Shoalhaven District Geology

FIELD GEOLOGY OF THE SHOALHAVEN DISTRICT                                              (PART 18) Chapter 10. The Wandandian and Conjola Districts   This is largely an area of uncleared bushland. Features of interest lie along the highway or on the coastal strip. Other than the Wandrawandian Siltstone and the Conjola Formation, the only variation in the geology is provided by an occasional dyke or inlier of basement rocks.  Several dolerite dykes will be seen on these excursions; they are all similar, being composed of a bluish-black olivine dolerite with phenocrysts of plagioclase up to 1 inch across. The dykes are up to 60 feet wide and are traceable for several miles.  The deep valleys of Wandandian and Conjola Creeks have exposed highly folded strata of unknown age, usually taken to be Ordovician like the metamorphic rocks of Tolwong and Nerriga. These have...

  FIELD GEOLOGY OF THE SHOALHAVEN DISTRICT (PART 14) Chapter 8. The Tomerong District   In earlier days, when there were few casual visitors to the South Coast,  Tomerong  was much more a rural centre than it is today. The growth of holiday areas around Jervis Bay and St George’s Basin has rendered it less important.  Tomerong is situated where the southern road first passes through the Nowra Sandstone onto the widespread Wandrawandian Siltstone. The change is marked by a noticeable improvement in the soil, and this in turn has led to the growth of spotted gums and turpentine, in contrast to the poorer types growing on sandstone soils. The sawmills around Tomerong and Wandandian capitalise on this forest wealth and provide local employment.  North and west of Tomerong are outcrops of the overlying sandstone and the Berry Formation. Elsewhere, the Wandrawandian Siltstone is the dominant rock type, except along the shores of Jervis Bay, where a dome structure...