WHERE DID THE QUARTZITE COME FROM?
We could end here, if we wish. But all of this begs one final question: If the quartzite pre-existed the syenite, then when and how was the quartzite formed? To answer this question we must venture even further back in time, back almost to the first continents of Earth. Quartzite is sandstone that has been altered (“metamorphosed”) by heat to the extent that the original quartz grains of the sandstone have been fused with the silica that served to cement them together in its original sedimentary state. So now we must explain the original sandstone! Like sand we find today along rivers and on beaches, the sand grains of the sandstone must have come from the erosion of the land. This land must have been created even further back in time. It is thought that this land was part of an “Archaean Supercontinent” (think of this as an Archaean version of the Phanerozoic’s “Pangaea”). The erosion that produced the sand was happening on this ancient continent about 2.5 – 2.2 billion years ago. Muc
