Logged to 3901.6 feet, interpreting through a haze of alteration, complex flow/intrusion interaction

Despite the lack of blog updates lately, we have been busy logging box after box of core.  At ~3775 ft or so, the rock starts showing more alteration than above.  Some of the rock is so altered that little to no primary minerals are visible.  Vesicles are often partially or completely filled by clays and/or zeolites, and even the groundmass of the rock can be obscured by weathering products.  So far every unit contains enough decent rock for us to determine its basic features, though some of them are made more subtle by the overprint of alteration on the rock.  From boxing all this rock earlier, we know that the alteration will only increase with depth so we'll have to do the best we can to understand the rocks and how alteration has changed them. 

On a different note, the photo above is taken from one of our annotated core box logs.  Note the nearly vertical, complex interaction between units 216 & 217a (an aa flow and the dike that intrudes it, respectively) that persists for over five feet and extends into the next box where the interaction becomes too complex to trace!  The highly fractured fourth column of the box contains a mixture of aa and dike fragments that could not be pieced back together into their original orientation, thus the vertical contact line indicating the two units share this column.  There were a number of dikes near this depth interval in the core, but now that we've logged through this swarm of them there are only one or two more the rest of the way to the bottom of the hole.