Lake Bosumtwi, Ghana Late Quaternary Magnetic Mineral Data Peck, J.A.; Green, R.R.; Shanahan, T.; King, J.W.; Overpeck, J.T.; Scholz, C.A. Peck, J.A. Green, R.R. Shanahan, T. King, J.W. Overpeck, J.T. Scholz, C.A. earth science/paleoclimate/paleolimnology (volume magnetic susceptibility,sediment,null,dimensionless (SI system),null,paleolimnology,null,magnetic susceptibility measurement with ring or loop sensor,N,x10-5 units) earth science/paleoclimate/paleolimnology (S-ratio,sediment,null,dimensionless,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (saturation isothermal remanent magnetization,sediment,null,milliampere square meter per kilogram,null,paleolimnology,null,null,N,Mrs) earth science/paleoclimate/paleolimnology (coercivity of remanence,sediment,null,millitesla,null,paleolimnology,null,null,N,Hcr) earth science/paleoclimate/paleolimnology (depth,null,null,centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (organic matter,sediment,null,weight percent,null,paleolimnology,null,loss on ignition,N,null) earth science/paleoclimate/paleolimnology (saturation isothermal magnetization,sediment,null,milliampere square meter per kilogram,null,paleolimnology,null,null,N,Ms) earth science/paleoclimate/paleolimnology (age,null,null,year Common Era,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (saturation isothermal remanent magnetization/saturation isothermal magnetization,sediment,null,dimensionless,null,paleolimnology,null,null,N,Mr/Ms) earth science/paleoclimate/paleolimnology (initial magnetization slope,sediment,null,cubic meter per kilogram,null,paleolimnology,null,null,N,IS) earth science/paleoclimate/paleolimnology (age,null,null,radiocarbon year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (coercivity,sediment,null,millitesla,null,paleolimnology,null,null,N,Hc) earth science/paleoclimate/paleolimnology (coercivity of remanence/coercivity,sediment,null,dimensionless,null,paleolimnology,null,null,N,Hcr/Hc) earth science/paleoclimate/paleolimnology (age,null,null,calendar year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (saturation isothermal remanent magnetization/initial magnetization slope,sediment,null,kiloampere per meter,null,paleolimnology,null,null,N,Mrs/IS) earth science/paleoclimate/paleolimnology (Lake Bosumtwi>LATITUDE 6.5>LONGITUDE -1.4167) We report magnetic hysteresis results from sediment cores obtained from Lake Bosumtwi, Ghana. As a hydrologically closed basin, the water budget of Lake Bosumtwi is extremely sensitive to changes in the precipitation/ evapotranspiration balance. Lake Bosumtwi lies in the path of the seasonal migration of the intertropical convergence zone (ITCZ); hence, the lake is ideally situated to study monsoon variability in West Africa. Five distinctive magnetic mineral zones (A-E) were identified in the 11-m-long sediment cores that span the last 26,000 calendar years. Prior to 12 calendar (cal) ka, low concentrations of multidomain, high-coercivity magnetic minerals are present. Three prominent shifts towards very high concentrations of high-coercivity iron sulfide (greigite) magnetic minerals are centered at 12,470, 17,290, and 22,600 calendar years during the last glacial period (magnetic zones D1-3). Between 12 and 3.2 cal ka, there is an abrupt shift to moderately high concentrations of mixed multidomain and single-domain, low-coercivity minerals and an organic-rich sapropel lithology. Since 3.2 cal ka, the magnetic mineral parameters reveal a shift to increased amounts of high-coercivity magnetic minerals. STUDY NOTES: Physical property logging of whole core volumetric magnetic susceptibility and gammaray attenuation (an estimation of wet bulk density) was conducted on the piston cores using an automated Geotek multisensor core logger. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Peck, J.A. Investigator : Green, R.R. Investigator : Shanahan, T. Investigator : King, J.W. Investigator : Overpeck, J.T. Investigator : Scholz, C.A. 2007-01-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/5454 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/bosumtwi2004.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/bosumtwi2004.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/bosumtwi2004.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/bosumtwi2004.txt English https://www.ncdc.noaa.gov/paleo/study/5454 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/bosumtwi2004.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/bosumtwi2004.txt Peck, J.A., R.R. Green, T. Shanahan, J.W. King, J.T. Overpeck, C.A. Scholz. 2004. A magnetic mineral record of Late Quaternary tropical climate variability from Lake Bosumtwi, Ghana. Palaeogeography, Palaeoclimatology, Palaeoecology Vol. 215, pp. 37- 57 START YEAR: 26655 cal yr BP * END YEAR: 152 cal yr BP -1.4167 6.5 -1.4167 6.5