In 1994 an experienced bushwalker and rock climber abseiled into a remote gorge in Wollemi National Park, west of Sydney and found himself in a narrow canyon. He realized that the trees growing along the creek were unusual. The large, glossy evergreen trees had bark that peeled from young stems in red-brown scales and the older bark resembled bubbling chocolate (or coco puffs). Male and female cones were found at the tips of branches on the trees, with a majority of the female cones at the top of the trees.
They proved to be a tree new to science and, prior to this discovery of living trees, the genus was known only from fossils. The Wollemi pine (Wollemia nobilis) belongs to the ancient conifer family Araucariaceae. The other two genera in this family are the Araucaria (that includes the bunya, hoop pine, monkey puzzle tree and Norfolk Island pine) and the Agathis (that includes the kauri). The Wollemi pine has some structural characteristics of the Araucaria and the Agathis, but it also has some unique features. The genus is thought to be about 100 million years old under the uniformitarian (geologic) time scale. So prior to this discovery, these pines were thought to be extinct for millions of years. (more…)
In January 1990 a span of London Bridge collapsed, so its name was changed to London Arch. The arch is a tourist attraction along the Great Ocean Road near Port Campbell in Victoria, Australia. Before the collapse, visitors were able to walk from the mainland across the double-span natural bridge. Oceanic erosion of the limestone coastal cliffs caused the formation of the bridge and also caused its collapse to form an arch. Eventually arches collapse to form stacks like The Twelve Apostles, which are icons of the Australian landscape in the vicinity of London Arch (Appendix A).
In this post we will see that rock coastlines are eroding faster than we think. (more…)