How Golda Meir, Indira Gandhi, and Margaret Thatcher Wrought a New Standard of Leadership. It is surely time to recognize what an immense improvement has been wrought in world standards of governance by the rise of female national leaders.
Shield volcanoes, the third type of volcano, are built almost entirely of fluid lava flows. Flow after flow pours out in all directions from a central summit vent, or group of vents, building a broad, gently sloping cone of flat, domical shape, with a profile much like that of a warrior's shield.
Rhyolitic lava erupts at lower temperatures (800-1000 oC) and contains more silica (> 65 wt. % SiO2) than basaltic lava. Rhyolitic lava is therefore more sluggish, moves more slowly and builds thicker lava flows than basalt. 4. Andesitic lava has a silica content intermediate between basalt and rhyolite (55 - 65 wt. % SiO2) and therefore has flow characteristics intermediate between these two lava types.