Integrated biostratigraphy of the lower Silurian of the Kolka-54 core, Latvia

Abstract

AbstractIntegrated graptolite, conodont and chitinozoan biostratigraphical data are presented from the Llandovery and Wenlock of the Kolka-54 core, Latvia. Correlations between graptolite and chitinozoan biozones are consistent with those published from other East Baltic sections and the Welsh Basin. While most correlations between graptolite and conodont biozones agree with those presented in previous studies, there are important exceptions. Significantly, we report here the discovery ofDistomodus staurognathoidesBiozone conodonts in the lowest AeronianDemirastrites triangulatusgraptolite Biozone. The base of theD. staurognathoidesBiozone was previously considered to lie much higher in the Aeronian. Also it is shown thatWalliserodussurvived the late Wenlock Mulde Event, during which it was considered previously to have become extinct.