Mystery Bay Kink Zone Earthcache
There Is no physical container at this location,to log this Earthcache you will need to visit the posted coordinates,and answer the related questions listed below
The rocks here which are such a dominant feature are chert, black mudstone and slate date back nearly 500 million years to the Ordovician period. The outcrops lie in what is called in geological terms a kink zone, which means they’ve been subjected to great pressure during the moving of tectonic plates. A feature called foliation(parallel alignment of the textural and structual features of a rock), which has formed during movement at high pressure and which has enabled further deformation, is apparent in the kinks and breaks in the angular brittle rocks, which makes these rocks look as if they could have been pieced together one by one. Kinks zones are widely developed, but are particularly well shown here in this area of Eurobodalla’s coastline.
Folds And Foliations
Geometry of Folds - Imagine a carpet lying flat on the floor. Push on one end of the carpet, and it will wrinkle or contort into a series of wavelike curves. Stresses developed during mountain building can similarly warp or bend bedding and foliation (or other planar features) in rock. The result a curve in the shape of a rock layer is called a fold.
Not all folds look the same some look like arches, some look like troughs, and some have other shapes. To describe these shapes, we must first label the parts of a fold (figure above a). The hinge refers to a line along which the curvature is greatest, and the limbs are the sides of the fold that display less curvature. The axial surface is an imaginary plane that contains the hinges of successive layers and effectively divides the fold into two halves. With these terms in hand, we distinguish among the following: Anticlines, synclines, and monoclines: Folds that have an arch-like shape in which the limbs dip away from the hinge are called anticlines (figure above a), whereas folds with a trough-like shape in which the limbs dip toward the hinge are called synclines (figure above b). A monocline has the shape of a carpet draped over a stair step (figure above c). Non-plunging and plunging folds: If the hinge is horizontal, the fold is called a non-plunging fold, but if the hinge is tilted, the fold is called a plunging fold (figure above d). Domes and basins: A fold with the shape of an overturned bowl is called a dome, whereas a fold shaped like an upright bowl is called a basin (figure above e, f). Domes and basins both display circular outcrop patterns that look like bull’s-eyes the oldest layer occurs in the centre of a dome, whereas the youngest layer is located in the centre of a basin.
Earth Lesson Questions
1- Looking at the rock structure here describe the colours, texture and the formation you see and explain your reasons why you think it has this appearance?
2 - Using the figures shown above what type of fold would you consider this to be here?
3 - Looking at this feature from what direction do you think the main pressure of the push has occurred from?
(a) - East to West
(b) - West to East
(c) - Upwards
(d) - All of the above
4 - (optional) - Post a photo of yourself or your device near GZ
Please send me your answer via Geocaching.com before logging your find,you do not need to wait for my reply to log this cache however any unsatisfactory logs will be deleted.
Enjoy your visit to Mystery Bay!
How to get there
Mystery Bay is 15km south of Narooma, and 70km south of Batemans Bay. It is a short 2km from the Princes Highway. From the highway turn on to Mystery Bay Road. Follow Mystery Bay Road into Mystery Bay. There is car parking out side the camp ground at the northern end of the beach as you enter Mystery Bay,from here a short walk through the camp ground will bring you to the trailhead coordinates leading you to GZ.
History - The Mystery At Mystery Bay
In 1880, gold was discovered at a site in NSW called Montreal (see Montreal Goldfield elsewhere on this site) near Bermagui. The Mines Department sent Lamont Young, one of its geologists, to inspect and report on the find. He was accompanied by a German friend, Louis Schneider, a botanist. After arriving at Batemans Bay by steamer, Lamont secured a boat and a crew of three to row them to the Montreal Goldfield. The crew included the boat's owner, Thomas Towers of Batemans Bay, and two of Towers' friends: William Lloyd and Samuel Casey. However rather than going directly to the Montreal Goldfield, Young apparently changed his plans: after 4 pm on the Saturday of his arrival, he was never seen again. At about 7am on the Sunday morning, his rowing boat, a green eight-metre vessel, was seen by several residents leaving Bermagui and others noticed it as it moved slowly north along the coast. At about 4pm that afternoon, a man riding along the coast found the boat on the rocks known locally as Mutton Fish Point, about fifteen kilometres north of Montreal, but there was no trace of any of the men who had left that morning. Police, who hurried to the scene and examined the boat, noted that it had been carefully steered through about 70 metres of jagged rocks. There were four large holes in the hull but the planking had been stove out, not in. On the seats were bait, a pocket knife, pipe and tobacco, crumbs and other food. There was also a bag of potatoes and a bag of mixed personal articles like clothing, bedding, tools and sundries. The anchor and stern lines were missing but some large stones had been placed in the boat. Scattered on the beach nearby were a pipe, sheath knife, an axe and shovel. Other items which may have been linked to the mystery were three mother-of-pearl studs, a portion of a meal and three cigar butts. Young, Schneider and the three boatmen were not at Bermagui and were never heard of again despite subsequent searches, rewards, government inquiries and wide media coverage. The name 'Mystery Bay' is the result of this bizarre event and a memorial at Mystery Bay was unveiled on 10 October 1980 on the centenary of the incident.This monument is located just in front of the car parking area at the marked waypoint
