RR 290 - Melajo Clay, Melago River area: Late/Upper Miocene, Trinidad and Tobago

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Bivalvia - Arcida - Arcidae
Anadara (Scapharca) placata
original and current combination Scapharca
Bivalvia - Pholadida - Corbulidae
Caryocorbula (Caryocorbula) sp. Gardner 1926
Bivalvia - Cardiida - Veneridae
Chione (Lirophora) caroniana
original and current combination Lirophora
Bivalvia - Cardiida - Tellinidae
Moerella (Moerella) elinguis
spelled with current rank as Tellina (Moerella)
Merisca trinidadensis
Bivalvia - Cardiida - Cardiidae
Trigoniocardia (Trigoniocardia) maturensis
Bivalvia - Lucinida - Lucinidae
Lucina (Lucinisca) roigi
original and current combination Lucinisca
Bivalvia - Protobranchia - Nuculanidae
Nuculana (Saccella) ludificans
original and current combination Saccella
Gastropoda - Neogastropoda - Olividae
Olivella (Minioliva) fundarugata
Gastropoda - Neogastropoda - Nassariidae
Calophos rohri (Rutsch 1942)
    = Gordanops baranoanus Anderson 1929
Landau and Marques da Silva 2010
Gastropoda - Neogastropoda - Terebridae
Strioterebrum aff. baculiforme
Strioterebrum aff. laevifasciola (Maury 1917)
Gastropoda - Naticidae
Polinices stanislasmeunieri Maury 1917
Gastropoda - Calyptraeidae
Calyptraea centralis (Conrad 1841)
Gastropoda - Sorbeoconcha - Turritellidae
Turritella (Broderiptella) bifastigata (Nelson 1870)
Subspecies: T. (B.) bifastigata cartagenensis
Turritella (Broderiptella) aff. mimetes (Brown and Pilsbry 1911)
Gastropoda - Trochidae
Calliostoma olssoni (Maury 1925)
recombined as Calliostoma (Elmerlinia) olssoni
Scaphopoda - Dentaliida - Dentaliidae
Dentalium (Dentalium) divulgatum
see common names

Geography
Country:Trinidad and Tobago
Coordinates: 10.6° North, 61.1° West (view map)
Paleocoordinates:10.5° North, 59.6° West
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period:Neogene Epoch:Miocene
10 m.y. bin:Cenozoic 6
Key time interval:Late/Upper Miocene
Age range of interval:11.60800 - 5.33300 m.y. ago
Stratigraphy
Formation:Springvale Member:Melajo Clay
Regional section:Melajo River
Stratigraphic resolution:bed
Stratigraphy comments: The Melajo Clay Member of the Springvale Formation is correlated with the Savaneta Glaconitic Sandstone Member of the Springvale Formation, although part of it may be younger. The Melajo fauna is late Miocene in age. The Melajo Clay rests transgressively on the phyllites of the Northern Range with a basal conglomerate of about 1 m thickness. The conglomerate graes into a 1.5 m thick limestone, which is overlain by a bed of sand of about 1 m thickness. Above the sand is the Melajo Clay. The total thickness of the Melajo Clay is about 200 ft. It is unconformably overlain by Pleistocene sand and gravel deposits.
Lithology and environment
Primary lithology:yellow,blue unlithified silty claystone
Secondary lithology:coarse unlithified sandstone
Includes fossils?Y
Lithology description: Blue, yellowish weatheirng clay and silty clay with occasional sandy layers. Sand is probably coarse.
Environment:offshore
Geology comments: The Melajo fauna can be divided into two assemblages: one occurring the limestone and coarse sand near the base of the Melajo Clay, the other on in the overlying clay and silty clay. The difference of the two assemblages is facies controlled. The basal assemblage represents a typical, tropical, near-shore fauna, whereas the overlying assemblage points to a deeper environment. This collection is derived from the clay assemblage, a siliciclastic and deeper water environment and is hence assigned to a siliciclastic - offshore environment.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Preservation of anatomical detail:good
Collection methods and comments
Collection excludes:some macrofossils,some microfossils
Collection methods:selective quarrying,field collection
Reason for describing collection:taxonomic analysis
Museum repositories:PRI,USNM
Collection method comments: All material descibed in this report is reposited in the Naturhistorisches Mueum, Basel, or the USNM. Additional material collection from this unit is found at PRI.
Taxonomic list comments:Exhaustive for Mollusca, although author suggests that further collection would reveal additional forms. Corals, bryozoa and spines of echinoderms also exists in the unit, though are not listed. Van de Bold (1963) also lists ostracords from several localities. Foraminiferal assemblages are also listed in unpublished reports by Saunders.
Metadata
Database number:60633
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:A. Hendy Research group:marine invertebrate
Subset of collection #:60399
Created:2006-05-19 08:17:42 Last modified:2013-11-25 13:37:23
Access level:the public Released:2006-05-19 08:17:42
Creative Commons license:CC BY
Reference information

Primary reference:

17317. P. Jung. 1969. Miocene and Pliocene mollusks from Trinidad. Bulletins of American Paleontology 55(247):293-697 [A. Miller/A. Hendy]

Secondary references:

36423 B. Landau and C. Marques da Silva. 2010. Early Pliocene gastropods of Cubagua, Venezuela: Taxonomy, palaeobiogeography and ecostratigraphy. Palaeontos 19:1-221 [A. Hendy/A. Hendy]