کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4691037 1636188 2006 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mio-Pliocene volcaniclastic deposits in the Famatina Ranges, southern Central Andes: A case of volcanic controls on sedimentation in broken foreland basins
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Mio-Pliocene volcaniclastic deposits in the Famatina Ranges, southern Central Andes: A case of volcanic controls on sedimentation in broken foreland basins
چکیده انگلیسی
A well-constrained record of Miocene-Pliocene explosive volcanism is preserved within the broken foreland of Western Argentina along the Famatina Ranges. This paper focuses on the volcaniclastic record known as the Río Blanco member of the El Durazno Formation. Three facies can be recognized in the study area: (1) massive tuffs; (2) volcaniclastic conglomerates and (3) pumiceous sandstones. These facies are interpreted as primary pyroclastic flow deposits (ignimbrites) and reworked volcanogenic deposits within interacting volcanic-fluvial depositional systems. Alternation between ignimbrites and volcanogenic sandstones and conglomerates suggest a recurrent pattern of sedimentation related to recurrent volcanic activity. Considering the facies mosaic and relative thicknesses of facies, short periods of syn-eruption sedimentation (volcaniclastic deposits) seem to have been separated by longer inter-eruption periods, where normal stream-flow processes were dominant. The volcaniclastic component decreases up-section, suggesting a gradual reduction in volcanic activity. The mean sedimentation rate of the Río Blanco member is higher (0.44 mm/year) than those obtained for the underlying and overlying units. This increase cannot be fully explained by foreland basement deformation and tectonic loading. Hence, we propose subsidence associated with volcanic activity as the causal mechanism. Volcanism would have triggered additional accommodation space through coeval pyroclastic deposition, modification of the stream equilibrium profile, flexural loading of volcanoes, and thermal processes. These mechanisms may have favored the preservation of volcaniclastic beds in the high-gradient foreland system of Famatina during the Mio-Pliocene. Thus, the Río Blanco member records the response of fluvial systems to large, volcanism-induced sediment loads.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Sedimentary Geology - Volume 186, Issues 1–2, 15 April 2006, Pages 51-65
نویسندگان
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