1. An Introduction to Deep Time
Marc Hirschmann
University of Minnesota

2. “How did early Earth become our modern world?” July 1 – August 10
CIDER Summer Program 2012
“DEEP TIME”
“How did early Earth become our modern world?”
July 1 – August 10
Tutorial/Workshop July 15-August 10
Application Deadline February 1st, 2012
Instructors (some additions expected)
Geochemistry: Rick Carlson, Mark Harrison, Bill McDonough, Sujoy Mukhopadhyay
Geodynamics: Bruce Buffett, Michael Manga, Dave Stevenson
Mineral Physics: Marc Hirschmann, Jie Li, Dave Rubie
Seismology: Ed Garnero, Guy Masters, Barbara Romanowicz
Other Confirmed Faculty Participants:
Thorsten Becker, Adam Dziewionski, Abbie Kavner, Louise Kellogg, Sarah Stewart, Kevin Zahnle

3. How did early Earth become our modern world?
WHAT IS DEEP TIME?
WHAT IS CIDER DEEP TIME?
How did early Earth become our modern world?

4. How did early Earth become our modern world?
CIDER DEEP TIME?
How did early Earth become our modern world?
Some Principles
There were many early Earth processes that had profound influence on the subsequent evolution of our planet
2. There are many important features of Earth that arose at some early time and subsequently remained as key characteristics of the planet.
These features did not arise synchronously. For each, “Deep Time” is the period before and during their origin.
4. Deep Time is broad and diverse. Attempting to cover it comprehensively goes beyond a manageable CIDER summer program. Some important and key aspects of Deep Time will not be emphasized (e.g. planetary topics, climate evolution, origin of life). A Deep Earth perspective will be emphasized.

5. (Giant Molecular Clouds)
How far back can we go?
Star Nursuries
(Giant Molecular Clouds)
Accretion in the solar nebula

6. Accretion/Core Formation/Magma Ocean(s)
Energetics, geochemical differentiation, etc.
Rubie et al. 2011
Wood and Halliday, 2005

7. Canup, 2004

8. The bulk composition of
the Earth is a key constraint on
Its modern geochemistry
Righter+Drake

10. Antiquity of the geodynamo
Usui et al G3

11. Superplumes/LLSVPs: Origin? Ancient Features? Basal Magma Ocean?
Sun et al. 2010
Labrosse et al. 2007

12. What was and what were the effects
of the Late Heavy Bombardment?
Figure from Valley (2002)

13. Gradual “Mixing In” of PGEs from Late Veneer (?)
Wolfgang et al. 2009

14. When did the principal mantle geochemical reservoirs arise (and how did they arise through differentiation, mixing of “primitive” and “recycled” components, stirring, etc.
Tackley, 2000
Hart et al. (numerous papers))

15. When did plate tectonics begin?
(A) Silicate inclusion initial Nd isotopic composition versus Sm-Nd age for diamonds of peridotitic (circles), lherzolitic (triangles), and eclogitic (diamonds) parageneses. Solid symbols are isochron studies for composites of garnet and clinopyroxene grains; open symbols are model age studies for composites of garnet only. Unlabeled points on convecting mantle curve are mantle extraction ages extrapolated from labeled points (11). (B) Sulfide inclusion initial Os isotopic composition versus Re-Os age. Solid symbols are isochron studies; open symbols are model age studies for single grains. For isochron studies, mantle extraction ages extrapolated from labeled points are typically <100 million years (one scale division) older than the isochron age (11). In (A) and (B), WC 1-2 denotes Wilson cycle rifting (stages 1 and 2) for the Pilbara craton (6); WC 5-6 denotes Wilson cycle continental closure (stages 5 and 6) for the Kaapvaal craton. Locality abbreviations are given in table S1.
S B Shirey, S H Richardson Science 2011;333:
Brown, 2006

16. What has been the thermal evoultion of
the Earth through time?
Mantle Temperature
Based on basalt chemistry
Thermal Evoultion of the Mantle
Taking Into Account Influence of H2O
Korenaga – in press
Herzberg et al. 2010

17. What is the inventory of volatiles in the modern Earth?
How much was delivered during accretion?
Delivery of H2O to growing terrestrial planets
Raymond et al. 2006

18. Zahnle et al. 2007

20. The NORMAL JACK HILLS WORLD Trail et al. 2011 Hopkins et al. 2008
Wilde et al. 2001
Trail et al. 2011

21. Origin and Stabilization of Continents And Continental Cratons
Yuan and Romanowicz, 2010
Cratonic Xenolith Model Ages
(Carlson et al. 2005)

22. Origin of Life, Evidence for Early Life
Isotopically Light Carbon Nanoparticles
Rosing, 1999