Metamorphic rocks have been modified by heat, pressure and chemical processes, usually while buried deep below Earth's surface. Exposure to these extreme conditions has altered the mineralogy, texture and chemical composition of the rocks. There are two basic types of metamorphic rocks.Foliated metamorphic rocks such as gneiss, phyllite, schist, and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure.uartzite is a non-foliated metamorphic rock that is produced by the metamorphism of sandstone. It is composed primarily of quartz. The specimen above is about two inches (five centimeters) across.
Sydney Tower. Sydney Tower is Sydney's tallest structure and the second tallest observation tower in the Southern Hemisphere. Auckland's Sky Tower is taller but Sydney Tower's main observation deck is almost 50 m (164 ft) higher than the observation deck on Auckland's Sky Tower.
The tip of the Tower is 320 metres above sea level. Eight-floor turret, golden basket, has 420 windows. AMP Tower was sold in mid 2002 and now owned by Westfields PTY LTD. A lightning rod was added to the top of spire in 1998 which extended its overall height to 309m (327m above sea level). Ascent of the tower is achieved by 3 high speed double deck elevators which complete the trip in around 40 seconds.