Ebro margins sedimentary system in the western Mediterranean Sea, from delta to deep sea

Conference · Mon Aug 01 04:00:00 EDT 1988 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5749763

Nelson, C H; Maldonado, A ^[1]

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1. Geological Survey, Menlo Park, CA (USA)

During Holocene high sea level, delta-front lobes of silty mud have deposited beside a lobate Ebro delta. Topset and foreset beds of these lobes extend up to 20 km offshore in up to 30 m of water. Geostrophic currents advect fine silt and clay from river discharge and storm wave resuspension in the delta front and deposit up to 20 m of bottomset beds in a distal prodelta clay belt formed on the inner to middle shelf for 70 km south from the delta. Intensified water circulation and increased bottom-current speeds inhibit prodelta progradation over the outer shelf and north of the delta and south of the clay belt, where the shelf narrows. Deposition of Holocene hemipelagic mud on the upper slope is restricted, but some modern Ebro sediment apparently bypasses to the deep margin. During Pleistocene low sea level, a series of shelf-edge deltas resulted in extensive progradation of foreset mud beds over the continental slope east of the modern delta and south to the Columbretes Islands. In the north, rapid sediment progradation has resulted in large canyons ({plus minus}5 km wide), unconfined sediment gravity flows, and deposition of large sediment aprons (50 km diameter) downslope from canyon mouths. In the south, narrow canyons ({plus minus}2 km wide) have funneled turbidity currents to side-by-side channel-levee complexes younger and smaller to the southwest. Subsidence of the Valencia trough has facilitated sediment transport from these channel-levee complexes into Valencia Valley and thence to the Valencia fan, 200 km to the northeast. Consequently, during low sea level stands a major portion of Ebro sediment is transported north to the Valencia fan, whereas the main progradational history of the Ebro margin has been offshore and to the south of the present delta.

• OSTI ID: 5749763
• Report Number(s): CONF-8809346--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 72:8
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
CENOZOIC ERA
GEOLOGIC AGES
GEOLOGIC HISTORY
LEVELS
MEDITERRANEAN SEA
QUATERNARY PERIOD
SEA LEVEL
SEAS
SEDIMENTATION
SURFACE WATERS