Monthly Archives: July 2014

Basalt types: tholeiites vs alkali basalts

Essentially, tholeiites are less evolved. They have different normalized rare earth element REE signatures: when normalized by chondrites, the more primitive tholeiites have flatter REE patterns, while calc-alkalis show enrichment in the light REEs (LREE). Tholeiites are associated with oceanic spreading centers (shallow), while alkali basalts are associated with collisional zones (deeper). Read more

Quick facts about the layers of the Earth

Here is an easy chart gathering together basic facts about each of the earth's layers, from top to bottom: the crust, the mantle, and the core. The crust and uppermost part of the mantle (down to 70 km) from the rigid lithosphere, which contains tectonic plates, underneath which lies the fluid taffy-like asthenosphere, which drives plate motion. Unsurprisingly, as you travel deeper into the earth, things get denser, hotter, and and more pressurized.

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The firefly fairy (Angelicae lampyridae)

The firefly fairy (Angelicae lampyridae) collects coins during the day and stores them in a pouch about her waist. She takes great care to polish the coins to a most desirable shininess. At night, when she runs across a firefly trapped inside a jar by an awestruck human, she frees the captive and leaves a quarter in his or her place. Although she develops endurance and strength from carrying coins, the firefly fairy naturally possess incredible energy, most likely to match that of fireflies. Read more