Hello! Yes it is shell related. Does anyone know where I may obtain information on sea level rise and fall [S. Florida/Caribbean] from present to about 85K years past. I have the book from UF on geology of Florida but it is not too specific. Later, Emilio Jorge Power Please visit; "The Liguus Home Page" http://www.geocities.com/Eureka/Gold/9440/liguus/lighompa.html "The Polymita Homepage" http://www.geocities.com/Eureka/Gold/9440/polymita/polyhompg.html West Melbourne, Florida USA