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-type. faunas have been preserved in a number of Middle Cambrian localities off the. Cathedral Escarpment of the northern margin of Laurentia (Collins, Briggs, and. Conway Morris, 1983), and there is evidence for world-wide occurrence of such faunas. during the Early and Middle Cambrian (Conway Morris, 1989a,b, 1998 p. 116-137). Various mechanisms have been proposed for the fossilization of the soft-bodied. and lightly armored fauna of the Burgess Shale.