Zhangjiajie’s “floating sky mountains”, hundreds of kilometers inland, house Ordovician reefs: they are made of quartz sandstone. Rock made of quartz grains brought towards the sea by rivers. Then, compacted and cemented. From the early to late Ordovician, algal and coral reefs grew on the sandstone. From the Silurian onwards, they were pushed gradually inland, transforming from a seashore to mountains.
a part of history : what's unwritten
Manhattan schist was formed about 450 million years ago, making it the second oldest of New York City’s bedrocks, after Fordham gneiss. At that time, the continents of the world existed as a single supercontinent, called Pangea.
apart from history : what's unspoken
Andesite was named after the Andes Mountains, but is usually more abundant elsewhere along the Ring of Fire, such as in Indonesia, the Philippines, and its northern part. It is among the components of Mayon eruptions. Since it forms from magma, variations in andesite composition reflect tectonic settings happening during its time of eruption. Some andesites trap bubbles of gas as they cool, preserving information about ancient atmospheres. Today, it is used in roads, buildings, terrariums, aquariums, landscaping, and cemetery markers.
departing history : what's unthought
Decades ago, we all lay in a circle for siesta, talking about what we would become drifting in and out of sleep. We had an old encyclopedia at the center. We talked about what life must have been like thousands of years ago. We watched the clouds outside moving. I wondered if these same formations appeared back then. We made plans for how we would want to die. We wondered what people, generations after us, would say about us, if they unearthed all our belongings. If we wrote anything, would language have changed then? We all agreed it didn’t really matter. Anything we said or thought is just clouds. This is all I think about. In online meetings during the afternoon.