Following the Last Glacial Maximum (LGM), deglaciation of the Humboldt Massif in the northern Venezuelan Andes began sometime after 12,000 yr BP, leaving large, magnificent flutings in gneissic terrain of the Coromoto Catchment from 3900 to 3300 m a.s.l. Traces of a left lateral moraine at 4200 m a.s.l. in the Coromoto Catchment mark the position of the Last Glacial Maximum (LGM) equilibrium line altitude (ELA) for the main ice cover draining northwest from Pico Humboldt, to its lower limit at 3000 m a.s.l. at Lago Coromoto, where it emplaced a bouldery end moraine, with fine matrix material washed away. Above the 4200 m ELA, small recessional end moraines near Lago Verde (3950 m a.s.l.) presumably emplaced during the Late Glacial, mark the position of the retreating Humboldt Glacier. Reconnaissance soil stratigraphy on these moraines shows a degree of soil development and clay mineral weathering similar to that found on recessional moraines emplaced by the decaying LGM ice near Lago Mucubaji (MAHANEY & KALM 1996). Above the Late Glacial moraines at Lago Verde, the pre-LIA (Little Ice Age) Neoglacial limit reached 4150 m a.s.l. where an end moraine marks the lower ice limit. Several LIA recessional moraines mark the lower ice limit near Laguna el Suero (4200 m a.s.l.) and subsequent decay of ice starting approximately 100 yrs ago. The low ELA for Neoglacial ice and present-day ice (approximately at 4700 m a.s.l.) is in response to a north-facing aspect during the summer rainy season, high cloud cover, and enclosing ridges reaching to 4900 m a.s.l.
|Original language||English (US)|
|Number of pages||18|
|Journal||Zeitschrift fur Geomorphologie, Supplementband|
|State||Published - Dec 1 2000|