Canada's Baffin Island, where researchers found the geochemical signature of material left over from Earth's early development, about 4.5 billion years ago. https://www.yahoo.com/news/volcanoes-spit-4-5-billion-old-pieces-earth-110255964.html
more clue about our planet formation. Scientists have found evidence of a huge asteroid that struck the Earth early in its life with an impact larger than anything humans have experienced. Tiny glass beads called spherules, found in north-western Australia were formed from vaporized material from the asteroid impact, 3.46 billion years ago. https://www.sciencedaily.com/releases/2016/05/160516095132.htm Cyanobacteria are photosynthetic organisms, a relatively complex lifeform. The earliest fossils recorded so far are those of sulfur-reducing bacteria in Western Australia. It is certain that cyanobacteria evolved from something like iron- or sulfur-reducing bacteria. The first living things appeared about 400 million years before the earliest fossils were laid down. Those were probably ribozymes, which were self-catalyzing, self-replicating molecules of a single-strand nucleic acid such as ribonucleic acid or glycol nucleic acid. The formation of marble have anything to do with asteroid impact ?