Borehole Seismic Data Processing (Re-Entry Phase 3)
IODP-USIO logging contractor: LDEO-BRG
Hole: 1256D, re-entry (Logging Phase 3)
Expedition: 312
Location: Guatemala Basin (NE equatorial Pacific)
Latitude: 6° 44.163' N
Longitude: 91° 56.061' W
Logging date: December 20-23, 2005
Sea floor depth (driller's): 3645.4 mbrf
Sea floor depth (logger's): 3643.5 mbrf
Total penetration: 1507.1 mbsf
Total core recovered: 252 m (18.5 % of cored section)
Oldest sediment recovered: Calcareous nannofossil ooze (Middle Miocene) at Hole 1256B during ODP Leg 206
Lithologies: Clay-rich sediments and calcareous nannofossil ooze (sediments); basalt and gabbro (basement)
TOOL USED: VSI (Vertical Seismic Imager)
The logging data was recorded by Schlumberger in DLIS format. All processing, including first arrival picking and stacking, was performed by Schlumberger during Expedition 312. The data was then converted into SEGY format at the Borehole Research Group of the Lamont-Doherty Earth Observatory, using the SEGY Save module in GeoFrame.
Stacks are generally calculated with at least nine good traces.
All the data in the SEGY files are sorted shot by shot (i.e. chronologically).