Evidence for Lake Formation as a Response to an Inferred Holocene Climatic Transition in Brazil
Saulo Rodrigues-Filho
Hermann Behling
George Irion
German Müller
Abstract
Geochemical, mineralogical, and palynological records from a Holocene sediment core 12.7 m long from Lake Silvana, southeastern Brazil, served to identify the source of detrital sediments within catchment soils. The lake basin was first flooded in the early Holocene (9400 14C yr B.P.), when a gibbsite-rich B soil horizon started to accumulate. Four distinct hydrologic phases are consistent with vegetational changes indicated by pollen data. Phases of slope instability (colluviation) and low lake level correspond to pollen-free intervals and point to a severe retreat of the vegetation cover. The rapid sedimentation of slope-wash sediments alternating with alluvial sediments appears to have formed a tributary fan 7.8 m thick that dammed the Lake Silvana Basin 8500 14C yr B.P., probably as a response to a drastic increase in precipitation rates.
Rodrigues-Filho S., Behling H., Irion G. and Müller G. (2002) Evidence for Lake Formation as a Response to an Inferred Holocene Climatic Transition in Brazil. Quaternary Research 57(1): 131-137. 10.1006/qres.2001.2281
@article{Rodrigues-Filho2002,
Title = {Evidence for Lake Formation as a Response to an Inferred Holocene Climatic Transition in Brazil},
Author = {Rodrigues-Filho, Saulo and Behling, Hermann and Irion, George and Müller, German},
Editor = {},
Journal = {Quaternary Research},
Year = {2002},
Pages = {131-137},
Volume = {57},
Doi = {10.1006/qres.2001.2281},
Abstract = {Geochemical, mineralogical, and palynological records from a Holocene sediment core 12.7 m long from Lake Silvana, southeastern Brazil, served to identify the source of detrital sediments within catchment soils. The lake basin was first flooded in the early Holocene (9400 14C yr B.P.), when a gibbsite-rich B soil horizon started to accumulate. Four distinct hydrologic phases are consistent with vegetational changes indicated by pollen data. Phases of slope instability (colluviation) and low lake level correspond to pollen-free intervals and point to a severe retreat of the vegetation cover. The rapid sedimentation of slope-wash sediments alternating with alluvial sediments appears to have formed a tributary fan 7.8 m thick that dammed the Lake Silvana Basin 8500 14C yr B.P., probably as a response to a drastic increase in precipitation rates.},
}
TY - JOUR
AU - Rodrigues-Filho, Saulo
AU - Behling, Hermann
AU - Irion, George
AU - Müller, German
TI - Evidence for Lake Formation as a Response to an Inferred Holocene Climatic Transition in Brazil
T2 - Quaternary Research
PY - 2002
SP - 131-137
VL - 57
DO - 10.1006/qres.2001.2281
AB - Geochemical, mineralogical, and palynological records from a Holocene sediment core 12.7 m long from Lake Silvana, southeastern Brazil, served to identify the source of detrital sediments within catchment soils. The lake basin was first flooded in the early Holocene (9400 14C yr B.P.), when a gibbsite-rich B soil horizon started to accumulate. Four distinct hydrologic phases are consistent with vegetational changes indicated by pollen data. Phases of slope instability (colluviation) and low lake level correspond to pollen-free intervals and point to a severe retreat of the vegetation cover. The rapid sedimentation of slope-wash sediments alternating with alluvial sediments appears to have formed a tributary fan 7.8 m thick that dammed the Lake Silvana Basin 8500 14C yr B.P., probably as a response to a drastic increase in precipitation rates.
ER -
