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Oswego Iron EarthCache

Hidden : 8/10/2011
Difficulty:
2 out of 5
Terrain:
1.5 out of 5

Size: Size:   other (other)

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Geocache Description:

The geological features of Oswego’s location provided nearly all the resources necessary for the iron industry, including the lake as a water source for power, forested land for charcoal, and brown and red limonite ore. Ore was tested and found to contain 40-76% pure iron, with a temptation that great, capitalizing on the material could not be resisted.

Built in 1866, the Oswego Iron Furnace was the first blast furnace on the Pacific and is the only surviving stone furnace west of the Rocky Mountains.


The Oswego Furnace was Oregon's largest manufacturing enterprise in the nineteenth century. It consumed ore from two mines and charcoal from 22,000 acres of timber. The two mines were the Prosser Mine on Iron Mountain and the Patton Mine.
The type of ore found in Oswego is a hydrated form of hematite known as bog ore or limonite. Bog ore was created millions of years ago by blue-green algae living in airless swamps. The ore seam on Iron Mountain is sandwiched between two layers of volcanic rock. This resource was never exhausted before the furnace shut down.


The furnace was heated by a blast engine, which was powered by a thirty-foot, six-inch
waterwheel under a forty-foot head water. Hot blasts of heat were injected into the furnace and combusted the ore, charcoal and limestone inside. A chemical reaction occurs in this process that removes the oxygen from the iron oxide ore and leaves a metallic iron with high carbon content. As the heat from the furnace reduces the iron, the limestone flux causes the impurities to float to the surface as slag (as pictured on this page), the waste byproduct of iron production.

Come and visit Oswego Iron and see, touch, and experience this process in person. You will observe masses of iron, you can see one of the old pilings that held the ramp where the slag was deposited. Slag is still present all over the beach area and some of it is very pretty as it can appear in blues, greens and purples. There really is a whole lot to see and experience in such small area.


Pictures are not required but we and others always enjoy seeing the images cachers take.


To log this cache answer these questions.
Do not list the answers in your log or the log will be deleted.
Email me the answers.Logs without emails answers will be deleted.

1. Pig iron is a __________ form of iron.
2. There are two iron masses here, these are called “____________”
3. How much does the heaviest one weigh?
4. What is the recipe for one ton of iron?
5. What makes iron rigid?

So we know the answers were not researched online answer this last question from the information boards.
6. Find the picture of the sow feeding her piglets on the information boards. How many piglets is the sow feeding?

Additional Hints (No hints available.)