-bearing (>15% iron) sedimentary rock, in which the iron minerals are interlayered with quartz, chert, or carbonate. The term was coined by Minnesota State Geologist Newton Horace Winchell during his pioneering investigations of the PrecambrianBiwabik Iron Formation of northeastern Minnesota due to its superficial resemblance to iron-bearing rocks he was familiar with in the Taconic Mountains of New York. The iron content of taconite, commonly present as finely dispersed magnetite, is generally 25 to 30%. In the late 19th and early 20th centuries, available iron ore was of such high quality that taconite was considered an uneconomic waste product. After World War II, much of the high grade iron ore in the United States had been mined out, and taconite became a new source of iron. To process taconite, the ore is ground into a fine powder, the magnetite is separated from the waste rock by strong magnets, the powdered iron concentrate is combined with a binder such as bentonite clay and limestone as a flux, and rolled into pellets about one centimeter in diameter containing approximately 65% iron. The pellets are fired at a very high temperatures to harden and make them durable. This is necessary to ensure that the blast furnace charge remains porous to allow heated gas to pass through and react with the pelletized ore. Firing the pellet oxidizes the magnetite (Fe3O4) to hematite (Fe2O3), an exothermic reaction which reduces the energy cost of pelletizing the concentrate. E.W. Davis of the University of Minnesota Mines Experiment Station is credited with developing the pelletizing process. Since the commercial development of this process in the Lake Superior region in the 1950s, the term taconite has been used globally to refer to iron ores amenable to upgrading by similar processes.
Major producers of iron ore pellets from taconite in North America include Cliffs Natural Resources, U.S. Steel, and ArcelorMittal. These pellets are also referred to as "taconite ore pellets" or "taconite" [1]
Processed Taconite pellets as used in the steelmaking industry, with a
US Quarter shown for scale.
The Mesabi Iron Range region of the American state of Minnesota is a major production area. The taconite iron ore pellets are hauled by railroad through the ports of Silver Bay, Two Harbors and the Twin Ports of Duluth, Minnesota and Superior, Wisconsin, all on Lake Superior. The ore is generally shipped by lake freighters to locations on the lower Great Lakes. Many steelmaking centers are located near Lake Erie.