Long-term interaction between mid-ocean ridges and mantle ... · Long-term interaction between...
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Long-term interaction between mid-ocean ridges and mantle plumes
Whittaker, J. M., Afonso, J. C., Masterton, S., Müller, R. D., Wessel, P., Williams S. E. and Seton, M.
SUPPLEMENTARY INFORMATIONDOI: 10.1038/NGEO2437
NATURE GEOSCIENCE | www.nature.com/naturegeoscience 1
Long-term interaction between mid-ocean ridges and mantle plumes
Whittaker, J.M., Afonso, J.C., Masterton, S., Müller, R.D., Wessel, P., Williams, S.E., and Seton, M.
Supplementary Information
Supplementary Figure 1: Present-‐day distribution of LIPs (Coffin and Eldholm, 1994). Colour-‐coded by age of formation (Supp. Table 1).
Supplementary Figure 2: LIPs (Coffin and Eldholm, 1994) reconstructed to location at time of formation. Colour-‐coded by age of formation. Note the clusters of LIPs exhibit significant ranges in age (Supp. Table 2).
0 - 22 Ma
22 - 40 Ma
40 - 56 Ma
56 - 67 Ma
67 - 80 Ma
80 - 95 Ma
95 - 111 Ma
111 - 126 Ma
126 - 153 Ma
153 - 200 Ma
Supplementary Figure 3: Histogram of the number of LIPs (Coffin and Eldholm, 1994) associated with each deeply sourced plume (Courtillot et al., 2003; Montelli et al., 2004) only. LIPs were assigned to the closest deeply sourced plume based on their reconstructed position at formation. A)
B)
C)
D)
E)
F)
G)
H)
I)
Supplementary Figure 4: Reconstructed LIPs (Coffin and Eldholm, 1994) clustered around a) Bouvet/Shona, b) Cape Verde, c) Galapagos, d) Iceland, e) Kerguelen, f) Marion, g) Marqueses, h) Reunion, and i) Tristan de Cunha plume.
Supplementary Figure 5. Workflow for the construction of predicted volume of extracted mantle (VEM).
Supplementary Figure 6: Distribution of mean palaeo-‐ridge positions within each grid cell following division of Earth's surface into a regular global grid of resolution a) 1° x 1°, b) 2° x 2°, c) 3° x 3° and d) 5° x 5°. Mean positions are colour-‐coded by the number of irregularly-‐ spaced age points that have been averaged within each grid cell: n < 5 (red), 5 < n ≤ 15 (orange), 15 < n ≤ 25 (green), 25 < n ≤ 35 (blue), n > 35 (cyan). Areas with no data coverage have not experienced seafloor spreading in the past 140 Myr. Grid resolution 5° x 5° is used as majority of grid cells comprise n > 15.
Supplementary Figure 7: Age distributions of reconstructed palaeo-‐MOR points within a 5° x 5° grid: a) Total – interquartile age ranges; b) colour-‐coded locations (stars) of grid cells selected for age distribution examination; selected cells exhibit large differences between total and interquartile age ranges; c) Box-‐and-‐whisker plots of age distributions in selected grid cells (colour-‐coded to stars in b)). Coloured blocks show upper and lower age quartiles; median age is a black line within each block; Red circles: mean age; Black `whiskers': total age range; Red `whiskers': standard deviation about mean age.
Supplementary Figure 3: Age distributions of reconstructed palaeo-MOR points within a
5° x 5° grid: a) Total – interquartile age ranges; b) colour-coded locations (stars) of grid cells
selected for age distribution examination; selected cells exhibit large differences between
total and interquartile age ranges; c) Box-and-whisker plots of age distributions in selected
grid cells (colour-coded to stars in b)). Coloured blocks show upper and lower age quartiles;
median age is a black line within each block; Red circles: mean age; Black `whiskers': total
age range; Red `whiskers': standard deviation about mean age.
Supplementary Figure 8: a) Mean full seafloor palaeo-‐spreading rate and b) interquartile age range of palaeo-‐spreading centres within 5° x 5° grid cells.
Supplementary Figure 9: Schematic of the derivation of units for estimated relative mantle extraction within each cell within a 5° x 5° grid.
Supplementary Figure 5: Schematic of the derivation of units for estimated relative mantle
depletion within each cell within a 5° x 5° grid.
Supplementary Figure 10: Distribution of non-‐backarc MORB samples from Gale et al. (2013) relative to deeply-‐sourced plumes (Courtillot et al., 2003).
Supplementary Figure 11: Estimated global Volume of Extracted Mantle (VEM) compared with major element geochemistry (CaO/Al2O3, Na8.0, Fe8.0; Gale et al. (2013)) from present-‐day MOR segments that are >1,400 km from the nearest deeply-‐sourced plume(Courtillot et al., 2003).
Supplementary Figure 12: Mantle flow pattern (white arrows) from numerical simulations of MORs without (a) and with (b) ridge migration. The standard equations of mass, momentum and energy under the Boussinesq approximation are solved with staggered and regular 2D finite difference grid (Gerya, 2009) and Newtonian viscosity. The numerical box represents a domain of 14,000 (length) x 600 (depth) km. Background color represents temperature distribution. In (b) the rate of MOR migration is 1/3 that of the spreading rate. Lateral boundary conditions are “external no slip” (Gerya, 2009); top and bottom boundary conditions are no slip. Schematic Figs. 3b and 3c in the main text are based on these simulations.
Supplementary Table 3. Statistical analysis of the distance from each LIP at the time of formation to the nearest plume using alternative absolute reference frames for either the Indo-‐Atlantic or Pacific LIPs. Bold type shows reference frames used. Note that in both regions alternative reference frames result in very similar results.
Doubrovine et al. (2012)
O’Neill et al. (2005)
Müller et al. (1993)
van der Meer et al. (2010)
Torsvik et al. (2008)
Wessel and Kroenke (2008)
Chandler et al. (2012)
Andrews et al. (2006)
Indo-‐Atlantic Median (km)
428 km 3.85°
268 km 2.41°
338 km 3.05°
498 km 4.49°
262 km 2.36°
St.Dev (km)
357 km 3.22°
390 km 3.51°
360 km 3.24°
349 km 3.14°
381 km 3.43°
Pacific Median (km) 518 km
4.67° 519 km 4.68°
528 km 4.76°
St. Dev. (km) 382 km
3.44° 430 km 3.87°
369 km 3.32°
T [oC]
200
600
1000
100
100
200
200
0
0
Dep
th [k
m]
Dep
th [k
m]
distance [km]
a
b-700 -350 0 350 700
References
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