temporal evolution of surface processes inferred from...

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2 1.5 1 0.5 0 Time BP (Ma) 0.0 0.5 1.0 1.5 2.0 2.5 Apparent diffusion coefficient D (cm 2 /a) 0.5 1.0 2.0 5.0 Measured [ 10 Be] (10 6 at/g) 0.5 1.0 2.0 5.0 Modelled [ 10 Be] (10 6 at/g) U M V O N PW S T Time varying D (best fit model) Constant D 5 10 20 50 Measured [ 26 Al] (10 6 at/g) 5 10 20 Modelled [ 26 Al] (10 6 at/g) U M V O N PW S T 0.5 cm 2 /a 1 cm 2 /a 1.5 cm 2 /a 2 cm 2 /a 5 cm 2 /a 1:1 +20% -20% Best t model Mid-Pleistocene Transition Lisiecki and Raymo (2005) Probability low high Inversion of TCN data F © Authors. All rights reserved Southern Espinhaço Range Pléiades images extent Hilltop sampling site Stream-sediment sampling site (0.6) Apparent denudation rate (m/Ma) Minas Gerais A Temporal evolution of surface processes inferred from cosmogenic nuclides in a slow erosion setting Insights from the Sera do Cipo range, Brazil 1 Aix-Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE, Aix-en-Provence, France 2 Department of Geography, Minas Gerais Federal University, Brazil V. Godard 1 , A. Salgado 2 , L. Siame 1 , J. Fleury 1 , ASTER Team 1 Sera do Cipo landscapes Hilltop sampling sites B 0.00 0.01 0.02 0.03 0.04 0.05 Hilltop curvature (1/m) 0 1 2 3 4 5 6 Denudation rate (m/Ma) M N O P S T U V W Hilltop curvature vs apparent denudation rates Bedrock exposure Probabale weathering-limited regime E Hilltop curvature calculation High-resolution (1m) DEM derived from tri-stereo Pléiades images C 0 2 4 6 8 10 [ 10 Be] (10 6 at/g) 4.0 4.5 5.0 5.5 6.0 6.5 7.0 26 Al/ 10 Be M N O P S T U V W Steady state erosion Constant exposure 10 Be and 26 Al measurements in hilltop quartz veins D

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Page 1: Temporal evolution of surface processes inferred from ...presentations.copernicus.org/EGU2020/EGU2020-9427_presentation.pdfInsights from the Sera do Cipo range, Brazil 1Aix-Marseille

2 1.5 1 0.5 0

Time BP (Ma)

0.0

0.5

1.0

1.5

2.0

2.5

Appa

rent

diff

usio

n co

effic

ient

D (c

m2 /a

)

0.5 1.0 2.0 5.0

Measured [10Be] (106 at/g)

0.5

1.0

2.0

5.0

Mod

elle

d [10

Be](

106

at/g

)

●●●

●●●

U

M

VO

N

PW

S

TTime varying D (best fit model)Constant D

5 10 20 50Measured [26Al] (106 at/g)

510

20M

odel

led

[26Al

](10

6at

/g)

●●●

●●●

U

M

V O

N

PW

S

T

0.5 cm2 /a

1 cm2 /a

1.5 cm2 /a

2 cm2 /a

5 cm2 /a

1:1+20%

-20%

Best fit model

Mid-Pleistocene Transition

Lisiecki and Raymo (2005)

Probability

low high

Inversion of TCN data F

© A

uth

ors

. A

ll r

igh

ts r

eserv

ed

South

ern

Esp

inhaço

Range

Pléiades images extent

Hilltop sampling site

Stream-sediment sampling site

(0.6) Apparent denudation rate (m/Ma)

Minas Gerais

A

Temporal evolution of surface processes inferred from cosmogenic nuclides in a slow erosion setting Insights from the Sera do Cipo range, Brazil

1Aix-Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE, Aix-en-Provence, France2Department of Geography, Minas Gerais Federal University, Brazil

V. Godard1, A. Salgado2, L. Siame1, J. Fleury1, ASTER Team1

Sera do Cipo landscapes Hilltop sampling sites

B

0.00

0.01

0.02

0.03

0.04

0.05

Hillt

op c

urva

ture

(1/m

)

0 1 2 3 4 5 6

Denudation rate (m/Ma)

M

N

O

P

ST

U

V

W

Hilltop curvature vs apparent denudation rates

Bedrock exposureProbabale weathering-limited regime

E

Hilltop curvature calculationHigh-resolution (1m) DEM derived from tri-stereo Pléiades images

C

0 2 4 6 8 10[10Be] (106 at/g)

4.0

4.5

5.0

5.5

6.0

6.5

7.0

26Al

/10Be

M

NO

PS

T

U

V

W

Steady state erosion

Constant exposure

10Be and 26Al measurements in hilltop quartz veins

D