Baltica
From Palaeos.org
(a) Paleoproterozoic to Late Ordovician Continent; (b) Neoarchean to Present Craton. The continent of Baltica consisted of the lands which now surround the Baltic Sea. Baltica was one of a number of continental blocks that broke away from the supercontinent Rodinia, but refused to get involved in the whole Gondwana thing (the others non-conformists being Laurentia, Siberia, and Kazakhstania). Each of these continental blocks carried with it a broad and shallow coastal shelf where Cambrian marine life flourished, with a unique and indigenous fauna developing around each continent.
During the Ordovician, Baltica and Siberia drifted toward Laurentia (Baltica drifting mostly west), creating a loose collection of large land masses separated by shallow coastal seas. The Silurian meeting of the continents Laurentia and Baltica to form Euramerica (or Laurussia) caused the Acadian / Caledonide Orogeny (mountain building period), with all the usual belching of volcanoes, messy climate changes, etc. that generally accompany this sort of thing. By this time, Baltica was also in the process of consolidating eastern Avalonia, Armorica, and other bits and pieces, thus becoming Europe.
Baltica is also used to refer to the underlying continental craton. This was probably assembled from at least two Archean blocks, Fennoscandia (possibly two separate blocks) and Sarmantia (centered in the Ukraine). At some point, Baltica picked up additional real estate in the regions of Novaya Zemlya and Spitsbergen. Baltica is one of the older cratons, probably built on basement rock dating back to late Archean or Paleoproterozoic times. Hacker et al. (2003).
MAK. Revised ATW080321. Wikified HAJ090204
