Climatic control of brachiopods in the lower Namurian



The fauna and lithology of a marine band in the lower Edale Shales (Namurian E2b) at Edale, Derbyshire, England, are described quantitatively. Two brachiopods, Rugosochonetes sp. and Productus hibernicus were the dominant elements of the fauna. The average age at death was about 3 years, although the maximum age of Rugosochonetes (ca. 7 years) was probably a little greater than that of Productus (ca. 5 years). Both sediment deposition and fauna were climatically controlled. The climate was seasonal from wet to dry. Quartz was deposited and Rugosochonetes sp. flourished during the wet periods. Carbonate deposition and Productus hibernicus were dominant during the dry periods.