Limits...
Cenozoic Methane-Seep Faunas of the Caribbean Region.

Kiel S, Hansen BT - PLoS ONE (2015)

Bottom Line: They consist mainly of large globular lucinid bivalves including Meganodontia, and moderately sized vesicomyid bivalves.After the late Miocene many large and typical 'Cenozoic' lucinid genera disappeared from the Caribbean seeps and are today known only from the central Indo-Pacific Ocean.We speculate that the increasingly oligotrophic conditions in the Caribbean Sea after the closure of the Isthmus of Panama in the Pliocene may have been unfavorable for such large lucinids because they are only facultative chemosymbiotic and need to derive a significant proportion of their nutrition from suspended organic matter.

View Article: PubMed Central - PubMed

Affiliation: Georg-August-Universität Göttingen, Geoscience Center, Geobiology Group, Goldschmidtstr. 3, 37077, Göttingen, Germany; Naturhistoriska riksmuseet, Department of Palaeobiology, Box 500 07, 104 05, Stockholm, Sweden.

ABSTRACT
We report new examples of Cenozoic cold-seep communities from Colombia, Cuba, the Dominican Republic, Trinidad, and Venezuela, and attempt to improve the stratigraphic dating of Cenozoic Caribbean seep communities using strontium isotope stratigraphy. Two seep faunas are distinguished in Barbados: the late Eocene mudstone-hosted 'Joes River fauna' consists mainly of large lucinid bivalves and tall abyssochrysoid gastropods, and the early Miocene carbonate-hosted 'Bath Cliffs fauna' containing the vesicomyid Pleurophopsis, the mytilid Bathymodiolus and small gastropods. Two new Oligocene seep communities from the Sinú River basin in Colombia consist of lucinid bivalves including Elongatolucina, thyasirid and solemyid bivalves, and Pleurophopsis. A new early Miocene seep community from Cuba includes Pleurophopsis and the large lucinid Meganodontia. Strontium isotope stratigraphy suggests an Eocene age for the Cuban Elmira asphalt mine seep community, making it the oldest in the Caribbean region. A new basal Pliocene seep fauna from the Dominican Republic is characterized by the large lucinid Anodontia (Pegophysema). In Trinidad we distinguish two types of seep faunas: the mudstone-hosted Godineau River fauna consisting mainly of lucinid bivalves, and the limestone-hosted Freeman's Bay fauna consisting chiefly of Pleurophopsis, Bathymodiolus, and small gastropods; they are all dated as late Miocene. Four new seep communities of Oligocene to Miocene age are reported from Venezuela. They consist mainly of large globular lucinid bivalves including Meganodontia, and moderately sized vesicomyid bivalves. After the late Miocene many large and typical 'Cenozoic' lucinid genera disappeared from the Caribbean seeps and are today known only from the central Indo-Pacific Ocean. We speculate that the increasingly oligotrophic conditions in the Caribbean Sea after the closure of the Isthmus of Panama in the Pliocene may have been unfavorable for such large lucinids because they are only facultative chemosymbiotic and need to derive a significant proportion of their nutrition from suspended organic matter.

No MeSH data available.


Related in: MedlinePlus

Petrography of the seep carbonates from Trinidad.Scanned thin sections. A: Godineau River. B: Freeman’s Bay. C: Jordan Hill.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4607474&req=5

pone.0140788.g009: Petrography of the seep carbonates from Trinidad.Scanned thin sections. A: Godineau River. B: Freeman’s Bay. C: Jordan Hill.

Mentions: The Cenozoic seep faunas of Trinidad reported so far were found along the shore of Freeman’s Bay to the West of San Fernando, in the vicinity of the mouth of Godineau River. Here they were collected as float material on the beach, as mentioned in various reports [14, 20, 21, 51] and indeed, many of the samples investigated here have numerous small extant barnacles attached to them. The fossils were reported to be associated with sediments of the Lengua Formation, which were either considered as middle Miocene [52] or late Miocene [53]. They were reported from two different lithologies (Fig 9) associated with two different preservational styles: (i) from a large, isolated, impure limestone block on the costal mudflat where fossils occur as internal molds, and (ii) from often brecciated, oil-impregnated calcareous mudstone lenses surrounded by greenish, unctuous and slickensided clays in the adjoining coastal section where the fossils occur as black, oil-impregnated specimens often with original shell material [14, 51]. The impure limestone block was given its own lithostratigraphic unit, the “Freeman’s Bay limestone Member”, the oil-impregnated calcareous mudstone lenses were interpreted as having formed at mud diapirs [14]. Despite these differences, paleoecologic interpretations were considered as difficult to reach and the available fossils were reported as a single seep fauna [14].


Cenozoic Methane-Seep Faunas of the Caribbean Region.

Kiel S, Hansen BT - PLoS ONE (2015)

Petrography of the seep carbonates from Trinidad.Scanned thin sections. A: Godineau River. B: Freeman’s Bay. C: Jordan Hill.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4607474&req=5

pone.0140788.g009: Petrography of the seep carbonates from Trinidad.Scanned thin sections. A: Godineau River. B: Freeman’s Bay. C: Jordan Hill.
Mentions: The Cenozoic seep faunas of Trinidad reported so far were found along the shore of Freeman’s Bay to the West of San Fernando, in the vicinity of the mouth of Godineau River. Here they were collected as float material on the beach, as mentioned in various reports [14, 20, 21, 51] and indeed, many of the samples investigated here have numerous small extant barnacles attached to them. The fossils were reported to be associated with sediments of the Lengua Formation, which were either considered as middle Miocene [52] or late Miocene [53]. They were reported from two different lithologies (Fig 9) associated with two different preservational styles: (i) from a large, isolated, impure limestone block on the costal mudflat where fossils occur as internal molds, and (ii) from often brecciated, oil-impregnated calcareous mudstone lenses surrounded by greenish, unctuous and slickensided clays in the adjoining coastal section where the fossils occur as black, oil-impregnated specimens often with original shell material [14, 51]. The impure limestone block was given its own lithostratigraphic unit, the “Freeman’s Bay limestone Member”, the oil-impregnated calcareous mudstone lenses were interpreted as having formed at mud diapirs [14]. Despite these differences, paleoecologic interpretations were considered as difficult to reach and the available fossils were reported as a single seep fauna [14].

Bottom Line: They consist mainly of large globular lucinid bivalves including Meganodontia, and moderately sized vesicomyid bivalves.After the late Miocene many large and typical 'Cenozoic' lucinid genera disappeared from the Caribbean seeps and are today known only from the central Indo-Pacific Ocean.We speculate that the increasingly oligotrophic conditions in the Caribbean Sea after the closure of the Isthmus of Panama in the Pliocene may have been unfavorable for such large lucinids because they are only facultative chemosymbiotic and need to derive a significant proportion of their nutrition from suspended organic matter.

View Article: PubMed Central - PubMed

Affiliation: Georg-August-Universität Göttingen, Geoscience Center, Geobiology Group, Goldschmidtstr. 3, 37077, Göttingen, Germany; Naturhistoriska riksmuseet, Department of Palaeobiology, Box 500 07, 104 05, Stockholm, Sweden.

ABSTRACT
We report new examples of Cenozoic cold-seep communities from Colombia, Cuba, the Dominican Republic, Trinidad, and Venezuela, and attempt to improve the stratigraphic dating of Cenozoic Caribbean seep communities using strontium isotope stratigraphy. Two seep faunas are distinguished in Barbados: the late Eocene mudstone-hosted 'Joes River fauna' consists mainly of large lucinid bivalves and tall abyssochrysoid gastropods, and the early Miocene carbonate-hosted 'Bath Cliffs fauna' containing the vesicomyid Pleurophopsis, the mytilid Bathymodiolus and small gastropods. Two new Oligocene seep communities from the Sinú River basin in Colombia consist of lucinid bivalves including Elongatolucina, thyasirid and solemyid bivalves, and Pleurophopsis. A new early Miocene seep community from Cuba includes Pleurophopsis and the large lucinid Meganodontia. Strontium isotope stratigraphy suggests an Eocene age for the Cuban Elmira asphalt mine seep community, making it the oldest in the Caribbean region. A new basal Pliocene seep fauna from the Dominican Republic is characterized by the large lucinid Anodontia (Pegophysema). In Trinidad we distinguish two types of seep faunas: the mudstone-hosted Godineau River fauna consisting mainly of lucinid bivalves, and the limestone-hosted Freeman's Bay fauna consisting chiefly of Pleurophopsis, Bathymodiolus, and small gastropods; they are all dated as late Miocene. Four new seep communities of Oligocene to Miocene age are reported from Venezuela. They consist mainly of large globular lucinid bivalves including Meganodontia, and moderately sized vesicomyid bivalves. After the late Miocene many large and typical 'Cenozoic' lucinid genera disappeared from the Caribbean seeps and are today known only from the central Indo-Pacific Ocean. We speculate that the increasingly oligotrophic conditions in the Caribbean Sea after the closure of the Isthmus of Panama in the Pliocene may have been unfavorable for such large lucinids because they are only facultative chemosymbiotic and need to derive a significant proportion of their nutrition from suspended organic matter.

No MeSH data available.


Related in: MedlinePlus