RED SKIN ISLAND CAVE

Herbert Daniel Gebauer - 14/05/2016

A tourist & travel guide book (sorry: source lost, page 625) mentions caves in the rocky north of Redskin Island in what once had been called the Wandoor National Marine Park. SITUATION: Wandoor, a tiny speck of a village 29 km south-west of Port Blair (Portblair, N11°40': E092°45'), is accessible by local bus (1h30, IRs 8) and provides the facility of paying a hefty entrance fee (in 2008 IRs 500 for foreigners) for the Mahatma Gandhi Marine National Park (re-named from Wandoor National Marine Park) where one is not allowed to stay overnight. At the Wandoor Jetty, one is allowed to pay for a seat in a boat (in 2008 IRs 300) taking tourists for a few minutes to several snorkeling points, which include a sandy beach fringed by mangrove forest on the west coast of Redskin Island.At a walking distance of about 150 m north from what had been in 1997 the usual landing point (± 50 m N11°34'20": E092°35'45"), a low rocky outcrop of a sandstone (Eocene, Lower Lutetian, Port Blair?) is sooner or later encountered. At some places, the rock surface shows up to 1 m long karren of up to 5 cm in depth and width. During low tide, a series of mostly crawling sized cave entrances is found at a level of the wave's reach. Most cave passages are relatively short (±5 m) and either lead, decreasing in size, to closed fissures, or penetrate as 1 m diameter tubes to rear entrances. In some caves rimstone was seen growing from fissures. Also observed were deteriorating flowstone speleothems, in cases exhibiting embedded shells. There are also a few small-scale remnants of perched calcite floors. The cave walls are smooth. The floor is mostly covered with sand and a few rounded boulders or is otherwise represented by bare rock which is inclined in accordance with the local dip of the strata (about 3° to 6° to the approximate north).The caves are understood to originate from fresh water seeping through clefts and fissures. The original micro conduits develop subsequently into caves through dissolution by fresh water mixing corrossion with brine. Once initialised, wave action and gravitational decay continue and finally terminate cave evolution. CAVE DESCRIPTION: Three cave entrances (E1: 3.5 m wide and 1.2 m high, facing south. E2: 2.5 m wide and 0.9 m high, facing south-east. E3: 6.5 m wide and 3.0 m high, facing east) give access to murky cave passages guided by fissures aligned NNE (north-northeast) to SSW (south-south-west).