scholarly journals Multi-proxy evidence of Caribbean-sourced marine incursions in the Neogene of Western Amazonia, Brazil

Geology ◽  
2022 ◽  
Author(s):  
Lilian M. Leandro ◽  
Ana P. Linhares ◽  
Marcelo A. De Lira Mota ◽  
Gerson Fauth ◽  
Alessandra Santos ◽  
...  
Keyword(s):  
Late Miocene ◽  
Middle Miocene ◽  
Drainage System ◽  
Primary Source ◽  
Source Area ◽  
Caribbean Sea ◽  
Geochemical Data ◽  
Continental Scale ◽  
The Caribbean ◽  
First Time

The timing of continental-scale marine flooding events in Western Amazonia during the Neogene is still an unsolved question. Despite broad proxy-based evidence of such events, the pathways and duration of late Miocene marine incursions remain controversial. We provide coupled calcareous and organic microfossil and geochemical data from six onshore cores from Neogene sequences of the Solimões Basin, Brazil. Our records support minor marine influence in the early Miocene (23.0, 21.1, 18.6, and 16.3 Ma), middle Miocene (14.9, 13.7, and 12.9 Ma) and early Pliocene (4.7, 4.2–4.1, and 3.8 Ma), and conspicuous marine incursions in the late Miocene (11.1–8.8 Ma) suggested by the consistent presence of salinity-indicative microfossils and geochemical data. Our findings challenge the view of major marine incursions in the early and middle Miocene in the studied area. We propose for the first time a new late Miocene incursion (LMI) event as the main marine flooding event in Western Amazonia during the Neogene. These onshore records are compared with three offshore cores from the Atlantic and Pacific Oceans. The similarity between microfossil assemblages of the Solimões Basin and the Caribbean Sea, and evidence of increased runoff from the Orinoco river drainage system, strongly suggest the Caribbean Sea as the primary source area of the marine incursions, supporting a Venezuelan seaway. We further show for the first time the potential linkage between Neogene marine incursions (mainly the LMI) into the Solimões Basin and major disturbances in the global carbon cycle.

scholarly journals REVISIÓN TAXONÓMICA DEL CORAL PORITES COLONENSIS (SCLERACTINIA: PORITIDAE) EN EL CARIBE COLOMBIANO

2016 ◽  
Vol 37 (2) ◽  
Author(s):  
Dagoberto E. Venera Pontón ◽  
Javier Reyes ◽  
Guillermo Diaz Pulido
Keyword(s):  
Continental Shelf ◽  
Taxonomic Revision ◽  
Caribbean Sea ◽  
South American ◽  
Large Variability ◽  
Porites Astreoides ◽  
Taxonomic Review ◽  
Natural Park ◽  
The Caribbean ◽  
First Time

Porites colonensis is a coral from the Caribbean Sea; colonies are foliaceous, undulated, and plate-like. Polyps are dark brown or red with small bright white or green centers; pali are present in corallites and the septal plan is bisymmetrical, conformed by three fused ventral septa, a dorsal solitary septum, and two pairs of lateral septa at each side of the dorso-ventral axis. P. colonensis is similar and can be confused with the smooth varieties of Porites astreoides and Porites branneri. There are three specimens collected from Colombia and previously identified as P. colonensis: one from Golfo de Urabá (Darién ecoregion), other from Islas del Rosario (Coralline Archipelagos ecoregion), and another from an unspecified locality, in addition to one published observation from the Golfo de Urabá without collected specimens. A recent finding of other specimens in the Tayrona National Natural Park (TNNP, Tayrona ecoregion) and the absence of a rigorous taxonomic revision for all specimens collected from Colombia showed that it was necessary to review the presence and distribution of P. colonensis in the Colombian Caribbean. A taxonomic review was done for all specimens collected from Colombia and previously identified as P. colonensis. Then, the morphologic variability of specimens that were confirmed as P. colonensis was described. Only the specimens from TNNP agreed with the holotype description of P. colonensis, while others agreed with flat varieties of P. astreoides. Thus, the presence of P. colonensis is confirmed for the first time for Colombia, but its presence in other Colombian localities outside Tayrona ecoregion could not be demonstrated. This is the only confirmed record of this species for the South American continental shelf. Furthermore, the skeletal characteristics of Colombian P. colonensis corallites showed large variability, exceeding the ranges previously described for the species.

Late Miocene sediment delivery from the axial drainage system of the East Carpathian foreland basin to the Black Sea

Geology ◽  
2020 ◽  
Vol 48 (8) ◽  
pp. 761-765 ◽  
Author(s):  
Arjan de Leeuw ◽  
Stephen J. Vincent ◽  
Anton Matoshko ◽  
Andrei Matoshko ◽  
Marius Stoica ◽  
...  
Keyword(s):  
Black Sea ◽  
Late Miocene ◽  
Drainage System ◽  
Sediment Supply ◽  
Sediment Flux ◽  
Danube River ◽  
The Black Sea ◽  
Foreland Basins ◽  
Continental Scale ◽  
Slab Breakoff

Abstract We describe a late Miocene to early Pliocene axial drainage system in the East Carpathian foreland, which was an important sediment supplier to the Black Sea and the Dacian Basin. Its existence explains the striking progradation of the northwest Black Sea shelf prior to the onset of sediment supply from the continental-scale Danube River in the late Pliocene to Pleistocene. This axial drainage system evolved due to the diachronous along-strike evolution of the Carpathians and their foreland; continental collision, overfilling, slab breakoff, and subsequent exhumation of the foreland occurred earlier in the West Carpathians than in the East Carpathians. After overfilling of the western foreland, excess sediment was transferred along the basin axis, giving rise to a 300-km-wide by 800-km-long, southeast-prograding river-shelf-slope system with a sediment flux of ∼12 × 103 km3/m.y. Such late-stage axial sediment systems often develop in foreland basins, in particular, where orogenesis is diachronous along strike. Substantial lateral sediment transport thus needs to be taken into account, even though evidence of these axial systems is often eroded following slab breakoff and inversion of their foreland basins.

scholarly journals Molluscan diversification and extinction on opposite sides of the Isthmus of Panama

1992 ◽  
Vol 6 ◽  
pp. 144-144
Author(s):  
Jeremy B. C. Jackson ◽  
Peter Jung
Keyword(s):  
Late Miocene ◽  
Eastern Pacific ◽  
Tropical Eastern Pacific ◽  
Early Pliocene ◽  
Isthmus Of Panama ◽  
Late Neogene ◽  
Tropical America ◽  
The Caribbean ◽  
First Time ◽  
Final Closure

Molluscs are the most diverse and abundant tropical American macrofossils, but their distributions and evolution are not well understood. Classic studies by Olsson and Woodring documented a rich Late Miocene to Early Pliocene “Gatunian” fauna throughout the Caribbean and tropical Eastern Pacific, with many species in common between the oceans. This fauna was divided by formation of the Isthmus of Panama, and diverged into distinct Pacific and Caribbean faunas sometime thereafter. Diversity also decreased by about half in the Caribbean. However, the timing, rates and correlation of these major biological changes with changes in environmental conditions have not been resolved because of imprecise dating and taxonomy and failure to consider problems of sampling and biofacies in biological comparisons. We used the newly revised late Neogene stratigraphy for Panama and Costa Rica to date for the first time the radiation and extinction of molluscs on opposite sides of the Isthmus. Data include occurrences throughout tropical America for nearly 100 species of the Strombina-group (Gastropoda, Columbellidae) and for more than 500 gastropod and bivalve genera from 240 Late Miocene to Pleistocene isthmian collections.All evidence suggests that final closure of the Isthmus of Panama occurred between 3.5 and 2.5 My. Subgeneric divergence between the oceans was well developed, and trans-isthmian species were rare by the Early Pliocene, at least 2 Ma before final closure. Caribbean diversity remained high until 1.8 to 1.5 Ma when massive but selective extinction occurred. This was at least 1 Ma after final closure of the Isthmus, and may be correlated with onset of slightly cooler Caribbean sea surface temperatures in the Pleistocene. In contrast, Eastern Pacific diversity did not decline, and even increased during the Pleistocene.

scholarly journals FIRST RECORD OF THE GENUS HETERODINIUM (DINOPHYCEAE) FROM COASTAL WATERS OF THE COLOMBIAN CARIBBEAN

2016 ◽  
Vol 37 (1) ◽  
Author(s):  
Lina M. Ramos Ortega ◽  
Luís A. Vidal V.
Keyword(s):  
Gulf Of Mexico ◽  
Coastal Waters ◽  
Caribbean Sea ◽  
First Record ◽  
The Caribbean ◽  
First Time

Three species of the genus Heterodinium Kofoid are reported for the first time in coastal waters of the Colombian Caribbean. The identified species are Heterodinium rigdenae Kofoid, 1906, Heterodinium agassizii Kofoid, 1907 and Heterodinium angulatum Kofoid y Michener, 1911. Information about distribution of these species in the Caribbean Sea and the Gulf of Mexico is given.

On reproduction in Crouania pumila (Callithamniaceae, Rhodophyta), a new record for the Red Sea

2019 ◽  
Vol 62 (6) ◽  
pp. 595-598
Author(s):  
Razy Hoffman
Keyword(s):  
Red Sea ◽  
New Record ◽  
Algal Species ◽  
Caribbean Sea ◽  
Red Alga ◽  
Type Locality ◽  
Microscope Slide ◽  
New Information ◽  
The Caribbean ◽  
First Time

Abstract The minute red alga Crouania pumila (Callithamniaceae: Rhodophyta), recently described from the Caribbean Sea, is reported for the first time from the Red Sea, approximately 12,000 km from the type locality, based on microscope slide specimens collected 40 years ago by Dr. Yaacov Lipkin. These samples contribute new information regarding the reproduction of this algal species.

scholarly journals The Genus Gnathia Leach (Isopoda) from the Santa Marta area, Northern Colombia, with a Review of Gnathiidea from the Caribbean Sea and Gulf of Mexico

1988 ◽  
Vol 58 (1) ◽  
pp. 88-104 ◽  
Author(s):  
Hans-Georg Müller
Keyword(s):  
Gulf Of Mexico ◽  
Caribbean Sea ◽  
The Caribbean ◽  
First Time

Six species of the genus Gnathia (Crustacea: Isopoda: Gnathiidea) are recorded from the Caribbean Sea of northern Colombia. Gnathia gonzalezi n. sp., Gnathia magdalenensis n. sp., Gnathia samariensis n. sp., and Gnathia vellosa n. sp. are described; Gnathia beethoveni Paul & Menzies, 1971 and Gnathia virginalis Monod, 1926 are redescribed and recorded for the first time from Colombia. The Gnathiidea of the Caribbean Sea and Gulf of Mexico are reviewed.

scholarly journals Eustatic and tectonic change effects in the reversion of the transcontinental Amazon River drainage system

2016 ◽  
Vol 46 (2) ◽  
pp. 301-328 ◽  
Author(s):  
Mario Vicente Caputo ◽  
Emilio Alberto Amaral Soares
Keyword(s):  
South America ◽  
Atlantic Ocean ◽  
Sea Level ◽  
Late Miocene ◽  
Middle Miocene ◽  
Drainage System ◽  
Sedimentary Basins ◽  
Amazon River ◽  
Drainage Network ◽  
Sea Level Changes

ABSTRACT: The development of the transcontinental Amazon River System involved geological events in the Andes Chain; Vaupés, Purus and Gurupá arches; sedimentary basins of the region and sea level changes. The origin and age of this river have been discussed for decades, and many ideas have been proposed, including those pertaining to it having originated in the Holocene, Pleistocene, Pliocene, Late Miocene, or even earlier times. Under this context, the geology of the sedimentary basins of northern Brazil has been analyzed from the Mesozoic time on, and some clarifications are placed on its stratigraphy. Vaupés Arch, in Colombia, was uplifted together with the Andean Mountains in the Middle Miocene time. In the Cenozoic Era, the Purus Arch has not blocked this drainage system westward to marine basins of Western South America or eastward to the Atlantic Ocean. Also the Gurupá Arch remained high up to the end of Middle Miocene, directing this drainage system westward. With the late subsidence and breaching of the Gurupá Arch and a major fall in sea level, at the beginning of the Late Miocene, the Amazon River quickly opened its pathway to the west, from the Marajó Basin, through deep headward erosion, capturing a vast drainage network from cratonic and Andean areas, which had previously been diverted towards the Caribbean Sea. During this time, the large siliciclastic influx to the Amazon Mouth (Foz do Amazonas) Basin and its fan increased, due to erosion of large tracts of South America, linking the Amazon drainage network to that of the Marajó Basin. This extensive exposure originated the Late Miocene (Tortonian) unconformity, which marks the onset of the transcontinental Amazon River flowing into the Atlantic Ocean.

scholarly journals Heavy Minerals Study of Sandstone from the Late Miocene-Early Pliocene Mukdadiya Formation; Kirkuk, Iraq: Implications for Provenance

2021 ◽  
Vol 54 (1C) ◽  
pp. 30-40
Author(s):  
Abbas Ali
Keyword(s):  
Late Miocene ◽  
Primary Source ◽  
Source Area ◽  
Source Rocks ◽  
Heavy Minerals ◽  
Metamorphic Rocks ◽  
Continental Margins ◽  
Direct Derivation ◽  
Magmatic Rocks ◽  
Active Continental Margins

Mukdadiya Formation (Late Miocene-Pliocene) exposed in the northeastern limb of Baba anticline fold in Kirkuk structure. The selected section was located in the Shoraw area, northeastern Kirkuk city, Iraq. Twenty sandstone samples were collected to study heavy minerals. The study indicates that opaque and epidote group minerals forming the main heavy minerals, followed by amphibole, pyroxene, garnet, and chlorite. According to heavy minerals assemblage, the source rocks are interpreted to be composed essentially of sedimentary followed by igneous and metamorphic rocks and the high contents of unstable and metastable minerals confirm their direct derivation from the adjacent primary source. Ultra-stable and metastable heavy minerals relationship indicated that the sandstone of the Mukdadiya Formation is immature and moderate stability and showed that these minerals couldn't be transported for very long distances close to the source area and not represents polycyclic grain. MF-MT-GM Ternary diagram showed that the studied samples fall within the field of active continental margins which is characterized by a relatively high percentage of minerals (MF˃GM) derived from mafic magmatic rocks.

scholarly journals NEW RECORDS OF THE DISTINCTIVE BENTHIC DINOFLAGELLATE GENUS Cabra (DINOPHYCEAE)

2015 ◽  
Vol 30 (1) ◽  
pp. 63
Author(s):  
F. Gómez ◽  
R. M. Lopes
Keyword(s):  
Atlantic Ocean ◽  
Light Microscopy ◽  
Mediterranean Sea ◽  
New Records ◽  
Morphological Variability ◽  
Caribbean Sea ◽  
Original Description ◽  
Undescribed Species ◽  
The Caribbean ◽  
First Time

The benthic dinoflagellate genus Cabra is reported for the first time in the Mediterranean Sea and the South Atlantic Ocean, with additional records in the Caribbean Sea and the eastern Asian coasts. Cabra aremorica is reported for the first time after the original description. However, these records should be considered cautiously because the distinction between Cabra aremorica and C. reticulata is difficult based on routine light microscopy observations. It is uncertain whether there is a high intraspecific morphological variability or several co-occurring undescribed species. Cabra levis, a species recently described, is reported for first time beyond the type locality. Nuevos registros del distintivo género de dinoflagelado bentónico Cabra (Dinophyceae) El dinoflagelado bentónico del géneroCabrase describe por primera vez en el Mar Mediterráneo y el Océano Atlántico Sur, con registros adicionales en el Mar Caribe y las costas orientales de Asia. Cabra aremorica se cita por primera vez después de la descripción original. Sin embargo, estos registros deben ser considerados con cautela porque la distinción entre Cabra aremorica y C. reticulata es difícil basándose solo en observaciones rutinarias de microscopía óptica. No está claro si existe una alta variabilidad morfológica intra-específica o si existen varias especies no descritas que coexisten. Cabra levis, una especie recientemente descrita, se describe por primera vez más allá de su localidad tipo.

scholarly journals Deep-sea holothurians (Echinodermata, Holothuroidea) from the Colombian Southern Caribbean Sea

Check List ◽  
2020 ◽  
Vol 16 (3) ◽  
pp. 535-551 ◽  
Author(s):  
Giomar H. Borrero-Pérez ◽  
Luisa F. Dueñas ◽  
Jorge León ◽  
Vladimir Puentes
Keyword(s):  
Atlantic Ocean ◽  
Deep Sea ◽  
Caribbean Sea ◽  
Species Level ◽  
Southern Caribbean ◽  
The Caribbean ◽  
First Time ◽  
Video Surveys

Fifteen morphotypes of deep-sea holothurians were documented by photography or videography at depths of 596–2,566 m, using Remote Operated Vehicles (ROV) video surveys and towed camera transects, during hydrocarbon exploratory activities in the Colombian Southern Caribbean. Most of the morphotypes were identified to the species level based on the images. The species belong to four orders, Apodida (1 species), Persiculida (3 species), Elasipodida (8 species), and Synallactida (3 species). Four species, three genera, and three families are reported for the first time in the Colombian Caribbean Sea. Some of the reports also represent first records for the Caribbean Sea and the Atlantic Ocean.

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