There are igneous intrusions, folded sedimentary rocks, and several kinds of unconformities.
The images featured are mostly mine, but also include a substantial contribution from my colleague (and former student) Robin Rohrback, and a handful from other student researchers and 3 more from my colleague Ron Schott.
Following yesterday’s discourse on the logistics of virtual samples, I wanted to showcase some new collections of images, focused on giving students practice with relative dating.
Relative dating collection I (36 outcrops and samples) Relative dating collection II (24 outcrops and samples) These are super-high-resolution images (Giga Pans and GIGAmacros).
Deploy one set for a pre-lesson homework assignment to warm your students up, then another set/page for an in-class exercise, then a third for a post-lesson homework assignment, all offering opportunities for the students to get feedback from their instructor, both affirmational and corrective.
Rather than putting them into a photo album they are stacked up in a box. If a scientist finds one of those fossils, they can then assume the age of the rock based on the age of the fossil.
Where are the oldest pictures, by year, going to be in your stack? Often igneous intrusions will cut across layers of rock.
For example, carbon dating is used to determine the age of organic materials.
Once something dies, it ceases taking in new carbon-14, and the existing carbon-14 within the organism decays into nitrogen at a fixed rate.