On Monday, 5th September the Level 1 geography students traveled to view the Alpine Fault (AF) at various locations in the Grey District.
We were accompanied by Mary Trayes was our tour leader, having worked for the Regional Council for many years identifying issues related to the AF. Students visited sites at Turiwhate/Fitzgeralds Creek to learn about the geology of the area and landslides along the Wainihinihi Valley. At Wainihinihi Bridge we examined rocks made of serpentine, a metamorphosed (heat & pressure) ‘ultra-mafic’ rock. Following on we stopped at the Taramakau Valley to view where the fault looks like a V-shaped valley, here we discussed granitic rock like Mt. Turiwhate. At this stop the Pacific Plate side of the AF gets uplifted 1-3m! The plate on the west side known as the Australian Plate is shunted 4-7m north-east with each AF earthquake. At Griffin Creek we viewed the aggradation (river bed build up) and further along at Rocky Point, we viewed where the AF is visible in the gully across the road, collecting pieces of cataclasite. We travelled on from here to Inchbonnie and then to Lake Poerua where in the early 2000’s a housing subdivision was planned with the AF running directly through it. Our final stop at Rotomanu had us view where the AF travels along the lower slopes of the Alexander Range. All in all it was an informative and interesting day out. The students were a credit to our school and their families.