1. Carbon Isotope Chemostratigraphy from mid- Cretaceous Lacustrine in Northwest China
Kuzipa Kapayi
Mentor: Dr. Marina B, Suarez
University of Texas at San Antonio

2. OVERVIEW Background Purpose Methods Results Conclusions Future focus
Summary

3. BACKGROUND: Cretaceous Period

4. (+) excursion (-) excursion
From Leckie eta l., 2002

5. Cretaceous deposition of organic shales
Berner, 2003
Cretaceous Source Rock

6. BACKGROUND: Location—Gansu Province, China
Purpose: Develop a carbon isotope profile for the Xinminpu group at the Hanxia locality in Gansu province of China to:
1. improve stratigraphic correlation of fossiliferous strata
2. identify potential changes in climate due to C-cycle perturbations
Gansus
yumenensis
Auroraceratops

7. Methods Samples crushed using mortar & pestles Decarbonated, 3M HCL
Costech 4010 Elemental Analyzer
connected to a Mass Spectrometer

8. Results Section 2A Section 1A
The average d13C value of organic carbon from Gansu province is ‰ with a minimum of ‰ and a maximum of ‰ vs. V-PDB
Section 2A
Section 1A
Solid line represents a 3-point running average of the gray data points

9. Preliminary Interpretation
δ13C curve of Hanxia Section 1a corresponds with the lower Aptian while section 2a appears to occur within the middle to upper Aptian, specifically the C10 isotope excursion.
Section 1A
Bralower et al at the Ap12-14
of Herrle at al.,2004.
Section 2A

10. Summary and Future Work
Additional analysis between Section 1A and Section 2A will help confirm or refute the current preliminary correlation
If confirmed, this strata at the Hanxia locality may help elucidate potential climate change associated with the C10 isotope excursion.

11. Acknowledgements
Funding for this research was awarded by the National Science Foundation through the Louis Stokes Alliances for Minority Participation Grant. CIMA-LSAMP program award No
Samples were collected as a part of funding to Dr. Peter Dodson, Dr. Hailu You and Dr. Daqing Li from the National Science Foundation.
Assistance in the field was provided by Dr. Eric Morschhauser, Dr. Celina Suarez and Brandon Hendricks.
Assistance in the lab was provided by Joshua Cuellar, Christina Wilson, Adrianne Lopez and Matthew Brice.

12. References
Suarez, M.B., Ludvigson, G.A., Gonzalez, L.A., Al-Suwaidi, A.H., You, H Stable isotope chemostratigraphy in lacustrine strata of Xiagou Formation, Gansu, Province, NW, China.
Li, X., Xu, W., Liu, W., Zhou, Y., Wang, Y., Sun, Y., Liu, L Climatic and environmental indications of carbon and oxygen isotopes from the lower Cretaceous calcrete and lacustrine carbonates in Southeast and Northwest China. 181
Herrle, J.O., Kobler, P., Friedrich, O., Erlenkeuser, Hemblen, C., 2004, High-resolution carbon isotope records of the Aptian to Lower Albian from SE France and the Mazagan Plateau (DSDP Site 545): a stratigraphic tool for palaeoceanographic and paleobiologic reconstruction. Earth and Planetary Science Letters, v. 218, p
Bralower, T.J., CoBab, E., Clement, B., Sliter, W.V., Osburn, C.L., and Longoria, J., 1999, The Record of Global Change in Mid-Cretaceous (Barremian-Albian) Sections from the Sierra Madre, northeastern Mexico. Journal of Foraminiferal Research, v. 29, p

13. QUESTIONS?
Kuzipa Kapayi
(937)