240 likes | 246 Views
This expedition involved scientists from 8 countries studying the Megasplay fault. Key scientific results include measuring stress and pressure, conducting imaging studies of the plate boundary, and developing protocols for cuttings measurements. The expedition also successfully installed monitoring sensors in the fault and achieved deeper drilling using new tools and measurements. The findings provide clues about the behavior and geologic history of the fault.
E N D
Expedition 319 29 scientists 8 countries
Riser borehole: Measure stress and pressure. Conduct imaging study of plate boundary (W-VSP). Develop protocls for cuttings measurements. Activity, history of megasplay • Install monitoring sensors in megasplay fault
Drill Site Locations Riser drill site above locked fault Megasplay site
Riser Drilling: • - Control of borehole pressure • Deeper drilling • New tools & measurements • Stress, pressure • First time in IODP history
MDT Tool: Successful Stress, Pressure Measurement (Front view) (Rear view)
Stress directions and Magnitude Combined result from new data and Stage 1 boreholes Indicate changes in stress regime possibly related to locked fault below
Stress directions and Magnitude Narrow region of stress rotation above megasplay fault Provides clues about fault behavior beneath the drill sites
Stress directions and Magnitude Narrow region of stress rotation above megasplay fault Provides clues about fault behavior beneath the drill sites
Geologic History of Kumano Basin Cores and drill cuttings Provide clues about activity and geologic history
Size fractions from washed cuttings Chips of hard sediment Woody fragments
Cuttings Lithologic Components
Washed cuttings, 1-4mm, “silty clay” Unit III Unit IV
Geologic History of Kumano Basin Cores and drill cuttings
Geologic History of Kumano Basin Age of sediment: records rapid filling of the Kumano Basin Provides clues about activity and history of the Megasplay fault
Successful Installation of Retrievable Subseafloor Observatory: Monitoring the Megasplay
Primary Results New information on stress conditions above the locked plate boundary fault zone; achieved by riser drilling. New information about history of Mega-splay fault system. First observatory sensors installed by D/V Chikyu, and first observatory in NanTroSEIZE project.