Proterozoic

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Proterozoic

that period of geological time lasting from some 2600 million to 589 million years ago; the part of Cryptozoic time excluding the Archaean Period. Fossils dating from this period are mainly CYANOBACTERIA.
References in periodicals archive ?
These Late Proterozoic ages span from 1000 - 1100 Ma (Karunjhar grey granite) to 700-800 Ma (pink and other granites).
In reporting the La Rocque Lake discovery, Cameco noted that the high-grade uranium deposits of the Athabasca Basin are typically associated with the erosional boundary, or unconformity, between graphite-bearing metamorphic rocks of early Proterozoic age and middle Proterozoic sandstones.
The quartz veins in the B and C Zones are related to major fault zones of the Upper Proterozoic Age that cross-cut older metamorphic volcano-sedimentary rocks of the Guarayos Greenstone Belt.
These deposits, which are of Late Proterozoic age, contain 5 Mt with up to 25% [P.
Regional mapping undertaken by BRGM in 1986 identified a NE-SW trending package of Archaean to Proterozoic age quartzitic metasediment, gneiss and amphibolite, as well as numerous itabirite units containing millimetre to centimetre thick bands of magnetite.