3660 MINERALOGY AND PETROLOGY Metamorphic petrology, 1040 GEOCHEMISTRY Radiogenic isotope geochemistry, 1115 GEOCHRONOLOGY Radioisotope geochronology, 3652 MINERALOGY AND PETROLOGY Pressure-temperature-time paths Garnet's potential as a direct chronometer of tectonometamorphic processes and conditions was first realized over 30 years ago.
However, it is important to review a few case studies to show the development of the method. (1973) on the achondrite Juvinas, but with low analytical precision. (1975) obtained much more precise results on minerals from the same meteorite (Fig. These age determinations have since been superseded by Pb Pb dating studies (section 5.3).
However, the good agreement between the Sm Nd and Pb Pb dates has served the important function of confirming the Nd isochron for whole-rocks and minerals from the basaltic achondrite Juvinas. Nd dating of chondritic meteorites was not a high priority, due to the success of other methods.
Lu-hf garnet dating Evidence for an Historical Reading of Genesis 1: In contrast, Sm—Nd dates are equal to or younger than the — Ma age of peak metamorphism.
Astoria fan sediments, DSDP Site , Cascadia Basin: There are some obvious similarities between the Lu-Hf and Sm-Nd isotope systems and, as a result, they have long been used in concert in a wide range of studies e.
Many of these applications were also made before the UPb zircon method had reached its present level of development (section 5.2.2).
Therefore some of these units have subsequently been dated to greater accuracy and precision by the UPb method.
Sm, is not naturally occurring, but has a relatively long half-life of 103 Myr.
If Sm/Nd fractionation occurred within a few hundred million years of Sm nucleosynthesis then variations in the abundance of the daughter product, Sr (section 3.2) and can be plotted as an isochron diagram.
Range, the Red River shear zone evidence from the garnet Sm/Nd dating Nguyen Van Vuong* College of Science, VNU Received 26 January 2007 Abstract.
How accurate are Carbon-14 and other If that person is your boyfriend or girlfriend it becomes a whole different story.
Call for an improved set of decay constants for geochronological use.