The Lower Palaeozoic systems begin with the Cambrian, which are found in northern Tasmania near Latrobe, and contain Cambrian fossils as Dikelocephalus Tasmanicus and Conocephalites stephensi.
Over a large part of Siberia and in the north of China, even the Cambrian beds still lie as horizontally as they were first laid down.
A narrow Cambrian sea must have extended across central Australia from the Kimberley Goldfield in the north-west, through Tempe Downs and the Macdonnell chain in central Australia, to the South Australian highlands, central Victoria at Mansfield, and northern Tasmania.
The breaking up of the old Archean foundation block began in Cambrian and Ordovician times.
Of sandstones, clay-slates and limestones, which contain Cambrian fossils and are the equivalents of a part of the Sinian system of China.
Such restorations are possible because of the intimate fitness of animals and plants to their environment, and because such fitness has distinguished certain forms of life from the Cambrian to the present time; the species have altogether changed, but the laws governing the life of certain kinds of organisms have remained exactly the same for the whole period of time assigned to the duration of life; in fact, we read the conditions of the past in a mirror of adaptation, often sadly tarnished and incomplete owing to breaks in the palaeontological record, but constantly becoming more polished by discoveries which increase the understanding of life and its all-pervading relations to the non-life.
Undue stress is often laid on the fact that Lingula has come down to us apparently unchanged since Cambrian times, whilst Crania, and forms very closely resembling Discina and Rhynchonella, are found from the Ordovician strata onwards.
Archean gneiss, Cambrian sandstone, Silurian quartzite, limestone and schist, Jurassic sandstone and limestone, Cretaceous sandstone, and Tertiary basalts, gabbros, and granitic rocks all enter into the composition of the islands.
The Cambrian system - including the Upper (Durness-Eriboll Limestone) and the Lower (Serpulite grit, Fucoid Beds, Quartzite) - forms a narrow band which can be traced for too m.
Overlying these amongst the Palaeozoic rocks, we meet in many parts of Japan with slates and other rocks possibly of Cambrian or Silurian age.