Wave Rock is a 15 metre high concave wall of granite. Streaked with black and orange algal remains, it is a spectacular site – but, despite its name, it has nothing to do with the ocean.
The shape has been carved out of ther slopes of Hyden Rock by the weathering action of water in the soil that abuts the rock
・This soil is dampered by water running off the rock but near the surface it dries quite quickly
・Deeper down the soil remains moist for much longer, allowing the “rotting” action of this moisture to eat away at the face of the rock.
・As erosion exposes more and more of the outcrop this “flares slope” (or “wave”) seems to rise up – just like a breaker on a beach.
The “wave” here at Hyden Rock is unusually high and long – if it was water it would be a mecca for surfers from all over the world! But why?
・It formed in deeply fractured rock, which allowed water to penetrate easily;
・Run-off from a wide area above was naturally channelled to this face;
・The water here was alkaline (saline) and readily attacked the granite;
・The outcrop was stable for a very long time, keeping this surface underground;
・An old river channel just north of this face added even more moisture, and
・This old river eventually eroded the surrounded quite deeply, exposing the whole of the now-massive flared slope.
Other “wave” are found around Hyden Rock, at the Humps, on other rock outcrops across Western Australia, and all other the world – but few, if any, are as spectacular as Wave Rock.
Revealed by shifting sands, thousands of limestone pinnacles stand as monuments to a distant past，exposing an ethereal landscape with a mood that changes with the passage of day.A hot desolate landscape in the midday heat becomes warm and intriguing as the light from the setting sun sneaks through the vertical pillars of rock creating long contrasting shadows that play over the rippled sand．The Pinnacles Desert is a landscape that should not be viewed but experienced in all her moods．
Sculptured by the forces of nature，each pinnacle is unique，revealing the harsh environment from which it was created.
Many thousands of years ago lime sands accumulated on the shore and bed of an ocean，rich in marine life． These sands were blown inland forming high mobile dunes similar to those seen today along the Turquoise Coast． Water from winter rains percolated through a humus layer rich in decaying plant. material on the surface of these dunes, becoming acidic.
This mildly acidic water then dissolved and leached the calcium from the sand as it percolated deeper into the sandy soil leaving only the tough silica sand particles behind. Deep in the soil profile as around water levels fell in summer, calcium carbonate was deposited, cementing the silicate sand particles together to form limestone．Replenished by calcium-laden water the following winter，the process continued season after season, forming a hard layer of calcrete on the surface of the limestone deposit.
lt is here that part of the mystery of the pinnacles begins．They were hidden beneath the soil and formed over hundreds, if not thousands of years, and geologists are still divided as to how the limestone formed into columns creating the pinnacles. Some believe that the limestone between the pinnacles was leached away more rapidly in areas where plant roots increased the acidity of the soil; others believe that the pinnacles formed around the roots and trunks of buried trees. In both theories however, the pinnacles were formed beneath ground from the varied influence of acidic water as it percolated through the soil profile, first leaching then accreting calcium carbonate into interesting and diverse forms．
As the vegetation stabilizing the silicate sand was removed, probably by fire, the sand was blown away, exposing the pinnacles to the elements of the atmosphere. The pinnacles were sculptured further by wind, rain and the blistering sun into what we see today．
The Yued people have a more mythical explanation for this unique landscape that connects them to the land and carries the stories of their past．
The pinnacles experience is entirely personal and distinct．To some they are a pile of interesting rocks while others see them in a more spiritual or artistic light． Regardless, this is an experience of the Turquoise Coast that cannot be missed．
14:00、ピナクルズからセスナでパースに。旅行社Veltraのハンプによれば「上空からしか見られない、デッドピナクルズを通過します」という。Dead pinnaclesってなあに？ 「Fly over the Pinnacles & Dead Pinnacles (seen only from the air) to Perth」と英語でも同じように書いている。他に「a second collection of isolated structures, nestled amongst bush」（低木の中にある第２の孤立構造物）。写真はこれ？ それとも写真はただのピナクルズ？