Temperature and burial

Figure 12. Apparent growth temperatures for various Altiplano carbonates based on clumped isotope thermometry, plotted as a function of estimated maximum burial depth. Symbols discriminate among soil carbonates from sections near Callapa, Corque and Salla and lacustrine carbonates from near Tambo Tambillo, as indicated by the legend. The heavy solid line indicates an estimated burial geotherm, assuming a surface temperature of 20 °C and a gradient of 30 °C per km. The dashed lines define a 10° offset from this trend, which we consider a reasonable estimate of its uncertainty. Carbonates deposited within the last 28.5 Ma and buried to 5000 meters or less exhibit no systematic relationship between apparent temperature and burial depth, and show no evidence for pervasive resetting of deeply buried samples. Error bars are la (when not visible, these are approximately the size of the plotted symbol).

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