Wandering in Rock Country

Book excerpt: What is beyond the beauty of a piece of rock? How does a stand-alone rock come into being naturally? The book presents more than 100 pieces of stories for various rocks, most of which originate from desert, beach, and hillside in Southern California. The author points out the observables with the naked eye and explains their occurrences, putting together the principles of physics, chemistry, biology, and geology, which you know as common sense but the application of which you may not yet think about. To name just a few examples: it describes features of nature’s destruction and rejuvenation in sediments and carbonates; it tells the origin of geode, agate, chalcedony, and volcanic bombs; it argues natural carving and piercing of quartz through cyclic water freezing and ice thawing in the desert; it ponders ventifact and varnish as well as lichen (algae/fungi) growth on desert rocks; it considers fracturing and cracking in shaping the rocks by decompression expansion due to erosion and cooling contraction due to tectonic uplifting; and it addresses liquefaction by ground shaking and erratic sediment distribution by ice rafting and climate change.