JA Daily Science Report for Expedition 309, 11 August 2005


LOCATION: Site 1256


SCIENCE UPDATE: Cores 144R to 146R recovered 8.98 m of basalts from 1132.5 to 1145.2 mbsf (70.7% recovery). The rocks are massive sparsely (clinopyroxene)-plagioclase-olivine phyric microcrystalline basalt with some phenocrysts forming glomerocrysts.  Patchy development of a subophitic texture is distributed within the fine grained groundmass. These cores also display the first development of light green alteration patches consisting of moderate to strong replacement of groundmass by chlorite and albite.


Following the satisfying retrieval by the rig floor day crew of Core 146R with 117 % recovery, a 350 psi pressure drop was noticed when the drill string was lifted off bottom. Because these symptoms were similar to those manifest by the failed bit-sub earlier in the expedition it was decided that it would be prudent to trip the pipe so the BHA could be inspected.