کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
11033123 | 1635123 | 2018 | 66 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Foraminiferal assemblages, 14C ages, and compositional variations in two sediment cores in the western Gulf of Mexico
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Foraminiferal assemblages, 14C ages, and compositional variations in two sediment cores in the western Gulf of Mexico Foraminiferal assemblages, 14C ages, and compositional variations in two sediment cores in the western Gulf of Mexico](/preview/png/11033123.png)
چکیده انگلیسی
Foraminifera species distribution, 14C ages, and geochemistry data of sediment cores GM33 and GM34 recovered from the southwestern Gulf of Mexico were investigated to infer the age, sedimentation rate, provenance, heavy metal contamination, and depositional environment. Core GM34 (490â¯cm interval) reached an age of 34,346â¯Â±â¯280â¯calâ¯Yrs. BP and the average sedimentation rate was calculated as 0.014â¯cm/yr. The weathering indices like Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA) revealed a moderate intensity of weathering in the source area. The trace elemental ratios and rare earth element (REE) patterns indicated the derivation of sediments from intermediate rocks like andesite. The trace element based bivariate (La/Sc and Co/Th) and ternary (NiThV) diagrams revealed that the sediments were derived mostly from andesite located along the Gulf of Mexico coastal areas. The enrichment factor and geo-accumulation index suggested the absence of heavy metal contamination in sediment cores. The redox proxy trace elemental ratios like V/Cr, Ni/Co, Cu/Zn, and (Cu + Mo)Zn suggested an oxic depositional condition. The benthic foraminiferal assemblages, Mn and Mo concentrations indicated that the late Pleistocene abyssal waters in the Gulf of Mexico were more oxygenated than the present. An absence of significant compositional variations between the core sediments revealed that the depositional condition in the southwestern Gulf of Mexico was probably similar for the last 34,346 cal Yrs. BP.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of South American Earth Sciences - Volume 88, December 2018, Pages 480-496
Journal: Journal of South American Earth Sciences - Volume 88, December 2018, Pages 480-496
نویسندگان
Mayla A. Ramos-Vázquez, John S. Armstrong-Altrin, MarÃa L. Machain-Castillo, Frank R. GÃo-Argáez,