One of the most difficult problems in stratigraphy is that of developing a global biostratigraphic framework based on zonations involving different faunal groups, different depositional environments, and different geographic regions. One way to deal with this problem is to find a stratigraphic marker horizon to link the different zonations. At the present time, the only common, global and non-time-transgressive phenomena in the geological record are reversals of the earth's magneticf field. The unique structure of the Magnetic Polarity Tiume Scale in the vicinity of the Santonian/Campanian boundary makes this boundary a particularly convenient place to use magnetostratigraphy to establish a global marker horizon. PI will conduct magnetostratigraphic studies of sedimentary sequences that cross the Santonian/Campanian boundary in Europe and in the Western Interior of North America. The sequences in Europe include the stratotype for the boundary as well as other sections which are believed to be equivalent to it. Those in North America represent marine, marginal marine, and terrestrial sequences, all of which are believed to contain the boundary. By studying these sections, PI will be able to establish a correspondence between Santonian/Campanian biostratigraphic zonations on two different continents and involving a variety of different fossil groups. In addition, the sections in the Western Interior contain bentonite beds that will be used to obtain an absolute age for the Santonian/Campanian boundary. The proposed project represents a continuation of work conducted under a prior NSF grant, which looked at the magnetostratigraphy of sedimentary sequences that crossed the Santonian/Campanian boundary on the West Coast of North America, and it represents the next step in a systematic program to study the magnetostratigraphy of the Santonian/Campanian boundary in sedimentary sequences throughout the world.
