Rachold: Major Trace arui Rare Earth Element Geochemistry
211
heavy REE in the particulate fraction is balanced by a strong depletion in light REE in relation to
heavy REE in the dissolved fraction (Goldstein and Jacobsen, 1988; Elderfield et aI., 1990;
Sholkovitz, 1995) where Fe-organic colloids are major REE carriers (Sholkovitz, \995).
()
CJ)
«
~ c..
CJ)
10
5
0.5
10
5
0 .5
La Ce Pr Nd
La Ce Pr Nd
o Lena
• Amazon·
o Mississippi'
• Ohio·
Sm Eu Gd Tb Dy Ho Er Tm Vb Lu
Lena tributaries
o Chara (L 1)
• Al dan (L2)
o Vi lyuy (L3)
Sm Eu Gd Tb Dy Ho Er Tm Vb Lu
Figure 5: Shale normalized REE patterns of SPM from the Lena and its major tributaries Chara (Ll), Aldan
(L2), and Vilyuy (L3). Amazon, Mississippi, and Ohio SPM (Goldstein and Jacobsen, 1988) are shown for
comparison. Shale data (North American Shale Composite, NASC) are taken from Condie (1993).
Figure 5 presents the REE patterns of SPM of the Lena and other major rivers, i.e. the
Amazon, the Mississippi, and the Ohio (data are taken from Goldstein and Jacobsen, 1988).
The concentrations are normalized to the North American Shale Composite (NASC, Condie.
1993). As a result of the size of the Lena basin, the REE pattern of Lena SPM proves to be very
similar to other major rivers, for example the Mississippi. In contrast, the SPM of the Lena
tributaries Chara, Aldan, and Vilyuy, which drain smaller basins of less heterogeneous
geology, is characterized by different REE patterns (Figure 5). Chara SPM showed a more
pronounced enrichment in light REE and a stronger depletion in heavy REE in accordance with
REE patterns reported for rivers draining Archean crustal rocks (Goldstein and Jacobsen,