ebsi2001 said:
Now, if you feel up to it, explain, understandibly, the biological and chemical processes that caused the iron to precipitate out of the water and, over time, form bog iron
It could (and does) fill a book!
Briefly, take a low pH, very sandy soil, add a fluctuating water table, place in a moist temperate zone & wait a while. Under low pH, the iron that is a large component of many soils in the east will precipitate out. In a very sandy soil, this iron will rapidly leach thru the soil profile. A high water table (as occurs in much of the Pines) will restrict this movement, resulting (after time) in iron accumulating at or near the water table. Under saturated, anoxic conditions, bacteria will utilize the iron as an energy source, creating the "ochre sludge" that can be seen in some streams.
Soil quality (both good and bad!) was responsible for making southern New Jersey both the breadbasket and an important industrial center of colonial NJ. Some of the most productive soils in the nation occur in a belt extending from Pole Tavern to Salem (with a small chunk of pinelands in the middle). Some of the poorest soils in the heart of the pines allowed the development of the early iron and glass industries.
Do I sound like a soil scientist?
BTW, that was a great list of the furnaces!