What causes volcanoes? Geology
Volcano erupting Volcanoes are places where the plates of the Earth's surface have cracks in them, so that the very hot melted rocks that are under the tectonic plates bubble [...]
26
06, 2017
26
06, 2017
What are igneous rocks? Volcanic stone
Igneous rocks: Obsidian tools What does "igneous" mean? Igneous means "fiery", and igneous rocks are rocks that were made by heating them up in a fire. Usually that fire is [...]
25
06, 2017
Feldspar rock – a kind of igneous rock
A feldspar rock quarry in India Is feldspar rare? Feldspar is a very common igneous rock. More than half of the Earth's crust is made of feldspar. What are igneous [...]
25
06, 2017
What is basalt? Igneous rock
Where does basalt come from? Basalt is a fine-grained, hard rock that forms when bits of lava shoot out of volcanoes, so it's one kind of igneous rock. Igneous rocks Volcanoes All [...]
12
06, 2017
Ancient Economy – Simple economic history
Ancient economy: a bone sickle - the flint teeth are missing now Trade or self-sufficiency? Even today experts don't really understand how economics works. Historians also disagree about how economics [...]
24
05, 2017
What is basalt? Geology and Grindstones
A Roman road paved in basalt (This is from Trajan's Market in Rome) Basalt and volcanoes Basalt (bu-SALT) is a volcanic stone - it forms from the lava that volcanoes [...]
