Locations of measurement in the seismic crustal structure database. There are 4,773 data points for continents and their margins.
Pie chart of the percentage surface area of continental crust above sea level versus age of the crust. The age span for each age (Eon/Era) is presented in Table 1. Mesoproterozoic crust has an anomalously low surface area of 8% despite a long duration from 1.6 Ga to 1.0 Ga.
Mean crustal thickness of continental crust under two assumptions. Grey histogram corresponds to continental crust above sea level (mean value 40.4 km); Dashed line histogram corresponds to continental crust including continental margins (mean value 36.5). These mean values are calculated for all measurements, that is, without any area balance (i.e., adjustment for over-sampling of some regions, such as central North America).
Mean crustal thickness of each age category. Solid gray histogram corresponds to continental crust above sea level, light hashed histogram corresponds to continental crust including continental margins. SD, standard deviation; N, number of measurements.
Statistics
Pie chart of the percentage surface area of continental crust including the continental margin versus age of the crust.
Average Vp(z), Vs(z), Vp/Vs (z) and rho (z) with area weigh
A. P-wave velocity (Vp), B. S-wave velocity (Vs) and C. Vp/Vs ratio versus depth
for each age (Era/Eon)
Three-layer (Upper, middle, and lower crust) model for each age category showing their average thickness (A. Crust without continental margin and B. Crust including continental margin), P-wave velocity (bold font), and S-wave velocity (italic font) values for the crystalline crust above sea level and the uppermost mantle.
Densities for each age (Era/Eon).
Three-layer (Upper, middle, and lower crust) model for each age category showing their average thickness (A. Crust without continental margin and B. Crust including continental margin), P-wave to S-wave velocity ratio (Vp/Vs - bold font), and Density (italic font) values for the crystalline crust above sea level and the uppermost mantle.
Mantle velocities of P-wave (Vpn) of A. Archean, B. Paleoproterozoic, C. Mesoproterozoic, D. Neoproterozoic, E. Paleozoic, and F. Cenozic-Mesozoic.
Mantle velocities of S-wave (Vsn) of A. Archean, B. Paleoproterozoic, C. Mesoproterozoic, D. Neoproterozoic, E. Paleozoic, and F. Cenozoic-Mesozoic.
Appendix A.
Alternative age map
ZIP file including GIS map and README (.txt)
Alternative age map modified from Sawada et al., 2018. The ages are: Archean (3.6-2.5 Ga), Paleoproterozoic (2.5-1.6 Ga), Mesoproterozoic (1.6-1.0 Ga), Neoproterozoic (1.0-0. 54 Ga), Paleozoic (543-250 Ma), and Cenozoic-Mesozoic (250-0 Ma).
Locations of measurement in the seismic crustal structure database for continental crust and their margins. There are data points for continents and their margins.
Locations of measurement points in the USGS Global Seismic Catalog (GSC) of one-dimension (1D) crustal seismic velocity-depth models. Including key to the seismic methodology 9,399 measurements for continental crust (A) and 14,064 including continental margins (B).
