Investor Presentaiton

EGU2020-12777 DEM of the Guyana Shield (Roraima plateau extent in blue line) Altitude (m) N Jurassic 1000 500 0 -500 -1000 20 km Paleocene Guyana shield paleo-surfaces Altitude (m) -123-47 147 74 74 -98 98 114 114 137 137-180 180-274 274-351 351 - 487 487 648 648-919 1919-2872 Early Cretaceous S CC BY The relationship between age and altitude of preserved surfaces has largely been discussed since the mid XIXth century (Davis, 1889; King, 1953, Vasconcelos and Carmos, 2018) with a specific emphasis on craton shields under tropical climates. Indeed, is there a positive correlation between paleosurfaces altitude and their age? Scenarios have been proposed for the Guyana Shield, at the North of the Amazon, assigning an age for different paleosurfaces at specific altitudes. In this study we focused on the large extended Roraima plateau developed on Paleoproterozoic rocks which age is supposed to be Jurassic at around 1000 masl by dating the duricrusts on the surface by (U- Th)/He. (Age of the paleosurfaces in the Roraima Brazilian region after Schaefer et al., 1996) 2

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