Hadean
The Hadean () is a geologic eon of the Earth pre-dating the Archean. It began with the formation of the Earth about 4.6 billion years ago and ended, as defined by the ICS, 4 billion years ago. , the ICS describes its status as ""informal"". Geologist Preston Cloud coined the term in 1972, originally to label the period before the earliest-known rocks on Earth. W. Brian Harland later coined an almost synonymous term, the "Priscoan period", from "priscus", the Latin word for "ancient". Other, older texts simply refer to the eon as the Pre-Archean.
Dacian bracelets
Dacian civilization went through several stages of development, from the Thracian stage in the Bronze Age to the Geto-Dacian stage in the classical period that lasted from the 1st century BC to the 1st century AD. The Thracian stage is associated with the emergence of Thracian populations from the fusion of the local Chalcolithic stock with the incoming peoples of the transitional Indo-Europeanization Period. By the time of Bronze Age, and during the transitional period to the Iron Age, the cultures of this Carpathian area may be attributed to proto-Thracian and even Thracian populations—ancestors of the peoples known to Herodotus as the Agathyrsae and the Getae, and to the Romans as the Dacians (by Iron Age II). The culture of these nuclear groups were typified by military aristocracies.