MAORI BAY MUTTER Muriwai      Sun 4 Oct

This was more of a geology field trip rather than a proper tramp. Keith Hitching, a geology varsity graduate, selected an area of particular geological interest, and nineteen people had a very interesting time studying the different rock formations. Maori Bay, south of Muriwai, is often visited by groups of geology students because the cliffs show a variety of volcanic formations overlying beds of sedimentary (water-laid) sandstones and conglomerates. The most interesting lava formation pointed out to us was a group of pillow lavas above Collins Bay just south of Maori Bay. These are sausage-like globules of lava, in this case several meters long by about a metre wide, which have been formed by volcanic lava solidifying under the water. When a cross-section of a pillow lava is exposed by erosion, etc. it shows a shell inside which are radiating formations. To get close to these we had to scramble up a slope of vegetation. Paul and John went on to The Gut, just past a wharf-like formation. It is impossible to carry on past this except at spring low tide. Other things of natural interest we saw were one or two shell fossils, and numerous large eleven-arm starfish. Afterwards most of us went to the gannet colony to observe the gannets in their nesting season. It was fascinating to watch courting couples “kiss” and preen each other with their beaks. One bird was seen to stand on his partner and poke her head with his beak. COST: $5