Posted by curtm on June 8, 2006, at 13:31:10
In reply to dot, posted by llrrrpp on June 8, 2006, at 8:12:17
The "dot" crystallizes from hot carbon-rich fluids. This crystallization requires tremendous heat and pressure—1000 to 1200°C (1800 to 2200°F) of heat and 50 kilobars of pressure. (One bar is based on the pressure the atmosphere exerts at sea level, about 1.02 kg per sq cm, or 14.7 lb per sq in; 50 kilobars is 50,000 bars.) The pressures and temperatures at which it naturally forms only occur deep underground. Scientists believe that it forms at depths greater than 150 km (93 mi), and there is evidence that it forms as deep as 670 km (420 mi) beneath Earth’s surface.
poster:curtm
thread:654392
URL: http://www.dr-bob.org/babble/write/20060523/msgs/654514.html