Old rocks may be gold rocks

Why and how we analyze some of the oldest rocks

Gold (Au) and tungsten (W), uranium (U) and lead (Pb) are interesting metals found in rocks.

Living in Sudbury, we often hear that our region was hit by a giant meteorite 1.85 billion years ago, but how do geoscientists determine this? The technique is called geochronology (or, radiometric dating) and has been performed at the Harquail School of Earth Sciences, Laurentian University, since 2007. Such analysis is now more precise with our new High Resolution Multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS). This instrument accurately counts atomic masses, for example U and Pb that are found as trace amounts in rocks.

For more information about the Harquail School of Earth Sciences visit www.hes.laurentian.ca