1 / 28

Geological and Environmental Evolution of the Snake River Plain Hotspot

This comprehensive study delves into the geological, palynological, and climatic history of the Snake River Plain Hotspot. By examining the interplay of global climate changes, tectonism, and localized uplift and subsidence processes, this research offers insights into the region's volcanic activity and its impact on ecological succession. The findings highlight significant changes in paleoelevation and vegetation over millions of years, revealing how the Sierran rain shadow and hotspot dynamics shaped the area's unique environmental sequence.

mckayla
Télécharger la présentation

Geological and Environmental Evolution of the Snake River Plain Hotspot

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. HISTORY OF THE SNAKE RIVER PLAIN HOTSPOT • PALYNOLOGY • Environmental Sequence • Global Climate Change • Tectonism • Sierran Rain Shadow • Local Uplift/Subsidence • VOLCANOLOGY • SRP History • Plume – Crust Interactions • Hotspot Dynamics

  2. HISTORY OF THE SNAKE RIVER PLAIN HOTSPOT • PALYNOLOGY • Environmental Sequence • Global Climate Change • Tectonism • Sierran Rain Shadow • Local Uplift/Subsidence Dated Tephra Dated Flows Uplift/Subsidence • VOLCANOLOGY • SRP History • Plume – Crust Interactions • Hotspot Dynamics

  3. HISTORY OF THE SNAKE RIVER PLAIN HOTSPOT • PALYNOLOGY • Environmental Sequence • Global Climate Change • Tectonism • Sierran Rain Shadow • Local Uplift/Subsidence Dated Tephra Dated Flows Uplift/Subsidence Paleoelevation Interbed Ages Correlation • VOLCANOLOGY • SRP History • Plume – Crust Interactions • Hotspot Dynamics

  4. Strong influence of elevation on vegetation & palynology

  5. Climatic changes (glacial/interglacial) subtle

  6. Marked late-Neogene evolution of vegetation Climate = global + tectonic 4200 ft

  7. Trends: late Miocene – early Pleistocene (means of dating and correlating flows) 0.7 m.a. 5 m.a. 10 m.a.

  8. Composite of Bruneau and MHAB-1 cores 4000 ft

  9. Tentative Chronology (based on correlation) Pleisto Pliocene Terteling Spr 5-6 m.a. Mio Dated Lava

  10. Volcanic Tephra Chronology for palynology, Before Lake Idaho ~8 Ma ~11 Ma

  11. Interbedded Sediments: east of Lake Idaho younger than Lake Idaho 4 Ma 6.25 Ma

  12. Interbedded Sediments: cores & wells • INEL (thanks to Linda Davis) • Deerflat, Simplot, etc. 1.12 & 3.16 km 8.2 Ma

  13. Tentative Sequence

  14. Preliminary Palynological Results • Tentative vegetation-climate sequence • Potential value of long cores • Apparent ages consistent with HOTSPOT • Paleoelevation: large changes • INEL-1 ~km • Interbedded sediments provide: • Wider coverage (not just Lake Idaho) • Tephra & flow dates for Palynology sequence

  15. Horseshoe Bend

  16. Additional INEL, Hagerman Fossil Beds and Simplot Well samples

  17. Age: Nothing in “Lk Idaho” older than mid-Miocene?Elevation: big changes & high elev. flora very different

  18. Sand Spr. 0.095 Ma

  19. Snake River Plain Cross-section Homedale - Boise

  20. Surface elevation of Lake Idaho sensu lato Bruneau Fm.

  21. Miocene Riparian Vegetation

More Related