Orbitally-Tuned Sr Isotope Chemostratigraphy for the Late Middle to Late Miocene

• Published in: Paleoceanography
• Main Authors: Martin, E. E., Shackleton, N. J., Zachos, J. C., Flower, Benjamin P.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Digital Commons @ University of South Florida 1999
• Subjects: isotope chemostratigraphy; oceanography; sedimentation rates; paleoceanography; Life Sciences; Marine Biology; Planktonic foraminifera
• Online Access: https://digitalcommons.usf.edu/msc_facpub/20; https://doi.org/10.1029/1998PA900008; https://digitalcommons.usf.edu/context/msc_facpub/article/1019/viewcontent/Martin_et_al_1999_Paleoceanography.pdf; https://digitalcommons.usf.edu/context/msc_facpub/article/1019/filename/0/type/additional/viewcontent/readme.pdf; https://digitalcommons.usf.edu/context/msc_facpub/article/1019/filename/1/type/additional/viewcontent/miosrdat.tab

We present a Sr chemostratigraphic reference section for the late middle to late Miocene (14-5 Ma) from Ocean Drilling Program site 926 on the Ceara Rise. This site combines a precise, orbitally tuned timescale with a high sedimentation rate (15 m/m.y.), continuous deposition, and excellent biostratigraphic control. The Sr isotope curve is based on measurements of cleaned, planktonic foraminifera at 100-200 kyr sample intervals and it illustrates periods of rapid change in Sr-87/Sr-86 alternating with periods of little change. Chemostratigraphically-defined ages for these intervals can be determined within +/-0.8 m.y. and +/-1.6 m.y, respectively. There is excellent correlation with the published curve for site 588 [Hodell and Woodruff, 1994]; however the curve for site 747 [Oslick et al., 1994] exhibits less structure, which may be due to small errors in age estimates related to slow sedimentation rates, high-latitude fauna and an interval of complicated magnetics. Late Miocene data compare favorably with data from site 758 [Farrell et al., 1995].