Mixed carbonate and volcaniclastic slope facies in a middle to upper Miocene archipelago, Las Negras and Rodalquilar areas, southeastern Spain

Conference · Tue May 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:7061132

Franseen, E K ^[1]

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1. Univ. of Kansas, Lawrence (USA)

The Las Negras and Rodalquilar areas contain excellent exposures of middle to upper Miocene carbonate and volcaniclastic deposits that fringe earlier formed Neogene volcanic substrates in an archipelago setting. The Miocene sedimentary sequence consists of three depositional sequences composed of reworked volcanic rocks and reef crest to distal slope strata that display 100-200 m of relief over 0.5-2.0 km. The entire sequence is truncated by a regional subaerial unconformity. The lower two depositional sequences are composed predominantly of shallow-dipping, normal marine, distal to proximal slope wackestones and packstones. The two sequences are separated by a megabreccia composed of Tarbellastreaea and Porites blocks and volcaniclastic sandstones and conglomerates. The reef blocks likely developed as upslope patch reefs, and, with the volcaniclastics, were eroded and transported via mass movements and tractive currents to a distal slope position. The upper (third) depositional sequence consists predominantly of foreslope strata of a Porites-dominated fringing reef complex. The base of this sequence is characterized by a megabreccia of Porites reef blocks, shallow-marine packstones, or volcaniclastic conglomerates. Five volcaniclastic wedges, interpreted as fan delta deposits, alternate with prograding carbonate foreslope deposits likely as a response to high frequency relative sea level fluctuations during a new sea level fall. The apparent correlatability of similar deposition sequences throughout the region indicates the importance of sequence development from allogenic processes, including glacio-eustatic sea level fluctuations and tectonism associated with the isolation of the Mediterranean Sea during the latest Miocene.

• OSTI ID: 7061132
• Report Number(s): CONF-900605--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CARBONATE ROCKS
CENOZOIC ERA
CONGLOMERATES
CONTINENTAL MARGIN
CONTINENTAL SLOPE
DEPOSITION
DEVELOPING COUNTRIES
EUROPE
GEOLOGIC AGES
GEOLOGY
IGNEOUS ROCKS
LEVELS
OFFSHORE SITES
ROCKS
SEA LEVEL
SEDIMENTARY ROCKS
SPAIN
STRATIGRAPHY
TECTONICS
TERTIARY PERIOD
VOLCANIC ROCKS
WESTERN EUROPE