10.13023/ETD.2017.415Lo, Edward LiminEdward LiminLohttps://orcid.org/0000-0003-3299-4495University of KentuckyFluvial-Lacustrine Processes Shaping the Landforms of the Distal Paraguay Fluvial MegafanUniversity of Kentucky Libraries2017ThesisGeomorphologyHydrologySedimentologyStratigraphyTerrestrial and Aquatic EcologyPDFCopyright © Edward Limin Lo 2017Tropical wetlands such as the Pantanal help regulate global biogeochemical cycles, but climate change is modifying these environments. Controls on environmental changes can potentially be assessed from ancient, well-dated lacustrine sedimentary records. An integrated field and laboratory approach was undertaken to study the limnogeology of Lake Uberaba in the northern Pantanal, and test whether the lake has preserved a reliable record of environmental change in its strata. This study was designed to understand how the basin accumulates sediment and to assess its sensitivity to hydroclimatic variability. The data showed that modern Lake Uberaba is a highly dynamic, freshwater fluvial-lacustrine basin. Modern lake floor sediments are largely siliciclastic silts, with limited organic matter content and abundant sponge spicules. This sedimentary composition reflects the lake’s open hydrology and well-mixed water column. Limited data from sediment cores indicates that Lake Uberaba may have formed ~1760 CE, following an abrupt transgression over an oxidized floodplain depositional environment. The stratal contact between lacustrine and floodplain deposits suggests the presence of an erosional unconformity, the timing and duration of which remains unknown. The environmental change favoring lake formation appears to be linked to increased effective precipitation provided by the Intertropical Convergence Zone (ITCZ) in the northern Pantanal.National Science Foundation1541247GrantNational Geographic SocietyGrant to Drs. McGlue and YeagerFulbrightFellowshipGSAStudent Research AwardLacCoreTravel GrantUKMcNair FellowshipDepartment of Earth and Environmental SciencesBrown-McFarlan Travel AwardDepartment of Earth and Environmental SciencesPirtle Summer SupportDepartment of Earth and Environmental SciencesTeaching and Research AssistantshipsEmbrapa - PantanaFederal University of Mato Gro sso do Sul — PantanalUNESP - Rio ClaroFAPESP Project 2014/06889-2FUNDECTProject 083/2016CNPqProcesses 447402/2014-5 and 448923/2014-9PQ2312.386/2014-1Research Grant Awarded to Dr. SilvaPioneer Professorship Endowed Funds