CRE Sample Preparations and AMS Measurements

Supplementary Material

CRE sample preparations and AMS measurements

In situ-produced 10Be resulting from spallation and muonic reactions on Silicon and Oxygen were measured in cherts. After sieving, the selected fraction comprised between 1 and 0.250 mm passed through magnetic separation and the separated non-magnetic fraction undergone selective etchings in ﬂuorosilicic and hydrochloric acids to eliminate all mineral phases but silicates. Obtained silicates were etched in hydrofluoric acid to eliminate potential contamination by atmospheric 10Be (e.g., Brown et al. 1991). The cleaned cherts were then completely dissolved in hydroﬂuoric acid after addition in each sample of 100 µl of an in- house 3.10-3 g/g 9Be carrier solution prepared from deep-mined phenakite (Merchel et al.

2008). Beryllium was separated from the obtained solutions using both cation and anion exchange chromatography which eliminate iron, aluminum, manganese and other elements, followed by precipitation of the Be oxy-hydroxydes at pH=8. After their oxidation at 800°C, the resulting beryllium oxide was mixed with 325-mesh niobium powder prior to measurements by Accelerator Mass Spectrometry (AMS). All 10Be concentrations are normalized to 10Be/9Be SRM 4325 NIST reference material with an assigned value of

(2.79±0.03)10-11. This standardization is equivalent to 07KNSTD within rounding error. The

10Be half-life of (1.39±0.01)106 years used is that recommended by Korschinek et al. (2010) and Chmeleff et al. (2010) according to their two independent measurements. Analytical uncertainties (reported as 1σ) include a conservative 0.5% external uncertainty based on long- term measurements of standards, a one-sigma statistical error on counted 10Be events, and the uncertainty associated with the chemical blank correction (3.4±0.8)10-15 (Arnold et al. 2010).

To determine production rates, scaling factors for latitude and altitude corrections were calculated according to (Stone 2000) and using a modern 10Be production rate at sea level and

1 -1 high latitude of 4.5±0.3 atoms/g-SiO2.yr to account for the reevaluation of absolute calibration of 10Be AMS standards proposed by (Nishiizumi et al. 2007).

Regarding the carbonate samples, after crushing and sieving (250-500 µm fractions), the chemical extraction of 36Cl was performed following the chemical procedure recommended by

(Ivy-Ochs et al. 2004). The total 36Cl production rate depending on the bulk rock composition

(main target elements are Ca, K, Ti and Fe, see details in (Schimmelpfennig et al. 2009), a few grams of each sample were powdered (size fraction <50 µm) and the major and trace element concentrations were measured by ICP OES and ICP-MS at the SARM laboratory

(Nancy, France) (Suppl. Material, Table S3). One and a half milligram of a 35Cl-enriched chlorine carrier (35Cl/37Cl = 712 from Oak Ridge National Laboratory) was added after the first successive leaching in ultra-pure water (resistivity: ~18 MOhm) followed by partial dissolution (~10% weight) in 2N HNO3 of the samples allowing simultaneous determination of natural Cl by AMS isotopic dilution. Samples were then completely dissolved in 2N HNO3

36 and Cl precipitated as AgCl by the addition of AgNO3 solution. To reduce S isobaric interference during AMS measurement, the AgCl precipitate was then re-dissolved using

NH4OH and sulfur co-precipitated along with BaCO3 as BaSO4 by addition of a slightly basic saturated Ba(NO3)2 solution. The ﬁnal AgCl-target was produced by re-precipitation using

HNO3, repeated washing cycles with HNO3 and H2O, and drying at 80°C. The AgCl was then directly packed into nickel cathodes. All 36Cl concentrations were normalized to the

KNSTD1600 calibration material (35Cl/36Cl = 1.6x10-12 provided by K. Nishiizumi). The decay

-6 -1 36 5 constant of 2.303 ± 0.016x10 an used corresponds to a Cl half-life (T1/2) of 3.014*10 years. Analytical uncertainties (reported as 1σ) include a conservative 0.5% external uncertainty, a one-sigma statistical error on counted 36Cl events, and the uncertainty associated with the blank correction (36Cl/35Cl blank ratio was on the order of (0.816 ± 0.098)10-14). All

2 10Be and 36Cl measurements were performed at the 5 MV French national AMS facility,

ASTER, located at CEREGE, Aix en Provence, France (Arnold et al. 2010).

CRE dating results and minimum geological slip-rate (additional comments)

We mention in the Section 3.2 of the article that measured 10Be concentrations in cherts must be dominated by a long (and variable) pre-exposure history, the measured in-situ produced

10Be concentrations do not indeed decrease exponentially with depth along the profile . To verify this assumption, we run a simple modeling. Minimum 10Be CRE ages modeled considering that the measured 10Be concentrations only result from in-situ production yield exposure duration over several Ma (Suppl. Material, Table S1), whereas historical colluviums, for example, cannot be older than a couple of ka. This confirms that: 1/ most of the measured

10Be concentrations in cherts result from inheritance and, 2/ the fan aggradation and abandonment is recent relative to the pre-exposure history.

3 Supplementary tables

Table S1: Measured in-situ produced 10Be concentrations of samples collected along the depth profile at the sampling site (Figure 7c, 8 and 13).

Also reported is the minimum 10Be modeled age assuming measured 10Be concentrations would only result from in-situ 10Be production at the surface (no inheritance and zero denudation rate). 10Be half-life is (1.39±0.01) Ma (Chmeleff et al. 2010; Korschinek et al. 2010). We estimated bulk rock density to be ~1.8. Scaling factor for surface nucleonic production rate as a function of latitude and altitude is 1.01 (Stone et al. 1996).

Effective apparent attenuation lengths for neutrons, slow muons and fast muons are, respectively, 160 g.cm-2, 1500 g.cm-2 and 4320 g.cm-2

(Braucher et al. 2011). The relative contributions of the three reactions (Pspall, Psm, Pfm) to the total 10Be production have been calculated following (Braucher et al. 2003). Pspall: neutron-induced spallation; Psm: slow muon capture; Pfm: fast-muon induced reaction. χ2 = (Modeled

10Be - Measured 10Be)2 / (Error measured 10Be).

Measured Error Modeled in- Denu- Modeled Depth Depth Stone 2 Geological Sample Pspall Psm Pfm 10 10 χ (cm) g/cm2 scaling Be measured situ Be dation exposure time Material (.106at/gr) 10Be (± at/gr.) (.106at/gr) rate (years) Be 1 100 180 1.01 4.535 0.012 0.037 1 527 833 54 587 1 527 833 0 1 399 239 0.0000 Historic Be 2 120 216 1.01 4.535 0.012 0.037 2 395 529 74 342 2 395 529 0 7 907 254 0.0000 colluviums Be 3 135 243 1.01 4.535 0.012 0.037 1 934 296 74 304 1 934 297 0 5 366 534 0.0000 Be 4 155 279 1.01 4.535 0.012 0.037 13 615 976 523 927 1 674 953 0 53 687 091 519.4475 Be 5 182.5 328.5 1.01 4.535 0.012 0.037 3 914 113 122 053 1 251 297 0 53 687 091 475.9754 Be 6 215 387 1.01 4.535 0.012 0.037 336 784 18 001 336 784 0 947 302 0.0000 Alluvial Be 7 275 495 1.01 4.535 0.012 0.037 2 573 496 87 750 493 546 0 53 687 091 561.8389 fan Be 8 325 585 1.01 4.535 0.012 0.037 380 714 25 873 314 241 0 53 687 091 6.6010 Be 9 460 828 1.01 4.535 0.012 0.037 560 376 34 294 125 306 0 53 687 091 160.9425 Be 10 525 945 1.01 4.535 0.012 0.037 3 194 212 109 046 96 054 0 53 687 091 807.2110

4 Table S2: Maximum denudation rates obtained considering samples at the surface and infinite exposure duration. Modeling parameters are listed in the Table S1 caption.

Error Modeled Measured Denudation Modeled time Sampl Depth Depth measured in-situ 10Be Rate exposure χ2 e (cm) g/cm2 10Be (± 10Be (106at/gr) (m/Ma) (years) at/gr.) (.106at/gr) Be 1 0 0 1 527 833 54 587 1 527 833 2.33302 20 000 000 000 0.0000 Be 2 0 0 2 395 529 74 342 2 395 529 1.29966 20 000 000 000 0.0000 Be 3 0 0 1 934 296 74 304 1 934 296 1.73039 20 000 000 000 0.0000 Be 4 0 0 13 615 976 523 927 9 171 287 0.00000 20 000 000 000 71.9683 Be 5 0 0 3 914 113 122 053 3 914 113 0.60995 20 000 000 000 0.0000 Be 6 0 0 336 784 18 001 336 784 13.16404 20 000 000 000 0.0000 Be 7 0 0 2 573 496 87 750 2 573 496 1.17567 20 000 000 000 0.0000 Be 8 0 0 380 714 25 873 380 714 11.51360 20 000 000 000 0.0000 Be 9 0 0 560 376 34 294 560 376 7.50736 20 000 000 000 0.0000 Be 10 0 0 3 194 212 109 046 3 194 212 0.85347 20 000 000 000 0.0000

Table S3: Chemical composition: major elements of samples collected for 36Cl CRE dating.

Measurements have been undertaken at the SARM facility (Nancy, France).

P2O Sample CaO MgO SiO2 Al2O3 Fe2O3 5 K2O TiO2 Na2O PF % % % % % % % % % % Cl 08 54.19 0.30 1.60 0.52 0.33 0.15 0.07 0.04 0.01 42.73 Cl 09 51.92 2.80 1.53 0.46 0.16 0.06 0.06 0.04 0.01 43.36 Cl 10 51.30 3.23 1.21 0.38 0.17 0.08 0.06 0.03 0.01 43.43 Cl 14 54.62 0.48 1.32 0.40 0.15 0.24 0.07 0.03 0.01 42.74 Mean 53.00 1.70 1.42 0.44 0.20 0.13 0.06 0.03 0.01 43.07 value

5 References

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6 Figures captions

Fig. S1 Extract of the geological map of Katouna area and its legend (Institute of Geology and

Mineral Exploration (IGME), 1987). We superimposed the catchment area of the offset stream selected to perform CRE dating (Fig. 12). Ionian zone formations containing cherts are: the Dogger siliceous schist, the Malm-Albian Vigla limestone, the Upper Albian

Turonian Cherts and the Eocene limestones; nearly none of these formations crop out within the catchment area. The upper catchments of the offset stream are presently eroding the paleo- surface cut on the Triassic formations, which are more likely the origin of cherts. In contrast, the carbonates clasts are eroded essentially from the Triassic Breccias and Upper Triassic-Lias

Pantocrator limestones that crop out within the catchment area.

Fig. S2 Offset stream with shutter ridge along the southern Katouna fault segment. (a)

Measured offset stream considering a near-field eastern piercing point yields ~50m; (b)

Measured offset stream considering a far-field eastern piercing point yields ~58m. Satellite images from Google Earth.