At the light-colored extreme are rocks made up mainly of quartz and the feldspars, with about 70% silica. Such rocks are called granitic rock. Rocks which contain large amounts of the ferromagnesian dark matter and about 50% silica are said to have basaltic composition.
It became the House of Burgesses â the first legislative assembly in the American colonies. The first assembly met on July 30, 1619, in the church at Jamestown. Present were Governor Yeardley, Council, and 22 burgesses representing 11 plantations (or settlements) Burgesses were elected representatives.
Burgess Shale fossils are from the late Cambrian. Diversity had increased dramatically. There are at least 12 species of trilobite in the Burgess Shale; whereas in the Sirius Passet, there are only two. It is clear that representatives of every animal phylum, excepting only the Bryozoa, existed by this time.