Rock Varnish in Death Valley: Shoshone, California · DEATH VA LLEY NAT'L PARK Desert Varnish...

study site

area below sea level

national park

0

0 25 km

25 mi

650

5 50

6 0 0

Shoshone

A m argo sa R i v e r

Ama r go sa R i v e r

500

700

650

600

550

700

750

800

850

750

600

800

650

O l dR a i l r o a d

G r a d e

1 7 8

1 2 7

1 2 7

1 7 8

0 1/2 1 mileNORTH

Du b l i n

H i l l sNEVADA

CALIFORNIA

DE

AT

H

VA

LL

EY

PA

NA

MI

NT

RA

NG

E

Funeral Mountains

Greenwater Range

AM

AR

GO

SA

RA

NG

E

D EATH

VALLEY

NAT'L

PAR K

Desert Varnish is a shiney dark coating,

dominated by manganese oxide, that

forms on rocks in arid or semi-arid areas,

after long-term exposure to air.

Shoshone, California is one study

site location of a Summer 2002 project

examining desert varnish on relict lobes

on alluvial fans near Death Valley National

Park.

M e t h o d s : R o c k

samples were collected

from adjacent varnished

and unvarnished alluvial

surfaces.

Results: Desert varnish is more prevalent and darkeron older, inactive, deflated alluvial sur faces.

Conclusion: Desertvarnish is a goodindicator of relativeweathering, or rate ofweathering, on alluvialfan surfaces.

Map source: USGS 7.5 minute topographic map,Shoshone Quadrangle. Location map source: Dick Gilbreath

Map compiled by: Kristin Adams

Shoshone

Rock Varnish in Death Valley: Shoshone, California