N. Ohkouchi et al., LATITUDINAL DISTRIBUTIONS OF TERRESTRIAL BIOMARKERS IN THE SEDIMENTS FROM THE CENTRAL PACIFIC, Geochimica et cosmochimica acta, 61(9), 1997, pp. 1911-1918
Twenty-three deep-sea surface sediments collected from the Central Pac
ific across a latitudinal transect at 175 degrees E from 48 degrees N
to 15 degrees S were studied for lipid class compounds including C-25-
C-36 n-alkanes, C-24-C-28 fatty alcohols, and C-23-C-34 fatty acids, w
hich are derived from terrestrial higher plants. Although all of these
terrestrial biomarkers were most likely transported long distances in
the atmosphere over the Central Pacific, their latitudinal distributi
on patterns are specific to each compound group. n-Alkanes (C-25-C-36)
are most abundant in the highest latitude (48 degrees N) and graduall
y decrease toward the lower latitude (13 degrees N). Fatty alcohols (C
-24-C-28) rapidly decrease from 48 degrees N to 30 degrees N and stay
relatively low in the lower latitudes. By contrast, abundances of fatt
y acids (C-23-C-34) are relatively high in the lower latitudes, althou
gh they increase from mid to high latitudes of the Northern Hemisphere
. In addition, distributions of n-alkanes (C-25-C-36) in 48 degrees N-
19 degrees N are characterized by CPI (carbon preference index) of 4.9
-8.2 (av. 6.6), which are significantly higher than those (1.9-4.9; av
. 2.8) in the low latitudes (15 degrees N-15 degrees S). These latitud
inal patterns of terrestrial biomarkers in the Central Pacific sedimen
ts are generally interpreted in terms of the different wind regimes be
tween high and low latitudes; that is, distributions of organic molecu
les transported from Asia to the North Pacific by westeries are differ
ent from those by trade winds which transport aerosols from Central an
d South Americas to the tropical Pacific. Copyright (C) 1997 Elsevier
Science Ltd.