Predictability of Silurian Fossil-Konservat-Lagerstatten in North America



Fossil-Konservat-Lagerstätten from a limited time frame can be classified in a way that provides predictive value, demonstrating that it is possible to prospect for additional deposits of exceptionally preserved fossils. Q-mode cluster analysis reveals that eight Silurian Lagerstätten in North America are divisible into two groups on the basis of biotic components and sedimentary features: eurypterid-phyllocarid-dominated (EP) biotas (Williamsville, Syracuse, Pointe-aux-Chenes, Kokomo, Waubakee) and dendroid-graptolite-characterized (DG) biotas (Brandon Bridge, Lecthaylus, Mississinewa). AU fossil deposits are characterized by fine-grained, laminated, carbonate sediment bearing evidence of anoxic depositional conditions. The EP biotas were deposited in hypersaline peritidal lagoons limited stratigraphically to Upper Silurian strata surrounding the Michigan Basin, similar Lagerstätten maybe predicted for this type of setting in North America and elsewhere in strata of like age. DG biotas are taxonomically, ecologically, stratigraphically, and areally more diverse than EP biotas, and these Lagerstunen are less easily predicted. OFOSSIL-KONSERVAT-LACERSTÄTTEN, Silurian, cluster analysis, prediction.