Palynofacies analysis of the late Holocene San Nicolás terrace of the Cauca paleolake and paleohydrology of northern South America
Por:
Garcia, Yuri C., Ignacio Martinez, J., Velez, Maria I., Yokoyama, Yusuke, Battarbee, Richard W., Suter, Fiore D.
Publicada:
1 ene 2011
Resumen:
The detailed palynofacies analysis of the late Holocene laminated succession of the San Nicolás terrace in the middle Cauca Valley, northern Colombia, is interpreted as the product of sedimentation in a lacustrine to fluvial dominated setting. Radiocarbon analyses reveal that the succession was deposited between ~. 3500 and a few hundreds of years with sedimentary rates in excess of ~. 600. cm/ka. The milimetric laminae and the high frequency fluctuations in the content of the palynodebris of terrestrial origin, i.e., the high altered ligno-cellulosic debris/amorphous organic matter ratio, together with diatoms typical of fluvial conditions, such as Aulacoseira granulata do suggest an intermittent and continuous hydrological and biological connectivity with the Cauca River, akin to a varzea lacustrine environment. Drier to wetter conditions appear to occur, moving upward in the succession. This might reflect regional precipitation conditions all along the Cauca Valley and the southern migration of the intertropical convergence zone. © 2010 Elsevier B.V.
Filiaciones:
Garcia, Yuri C.:
Univ EAFIT, Area Ciencias Mar, Dept Geol, Medellin, Colombia
Ignacio Martinez, J.:
Univ EAFIT, Area Ciencias Mar, Dept Geol, Medellin, Colombia
Velez, Maria I.:
Univ Regina, Dept Geol, Regina, SK S4S 0A2, Canada
Yokoyama, Yusuke:
Univ Tokyo, Dept Earth & Planetary Sci, Tokyo 1138654, Japan
Battarbee, Richard W.:
UCL, ENSIS Environm Change Res Ctr, London WC1E 6BT, England
Suter, Fiore D.:
Univ EAFIT, Area Ciencias Mar, Dept Geol, Medellin, Colombia
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