Thursday, November 22, 2007
No helo trip, but core with calcite veins
The weather turned bad with snow across the sound so we did not get out on our helo trip. Instead, we logged more core (we still have 111 m to go to complete the 1011 m that were drilled). The core had multiple fractures and faults last night, evidence of brittle deformation associated with tectonics. The Earth's crust is spreading apart in this area: we call this a rift and that causes the fracturing and faulting in the rock, as well as the volcanism in this area. One calcite vein fill was truely spectacular: so here is the photograph. Calcite precipitates from the fluids that circulate through the rock.
Posted by Sandra Passchier at 12:09 PM