skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

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

Abstract

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 levelmore » 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.« less

Authors:
 [1]
  1. (Univ. of Kansas, Lawrence (USA))
Publication Date:
OSTI Identifier:
7061132
Alternate Identifier(s):
OSTI ID: 7061132
Report Number(s):
CONF-900605--
Journal ID: ISSN 0149-1423; CODEN: AABUD
Resource Type:
Conference
Resource Relation:
Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA); Journal Volume: 74:5; Conference: Annual convention and exposition of the American Association of Petroleum Geologists, San Francisco, CA (USA), 3-6 Jun 1990
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; CARBONATE ROCKS; STRATIGRAPHY; SPAIN; VOLCANIC ROCKS; CONGLOMERATES; CONTINENTAL SLOPE; DEPOSITION; OFFSHORE SITES; SEA LEVEL; TECTONICS; TERTIARY PERIOD; CENOZOIC ERA; CONTINENTAL MARGIN; DEVELOPING COUNTRIES; EUROPE; GEOLOGIC AGES; GEOLOGY; IGNEOUS ROCKS; LEVELS; ROCKS; SEDIMENTARY ROCKS; WESTERN EUROPE 580000* -- Geosciences

Citation Formats

Franseen, E.K. Mixed carbonate and volcaniclastic slope facies in a middle to upper Miocene archipelago, Las Negras and Rodalquilar areas, southeastern Spain. United States: N. p., 1990. Web.
Franseen, E.K. Mixed carbonate and volcaniclastic slope facies in a middle to upper Miocene archipelago, Las Negras and Rodalquilar areas, southeastern Spain. United States.
Franseen, E.K. Tue . "Mixed carbonate and volcaniclastic slope facies in a middle to upper Miocene archipelago, Las Negras and Rodalquilar areas, southeastern Spain". United States. doi:.
@article{osti_7061132,
title = {Mixed carbonate and volcaniclastic slope facies in a middle to upper Miocene archipelago, Las Negras and Rodalquilar areas, southeastern Spain},
author = {Franseen, E.K.},
abstractNote = {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.},
doi = {},
journal = {AAPG Bulletin (American Association of Petroleum Geologists); (USA)},
number = ,
volume = 74:5,
place = {United States},
year = {Tue May 01 00:00:00 EDT 1990},
month = {Tue May 01 00:00:00 EDT 1990}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • During the Serravallian through Messinian, reefs fringed topographic highs that rimmed Neogene basins in the western Mediterranean. Detailed studies of middle to upper Miocene carbonate strata in the Nijar and Las Negras areas (southeastern Spain) document the effects of relative sea level change on sedimentation, biotic composition, reef development, and diagenesis. The authors have identified several previously unrecognized, regionally correlatable depositional sequences and erosional breaks that the authors interpret resulted from sea level fluctuations. Limited microfossil dating and correlation of depositional successions with third-order eustatic sea level curves suggest that most carbonate deposition occurred during the Serravallian and Tortonian, notmore » Messinian as formerly thought. Uppermost strata (upper Tortonian> predominately comprise pack-stones and grainstones of distal to proximal reef-foreslope and reef-talus facies that dip 10/sup 0/-30/sup 0/. Reef core, mostly Porites framework, is locally preserved. Field geometries indicate minimum self-to-basin relief of 100 m. The authors' results of studies suggest that detailed field studies coupled with the use of published eustatic sea level curves may provide a powerful tool for correlation of middle to upper Miocene strata not only in Spain, but in the entire western Mediterranean.« less
  • Reef complexes in the Las Negras area and the island of Mallorca, over 600 km to the northeast, contain dolomite with remarkably similar stratigraphic distribution and petrographic characteristics. In both reef complexes dolomite occurs as 5-50 {mu}m euhedral cements and microcrystalline replacement of red-algal fragments and muds. In addition, anhedral, moldic-zoned dolomite cements (5-20 {mu}m) are abundant in the youngest reefs of both areas. All inter-reefal erosional surfaces are cross-cut by dolomite cements. Distribution of dolomite within the reefal sequences is controlled by (1) proximity to the youngest reef margin. Dolomite abundances decrease from 100% to 0% over a 10more » km transect into the platform interior in Mallorca. Stratigraphic and petrographic timing support a dolomitization event following exposure of the reefs, during initial deposition of the onlapping Messinian sequence in Mallorca, and before Pliocene deposition in Las Negras. In both areas, dolomitization took place as a Messinian transgression covered the reefs. Evidence for multiple dolomitization events has not been found. Mallorcan dolomites have heavy stable isotopes suggesting saline dolomitizing fluids. One hypothesis for dolomitization invokes brines associated with the deposition of extensive Messinian basinal evaporites. An early Messinian evaporitic lowstand could concentrate marine brines, and with the ensuing transgression bring them in contact with CaCo{sub 3} platforms, dolomitizing them. The similar styles and timing of dolomitization in these two distinct and distant reef settings suggest that dolomitization of late Miocene reefs around the western Mediterranean may have been genetically related to the Messinian salinity crisis.« less
  • Middle to Upper Devonian Catskill facies sandstones exposed in southeastern New York form part of a regressive alluvial plain sequence, 1.5 km thick, deposited in a foreland basin as a result of the Middle Devonian Acadian orogeny. Petrologically, most Catskill sandstones are litharenites whose detrital composition was important in determining the course of diagenesis. Foliated metamorphic rock fragments, sedimentary rock fragments, monocrystalline quartz, and polycrystalline quartz volumetrically comprise 80% or more of the Catskill sandstones. Metamorphic rock fragments are by far the most important rock fragment type. Both sandstone grain size and the modal percentages of monocrystalline and polycrystalline quartzmore » increased stratigraphically upsection in the facies. These two trends reflect progradation and a possible change in sandstone provenance during Catskill facies deposition. Point counting using cathodoluminescence petrography demonstrated that these sandstones are characterized by abundant pseudomatrix. Ductile-grain deformation and alteration of metamorphic and sedimentary rock fragments contributed heavily to the formation of pseudomatrix. Compaction and chemical diagenesis have effectively reduced Catskill sandstone porosity to irreducible levels. Porosity ranges from 7.1 to 0.9%, whereas permeability ranges from 0.06 to less than 0.001 md (unstressed measurements). Much of the porosity is present as microporosity. Chemical diagenetic events recognized in the Catskill sandstones include (listed in general paragenetic order): (1) authigenic quartz overgrowths; (2) chlorite and illite clay recrystallization, replacement, and pore filling; (3) calcite replacement; (4) dolomite pore filling/replacement; and (5) secondary porosity formation and kaolinite replacement/pore filling.« less
  • Outcrops of Late Miocene depositional sequences in the Cabo de Gata area of southeastern Spain consist of basal Tortonian carbonate ramps that formed the substrate on which Messinian fringing reef complex and topography-draping strata of the terminal carbonate complex were deposited. Location, facies distribution, and geometry of the Tortonian ramps were largely controlled by paleoslope of the substrate combined with relative sea level position. Ramp strata onlap onto erosionally sculpted volcanic basement, the upper surface of which extended significantly upslope of the point of onlap. During ramp development sea level was at a high position well above the point ofmore » onlap. Strata are characterized by fining upward subtidal cycles (2-15 in thick) consisting of foramalgal packstone-grainstone facies, some with resedimented grains, and fine grained wackestone-packstone facies interpreted to have been generated in about 40m to 100+m water depths. These subtidal cycles lap out against volcanic basement without any indication of facies changes approaching the lap out. Thus, shallow-water and deeper-water carbonate sediments must have been generated on steeper volcanic substrate in upslope positions, but were bypassed downslope onto catchment areas of low basement paleoslope. Facies variation likely reflects fluctuating relative sea level but ramp location and geometry reflect accumulation of sediment bypassed from upslope positions onto areas of lower basement paleoslope rather than sea-level control. The decreased substrate paleoslope provided by ramp deposition appears to have provided a preferential substrate for accumulation of later fringing reefs. This new model for substrate paleoslope control on bypass ramp accumulation is predictable for sequence stratigraphy interpretations and has potential for locating reservoir facies using subsurface data on substrate paleoslope.« less
  • Miocene reef complexes are well exposed in the Alicante-Almeria region of southeast Spain. Predominant reservoir lithofacies are (1) in the off-reef environments (i.e., fore-reef slope deposits and overlying shallow platform sediments), a porous leached microsucrosic to spherulitic dolomite with mostly moldic and intercrystalline porosity and good to very good matrix permeability, and (2) in the reef-core framework, (A) a tight, karstified (i.e., fissured), coarsely crystalline dolomite with poor matrix reservoir potential but good to very good fissure porosity with darcy permeability and (B) a porous, leached, coarsely crystalline dolomite with vuggy matrix porosity and good matrix permeability. The most significantmore » conclusion in terms of reservoir geology is that these reefs do not have a homogeneous reservoir quality. Each rock lithofacies has different geometries and capillary characteristics. In volumetric terms, the most significant reservoir unit in such reefs would be the fore-reef slope deposits. Assuming typical values for reservoir properties, such fore-reef deposits could contain 75% of the total hydrocarbons in comparable reservoirs. However, the best productivities could be obtained from fissured reservoirs, that is, from the reef-core framework, although low production rates might be required to avoid premature water or gas breakthrough along highly permeable channel conduits of karstic origin.« less