Cr, in Standard Deviations

< 717.45 < 67.79 < 649.71 < 54.82 < 158.24 < 71.72 < 928.83 < 199.87 < 2,309.82 < 80.10 < 954.39 < 77.85

717.46 – 911.04 67.80 – 77.70 649.72 – 828.14 54.83 – 62.82 158.25 – 196.65 71.73 – 82.07 928.84 – 1,172.31 199.88 – 245.51 2,309.83 – 2,893.44 80.11 – 97.98 954.40 – 1,207.80 77.86 – 82.80

911.05 – 1,104.63 77.71 – 87.61 828.15 – 1,006.57 62.83 – 70.82 196.66 – 235.05 82.08 – 92.42 1,172.32 – 1,415.78 245.52 – 291.15 2,893.45 – 3,477.07 97.99 – 115.86 1,207.81 – 1,461.21 82.81 – 87.75

1,104.64 – 1,298.22 87.62 – 97.51 1,006.58 – 1,185.00 70.83 – 78.81 235.06 – 273.46 92.43 – 102.78 1,415.79 – 1,659.26 291.16 – 336.79 3,477.08 – 4,060.69 115.87 – 133.74 1,461.22 – 1,714.62 87.76 – 92.70

1,298.23 – 4,110.00 97.52 – 123.00 1,185.01 – 5,850.00 78.82 – 78.00 273.47 – 926.50 102.79 – 697.00 1,659.27 – 4,540.00 336.80 – 2,980.00 4,060.70 – 10,000.00 133.75 – 478.00 1,714.63 – 10,000.00 92.71 – 70.00

Cr, in equivalent parts per million [z-scores]

Central Mauritanides Kîffa-Néma Nord East Nord West Southern Mauritanides Tasiast-Tijirit

Rock Unconsolidated Rock Unconsolidated Rock Unconsolidated Rock Unconsolidated Rock Unconsolidated Rock Unconsolidated

n = 722 n = 163 n = 539 n = 18 n = 451 n = 1388 n = 509 n = 1287 n = 1170 n = 3006 n = 868 n = 2

5° W

6° O

6° W

7° O

7° W

8° O

8° W

9° O

9° O

10° O

10° O

11° O

11° O

12° O

12° 0

13° O

13° 0

14° O

14° O

15° O

15° O

16° O

16° O17° O

27° N 27° N

26° N 26° N

25° N 25° N

24° N 24° N

23° N 23° N

22° N 22° N

21° N 21° N

20° N 20° N

19° N 19° N

18° N 18° N

17° N 17° N

16° N 16° N

15° N 15° N

!.

!.

!.

!.

!.

!.

!.

!.

!.

!.

!.

!.

!.

Aleg

Atar

NémaKîffa

Rosso

Kaédi

Akjoujt

Zouérate

Sélibabi

Tidjikja

Nouâdhibou

Nouakchott

'Ayoûn el 'Atroûs

> 3.00 SD

2.51 - 3.00 SD

2.01 - 2.50 SD

1.51 - 2.00 SD

< 1.50 SD

UnconsolidatedRock

Areas are geologically-based statistical domains used in processing the data

Kîffa-Néma

Southern Mauritanides

Central Mauritanides

Tasiast-Tijirit

Nord-est

Nord-ouest

Geochemical Areas

GEOCHEMISTRYEXPLANATION

BASE MAPEXPLANATION

Productive water source

!. Major cities

Stream - intermittent

Stream - permanent

Road - minor

Road - arterial

Road - major

Railroad

Country boundary

Explanation

This map was produced as part of the "Second Projet de Renforcement Institutionnel du Secteur Minier (PRISM II)"co-financed by the Government of Mauritania and the World Bank (Credit No. IDA-38100 MAU).

25 0 25 50 75 100 MILES

25 0 25 50 75 100 KILOMETERS

SCALE 1:1 000 000

APPROXIMATE MEANDECLINATION, 2007

MAG

NET

IC N

OR

THT

RU

E N

OR

TH

4 / °1 2

Transverse Mercator projection, WGS 84 DatumScale factor 0.9996; Longitude of central meridian 11° W.; latitude of origin 0°

U.S. Department of the InteriorU.S. Geological Survey

By Stuart A. Giles and Robert G. Eppinger

2012

RÉPUBLIQUE ISLAMIQUE DE MAURITANIEMinistère du Pétrole, de l’Energie et des Mines

Geochemistry of Rocks and Unconsolidated Materials — Chromium