Welcome to the SkyBridge. From here you will enjoy a magnificent view of Langkawi archipelago.
Completed in 2004, this bridge is suspended from a 82m high single pylon and hangs at about 100m above ground. Measuring at 125m in length, the structure ranks among the world’s longest curved suspension bridges. You need to take the SkyCab ride in order to reach the suspension bridge.
The SkyBridge on Machinchang Mountain.
General geology of the area
The scenic Machinchang Mountain is located in the northwestern corner of Langkawi Island. The mountain scenery is rather unique with its barren rocky peaks and vertical cliffs often being misinterpreted as limestone. As a matter of fact, the mountain is essentially made of sandstone, varying in grain size and thickness with subordinate amount of shale, mudstone and conglomerate. This rock assemblage formed the country's oldest rock, the Cambrian Machinchang Formation (550-490 million years old). The rock of Machinchang Formation exhibits excellent sedimentary structures such as various types of cross-beds, ripple marks, load structures, etc. In addition, Machinchang rocks also yield various types of trace fossils including trilobites and brachiopods. These fossils and sedimentary structures are among the best data for interpreting the ancient depositional environment of the Machinchang sediments.
Machinchang formation as a whole, comprises deltaic and shallow marine deposits. Toward the top of the formation, however, the depositional environment gradually became deeper prior to the deposition of the Setul Formation (490-370 million years). The latter overlies the Machinchang Formation comformably. The Setul Formation is dominated by shallow marine carbonate. Both the Machinchang and Setul Formations were intruded by late Triassic (220-210 million years) Sawar Granite, which transformed them into quartzite and marble, respectively. Apart from being selectively metamorphosed, the Machinchang rock have also undergone various degree of deformation, most conspicuously the brittle type of deformation.
Despite its old age, the Machinchang's hard clean sandstone shows strong resistance against tropical chemical weathering. as a result of prolonged erosion, the sandstone produced outstanding landscapes with crested ridges, spurs, deep narrow gorges, valleys, steep cliffs, waterfalls, and seascapes with sea fountains, sea cliffs, see scarps, headlands, sea caves and remnant islands. These breathtaking landscapes have given the unique Machinchang Cambrian Geoforest park a class of its own the one and only geoforest park in the country.
Aerial view of Machinchang Mountain with the platforms and SkyBridge.
Rock and mineral diversity
Machinchang Formation is dominated by yellowish, moderate to thickly bedded sandstone, but occasional lighter coloured or brownish sandstone also occurs. In places, the sandstone layers are interbedded with dark to light grey shale and mudstone. Conglomerate is rare and usually contains larger clots of white quartz, possibly originating from quartz veins.
Intruding in the Machinchang Formation is the Bukit Sawar Granite, which commonly consists of large crystals of k-feldspar, rectangular in shape and often perfectly zoned, some of which reach 10 cm in length, embedded in relatively finer grained groundmass. This gives the granite a porphyritic texture. Several dark coloured dolerite dykes are seen cutting across the granite at Buray Bay, while a quartz dyke cutting the Machinchang rocks at Tanjung Buta exhibits beautiful clear quartz crystals.
Sedimentary structure diversity
Machinchang Formation reveals various kinds of sedimentary structures in an excellent state of preservation. Among the most common sedimentary structures are cross-bedding, ripple marks and load structures. There are various kinds of cross-bedding structures found within the sandstone beds of Machinchang Formation, the most common of which is planar cross-bed. Through cross-beds are also present within the sandstone. the cross-beds of the Machinchang Formation are often enhanced by laminae of iron oxide instead of mad/clay as in other typical cross-beds. occasionally, paired iron laminae as in the form of iron couplets are also present.
On bedding surfaces, various types of ripple marks including asymmetrical and linguoidal ripples are commonly developed. load structure is also commonly developed whenever there are alternations between thick sandstone and thick shale/mudstone. Interestingly, the Machinchang formation possesses perhaps one of the most complete series of load related sedimentary structures from merely a gentle load cast to the formation of flame and mud escapism structures. The presence of graded bedded is also ubiquitous within the coarser sandstone and conglomerate.
Fossil diversity
Fossils are not particularly abundant within the Machinchang Faormation as only the top part of the formations are known to be fossiliferous. As a matter of fact, trace fossils of Machinchang Formation are dominated by horizontal burrows including Dictyodora ichnosp., Pelaeodictyon ichnosp., etc. Body fossils consist mainly of fragmentary trilobite remains mostly from the saukiid family and several orthid brachiopods. These fossils are preserved in forms of mould and cast as a result of dissolution of original shells by deep tropical weathering. These trilobites and brachiopods suggest a possible Late Cambrian age to the upper part of the Machinchang Formation.
Landscape diversity
Machinchang Cambrian Geoforest park has its own unique landscape diversity as compared to the other geoforest parks of Langkawi. this is due to the different physical properties between the hard clean sandstone and quartzite of the Machinchang formation in the Machinchang geoforest park as compared to the rather reactive limestone and marble of Setul and Chuping Formations in two other geoforest parks. Onshore, the Machinchang landscape is dominated by mountains ranging from gentle slope to vertically truncated cliff exposing the rock sequence very nicely. Tall waterfalls and rapids can also be found within this mountainous geoforest park.
At the top of the mountain, the landscape is dominated by narrow ridges often with sharps crests. The mountains are dissected by narrow deep gorges representing several fault lines including the northeast-southwest lateral fault, one that controlled the lineament of several peaks of Machinchang. Taking a closer view, one could see many sandstone cubicles result from erosion along two sets of fractures that are regularly spaced.
Along the coastline, the landscape differs from the rather monotonous sandstone cliffs that are dipping into the water on the western coastline to the more varied landforms as the bedding strike meets the coastline almost at a right angle in the north. Along this irregular coastline several white sandy pocket beaches are developed in between the generally rocky coastlines. Rocky coastlines of Machinchang reveal several ancient abrasion platforms, ancient and present sea-caves, sea stacks, headlands, remnant islands and tombolos. Selective erosion upon the vertically embedded sandstone and mudstone sometimes form sail-rocks.
View from the SkyCab cable car platform.
Machinchang Peak Geosite
The nearly vertical lift from the Cable Car Terminal to the Middle Station will give riders the enjoyment of viewing the natural landscape of Machinchang from above. Among the attractive sceneries are the Telaga Tujuh Waterfall, Pulau Anak Barau, Machinchang Ridge and last but not least, the hundreds of metres thick sequence of Machinchang sandstone exposures. Apart from Telaga Tujuh Waterfall, during the rain season, one could also observe several more smaller waterfalls rushing down the mountain along intermittent streams. The rocky wall of Machinchang proudly reveals a thick pile of flat lying sandstones, mostly thickly bedded. Large-scale cross-beds are also common features within these sandstone beds.
For those who seek a little more adventure, there is the Machinchang walking trail. This short trail guides you through the Machinchang jungle, where several rare species of mountain plants and animals, including the climbing bamboo Dinochloa malayana, can be observed. Patches of rocky outcrops show excellent sedimentary structures within the Machinchang Formation including the broken or rip-up mud clasts, and through and planar cross-beds. At the Top Station one can observe beautifully preserved ripple marks and planar cross-beds. The trails is also cutting across the Machinchang gorge with sharply cut vertical cliffs on both sides.
On a good day with clear blue skies, the highest platform (708 m) offers a 360° panorama to remember. The panorama ranges from the rugged ad choppy peaks of Machinchang to the smooth and rather conical peak of Gunung Raya (881 m), from the greener landscapes of low and undulating hills of Singa Formation to ghostly gray rugged landscape of the Setul and Chuping limestones. At the right angle, one could also view some of Langkawi's most beautiful beaches and different shapes of large and small islands. It is noteworthy that here, we are very close to the Thai border.
How to claim this EarthCache?
The object of this EarthCache is the peak and rockface southwest of the given coordinates (there's a viewing platform on top of it). If you've picked up the clues provided in the listing, you should have no problems answering the questions.
Send me the following;
1. The text "GC81GQ7 Machinchang Geoforest from SkyBridge" on the first line.
2. The answers to the following questions;
- Would you classify this peak as part of the Setul or Machinchang Formation?
- Looking at the rockface, what does "a thickly bedded rock sequence" refer to?
- The sandstone layers have a natural tilt, estimate their angle.
- The peak appears to have been split, what is the reason for this?
- What geometrical shapes have been created by the weathering process?
- How many glass floor panels does the bridge contain?
3. Provide a photo of yourself or a personal item to prove you have visited the site.*
References
* Effective immediately from 10 June 2019, photo requirements are permitted on EarthCaches. This task is not optional, it is an addition to existing logging tasks! Logs that do not meet all requirements posed will no longer be accepted.
For additional information, visit; Geosociety.org, Geocaching.com Help Center and Geocaching.com Forum.
Finding the answers to an EarthCache can often be challenging, and many people tend to shy away from these caches because of this. However, it is my opinion that geocaching is also meant to be a fun family experience that simply aims to introduce interesting and unique locations such as this one. Flexibility on logging requirements, however, can only be applied if it can be established that you have actually taken the time to visit the site. For this reason, a proper log describing your adventure accompanied by a good number of photos would be much appreciated.
For more information: Panorama Langkawi
