The lower part of the Sentosa sequence consists of medium and coarse-grained sandstone, pebbly sandstone and conglomerate alternating with purple-red mudstone and stiltstone with worm burrows.
Coral Skeletons
Slideshow : Coral fragments found around the beach head
Coral skeletons are made of aragonite, a form of calcium carbonate. To grow up toward sunlight, corals construct a framework of aragonite crystals. At the same time, they buttress this framework with bundles of additional crystals, which thicken and strengthen the skeletons to help them withstand breakage caused by currents, waves, storms, and boring and biting by worms, molluscs, and parrotfish.
3D Scanned coral skeleton
Fossil?
We chanced upon this rock during our field trip and suspected it to be a fossil? The textures on the rock had stark similarities to that of fossils. Rock type has not been identified for now.
3D scanned version of the rock with the possible fossil.
Extra : Fossil Purchase
Lepidodendron, extinct genus of tree-sized lycopsid plants that lived during the Carboniferous Period (about 359 million to 299 million years ago). Lepidodendron and its relatives—Lepidophloios, Bothrodendron, and Paralycopodites—were related to modern club mosses. They grew up to 40 metres (130 feet) in height and 2 metres (about 7 feet) in diameter. During their juvenile stages, these plants grew as unbranched trunks with a shock of long, thin leaves that sprouted near the growing tip. They branched at later stages, either in even dichotomies at the growing tip or in lateral branches that were later shed. After branching, the leaves became shorter and awl-shaped. As the plant grew, it shed leaves from older parts of the stem that left diamond-shaped leaf bases. Stems were characterized by a slender central strand of wood and a thick bark. Since Stigmaria—the underground parts of the plant—resembled stems, they are not considered true roots. The shape of leaf bases and the arrangement of their vascular strands distinguish the different genera within the group of arborescent lycopsids.
A lepidodendron fossil purchased from Poland
3D scanned version of the lepidendron