Defining the Jurassic/Cretaceous Boundary: An Integrated Study from North America with Implications for World-Wide Resolution

9304459 Pessagno PI将：1)将放射虫和其他微体化石与菊石和布希亚生物地层学相结合，以便在北美(加州，墨西哥)选定的剖面中放置侏罗纪-白垩纪界线；2)建立磁性地层学并将其与这些剖面中的生物地层学联系起来；3)将生物带与地质计时数据联系起来；以及4)检查这些剖面中的锶同位素值。样本将从基默里吉亚到瓦兰吉尼亚地层采集，并外包给放射虫和有孔虫以外的菊石和微化石专家。这项工作将有助于确定J/K界线，并有助于更准确地对北美放射虫分区进行基于菊石的年代地层定标。

9304459 Pessagno PIs will: 1) integrate radiolarian and other microfossils with ammonite and Buchia biostratigraphy in order to place the Jurassic- Cretaceous boundary in selected sections in North America (CA, Mexico); 2) establish magnetostratigraphy and relate it to biostratigraphy in these sections; 3) relate biozones to geochronometric data; and 4) examine Sr isotope values in these sections. Samples will be collected from Kimmeridgian to Valanginian strata and farmed out to experts on ammonites and microfossils other than radiolarians and forams. This work will aid in defining the J/K boundary, and contribute to a more accurate ammonite-based chronostratigraphic calibration of North American radiolarian zonation.