Mountains & Hills

Piedmont Slope(Bajada)

Basin Floor

Mountains & Hills

Rio GrandeValley

BorderBasin Floors

Mountains

& Hills

JornadaExp. RangeHeadquarters

New MexicoState Univ.

faul

t

HCM

Jr.

Gile et al. 1981

alluvial fill

Tertiaryvolcanicrocks

Tertiaryplutonicrocks

Precambrianrocks

Paleozoicsedimentaryrocks

Paleoclimate and Landscape Evolution

Basin Flo

orPiedm

ont Slope (B

ajada)

Mountains & H

ills A.

Major Landscape Components

alluvial fl

at

playa

alluvial fa

n remnant

s

ballenas

fan piedmont

alluvial

fan rem

nants

LandformsB.

After Peterson 1981

Mountains

San Andres Mountains

Piedmont Slope (Bajada)

Basin Floor

Mount Summerford

scarp

alluvial plaineroded

& Hills

fan piedmont

alluvial fan collar

remnant fan terraces, ridges, and inter-ridge valleys

B.

A.

fan piedmont

ballenas

alluvial fan remnants

interfan valleys

mountains A.

B.

Basin FloorPiedmont Slope

BF P

P

A1A2

A3

After Peterson 1981

clay coatings &iron oxides

quartz

rockfragment

quartz

quartz

quartz

quartz

qtz

qtz

qtz

qtz

qtz

qtz

rock fr

ag

alluvium from limestone

eolian quartzose sandcharcoal date930 +/- 100 yr bp

San AndresMountains

A.

B.

fan piedmont

ballenas

Basin Floor

Piedmont Slope

BF P

P

A1

A2

A3

After Peterson 19

Before Desertification

After Desertification

Before Desertification

After Desertification

C4 grassland

C3 shrubland

pluvial lakesmtn glaciersrock glacierspackrat middenscarbon-13

lake desiccationpackrat middensC-13

lake desiccationerosionfossil pollen(mega fauna)

pluvial lakes

lake desiccationerosiondune formationC-13 fossil pollen

soil formationfossil pollen

erosionfossil pollen

erosionfossil pollen

little ice agedesertification