STein et at.: Late Ouaternary Organic Carbon and Biomarker Records from the Laptev Sea
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Table I: Water depths, total organic carbon (TOC) contents, organic-geochemical bulk parameters (hydrogen
index and C/N ratio), and biomarker composition in surface sediments from cores PS2471, PS2474, and PS2476
(Fahl and Stein, 1997a),
Surface sediments
PS2476
PS2474
PS2471
Parameter
Laptev Sea Continental Margin
TOC(%)
LlO
1.36
L52
HI (mgHC/gTOC)
97
68
52
C/N
7,2
8.0
8.2
C17+CI9 (~g/gTOC)
28.0
20.8
27.9
C27+C29+C31 (~g/gTOC)
179.4
100.8
117.9
(C27+C29+C31)/(CI7+CI9)
6.4
4.9
4.2
CPI
4.1
3.4
2.6
long-chain wax ester (C42) (~g/gTOC)
3.5
4.2
2.5
fatty acids (~g/gTOC)
264
249
47
alkenones (C37:2+C37:3) (~g/gTOC)
n.d.
n.d.
0.57
Table 2: Core position and water depths and accumulation rates of total organic carbon. Data from cores PS2163
and PS2170 from Stein et al. (1994). For further explanation see text (methods).
PS2476
PS2474
PS2471
PS2163
PS2170
Laptev Sea Continental Margin
Central Arctic Ocean
Core Position
Latitude
n023.51' N n040.15'N 79°097' N
86° 14.5' N
87°35.8' N
Longitude
118°11.45'E 118°34.5' E 119°47.55' E
59° 12.9' E
60°537' E
Water depth (m)
524
1494
3047
3040
4083
Oxygen Isotope Stage 1
0-600cm
0- 270 em
0- 50 em
(0·12 ka)
Mean LSR (cm/ky)
50
22
4
0.7
0.85
Mean TOC (%)
0.99
1.14
0.68
(J.SS
0.7
Mean Grain Density (g/cm3)
2.65
2.65
2.65
Mean Wet Bulk Density
1.43
1.43
1.43
(g/cm3)
Mean Dry Density (g/cm3)
0.66
0.66
0.66
0.75
0.75
Mean Porosity (%)
75
75
75
Mean Bulk Accumulation
33
14.5
2.6
0.53
0.64
Rate (g/cm2/ky)
Mean TOC Accumulation
0.33
0.17
0.02
0.003
0.004
Rate (gC/cm2Iky)
Sea shelf which is characterized by the deposition of dominantly terrigenous organic matter
supplied by the major Siberian rivers (Stein, 1996; Fahl and Stein, 1997a). The predominance