-
130˚ 140˚
20˚
30˚
40˚
50˚170˚
)9371 DA( a-aT)4961 DA( 2c-oK
1968M 7.9
1952M 8.2
2003M 8.0
1973M 7.4
1894M 7.9
1856M 7.5
1843M 8.0
100 km
N
145˚ 43˚
a b
c 3
N
146˚
43˚30'
cbHokkaido
B-Tm(AD 937-938)
N
)C ht01 .ac( b-aM
30 km
fo ytilibaborP
6.8 M
8 cm/year
a
B-2
(m)
5
0
-5
-10
B-2B-1
B'B
200 m
C C'C-4
C-1 C-2 C-6
C-8
C-7
C-5
5
0
-5
-10
-15
-20
(m)
-25
-30200 m
C-3
C''
C-9C-10
C-11 C-12C-13
C-14
B
''
A
A'A''
A'''
2000 m
N
C??
BC C
A
C-1 C-2 C-3 C-4C-5C-6C-7C-8C-9C-10 C-11 C-12 C-13 C-14
A-1 A-2 A-3 A-4A-5A-6
A-7 A-8
A-9 A-10A-11A-12A-13
A-17 A-16 A-15 A-14B-1B-2B-3N
2000 m
144
50
00
43 02 00
Inner Bay Facies
Lagoonal Facies
Barria Facies?
Barria Facies?
Lacustrine Facies
Marsh Facies
Tidal Flat Facies
A-14A-11
A-13A-10
A-8A-7
100(m)
Ma-f(7.5 ka)
A-15
A-16 A-17
A-6A-5A-4A-3
A-1 A-2
A-9 A-12
5
0
-5
-10
-15
-20
-25
-30
-35
-40
-45
-50
-55
-60
-65
-70
-75
(m)A
WNW ESE NNEA'' A'''A'
N
a
b
Developmental processes of Holocene barrier system based on borehole data around Akashi bay area, eastern Hokkaido, Japan
Key wardsL
ac
ustr
ine
Fa
cie
sT
i da
lF
lat
Fa
cie
sI n
ne
rB
ay
Fa
cie
sBa
rria
Faci
es
Age (cal yrs BP)
)m(edutitl
A
Ta-d (ca. 9.1 ka)
TS at ca. 11.4 ka
sea-levelcurve
depositional curve
-10
-15
0
5
-5
-20
-25
-30
-35
-40
-45
-50
-55
-60
H-20-1-(6) (-27.30m)
H-20-D (-49.7m)
uppershoreface
lowershoreface
sandytidal flat
muddytidal flat
HWL=1.50m
LWL=-0.10m
innershelf
lacustrine
PebblesClay
Silt
SandShellsBurrows Wood Plant
LaminatiomsMud clasts
H-20-E (-60.8m)
12000 11000 10000 9000 8000 7000 6000 5000 4000 3000 2000 1000 0
SB at ca. 13.8 ka
H-20-(3) (-13.30m) H-20-1
(-9.85m)
H-20-2 (-23.87m)
H-20-3 (-43.85m)
H-20-A (-13.65m)
H-20-C (-30.90m)
H-20-(1) (-6.23m)
H-20-(2) (-8.30m)
H-20-(4) (-17.30m)
H-20-(5) (-22.30m)
H-20-1-(7) (-39.30m)
H-20-1-(8) (-39.30m)
H-21-5 (-6.76m)
H-21-2 (-46.86m)
tidal channel
Altitude (m)
0
-10
-20
-30
-40
-50
-60
yalc
sfv
tlis sf
sm sc
scv
SB
TS
Ta-d (ca. 9.1 ka)
viscosity model C (Maeda et al.,1992)
Chiraikaribetsu (Sawai and Misio, 1998)
Hichirippu (Sawai, 2007)Kiritappu(Sawai et al.,2009; Maeda et al.,2009
Akkeshi (Sugimura,1984)plantpeatshellscale
new AMS data
Mochirippu (Sawai et al., 2009)
Bekanbeushi (Matsushima.,2006
Chlamys farreri Callithaca adamsReticunassa
multigranosa Callithaca adamsi Ruditapes philippinarum
Batillaria cumingii Ruditapes philippinarum