![Ion microprobe 232Th-208Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics | American Journal of Science Ion microprobe 232Th-208Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics | American Journal of Science](https://www.ajsonline.org/content/ajs/316/5/470/F2.large.jpg)
Ion microprobe 232Th-208Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics | American Journal of Science
![Ion microprobe 232Th-208Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics | American Journal of Science Ion microprobe 232Th-208Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics | American Journal of Science](https://www.ajsonline.org/content/ajs/316/5/470/F11.large.jpg)
Ion microprobe 232Th-208Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics | American Journal of Science
![Ion microprobe 232Th-208Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics | American Journal of Science Ion microprobe 232Th-208Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics | American Journal of Science](https://www.ajsonline.org/content/ajs/316/5/470/F7.large.jpg)