Maybe some of my readers will remember that I am the proud owner of a piece of the Lyby drill core. When I looked closer at the rock sample I saw that it was grey, compact and contained a large number of shell fragments. It reminded me of the stone stairs in our summer house and the stone floor in Kronovall castle. Both are made of Komstad limestone. So my suspicion was that the piece of the Lyby drill core had nothing to do with Alum shale, but actually represented parts of the Komstad limestone.
Alum shale is dark grey to black and has distinct rusty spots; rocks from shallow depths are very fractured, fissured and broken up and easily fall apart. Thus the piece of rock I had in my hands did not at all resemble the pieces of Alum shale, which I had collected some months ago at Flagabro.
To be sure that the rock I had was indeed Komstad limestone, I showed it to colleagues at Lund University, whose research is actually concerned with these old time scales and rock types. And what did they tell me: the piece of the Lyby drill core belongs to the Komstad limestone … Let’s hope that ScandiVanadium managed to drill deeper and did reach their target, the Dictyonema shale (Dictyonemaskiffer), in their first drill hole.
Drilling hole #2 was, according to rumors, not very successful. The target, the Dictyonema shale occurs here at much deeper depths, very likely because of all the tectonic movements these rocks and layers have experienced. I am not really sure where drill hole #2 is located, but the map below shows that some of the selected drill sites in Lyby are placed close to dolerite dykes (pink lines on the map) and close to deformation zones. Not really ideal locations for drill cores. The map also shows that the geology here is really complicated because of all the deformation/fault systems. Tectonic movements have broken up the original horizontal layers and moved them both horizontally and vertically, which resulted in a complicated pattern.
Coring in Lyby started August 9th and according to ScandiVanadium, each of the five drill holes should be finished within 3-5 days. Working non-stop this would mean that within 25 days coring should have been accomplished. But it still seems to be going on, or did I miss the grand finale?
Barbara Wohlfarth 