1. SOME FIGURES FOR UNFINISHED MANUSCRIPTS (CONDENSED; FULL VERSION CAN BE REQUESTED VIA DROPBOX)

3. 410 650 eclogite harzburgite cold

4. Shear wavespeed Temperature BL High-T conduction geotherm Subadiabatic geotherm 1600 C adiabat Vs for self- compressed solid along adiabat Observed Seismic profile VSH>VSV VSV>VSH RIDGE OIB Tp=~1300 C ~1600 C 650 km 220 km 1 3 3 2 4 5 6 7 A mantle circulation model based on anisotropy, anharmonicity, absolute wavespeeds & gradients, allows for, and predicts, non adiabaticity disconnect

5. LIL Sheared mélange ridge UPPER MANTLE Tp 200 400 km Ancient eclogite cumulates Modern slab fragments LVZ TZ LIL THE “NEW” PARADIGM hotspots “the canonical box” ‘cold’

6. Sediments volatiles Intraplate volcanoes Midocean ridges Residual slab components LOWER MANTLE *Essentially the classical model of Birch, Tatsumoto, Wilson…

7. 200 Myr of oceanic crust accumulation TRANSITION ZONE (TZ) REGION B Super- adiabatic boundary layer Thermal max 600 km 300 km Tp decreases with depth 600 km Physics-Based Archimedian Paradigm* (RIP) (* Birch, Tatsumoto, J. Tuzo Wilson) Shear strain “fixed” Hawaii source MORB source Shear-driven magma segregation Sources deeper than ~ 150-200 km are effectively fixed (e.g.J.T.Wilson) OIB  (T),  (V,T), T CMB (t), (V,T), U(z,t), Th(z,t)… Pebbles Old Greeks Slabs The Eureka Solution Archimedes & Birch squeezin g

8. ISOTHERMAL ADIABATIC ISOTHERM 100 km HOMOGENEOUS jet STANDARD CONCEPTUAL MODEL (1988) No physics, no seismology (used as reference model; Herzberg, Asimow, Humphreys, Schmandt, Victor Camp…e.g…) No U, Th, K No secular cooling Ambient T constrained (<1600K)

9. Mechani cal boundar y layer Therm al bound ary layer Adiabatic interior Lithosphere Tp=1280 o Tp(max)~1600 o LID LLAMA subadiabat Negative Vs gradient 0 100 200 300 Depth (km) 1600 1200 800 400 0 T ( o C) BOUNDARY LAYER Cambridge nomenclature

10. UPPER MANTLE & LOWER MANTLE ARE COOLED BY LONG-LIVED FLAT (STAGNANT) SLABS Cold slab European, African, Asian (Changbai), Yellowstone & most continental intra- plate volcanoes (“hotspots”) are underlain by slabs Cooled mantle 49

11. COLD WARM REGION B TZ Ridges & hotspots COOL 410 650 No hotspots LVA STAGNANT SLABS–A FIXED REFERENCE FRAME SLIP-FREE BOUNDARY 50 There may be a concentration of CaO, Al 2 O 3, K…U, Th…in the upper mantle…Birch Fixed hotspot paradox

12. Boundary layer Midplate Ridge adiabat LLAMA(shearing) Plate (conducting) Depth 1600 1400 ToCToC T Depth B D”D” TZ CMB Illustrating the thermal bump and subadiabaticity UPPER MANTLE LOWER MANTLE The highest potential temperature in the mantle is near 200 km. Tectonic processes (shear, delamination) are required to access this. ridge midplate bump (& backarc) 400 200

13. (Lubimova, MacDonald, Ness) U, Th, K and other LIL are concentrated in the crust & the upper mantle boundary layer during the radial zone refining associated with accretion (Birch, Tatsumoto…). This accentuates the thermal bump.

14. Mesosphere (TZ) LID LVZLLAMA 200 400 Intraplate (delamination, CRB, Deccan, Karoo, Siberia) magmas are shear-driven from the 200 km thick shear BL (LLAMA) ridge km Cold slabs SUMMARY OIB Ridges are fed by broad 3D upwellings plus lateral flow along & toward ridges subadiabatic