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ins.: 2014-08-23 00:00; ( Age: 10 yrs )
By: Scientists
Category: COSC1

COSC: 2014-08-23

Did I write that we soon will leave the thrust ...
Benny marks the direction recorded by the Devico Devicore BBT tool on the drill core.

Did I write that we soon will leave the thrust zone behind us? Ah weeeeeeeellllllll … surprises are part of life! Yesterday night, before we (i.e. the "day"-shift) left the drill site, we got m-thick white and green quartzites, almost pure, only pervaded by some minor mylonite bands - Särv or Jämtlandian nappes? We didn’t know what of the two possibilities and hoped to find out tonight - but what we got instead in the first core run was 6 m of mylonite! What a surprise! And not the last one (surprise and mylonite). The next six meters were not much different - except that the lower part of the core run was stuffed with garnets, partly growing in and partly growing across the foliation. Garnet growth late during deformation(?), and the same with amphiboles. A completely different (and much less funny) surprise was to find that one of the tarp-covers for the drill core boxes was leaking. In the present weather it meant completely flooded core boxes with a diverse and colourful fungi population. Fortunately, it was only one stack with 12 boxes. We put all of them in the logging container for drying. The smell will soon decrease and conditions for geological logging will become acceptable again. Then the last core of the day came up at 23:00 - another 6 m of mylonites! Thanks to the Devicore BBT tool (at the drill site by courtesy of Devico for testing) all of the core through the mylonite zone is oriented - a real asset for subsequent studies on the drill core. Depth of the drill hole around midnight: c. 2425 m. The surface of the drill core shows first undulations after about 220 m with the same drill bit - one indication that the life of the drill bit is approaching its end.