Ten
thousand
years
of
environmental
change
and
human
habitation
in
NE
Iran
Final
Report
Dr.
Richard
Walker
Royal
Society
University
Research
Fellow
Department
of
Earth
Sciences,
University
of
Oxford
South
Parks
Road,
Oxford,
OX1
3AN
[email protected]
Abstract
Our
proposal
was
to
investigate
the
last
10,000
years
of
environmental
change,
and
its
effect
on
human
populations,
in
the
deserts
of
NE
Iran.
Our
field
study
had
two
foci,
the
first
was
an
abandoned
settlement,
sited
deep
within
a
now
inhospitable
desert
near
Dasht‐e‐Bayaz
in
NE
Iran,
which
was
sustained
through
a
network
of
surface
canals
fed
by
a
reservoir
of
1
km
diameter.
The
second
focus
was
an
exploration
of
caves
in
the
desert
interior
of
NE
Iran
that
contain
cave
speleothems
(stalagtites,
stalagmites,
flowstones).
The
existence
of
both
the
reservoir
and
the
cave
speleothems
indicate
a
much
wetter
climate
existed
in
NE
Iran
in
the
past.
Our
team
travelled
out
to
Iran
in
May
2011
for
two
weeks.
Along
with
our
collaborators
in
the
Geological
Survey
of
Iran,
University
of
Tehran,
and
University
of
Birjand,
we
were
able
to
visit
all
the
sites
we
had
hoped
to
visit
and
have
collected
a
number
of
samples
for
dating.
Initial
dating
of
lake
sediments
suggests
that
pre‐historic
humans
were
settled
in
the
arid
Dasht‐e‐Bayaz
basin
between
4,000‐6,000
years
before
present.
Preliminary
dating
of
the
speleothem
samples
suggests
that
we
can
construct
a
climate
record
throughout
the
last
~500,000
years
from
them.
We
are
currently
applying
for
large
research
grants
to
undertake
detailed
sample
analysis
and
to
determine
whether
the
climate
was
much
wetter
than
present
during
the
interval
of
occupation
at
Dasht‐e‐Bayaz.
1
Project
description
and
key
findings
Eastern
Iran
is
a
land
of
high
mountains
surrounded
by
inhospitable
desert
depressions;
with
the
large‐scale
morphology
largely
shaped
by
active
tectonic
processes.
The
extremely
arid
environment
across
much
of
the
country
forces
most
of
the
population
to
inhabit
relatively
narrow
fringes
of
land
flanked
by
high
mountains
on
the
one
side
and
by
barren
desert
on
the
other.
Even
at
the
desert
margins,
the
rivers
are
dry
except
during
rare
floods,
and
agriculture
relies
on
the
tapping
and
distribution
of
scarce
groundwater
supplies
by
networks
of
underground
canals
known
as
Qanats:
a
technology
that
was
first
developed
about
4,000
years
ago.
Unfortunately,
the
distribution
of
groundwater
supplies
is
closely
related
to
the
distribution
of
active
faults,
which
act
as
barriers
to
groundwater
movement;
much
of
the
population
of
Iran
is
therefore
forced
to
live
in
the
regions
where
the
risk
from
earthquakes
is
highest.
Although
being
one
of
the
hottest
and
most
arid
regions
on
Earth
at
present,
the
landscape
of
eastern
Iran
retains
evidence
that
a
much
milder,
and
wetter,
environment
existed
at
times
in
the
geologically
recent
past.
Most
of
the
existing
studies
of
the
late
Quaternary
landscape
of
eastern
Iran
‐
including
several
performed
by
my
team
of
collaborators
‐
focus
mainly
on
the
last
10,000
years.
Walker
&
Fattahi
(2011)
review
the
existing
constraints
on
the
development
and
subsequent
abandonment
of
alluvial
fan
surfaces,
river
terraces,
and
desiccated
lakebeds
across
eastern
Iran.
Taken
together,
the
results
suggest
that
from
~10
ka
to
at
least
7
ka
was
a
time
of
rapid
evolution
of
the
landscape.
The
few
dates
from
lakebed
sediments
suggest
that
the
lakes
were
at
their
highest
levels
between
~7‐8
ka.
It
therefore
appears
that
the
major
changes
in
landscape
occurred
at
a
time
when
water
was
more
abundant
than
at
present.
The
pre‐Holocene
record
of
landscape
change
is
fragmentary,
but
there
is
evidence
for
repeated
cycles
of
alluvial
fan
deposition
and
abandonment,
which
may,
in
turn,
be
related
to
changes
in
the
availability
of
water
at
40‐60
ka,
80
ka
and
120
ka
(Walker
and
Fattahi,
2011).
Given
the
apparent
large
changes
in
landscape
over
the
last
10
ka
it
is
possible
that
important
developments
in
human
society
within
eastern
Iran
occurred
under
climatic
and
environmental
conditions
that
were
very
different
from
those
seen
at
the
present
day
(e.g.
Fouache
et.al.
2008;
Schmidt
et.al.
2011).
Climatic
records
(obtained
from
cave
carbonates
‐
collectively
termed
speleothems)
in
the
eastern
Mediterranean
and
Arabian
regions,
despite
occurring
under
very
difficult
climatic
regimes
(Fig.
2),
show
similar
trends
towards
arid
conditions
from
a
peak
in
rainfall
at
7‐8
ka
(Bar‐Matthews
et.al.,
1997;
Fleitmann
et.al.,
2007).
Periods
of
abrupt
aridification
and
drought
at
5.2
ka
and
4.2
ka
in
the
Mediterranean
records
appear
to
correlate
with
rapid
decline
in
the
ancient
civilisations
in
western
Asia,
with
collapse
of
the
Akkadian
empire
of
Mesopotamia
being
the
most
famous
example
(e.g.
Cullen,
2000;
deMenocal,
2001;
Staubwasser
and
Weiss,
2006),
but
identification
of
whether
climatic
change
was
the
dominant
factor
in
influencing
societal
development
and
collapse
remains
problematic
due
to
the
fragmentary
2
archaeological
record
and
wide
range
of
(non‐climatic)
pressures
that
may
also
have
exerted
influence
on
these
early
communities
(e.g.
Schmidt,
2011).
Our
proposal
was
to
use
archives
from
cave
carbonate
deposits
(collectively
termed
speleothems)
to
provide
a
precise
chronology
of
climatic
change
in
eastern
Iran.
The
climate
record
will
provide
a
framework
for
the
investigation
of
societal
development
during
the
Holocene.
No
detailed
palaeoclimatic
records
exist
from
eastern
Iran,
and
the
effect
that
changes
in
environment
have
had
on
human
populations
is
not
known.
One
example
in
which
an
intimate
link
appears
to
exist
between
climatic
change
and
societal
development
in
the
prehistory
of
Iran
is
the
identification,
from
the
analysis
of
high‐resolution
IKONOS
satellite
imagery
(with
a
pixel
spacing
of
1
m),
of
an
ancient
settlement
deep
within
the
Nimbluk
plain
in
the
eastern
Iranian
desert.
Agriculture
around
the
settlement
was
enabled
through
a
network
of
surface
canals
fed
by
a
water
reservoir
of
1
km
diameter.
The
existence
of
the
site
therefore
relied
on
the
ability
to
collect
and
retain
water
within
the
reservoir:
something
that
is
improbable
in
the
present‐day
arid
climate.
Our
findings
are
as
follows:
1)
Dasht‐e‐Bayaz
ancient
settlement.
Our
Iranian
archaeological
colleagues
performed
a
brief
survey
of
pottery
fragments
at
the
surface
of
the
settlement,
The
pottery
is
of
early
medieval
age.
However,
a
large
tepe
(settlement
mound)
at
the
site
might
indicate
a
much
longer
and
earlier
history
of
settlement.
The
full
settlement
history
would
require
excavation
of
the
mound.
We
note
that
the
medieval
settlement
was
fed
by
a
qanat
(an
underground
canal)
and
the
construction
of
the
reservoir
may
substantially
predate
the
qanat
construction.
2)
Dasht‐e‐Bayaz
ancient
reservoir.
The
reservoir
feature
is
confirmed
as
being
a
man‐made
structure.
Dating
of
the
lake
sediments
laid
down
in
the
reservoir
provides
a
potential
indirect
way
of
dating
the
history
of
settlement
within
the
Dasht‐e‐Bayaz
desert.
We
have
collected
a
number
of
luminescence
samples
from
exposures
of
the
lakebeds.
Preliminary
work
on
these
samples
yields
ages
of
4,000‐
6,000
years
before
present:
a
time
that
we
suspect
was
less
arid
than
at
present
(see
earlier
discussion).
We
also
collected
the
lakebed
sediment
at
2cm
intervals
throughout
the
exposure
(for
palaeoenvironmental
reconstruction).
3)
Cave
climate
records.
With
guides
from
the
Mashad
caving
Society
we
explored
three
caves
for
cave
speleothems.
Two
of
the
three
yielded
stalagmites
suitable
for
sampling.
We
collected
~10
small
stalagmites
from
two
caves
that
are
now
in
Oxford
and
in
the
early
stages
of
analysis.
The
majority
of
these
samples
that
we
collected
were
from
the
cave
floor
(having
presumably
been
broken
during
earthquakes).
Speleothems
can
be
readily
dated
using
U‐Th
techniques
to
provide
probably
the
best
dated
of
all
palaeoclimate
records
and
thus
obtain
a
precise
and
accurate
chronology
of
past
wet
periods.
Depending
on
the
growth
rate
of
the
speleothems,
it
may
also
be
possible
to
extract
a
full
palaeoclimatic
record
from
the
cave
3
speleothems,
by
measuring
the
oxygen
and
carbon
isotopic
compositions
in
the
carbonates,
which
will
give
information
about
changes
in
the
amount
of
rain
and
vegetation
above
the
cave.
Preliminary
dating
of
the
speleothem
samples
suggests
that
we
can
construct
a
climate
record
throughout
the
last
~500,000
years
from
them.
We
are
now
in
the
analysis
stage
of
the
project
and
are
using
initial
age
results
as
leverage
to
apply
for
the
substantial
amount
of
funding
required
for
completing
all
analyses.
Preliminary
dating
analyses
were
performed
using
the
remainder
of
the
Oman‐Thesiger
Fellowship
funds.
It
is
through
this
important
stage
that
our
work
will
provide
a
precise
chronology
of
environmental
(and
climatic)
change
in
NE
Iran
through
the
last
500,000
years.
We
will
then
compare
the
history
of
habitation
gleaned
from
the
lakebed
deposition
record
with
an
independent
record
of
past
environmental
change
that
we
will
construct
from
analysis
of
cave
speleothems
from
Doruneh
cave.
The
interdisciplinary
nature
of
the
project
will
generate
interest
from
the
wider
public
and
we
would
be
very
happy
to
work
with
the
Royal
Geographical
Society
to
publicise
our
findings
through
lectures
and
through
written
articles
in
the
Society
magazine.
Bar‐Matthews,
M.,
et.al.,
1997.
Late
Quaternary
Palaeoclimate
in
the
Eastern
Mediterranean
region
from
stable
isotope
analysis
of
speleothems
at
Soreq
cave,
Israel.
Quat.
Res.,
47,
155‐168
deMenocal,
P.B.,
2001.
Cultural
responses
to
climate
change
during
the
late
Holocene,
Science,
292,
667‐673
Cullen,
H.M.,
deMenocal,
P.B.,
Hemming,
G.,
Brown,
F.H.,
Guilderson,
T.,
Sirocko,
F.,
2000.
Climate
change
and
the
collapse
of
the
Akkadian
empire:
Evidence
from
the
Deep
Sea,
Geology,
28,
379‐382.
Fleitmann,
D.,
et.al.,
2007.
Holocene
ITCZ
and
Indian
monsoon
dynamics
recorded
in
stalagmites
from
Oman
and
Yemen
(Socotra).
Quat.
Sci.
Revs.,
26,
170‐188
Fouache,
E.,
et.al.
2008.
A
study
of
the
climatic
crisis
of
the
end
of
the
third
Millenium
BC
in
Southeastern
Iran
through
the
lens
of
geomorphology
and
archaeology.
Proceedings
of
the
10th
Annual
Symposium
on
Iranian
Archaeology,
Bandar
Abbas,
Iran
Schmidt,
A.,
et.al.,
2011.
Holocene
settlement
shifts
and
palaeoenvironments
on
the
Central
Iranian
Plateau:
disentangling
linked
systems.
The
Holocene,
in
press
Staubwasser,
M.,
Weiss,
H.,
2006.
Holocene
climate
and
cultural
evolution
in
late
prehistoric‐early
historic
West
Asia.
Quat.
Res.,
66,
372‐387.
Walker,
R
&
Fattahi,
M.,
2011.
A
framework
of
Holocene
and
Late
Pleistocene
environmental
change
in
eastern
Iran
inferred
from
the
dating
of
periods
of
alluvial
fan
abandonment,
river
terracing,
and
lake
deposition.
Quat.
Sci.
Rev.
4
Images
The
Nimbluk
basin
at
Dasht‐e‐Bayaz
Mountains
near
Dasht‐e‐Bayaz
5
Entrance
to
Batoon
cave
near
Ferdows
Starting
on
the
hike
to
Doruneh
cave
in
the
Kuh‐e‐Sorkh
mountains
6
Group
photo
7
Final
Budget
Flights
(London‐Tehran
x
3):
£3167.36
Car/driver/fuel:
£2579.30
Flights
(Tehran‐Mashad
x
3):
£269.38
Food:
£152.69
Technician
expenses:
£590.50
(Initial
sample
prep.
in
Tehran)
Tip
for
drivers/cave
guides:
£500
Sundry
expenses
covered
more
than
the
remainder
of
the
award
Incident
report
There
are
no
incidents
to
report.
The
fieldwork
went
smoothly
and
to
plan.
8