Paleogeography of Miocene Western Amazonia: Isotopic composition of molluscan shells constrains the influence of marine incursions

Vonhof, Hubert; Wesselingh, Frank P.; Kaandorp, R.J.G.; Davies, Gareth R.; Hinte, J.E. van; Guerrero, Javier; Räsänen, Matti; Romero-Pittman, Lidia; Ranzi, Alceu

doi:10.1130/b25058.1

Cited by 81 publications

(101 citation statements)

References 22 publications

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“…Peters' respectively. Stable isotope analyses on molluscs were performed using the methodology outlined in Vonhof et al (2003). In this paper, we apply the timescale of the international stratigraphic commission and Gradstein et al, 2004. …”

Section: Methodsmentioning

confidence: 99%

Neogene stratigraphy of the Langenboom locality (Noord-Brabant, the Netherlands)

Wijnker

Bor²,

Wesselingh

et al. 2008

Netherlands Journal of Geosciences

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The locality of Langenboom (eastern Noord-Brabant, the Netherlands), also known as Mill, is famous for its Neogene molluscs, shark teeth, teleost remains, birds and marine mammals. The stratigraphic context of the fossils, which have been collected from sand suppletions, was hitherto poorly understood. Here we report on a section which has been sampled by divers in the adjacent flooded sandpit 'De Kuilen' from which the Langenboom sands have been extracted. The studied section covers part of the marine Miocene Breda Formation and Pliocene Oosterhout Formation, and is topped by fluvial Quaternary deposits of presumably the Beegden Formation. The Breda Formation (15 -18 m below lake surface) in this section is, based on organic walled dinoflagellate cysts, of an early-middle Tortonian age. The Oosterhout Formation (7 -15 m below lake surface) comprises two depositional sequences, the lower of which (12 -15 m below lake surface) presumably is the source of most Langenboom fossils. Combined dinoflagellate cyst and benthic mollusc indicators point to an early Zanclean -early Piacenzian age for this lower cycle. Its basal transgressive lag and (to lesser extent) top comprise reworked Tortonian taxa as well. Dinoflagellate cysts and a single benthic mollusc point to a Piacenzian age for the upper Oosterhout Formation sequence (7 -12 m below lake surface).

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Section: Methodsmentioning

confidence: 99%

Neogene stratigraphy of the Langenboom locality (Noord-Brabant, the Netherlands)

Wijnker

Bor²,

Wesselingh

et al. 2008

Netherlands Journal of Geosciences

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“…Before the Mid-Oligocene, ca 25 Myr, the Amazon Basin drained to the north into the Caribbean Sea in what is now western Venezuela ( Vonhof et al 1998( Vonhof et al , 2003, still ahead (to the east) of the advancing Caribbean plate. At present, the Orinoco River flows into the Atlantic Ocean east of the Lesser Antilles and rafts of material can be carried westward by ocean currents.…”

Section: Bahama Islandsmentioning

confidence: 99%

The West Indies as a laboratory of biogeography and evolution

Ricklefs

Bermingham

2007

Phil. Trans. R. Soc. B

216

267

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Islands have long provided material and inspiration for the study of evolution and ecology. The West Indies are complex historically and geographically, providing a rich backdrop for the analysis of colonization, diversification and extinction of species. They are sufficiently isolated to sustain endemic forms and close enough to sources of colonists to develop a dynamic interaction with surrounding continental regions. The Greater Antilles comprise old fragments of continental crust, some very large; the Lesser Antilles are a more recent volcanic island arc, and the low-lying Bahama Islands are scattered on a shallow oceanic platform. Dating of island lineages using molecular methods indicates over-water dispersal of most inhabitants of the West Indies, although direct connections with what is now southern Mexico in the Early Tertiary, and subsequent land bridges or stepping stone islands linking to Central and South America might also have facilitated colonization. Species-area relationships within the West Indies suggest a strong role for endemic radiations and extinction in shaping patterns of diversity. Diversification is promoted by opportunities for allopatric divergence between islands, or within the large islands of the Greater Antilles, with a classic example provided by the Anolis lizards. The timing of colonization events using molecular clocks permits analysis of colonization-extinction dynamics by means of species accumulation curves. These indicate low rates of colonization and extinction for reptiles and amphibians in the Greater Antilles, with estimated average persistence times of lineages in the West Indies exceeding 30 Myr. Even though individual island populations of birds might persist an average of 2 Myr on larger islands in the Lesser Antilles, recolonization from within the archipelago appears to maintain avian lineages within the island chain indefinitely. Birds of the Lesser Antilles also provide evidence of a mass extinction event within the past million years, emphasizing the time-heterogeneity of historical processes. Geographical dynamics are matched by ecological changes in the distribution of species within islands over time resulting from adaptive radiation and shifts in habitat, often following repeatable patterns. Although extinction is relatively infrequent under natural conditions, changes in island environments as a result of human activities have exterminated many populations and othersespecially old, endemic species-remain vulnerable. Conservation efforts are strengthened by recognition of aesthetic, cultural and scientific values of the unique flora and fauna of the West Indies.

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“…Disappearance of a mega-wetland in the western Amazonian basins was followed by the formation of the eastward-draining Amazon River, which has been attributed to Andean uplift [1][2][3][4][5] . However, South America's westward motion over cold, dense subducted slabs implies that regional subsidence and uplift east of the Andes may have been driven by mantle convection.…”

mentioning

confidence: 99%

Miocene drainage reversal of the Amazon River driven by plate–mantle interaction

et al. 2010

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Northern South America experienced significant changes in drainage patterns during the opening of the South Atlantic Ocean. Disappearance of a mega-wetland in the western Amazonian basins was followed by the formation of the eastward-draining Amazon River, which has been attributed to Andean uplift [1][2][3][4][5] . However, South America's westward motion over cold, dense subducted slabs implies that regional subsidence and uplift east of the Andes may have been driven by mantle convection. Here we use a coupled model of mantle convection and plate kinematics to show that dynamic subsidence of up to 40 m Myr . The resulting progressive tilt of northern South America to the east enabled the establishment of the Amazon River, suggesting that mantle convection can profoundly affect the evolution of continental drainage systems.During the Early Miocene (from ∼23 Myr bp), an inland fluviolacustrine/marginally marine Amazonian system partially flooded northwest South America with regional drainage mainly northwards towards the Caribbean 1-4 . This Amazonian megawetland existed at least from the Middle to Late Miocene 1,2 when the dominant fluvial drainage switched to its present course towards the Atlantic. This shift, initiating the fluviolacustrine system that is now the Amazon River is supported by sediment provenance, palaeo-transport direction and biostratigraphic studies [1][2][3]5 . The timing of this onset is estimated from offshore sedimentary records between 10.6 and 9.7 Myr bp (ref. 6). Any possible AmazonianCaribbean connection was fully closed by the Late Miocene 2 , with the Amazon River reaching its present shape and size from the Pleistocene onwards 2,7 (∼2.4 Myr bp). During the Early and Middle Miocene a restricted eastward-flowing palaeo-Amazon River may have drained to the Atlantic coast 7 . Stratigraphic data suggest that this fluvial system extended westward until limited by the Purus arch 7 (Fig. 1), a structural high that separated the Solimões and Amazonas basins and restricted the Amazonian mega-wetland to the west and the palaeo-Amazon River to the east.The main Miocene changes in drainage patterns, and the formation of the Amazon River, are commonly attributed to uplift in the northwest Andes 5,[8][9][10][11] . It has been proposed that the uplift of the Eastern Cordillera caused flexural subsidence in the foreland basins, and redirected a significant portion of the northwest Amazonas basin drainage, along the northward-flowing Palaeo-Orinoco and Magdalena rivers, to the east 2 . In addition, it has also been suggested that Amazon landscape evolution can be attributed to Early Tertiary to Holocene intraplate tectonics, including subsidence associated with a low-rate extension that contributed to a structural low 12 . The Late Miocene (∼11 Myr bp) is also well documented for a significant drop in sea level, which would have contributed to the disappearance of the Amazonian mega-wetland and marine incursions 13,14 , but could not have caused a fundamental change in the continental drainage pa...

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Paleogeography of Miocene Western Amazonia: Isotopic composition of molluscan shells constrains the influence of marine incursions

Cited by 81 publications

References 22 publications

Neogene stratigraphy of the Langenboom locality (Noord-Brabant, the Netherlands)

Neogene stratigraphy of the Langenboom locality (Noord-Brabant, the Netherlands)

The West Indies as a laboratory of biogeography and evolution

Miocene drainage reversal of the Amazon River driven by plate–mantle interaction

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