کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6349189 1622134 2016 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Chemostratigraphic age model for the Tornillo Group: A possible link between fluvial stratigraphy and climate
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Chemostratigraphic age model for the Tornillo Group: A possible link between fluvial stratigraphy and climate
چکیده انگلیسی
The expression of global climate trends (106 to 107 years) and events (105 years) in terrestrial sedimentary sections can only be assessed from long, continuous continental records. Such records are rare due to the paucity of well-dated terrestrial deposits covering millions of years. This study uses isotope chemostratigraphy to develop an age model for fluvial sedimentary rocks of the Tornillo Group (Tornillo Basin, TX) and to decipher the potential expression of global climate variations in this sub-tropical paleo-fluvial system. The carbon isotope ratio (δ13C) of Tornillo Group pedogenic carbonate correlates well with δ13C variations from benthic foraminifera and suggests deposition between ~ 69 Ma and ~ 52 Ma for the studied stratigraphic interval. Higher sediment accumulation rates occurred in the greenhouse period of the early Eocene than during the cooler middle Paleocene. Carbon isotope excursions associated with Eocene hyperthermals were not identified, but their predicted stratigraphic positions coincide with thick sand bodies. We interpret the long-term sediment accumulation rates and rapid shifts in facies distribution as reflecting change in sediment supply in the basin, possibly driven by fluctuations in precipitation seasonality and intensity driven associated with global temperature changes. Carbon and oxygen isotope ratios from pedogenic carbonates display a strong correlation throughout the section, interpreted as an expression of coupling between the hydrological cycle and soil processes. Those observations suggest that global climate variations, along with tectonic and eustatic sea-level changes, may be an important control of stratigraphic variations of the Tornillo Group at multiple timescales.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Palaeogeography, Palaeoclimatology, Palaeoecology - Volume 457, 1 September 2016, Pages 277-289
نویسندگان
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