Insights on the controls on floodplain-dominated fluvial successions: A perspective from the early–middle miocene santa cruz formation in río chalía (patagonia, argentina)
Abstract
The Santa Cruz Formation (SCF) in Río Chalía (Austral Basin, Patagonia, Argentina)
is a well-exposed fluvial succession with abundant and diverse fossil vertebrates
accumulated during the Miocene Climatic Optimum (MCO). Using facies analysis, characterization
of stratigraphic architecture, U–Pb geochronology and vertebrate palaeontology, we
assess the timing and interplay of controlling factors on the sedimentation, including
tectonics, global sea level, climate and sediment supply. Throughout the succession,
there occurred a constant aggradation of the floodplain-dominated fluvial system.
Seven zircon U–Pb ages constrain the time of accumulation between c. 18 and 15.2 Ma,
under a relatively constant sedimentation rate of 150 ± 50 m myr–1 . The large number
of fossil vertebrates indicates a Santacrucian fauna, showing no recognizable changes
through the section. The basin-scale, low-gradient anastomosed fluvial system of the
SCF records a period of about 3 myr of relatively constant environmental conditions
controlled by continuous basin subsidence and high sediment supply conditioned by
explosive volcanism together with weathering of uplifting terrains in the Andes. In
addition, the system was influenced by a temperate to warm and subhumid climate favoured
by the MCO before the onset of the Andean rain shadow, together to high global sea
levels.
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https://hdl.handle.net/10161/26492Published Version (Please cite this version)
10.1144/jgs2020-188Publication Info
Cuitiño, JI; Raigemborn, MS; Bargo, MS; Vizcaíno, SF; Muñoz, NA; Kohn, MJ; & Kay,
RF (2021). Insights on the controls on floodplain-dominated fluvial successions: A perspective
from the early–middle miocene santa cruz formation in río chalía (patagonia, argentina).
Journal of the Geological Society, 178(4). 10.1144/jgs2020-188. Retrieved from https://hdl.handle.net/10161/26492.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Richard Frederick Kay
Professor of Evolutionary Anthropology
I have two areas of research:1) the evolution of primates in South America; and 2)
the use of primate anatomy to reconstruct the phylogenetic history and adapations
of living and extinct primates, especially Anthropoidea. 1) Evolution of primates
and mammalian faunal evolution, especially in South America. For the past 30 years,
I have been engaged in research in Argentina, Bolivia The Dominican Republic, Peru,
and Colombia with three objectives:a) to reconstruct the evol

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