The updated geochemical atlas was an outgrowth of another project. Geologists and surveyors were on a mission to find rare earth elements and minerals that could be strategically important to the country.
"minerals"
Gardentalk – Composting
Horse manure is good for your compost bin, but no pet droppings
Rare Diamond Points To Mass Quantities Of Water In Earth’s Mantle
It was formed in a region of the mantle known as the transition zone, some 250 to 400 miles below the surface.
Are We Martians? Scientist Says We Just Might Be
As Adam Frank has said over on the 13.7 blog, “Earth and Mars have been swapping spit (astrobiologically speaking) for eons … [and] it is entirely possible we were Earth’s first alien invasion.”