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The mesosphere (/ ˈ m ɛ s ə s f ɪər, ˈ m ɛ z-, ˈ m iː s ə-,-z ə-/; [1] from Ancient Greek μέσος (mésos) 'middle' and -sphere) is the third layer of the atmosphere, directly above the stratosphere and directly below the thermosphere. In the mesosphere, temperature decreases as altitude increases.
As for life on land, in 2019 scientists reported the discovery of a fossilized fungus, named Ourasphaira giraldae, in the Canadian Arctic, that may have grown on land a billion years ago, well before plants are thought to have been living on land. [100] [101] [102] The earliest life on land may have been bacteria 3.22 billion years ago. [103]
The "Defining markers" column lists the evidence in the rock used to define the boundary. (Ideally, these are applicable in rock sections worldwide.) Most of the boundaries rely on the fossil record (biologic), paleomagnetic data (magnetic), and/or climate data determined by carbon and oxygen isotopes.
Mesoamerica and its cultural areas. Mesoamerica is a historical region and cultural area that begins in the southern part of North America and extends to the Pacific coast of Central America, thus comprising the lands of central and southern Mexico, all of Belize, Guatemala, El Salvador, and parts of Honduras, Nicaragua and Costa Rica.
The earliest evidence for life on Earth includes: 3.8 billion-year-old biogenic hematite in a banded iron formation of the Nuvvuagittuq Greenstone Belt in Canada; [30] graphite in 3.7 billion-year-old metasedimentary rocks in western Greenland; [31] and microbial mat fossils in 3.48 billion-year-old sandstone in Western Australia.
Plate tectonics (from Latin tectonicus, from Ancient Greek τεκτονικός (tektonikós) 'pertaining to building') [1] is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago.
The upper boundary is defined by the sharp increase in seismic wave velocities and density at a depth of 660 kilometers (410 mi). [8] At a depth of 660 km, ringwoodite (γ-(Mg,Fe) 2 SiO 4) decomposes into Mg-Si perovskite and magnesiowüstite. [8] This reaction marks the boundary between the upper mantle and lower mantle. This measurement is ...
'A Map of the Myriad Countries of the World'; Italian: Carta Geografica Completa di tutti i Regni del Mondo, "Complete Geographical Map of all the Kingdoms of the World"), printed by Italian Jesuit missionary Matteo Ricci at the request by Wanli Emperor in 1602, is the first known European-styled Chinese world map (and the first Chinese map to ...