Langkawi Geopark : Amazing Facts Oldest Rock Formation [www.langkawi geopark.com]
The natural construction of these features greatly influenced the types of rock formation. Datai Bay is a sequence of interbedded sandstone and shale which is called Machinchang Formation aged 550million years old and regarded as the oldest rock in Malaysia. Indeed this area is one of the most important geological sutes in Malaysia which must be preserved and protected for educational and reserceh purposes.

High Geological Value
Datai Bay also has a great diversity of rocks, structural and landform, which contributes to the high geological value of the site. The rock diversity is easily defined by the rocks types within the Machinchang Formation. At the Bay, this sedimentary rock as identified along the rocky beach is a layer of dark shale and fine to coarse grain sandstone. Most of the rocky beach to Tanjung Hulor. To the east, towards Anak Datai Island, the coarse grain sandstone becomes dominant. The diversity of rocks in Datai Bay is a record of environmental change during the period of sediment deposition 550million years ago. The deposition environment during that time is believed to be river deltas and shallow coastal areas.

Primary and Secondary Structures
Structural diversity in the Machinchang Formation can be viewed at the rock exposure along the rocky beach. Rock structures formed during the sediment deposition are called the primary structure, and by tectonic activity are known as the primary structure. Primary structures such as planar bedding and cross lamination are found along the rocky beach, while the secondary structure consists of faults, folds, joints and quartz veins intrusions.

Coastal Outlines and Soft Sand
The landform diversity at Datai Bay is a plethora of wonderful coastal types; rocky beach, sandy beach, pebbly beach, abrasion platform, depositional platform, gravel bar, sea tracks, sea caves and residual island. The sand here feels extremely soft beneath bare feet. The series of abrasion platforms along the rocky beach display the structure painted on them. Great persistence by the wave and erosion processes had shaped the pebbles on the beach into semi rounded, rounded and pellet like. The works of the tireless wave with the help of structures within the rock had eroded part of the promontory to form residual islands and at the small scale they are called sea tracks. At an area where the wave is strong, such as at the west of Anak Burau Island, the erosion along the vertical layer of rocks had formed sea caves and rocky arches.

Tourism Education
Datai Bay is one of the sites in South East Asia with significant geological history. It also perfectly showcases the coastal landscape for sedimentary rocks. The diverse landscape in this area provides a great opportunity for research and tourism education. Not to mention a living exhibition of beguiling rock formations.