The oldest rocks in the Clarence Moreton Basin of New South Wales are the
Chillingham Volcanics. These are from some time in the
Triassic period, and
crop out in a band north and south of
Chillingham. They consist of conglomerate at the base, rhyolite, lithic rhyolitic tuff, and shale. The
Nymboida Coal Measures extend from
Nymboida to Kangaroo Creek. They consist of lithic sandstones (wackes, minor arenites), siltstone, polymictic conglomerate, coal, rhyolitic tuff, and basalt. The total thickness is over . The outcrop is , and it forms a north west trending band long on the southwest tip of the basin. The
Basin Creek Formation includes the coal mined at Nymboida. The
Bardool Conglomerate forming a thick layer, is also a unit in the coal measures. The conglomerate includes a thick layer of basalt exposed at Copes Creek. The
Evans Head Coal Measures are correlated with these, but are further up the north coast at
Evans Head. The basin was next uplifted and eroded and then deepened considerably and Bundamba group rocks form a complete V shape on both sides of the basin. In the northern parts the rock is mostly friable sandstone, but in the south it is divided into conglomerate below and siltstone above. The Laytons Range Conglomerate rests on the basin floor and extends from
Baryulgil, to Nymboida. The
conglomerate often appears as a cliff. The Corindi Conglomerate is a local name for a hailstone sized gravel near
Corindi. The Mill Creek Siltstone. are often olive green or yellow-brown with bright red joint planes. extends for along the western side of the basin into Queensland from Corindi. It is mostly clay cemented cross bedded quartz sandstone, but this is interbedded with
claystone and shale. At the base is the Blaxland Fossil Wood Conglomerate Member at
Blaxlands Creek. The fossil wood is in the form of horizontal tree trunks up to long and in diameter. The fossilization process replaced the wood with
limonite and
hematite. forms a U shape around the east, south and west sides of the basin. It consists of claystone, shale, siltstone,
arenites, and coal seams and the plant fossils in it show a Jurassic age. This sandstone has saccharoidal texture, and glistens white and cream. This is not due to angular sand grains, but results from silica crystallization. It is up to thick. is the sedimentary unit in the core of the basin. It is the youngest of the beds being between Late Jurassic and Early Cretaceous. It occurs from
Grafton to
Casino consisting of soft sandstone, siltstone and claystone. Dolerite has intruded this at
Glenugie Peak, and near
Banyabba. == References ==