This soft cover, full colour book accompanies the Angledool 1:250 000 geology map and summarises the geology of the Lightning Ridge region in central northern NSW, including world renowned opal fields.

The oldest exposed rocks in the area are Early Cretaceous and form part of the Surat Basin. They host the precious black opal and a rich diversity of freshwater fossils, including invertebrates, dinosaurs and monotremes. 

Overlying Cenozoic alluvial sequences have also been mapped and described in detail.