Change of speaker for the evening talk on August 15th

Due to unforseen circumstances Dr John Davies will not give the talk on the 15th August. Instead Dr Chris simpson will give a talk entitled: "An Overview of San Francisco Geology."
The talk will summarise the last 200M years of geology as it affects the West Coast of the USA, and how this can be seen in the rocks of the San Francisco area today. It will also include some historical aspects of San Francisco, and a trip to the Yosemite National Park.