3 September 2013 Part II of Day 4: Geology, and Killer Whales

Durban Harbour and GeologyThe science that deals with the dynamics and physical history of the earth, the rocks of which it is composed, and the physical, chemical, and biological changes that the earth has undergone or is undergoing. in the Field - August 14, 2013

During the afternoon I participated in the long hike with a few other hardy soles. We scrambled over rocks and scree (broken rock fragments) as we climbed the slopes near Durban Harbour. We saw large sections of white rock. A discussion ensued as to whether it was marble or quartz. Luckily, we had Monte Marshall on the hike with us. Monte is a retired geologist and lecturer from San Diego State University who was vacationing with Linblad Expeditions. Monte immediately pulled out his hiking stick with the steel point on the end. He rubbed it across the white rock and it did not leave a mark.

The Mohs hardness scale is a great way to test rocks in the field. According to the scale, the hardness rating for marble is 4-5, a steel file is 6.5, and quartz is 7. Since there was no mark left behind, we concluded that the rock was quartz. Monte stressed that people with marble tile in their house need to be careful that they do not scratch it. Stevie said that his grandchildren like to call the white rocks diamonds, so I gave him a big "diamond" to take home to them.

Killer whales

As we were finishing our evening wrap-up prior to dinner, a call from the bridge announced killer whales outside. We quickly grabbed cameras and were treated to a pod of about a dozen whales including babies. They swam around and checked us out. One of the females even turned upside down and was lobbing her tail as I had seen numerous times in shows at Sea World with my children when they were younger. It was a spectacular sight, and even more special since it was whales thriving in their natural environment.