Dykes at Bingie Bingie Point

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At Bingie Bingie Point on the south coast of NSW Australia, at least four phases of dykes have intruded the Tuross Head Tonalite. The host plutonic rocks vary from tonalite (tagged ‘3’ near the top of the model) through diorite to gabbro. The largest of the dykes is a highly felsic microgranite dyke that makes up most of this model (~3 metres in true thickness). Its strike is ~125° and it dips at ~35° to the northeast (toward the viewer in this model). The dyke is dotted with numerous quartz-tourmaline nodules resulting from pooling of late stage boron-rich aqueous fluids. The microgranite dyke is cut here by three separate splits of a basaltic dyke striking ~065° with a near vertical dip. At least three basaltic dykes of this orientation (each with their own splits) occur across the headland. These basaltic dykes constitute the youngest of phase of dyking. One of these dykes (not pictured here) contains many large (up to 10 cm) lower crustal/upper mantle xenocrsysts including garnet and augite.