High resolution X-ray maps of Th, U, Pb, and Y in monazite can be used to construct age maps, which reveal the continuous spatial distribution of ages in a single grain of monazite. The age mapping algorithm and three examples are presented to illustrate the capabilities and applications of this mapping technique, the insights it can provide into monazite geochronology in general, and its limit...

Electron probe microanalysis (EPMA) of accessory minerals such as monazite, xenotime, and thorite for minorand trace-element concentrations and geochronology, requires consideration of beam irradiation effects (increasing heat and charge) as higher current densities and lengthy counting times are employed, and requires careful, detailed assessment of background intensities and interferences. A ...

The Woonasquatucket River in North Providence, RI, is a postglacial river flowing approximately 18 miles from its headwaters in North Smithfield, RI, to Providence, RI, where it joins the Moshassuck River and enters the Providence River. In 1776, a powder mill was constructed along the river to support the Colonies’ efforts in the American Revolutionary War. The powder mill exploded in 1779, se...

The ca. 2 Ga retrogressed eclogites in the Usagaran Belt central Tanzania are among oldest documented world. As such, they have been used to pinpoint thermal conditions of onset modern style subduction on Earth. Two samples mafic eclogite interrogated reconstruct metamorphic history subducted crust. several kilometres apart, separated by a mylonitic upper amphibolite-transitional granulite foli...