Between N 38 36.960 W 120 57.590 and N 38 37.500 W 120 57.830 (roughly) you will find pieces of iron slag strewn about the tracks. All along this portion of the trail I was finding slag, but some of the larger specimens and bulk of the slag was between these waypoints (at least I was seeing larger piece with more frequency between these points).
You will be looking for a piece of slag from between the waypoints listed on this cache. Keep your eyes open and observational lens scanning the trail, there is plenty of slag to choose from.
LOGGING REQUIREMENTS:
First and foremost, you need to bring some magnets with you for this cache (Special tools required, this is the reason for the 5 difficulty. The questions alone are maybe a 3). Stronger magnets work better, but if you have a couple of varying strengths it could make for a better experience. You do need at least one magnet.
Then, you must find a piece of iron slag along the trail to study and make observations on. Look for a good-sized piece (there are plenty) ideally around baseball to softball sized, golfball sized would work as well (but less impressive). Once observations are complete you can leave the slag, replace it along the tracks.
Finally, make observations and answer the following:
- List all those if your group, you only need to send answers one for the group as a whole.
- In your own words, explain what slag is.
- Describe the piece of slag you are studying (size, color, weight, texture, etc.)
- Is it magnetic? How strong is the magnetic pull (does is lightly attract, can you hold it upside down without the magnet falling off)? Compare the magnetic attraction of the slag to the magnetic attraction to the rails. How many magnets did you try? (You will need to bring a few magnets of various strengths to test this)
- There is a lot of this iron slag around here, especially along this section of trail. After reading the description explain briefly why you think this slag is here, for what purpose? And why specifically this iron slag, based on the history of El Dorado Country, why would they have an abundance of this iron slag to use.
- Snap a pic of your study specimen (take a pic of the slap piece you are working with). Feel free to post you pic in your log, posting a pic of your piece of slag will not spoil this earthcache for others, there is plenty to choose from.
LESSON:
What is Slag?
Slag is the leftover material, the byproduct, of iron and steel productions. It is the leftovers from melting off the impurities from various metals. Slag is a glassy, mineral-rich byproduct formed by melting impurities like silica, alumina, lime during iron and steel production. Iron slag forms during the melting of iron ore in a blast furnace. The iron slag is often magnetic due to the trapped iron particles left behind in the smelting process, or due to iron oxides formed during the heating process.
While the slag is a byproduct of impurities leftover after the purification process, slag does have uses. Blast furnace slag (typically the process that will create iron slag) is used for:
- Cement and Concrete
- Road Construction and Aggregates
- Railroad Ballast
- Agricultural Fertilizer
- Marine Construction
- Insulation
Iron slag and historical metal scraps are found along El Dorado County trails, particularly along the 13-mile El Dorado Trail in Placerville. These trails follow a historic Gold Rush-era mining rail line, and this section of the rail line has become part of the Rails to Trails, becoming a walking/biking trail as it is no longer used as a railway. These residues are remnants of mining, lumber operations, and early transportation, with some sites near old blast furnaces, mine pits, and the Sacramento-Placerville rail corridor. With the history of the Gold Rush through this area, the development of the railways was important to transport materials from mines to mills. Byproducts from the purification taking place at the mills could then potentially be used to help build, strengthen and support the expansion of the existing railways.
- El Dorado Trail (Placerville): This trail passes through areas with remnants of gold mining and transportation history, featuring metal pieces and old rail trestles.
- Iron Mountain Trail Area: Located in El Dorado County, this area near old logging operations features iron debris and abandoned fire lookout remains.
- Industrial Residuals: Some areas, specifically in mining or logging sectors, might contain industrial slag, metal scraps from early automobiles, or old structural pilings.
SOURCES:
ALL ABOUT SLAG: https://youtu.be/0zuiKQ02ZdA?si=E5QX8GQj0w8_gfIU
This is not a meteorite... https://www.jademellor.com/jadesjournal/2013/8/21/this-is-not-a-meteorite
Slag: https://en.wikipedia.org/wiki/Slag
Federal Highway Administration: https://www.fhwa.dot.gov/publications/research/infrastructure/structures/97148/bfs1.cfm#:~:text=ACBFS%20has%20been%20used%20as,or%20component%20of%20blended%20cement)
HELPFUL CACHES:
Coarse Slag - Ballast on the T.H.&B. Rail Trail - GC7KY8J
Don't Slag Off! (Henry Clay Iron Furnace) - GCAZZVZ