Spot the thrust belts!
Amazon S Brazil Niger Orange Nile Deep-water fold-thrust belts Angola
Bonga discovery 2001 Water-depth 1,145m Reserves 600 million barrels Recoverable oil….
Oceanic crust Akata Fm Agbada Fm
What is deformation and what stratigraphy?!
10 km
See Fowler et al. 2004, Geol Soc Memoir 29 Kutei Basin, E. Kalimantan
After Morgan 2004, Geol Soc Memoir 29
Amazon S Brazil Niger Orange Nile Deep-water fold-thrust belts Angola
Amazon S Brazil Niger Orange Nile Deep-water fold-thrust belts
THICKNESS OF DRIFT SUCCESSION Gas Isopach (in km) After Jungslager, 1998 Orange Basin S Africa Data from SA Petroleum Agency
NORTHERN ORANGE BASIN (Block 3B/4B – BHP Billiton) Pinotage prospect Extension up-slope balances contraction at toe
SCHEMATIC PROFILE ACROSS NORTHERN ORANGE BASIN
LATE CRETACEOUS TOE THRUST STRUCTURES
Deepwater NW Borneo From Ingrams et al. Mar.Pet.Geol 2004
Mud volcano (buried)
Shale diapirs
?
Gas hydrate
Artefacts Or Direct Hydrocarbon Indicator?
Deepwater fold belts The down-slope contraction for gravitationally collapsing sedimentary prisms… Weak detachment (overpressured shale, salt) Controls on timing….(tilting, sediment loading) Controls on location…. (Toe of slope….Edge of Detachment)
Branch line exercise Salt tectonics Controls in fold belts Salt movement and intrusion Vertical movement Lateral movement and salt allochthons
ZagrosSalt Range Examples: fold belts where SALT acts as detachment
Salt Range
From McClay et al (MPG)
From Sepehr 2004 (MPG) foredeep Topography & seismicity
Extrusion and flow of Salt Detachment on salt
From Sherkati et al (Mar. Pet. Geol. )
Salt intrusion in outcrop Cambrian salt penetrating Quaternary sediments, Indus Valley, Salt Range
Qeshm island, Iran 5 km
Seismic through salt domes and diapirs
Diapir from Zechstein salt: Danish/Norwegian N sea
Salt allochthons: Gulf of Mexico
From Grando & McClay (Mar.Pet.Geol. 2004) Sigsbee escarpment
From Grando & McClay (Mar.Pet.Geol. 2004)
Frampton anticline: Atwater fold belt GOM From Grando & McClay (Mar.Pet.Geol. 2004)
Movies from the Applied Geodynamic Lab, Bureau of economic geology, Uni Texas. Bruno Vendeville’s group Thin-skinned extension drives diapirism Lateral migration of sediment load migrates salt - Santos Basin, Brazil Toe-of-slope compression drives extrusion Open as Quicktime movies
Key reading: Chapter 5 Salt Tectonics In: Evaporites by John Warren (1999). Blackwells.