8 February 2019
Today’s featured Friday fold comes to us from “Effjot” – an environmental engineer with a focus on groundwater. In reply to my plea for fold imagery several weeks ago, he shared this example from Germany:
I note the well developed gently-inclined cleavage in the muddier layers, as well as the layer-perpendicular jointing in the blockier layers. Both limbs dip to the left, one steeply and one subhorizontally. The cleavage also dips that same direction, meaning that all else being equal, this steep limb (main focus of the photograph) is tectonically overturned.
Zoom in & see what I mean:
…Which is to say:
More detail in this blog post by the source author. (but it’s in German)
Also, he told me that, “This is the first fold I’ve come across as a child and realised rock could be bent. The first foundation for my interest in geology.”
What a great moment to have anchored in one’s memory – Realizing rock can bend – that’s huge! I remember a particular boulder of pinkish vein quartz that I learned as a child was called “rose quartz,” a term for a discrete phenomenon I could observe. Other phenomena, other terms would follow. For me, that boulder was my “geo-anchor,” the beginning of my Earth science awareness. This fold was Effjot’s.
Readers: Do you have a similar memory of the moment that geoscience became a subject of interest for you? If so, please share.