Geology

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Devonian Period – Gondwana, ferns, lungfish

By | 2017-06-24T00:33:03+00:00 June 24th, 2017|Biology, Geology|

Coelocanth Four hundred and sixteen million years ago, when the Silurian period ended and the Devonian period began, most of the land on Earth was clumped together into a supercontinent called Gondwana. At this time the only creatures that lived on land were small plants like moss and lichens, mushrooms, and other fungi, [...]

What happened in the Cretaceous Period?

By | 2017-06-24T00:28:54+00:00 June 24th, 2017|Geology|

Volcano erupting During the Cretaceous period, beginning about 145 million years ago, the continents continued to drift away from each other, so that the mammals, birds, and dinosaurs on different continents evolved separately and got more and more different from each other. As the continents separated, the climate got cooler and rainier, and [...]

Carboniferous Period – Geology

By | 2017-06-23T23:53:38+00:00 June 23rd, 2017|Geology|

Dragonfly With the end of the Devonian period about 359 million years ago, the Carboniferous period got started. Most of the land on Earth was warm and swampy, which was good for ferns, so that the continents were covered with big forests of ferns. When these ferns died, they formed thick layers of [...]

What happened in the Cambrian Period?

By | 2017-06-23T23:37:38+00:00 June 23rd, 2017|Geology|

Mossy rocks At the beginning of the Cambrian Period, about 542 million years ago, there were sea creatures like hydras, jellyfish, sponges and seaweed living in the oceans, but only one-celled algae on land yet. Small arthropods like beetles were beginning to appear, and by 540 million years ago the first land plants [...]

Clay, sand, and loam – Soil types

By | 2017-06-20T03:15:45+00:00 June 20th, 2017|Economy, Geology|

Soil types triangle All dirt is basically made of three different kinds of particles. These are clay, sand, and loam. Clay is very fine, small inorganic particles, worn down from rock. Sand is bigger, coarser particles, also from rock, often quartz or silica. Loam is organic particles (bits of dead plants). Geologists and [...]

What is marble? History of Art

By | 2017-05-25T11:18:07+00:00 May 25th, 2017|Architecture, Art, Geology|

Cycladic figurine from Greece, ca. 2000 BC Marble is a metamorphic rock made out of limestone. When limestone is subjected to tremendous pressure for a long time (like if limestone is buried under a lot of other rock or an ocean) it gets squashed into marble. Marble is more beautiful than limestone and [...]

What is limestone? History of Art

By | 2017-05-25T10:55:45+00:00 May 25th, 2017|Architecture, Art, Geology|

A block of limestone Limestone is a kind of sedimentary stone that is very common all over the world. This kind of stone is made out of the shells of zillions of little tiny sea snails and creatures like that. These snails and stuff lived in the sea, billions of years ago, and when they [...]

What is kaolin clay? History of Art

By | 2017-05-25T10:46:41+00:00 May 25th, 2017|Art, China, Geology|

A chunk of kaolin clay Kaolin is a kind of clay with a lot of aluminum, silica, and oxygen in it. It is the kind of clay you use to make porcelain. Kaolin clay starts out as a kind of igneous rock called feldspar. When feldspar erodes in places that are hot and wet, [...]