Mark Wilson July 7th, 2009
KURESSAARE, SAAREMAA, ESTONIA–Today in a cold drizzle we measured the last section and bagged the last sample for our field projects. Tomorrow we leave the beautiful island of Saaremaa and drive to Tallinn. The next day we will study fossils in the University of Tallinn collections to complete our survey of the Silurian communities preserved in this part of the Baltic.
Rob McConnell is sorting out the paleoecology and paleoenvironments of the upper Mustjala and lower Ninase Members of the Jaani Formation (Wenlock) at three sites on the northern coast of Saaremaa. He has some very cool stromatoporoids, corals and bryozoans which are sometimes complexly intergrown and are almost always bored with long, thin holes.
Palmer Shonk has a single locality on the Sõrve Peninsula of southwestern Saaremaa with an extraordinary accumulation of crinoids in both growth positions (as extensive holdfasts) and as storm-tossed skeletal debris. These rocks and fossils are part of the Aigu Beds (Kaugatuma Stage, Pridoli). We think that there were low mounds of calcareous mud colonized by numerous species of crinoids, bryozoans and stromatoporoids which were occasionally swept by strong currents and buried in coarse sand and gravel made almost entirely of crinoid bits. Palmer will work out the ecological structure of those original communities and then the environmental history which led to these thick storm deposits.