Igneous rocks make up volcanoes and the backbones of many mountain ranges.
Can radiometric dating be used on sedimentary rocks dating nik zahara
Thus, by measuring the amount of R and N in an igneous mineral grain – and taking a few other factors into consideration – it is possible to determine how many years have passed since the mineral formed.
That – the time passed - is the age of the igneous rock.
The magma itself may have come into existence much earlier in Earth’s history, but not the rock.
Talk to Paleontology Society volunteers about their work and you are certain to hear statements like “Yeah, it was a beautiful camel skull, about two millions years old”. This leads us into the subject of “geochronology”, about which many abstruse books have been written.
If you are of an inquiring nature you would be justified in thinking “Okay, the anatomy tells us it is a camel, and of course “beautiful” is in the eye of the beholder, but how in heck do you know its two million years old? What follows is an oversimplified overview Geologists classify rocks into three large families – igneous, sedimentary and metamorphic.