- Okhotsk microplate (Wikipedia)
The Okhotsk microplate is a proposed minor tectonic plate covering the Kamchatka Peninsula, Magadan Oblast, and Sakhalin Island of Russia; Hokkaido, Kantō and Tōhoku regions of Japan; the Sea of Okhotsk, as well as the disputed Kuril Islands.
- Metal Ages (Wikipedia)
The Metal Ages is a term for the period of human civilization beginning around 6,000 years ago in which metallurgy rapidly advanced and human populations started using metals such as copper, tin, bronze and finally iron, to make tools and weapons. By heating and shaping metals in hot furnaces, people also learned to use precious metals such as gold and silver to make intricate jewellery.