A Holocene sedimentary record from Lake Silvana, SE Brazil: evidence for paleoclimatic changes from mineral, trace-metal, and pollen data
Mineralogical-sedimentological & geochemical investigations in combination with pollen data of a 12.7-m-long dated sediment core from Lake Silvana, SE Brazil, permit the reconstruction of the climatic history over the past 10,000 years. The lowermost Section (I) reflects a coarse paleosol-type sediment with abundant plant debris & rootlets; pollen indicates grassland vegetation. Section II represents fine-grained lake sediments; pollen indicates a savanna-like vegetation. Section III represents a pollen-free, coarse-grained allogenic sediment deposited under high transportation energy (increased precipitation). Section IV, a greenish sequence with increasing C content towards the top, has a pollen spectrum of present-day vegetation (semideciduous forest). The different sediment sections show a connection with erosional phases in the catchment of the lake, based on mineralogy & geochemistry, which are a response to climate development.
What people are saying - Write a review
We haven't found any reviews in the usual places.
Other editions - View all
20 pm fraction AAS so XRF accumulation aggradation alluvial anoxic authigenic Average AAS/XRF basin Behling Brazilian carbon catchment cerrado characterized chemical climatic events colluvial unit contents core SB1 dams deposition Depth detrital sediments diagenesis dissolved distribution EG1/Coll environment erosion Fe and Mn Ferricretes formation geochemical and mineralogical Geochemistry gibbsite goethite hematite Hg concentrations Holocene IBGE ice cores increasing indicated kaolinite lacustrine lake sediments Lake Silvana lake system lateritic Limnological Metal concentrations middle Rio Doce mineral moister conditions Nahon observed occur organic matter oxides oxyhydroxides Paleoenvironmental zone parent rock pedologic Pflug pg/g Pleistocene pollen poorly ordered kaolinite quartz Quaternary radiocarbon dating rainfall redox reduction relative Rio Doce lakes Rio Doce Valley samples saprolite sediment core sedimentary sediments semideciduous forest sequence siderite siderite precipitation soils southeastern Brazil standard deviation stratification stratigraphy Tardy Tundisi Turcq vegetation water column weathering mantle weathering profile EG2 yr B.P.