Continuing our story of the respective rock families we reach the third great group, the metamorphic rocks. Igneous rocks were covered in What On Earth 2002 Fall issue and the Sedimentary rocks in the Spring issue of 2003. All three categories are now covered in a new teaching poster that can be obtained at a minor cost from What On Earth.
Lead is a very soft, bluish-gray, metallic element. Since it is so soft, lead is usually alloyed with other elements. Water pipes in ancient Rome, some of which still carry water, were made of lead. The English word plumber and pluming are derived from the Latin word for lead, plumbum. The properties of lead which make it an excellent material for many applications are its density, high level of stability, and it has high degree of flexibility, which makes it easy to work.
If you are a person interested in geoscience education, August 2003 was the month to be in Calgary. The meeting was hosted by the Canadian Geoscience Education Network a standing committee of the Canadian Geoscience Council, but run by a small group of local volunteers over four days of meetings preceded and followed by some fantastic fieldtrips.