Salts form 3.5% (more commonly stated as 35 ppt) of seawater by mass. If you evaporate seawater, the following minerals precipitate out in this order (the reverse of their solubility):
1) Calcite (CaCO3)
2) Gypsum (CaSO4 * 2H2O)
3) Halite (NaCl)
4) Sylvite (KCl)
You can remember the order because it's alphabetical!
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Metamorphic rocks form when a preexisting rock (protolith) is transformed into a different rock due to pressure, heat, or chemical alteration. Tectonics and burial can supply pressure and heat on a wide scale (regional metamorphism), while igneous intrusions can bake adjacent rocks (contact metamorphism). Hydrothermal fluids power chemical alteration. This page has useful diagrams of metamorphic processes, while this one has good notes, and this one has both! Read more
It can be hard keeping up with the differences between planets, comets, asteroids, and meteroids--especially when many people use the terms interchangeably. This list quickly distinguishes between these objects while providing a map (not to scale!) of the relative locations of the planets and other noteworthy cosmic features. Read more
Fossils, preserved remains or traces from ancient organisms, not only paint a picture of past life, they intrigue imaginations of all ages, make classic home decorations, and perhaps most notably, power society (petroleum is a chemical fossil). This post highlights the types of fossils, the stages of fossilization, the factors that increase the likelihood of an organism becoming a fossil, as well as the methods of preservation. Read more
I wrote this article in 2009 for another website I was running at the time. In this article, I cover my experiences with the ocarina, the history of the ocarina, selecting (or making) an ocarina, and how to play an ocarina.
At a renaissance festival, a musician lured me with whimsical melodies using a strange whistle-like device. Enchanted, I hovered over to her stand, where I discovered that she and her sister made ocarinas for a living, to my great surprise, because, although I had played The Legend of Zelda: Ocarina of Time, I never knew such instruments actually existed. A diehard Zelda fan and a lover of music, I stood staring at the shiny ocarinas of all shapes and sizes on the counters. Read more
This list briefly describes the creatures appeared (and not necessarily when they disappeared, if they did). Keep in mind that all of the creatures listed are marine, and most are soft-bodied invertebrates. Of course, this list doesn't even come close to covering all the Paleozoic creatures, just the ones I found worth mentioning -- if you think I missed one, let me know in the comments! Click on the images to enlarge; hover to see photo credit in alt-text (many are from Nobu Tamura). Read more
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
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.
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
We typically think of volcanoes as destructive, but their eruptions could be feeding tiny photosynthetic organisms that live in the ocean.
Primary productivity (how much photosynthesis occurs) in certain areas of the ocean is iron-limited: even though phytoplankton (photosynthetic microscopic organisms) have plenty of all the other nutrients they need, a shortage of iron limits their growth. Read more