| IODP Proceedings Volume contents Search | |||
 | |||
| Expedition reports Research results Supplementary material Drilling maps Expedition bibliography | |||
|
doi:10.2204/iodp.proc.345.114.2014 AlterationMeasured volatiles demonstrate a progressive degree of alteration within all studied samples. Gabbro has loss on ignition (LOI) values from 1.1 to 5.3 wt%, and troctolite has LOI values from 2.7 to 9.7 wt% (Table T1). The combined contents of H2O (but not CO2) are in good agreement with the LOI values. The dominant volatile component within Site U1415 plutonic rock is bound water or hydroxyl in secondary alteration phases. Positive correlations between H2O, optically quantified olivine, and Ni, a trace element compatible in olivine, point toward serpentinization as the dominant alteration process affecting the composition of the drilled troctolitic and gabbroic intervals. Apart from water addition, our data do not provide evidence of systematic elemental mobility caused by alteration. No parallels between CaO (prehnite) and/or Al2O3 (prehnite/chlorite) and H2O were observed. Also, the studied samples have no substantial amounts of CO2. Correlations between secondary sulfide minerals and the S abundances were not observed because of small-scale heterogeneities in the distribution of these minerals. |
|||
