| Abstrakt: |
Excellent exposures and the presence of lithological markers make it possible to reconstruct the fan facies pattern for a narrow (6000-60 000 yr), late Tortonian (7-8 Ma) time slice of a submarine fan complex that developed in the Tabernas basin. Unlike most classical fan models, which seem to refer to a single feeder-lobe system, the reconstruction from the Tabernas basin reveals at least three distinctive juxtaposed feeder-lobe systems: (I) a straight feeder valley terminating in a sandstone body consisting of stacked sand-filled scours (sand-rich system); (II) a straight feeder channel diverging in a broad front of nested scours in mudstones. These scours terminate in fine grained sheet-like turbidite deposits (muddy system); (III) a sinuous channel complex extending far into the basin without 'lobe' deposits at its mouth (solitary system). Sedimentary features indicate that in the Tabernas basin, initial basin floor morphology and mass-flow transport behavior controlled and eventually stopped formation of the sand-rich system (I), while depositional topography and slope instability controlled formation of the muddy system (II). The unusual narrowness (10-30 m) and length (8 km) of the solitary system (III) points to its confinement, possibly a result of an intrabasinal fault escarpment trending obliquely to the general direction of slope. Flow stripping (Piper & Normark, 1984) could then explain the absence of a lobe at the channel terminus. [ABSTRACT FROM AUTHOR] |
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