Stratotype for the Merida Glaciation at Pueblo Llano in the northern Venezuelan Andes

The Merida Glaciation (cf. Wisconsinan, Weichselian) as proposed by Schuber t(1974b) culminated at about 18 ka during the last glacial maximum (LGM) an d ended at about 13 ka as indicated by C-14 dating and correlation with the Cordillera Oriental of Colombia. Moraines of an early stade of Merida Glac iation reached to 2800 m a.s.l. and were largely overrun or eradicated by t he maximum Wisconsinan advance (LGM); where they outcrop, the older moraine s are characterized by eroded, weathered glacial diamictons and outwash fan s. At Pueblo Llano in the central Merida Andes (Cordillera de Trujillo), older to younger beds of contorted glacitectonized diamict, overlying beds of bo uldery till and indurated outwash, all belong to the early Merida stade, Ov erlying the early Merida stade, deposits of rhythmically bedded glaciolacus trine sediments are in turn overlain with contorted sand and silt beds capp ed with outwash, Above the outwash terrace a loop moraine of LGM age comple tely encircles the margins of the basin. A stream cut exposed by catastroph ic (tectonic or surge?) release of meltwater displays a lithostratigraphic succession that is bereft of organic material for radiocarbon dating. Five optically-stimulated luminescence (OSL) dates place the maximum age of the lowest till at 81 ka. Particle size distributions allow clear distinctions between major lithic u nits. Heavy mineral analysis of the middle and lower coarse units in the se ction provide information on sediment sourcing and on major lithostratigrap hic divisions. Trace element concentrations provide information on the rela tive homogeneity of the deposits. The HREE (heavy rare earth element) conce ntrations allow discrimination of the lower till from the rest of the secti on; the LREE (light rare earth element) concentrations highlight difference s between the lower till, LGM till, and the rest of the section. (C) 2000 E lsevier Science Ltd. All rights reserved.