U-Th-Pb systematics of the Estherville mesosideriteResults are presented on a detailed U-Th-Pb systematics of the Estherville mososiderite, which was performed in a study involving stepwise leaching experiments. The Pb-Pb internal 'isochrons' for Estherville yielded ages of 4556 + or - 35 Ma, 4506 + or - 75 Ma, and 4422 + or - 50 Ma, indicating that the silicate fraction of the Estherville mesosiderite is very heterogeneous and was formed early in the solar system history. Results clearly identifies the Pb-Pb isochron as a mixing line. The U-Pb lower-intercept ages could be divided into two groups: (1) around 3 Ga, and likely related to the 3.6 Ga heating event, and (2) close to 0 Ma and to 62 Ma.
Document ID
19900046427
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Brouxel, M. (Geological Survey Dover, DE, United States)
Tatsumoto, M. (USGS, Branch of Isotope Geology, Denver CO, United States)