Dynamic Subsidence and Lithospheric Evolution in Farallon Plate Analysis

1. Continental Lithosphere Deformation and Epeirogeny-the Farallon Plate and Buoyancy Contrasts within the Lithosphere • Inverse tomography and dynamic topography: Gurnis, Liu & Spasojevic • Kinematics of Farallon LIPs and the Laramide: Gurnis, Muller & J. Saleeby • So. California shallow subduction megathrust flat: Chapman, Herman, Kidder, Luffi, Yan & J. Saleeby • So. Sierra landscape evolution and faulting coupled to San Joaquin basin epeirogenic deformation: LePourhiet, Maheo, Z. & J. Saleeby • Uplift of the Colorado Plateau: Flowers, Huntington, Milman-Barris & Wernicke

3. Height (m) Age (Ma) Substantial discrepancy between East Coast Sea Level (Miller et al., 2005) w.r.t. inferred global changes since the Cretaceous (Haq, 1987) Well documented dynamic subsidence of W. interior sea way in North America interpreted by Mitrovica et al. and Burgess et al. in terms of changes in slab dip.

4. Farallon Slab at 40N: Inverse versus Tomography Liu & Gurnis

5. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

6. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

7. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

8. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

9. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

10. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

11. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

12. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

13. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

14. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

15. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

16. Dynamic topography in a plate frame as NA Sweeps west Over the Farallon Slab in inverse model Liu, Spasojevic & Gurnis

22. Pleistocene lithospheric structure beneath the Mojave Desert Sri = 0.706 at ~116°W Dish Hill Cima W E North American continental crust Pelona-Orocopia-Rand schists Farallon lithosphere (young & depleted) eNd > 0 North American lithospheric mantle (old & enriched) Farallon asthenosphere eNd < 0 ? upwards enriched, tectonically imbricated peridotite sequences with eNd > 0 and LREE depleted cpx peridotites with εNd < 0 and pyroxenite veins with εNd > 0 and LREE enriched cpx Based on Miller et al, 2000 and xenolith data from Dish Hill (this work) and Cima (this work and Mukasa & Wilshire, 1997)

23. Dish Hill med-…high-T xenoliths: bulk composition vs. temperature

24. 0.16 14 s s 1 1 48 Sr (ppm) TiO s s s 1 2 1 1 MgO CaO Al O 2 3 4 4 46 0.12 10 3 3 44 0.08 2 2 42 6 0.04 1 1 40 T ( °C ) T ( °C ) T ( °C ) T ( °C ) 0.00 2 T ( °C ) 38 0 0 900 950 1000 1050 1100 900 950 1000 1050 1100 900 950 1000 1050 1100 900 950 1000 1050 1100 900 950 1000 1050 1100 6 s s 1 1 Sc (ppm) Y (ppm) 16 90 s s s 1 1 1 Ni (ppm) V (ppm) Na O 2 2750 0.3 4 70 12 2500 0.2 50 2250 2 8 0.1 30 2000 T ( °C ) T ( °C ) 4 0 T ( °C ) T ( °C ) T ( °C ) 900 950 1000 1050 1100 900 950 1000 1050 1100 1750 0.0 10 900 950 1000 1050 1100 900 950 1000 1050 1100 900 950 1000 1050 1100 Dish Hill med-…high-T xenoliths: bulk composition vs. temperature

25. Pleistocene lithospheric structure beneath the Mojave Desert Sri = 0.706 at ~116°W Dish Hill Cima W E North American continental crust Pelona-Orocopia-Rand schists Farallon lithosphere (young & depleted) eNd > 0 North American lithospheric mantle (old & enriched) Farallon asthenosphere eNd < 0 ? upwards enriched, tectonically imbricated peridotite sequences with eNd > 0 and LREE depleted cpx peridotites with εNd < 0 and pyroxenite veins with εNd > 0 and LREE enriched cpx Based on Miller et al, 2000 and xenolith data from Dish Hill (this work) and Cima (this work and Mukasa & Wilshire, 1997)

27. Poster: Modeling Flat Subduction Initiation and Accretion of the Pelona SchistSteven Kidder , Frédéric Herman, Jason Saleeby, Jean-Philippe Avouac, Mihai Ducea 2D models of flat subduction initiation are inverted using the neighborhood algorithm of Sambridge (1999). Using thermochronologic constraints from the San Gabriel Mtns. and varying 10 model parameters, preliminary results constrain schists accretion rates to .5-1 mm/yr. Ongoing efforts are aimed at constraining stresses, tectonic models and exploring the significance of variations between schists. Inversion of thermal model. Each dot (n=13,500) represents a forward model in the parameter space (blue dots= good fit, maroon dots= poor fit)

28. Rapid exhumation of the Rand schist: constraints from natural garnet diffusion couples Alan D. Chapman Jason B. Saleeby Peter I. Luffi

29. Some garnets from the schist of the San Emigdio Mountains were broken during late stages of their growth. • Overgrowth along broken margins resulted in natural diffusion couples

30. Thermal relaxation of diffusion couple gives time constraints on schist exhumation history

34. Deconvolving SJB stratigraphy