“... Slope Point is the southernmost point of the South Island of New Zealand and is located in the Catlins region. The geology of this region dates back to over 150 million years ago, when the bedrock of the New Zealand continent was being assembled by thick sediments and volcanic arcs accreting onto the edge of the Gondwana supercontinent in a series of long thin terranes. The parallel hill ranges of the Catlins form part of the Murihiku terrane, which extends inland through the Hokonui Hills as far west as Mossburn. This itself forms part of a larger system known as the Southland Syncline, which links to similar formations in Nelson (offset by the Alpine Fault), the North Island and even New Caledonia, 3,500 km (2,200 mi) away. The Catlins ranges are strike ridges composed of Triassic and Jurassic sandstones, mudstones and other related sedimentary rocks, often with a high incidence of feldspar. Fossils of the late and middle Triassic Warepan and Kaihikuan stages are found in the area.
Both coastal and inland areas around slope point are popular with rock hounds. On the Southland coast between Waipapa Point and Haldane there are a number of pebbly beaches visited by fishermen and rock collectors. The cliffs contain layers of conglomerates with pebbles which weather out and collect on the beaches. At first glance they appear dark, but closer examination reveals a multitude of subtle colours and patterns. The most sort after item on these beaches is petrified punga (fern) ( 2 ,3 ). This material usually takes the form of black nodules which may or may not show very faint eyed grain of the fern. To bring the grain out collectors take home any rounded, black woody pieces and bleach them overnight after which the grain of wood or punga is revealed. Other items of interest that can be collected include pale granites; andersite with amygdales of quartz; porphyries, which are stones with large crystals (e.g. feldspars and quartz) set in a fine-grained mass; agates; breccias; rhyolites, these are often flowbanded and sometimes with small crystals of quartz or feldspar or are of the "Flower garden" variety and have white and grey circles and centres, but there are many colours and patterns including the spherulitic stones; and, rhyolites with turtle-back patterns. In inland areas it is possible to collect petrified wood and very occasionally petrified ferns. The easiest way to do this is to look in new dug drainage ditches. However, one must locate and ask permission of the land owner before doing so. Another area worth visiting in the Catlins is Curio Bay. This bay contains the petrified remains of a forest 160 million years old and represents a remnant of the subtropical woodland that once covered the region, only to become submerged by the sea. The fossilised remnants of trees closely related to modern kauri and Norfolk pine can be seen here. This area is protected and absolutely no collecting can be undertaken here. All in all the Catlins is a beautiful area that is well worth a look around. Even if you don’t find anything you will see some outstanding and interesting and memorable landscapes..”
written by Scott Hardwick, Christchurch, New Zealand