Bradley D. Cramer

Assistant Professor Bradley D. Cramer

Assistant Professor

Bio-Chemostratigraphy and Earth History Research

Interests: Earth System Science, deep-time Earth history, stable and radiogenic isotope geochemistry, chemostratigraphy, biostratigraphy, stratigraphic nomenclature, history of geology, geochronology, and the Geologic Time Scale. Effectively, I try to understand the major biotic, chemical, and physical events that punctuate the history of our planet by throwing every tool and proxy at the problem as is possible. Currently, I am the project leader for the International Geoscience Programme (IGCP) Project 591 – The Early to Middle Paleozoic Revolution. You can visit our website and join the project at

Publications: Cramer, B.D., Condon, D.J., Söderlund, U., Marshall, C., Worton, G.J., Thomas, A.T., Calner, M., Ray, D.C., Perrier, V., Boomer, I., Patchett, P.J., & Jeppsson, L. U-Pb (zircon) age constraints on the timing and duration of Wenlock (Silurian) paleocommunity collapse and recovery during the ‘Big Crisis’. (in press with GSA Bulletin).

Melchin, M.J., Sadler, P.M., & Cramer, B.D., 2012 Chapter 21: The Silurian Period, in Gradstein, F.M., Ogg, J.G., Schmitz, M. & Ogg, G., (eds.), The Geologic Time Scale 2012, Elsevier, New York, p. 525-558.

Cramer, B.D., Munnecke, A., Schofield, D.I., Hasse, K.M., & Haase-Schramm, A., 2011.  A revised 87Sr/86Sr curve for the Silurian: Implications for global ocean chemistry and the Silurian timescale. Journal of Geology, v. 119, p. 335-349.  doi: 10.1086/660117.

Cramer, B.D., Loydell, D.K., Samtleben, C., Munnecke, A., Kaljo, D., Männik, P., Martma, T., Jeppsson, L., Kleffner, M.A., Barrick, J.E., Johnson, C.A., Emsbo, P., Joachimski, M.M., Bickert, T., & Saltzman, M.R., 2010. Testing the limits of Paleozoic chronostratigraphic correlation via high-resolution (<500,000yrs) integrated conodont, graptolite, and carbon isotope (δ13Ccarb) biochemostratigraphy across the Llandovery-Wenlock (Silurian) boundary: Is a unified Phanerozoic timescale achievable?. Geological Society of America Bulletin, v. 122, p. 1700-1716, doi: 10.1130/B26602.1.

IGCP logo. Click to follow to IGCP homepage.