The researchers studied the rocks at Anak Datai beach in Langkawi, Malaysia, to understand how they were formed. They found that the rocks are mainly sandstone with some muddy layers, suggesting they were deposited in a wave-dominated upper shoreface environment. The sandstone is classified as metaquartzite sandstone and contains mainly quartz minerals. The researchers created sedimentary logs and identified four main types of sandstone facies. Overall, the rocks at Anak Datai beach are the oldest in Peninsular Malaysia, dating back to the Cambrian period.