Sedimentary Organic Matter Characterization on a Tropical Continental Shelf in Northeastern Brazil  

作　　者：Roberto Lima Barcellos Maria Cristina da Silva Sales de Melo Alcides Nobrega Sial Valdir do Amaral Vaz Manso Roberto Lima Barcellos;Maria Cristina da Silva Sales de Melo;Alcides Nobrega Sial;Valdir do Amaral Vaz Manso(Labogeo/GSGMar, Oceanography Department, Federal University of Pernambuco, Recife, Brazil;LGGM, Geology Department, Federal University of Pernambuco, Recife, Brazil;NEG-Labise, Geology Department, Federal University of Pernambuco, Recife, Brazil)

机构地区：[1]Labogeo/GSGMar, Oceanography Department, Federal University of Pernambuco, Recife, Brazil [2]LGGM, Geology Department, Federal University of Pernambuco, Recife, Brazil [3]NEG-Labise, Geology Department, Federal University of Pernambuco, Recife, Brazil

出　　处：《International Journal of Geosciences》2020年第6期393-419,共27页地球科学国际期刊（英文）

摘　　要：In continental shelf areas works where the focus is Geochemistry are widely relevant, due to the vast complexity and uses of these relief features (social, environmental and economic). On the Brazilian Northeast tropical shelves, with emphasis on the Pernambuco Continental Shelf (PCS), the published studies are limited and have aimed at portions closer to the coastline. The objective of the present work is the description of the characteristics and origin of sedimentary organic matter (SOM) in the inner and middle Pernambuco shelf, defining and classifying the local geochemical sedimentary facies. The sampling stations (136) were collected in the study area, and the grain-size, contents of total organic matter (TOM), calcium carbonate (CaCO_{<span style="font-family:Verdana;">3</span>}<span style="font-family:Verdana;">) were analyzed. The samples were processed in an elemental analyzer coupled with a mass spectrometer after the elimination of calcium carbonate. The obtained data were the grain-size, TOM, CaCO</span>_{<span style="font-family:Verdana;">3</span>}<span style="font-family:Verdana;">, elemental (C, N) and the stable isotopic ratios of </span><i><span style="font-family:Verdana;">δ</span></i>^{<span style="font-family:Verdana;">13</span>}<span style="font-family:Verdana;">C e </span><i><span style="font-family:Verdana;">δ</span></i>^{<span style="font-family:Verdana;">15</span>}<span style="font-family:Verdana;">N of SOM. Based on the measured values of carbon and nitrogen, the C/N ratio, associated to </span><i><span style="font-family:Verdana;">δ</span></i>^{<span style="font-family:Verdana;">13</span>}<span style="font-family:Verdana;">C e </span><i><span style="font-family:Verdana;">δ</span></i>^{<span style="font-family:Verdana;">15</span>}<span style="font-family:Verdana;">N, is observed that in the PCS predominates an organic matter of marine origin along its entire length: C < 1%, N < 1%, C/N < 5, </span><i><span style="font-family:Verdana;">In continental shelf areas works where the focus is Geochemistry are widely relevant, due to the vast complexity and uses of these relief features (social, environmental and economic). On the Brazilian Northeast tropical shelves, with emphasis on the Pernambuco Continental Shelf (PCS), the published studies are limited and have aimed at portions closer to the coastline. The objective of the present work is the description of the characteristics and origin of sedimentary organic matter (SOM) in the inner and middle Pernambuco shelf, defining and classifying the local geochemical sedimentary facies. The sampling stations (136) were collected in the study area, and the grain-size, contents of total organic matter (TOM), calcium carbonate (CaCO_{<span style="font-family:Verdana;">3</span>}<span style="font-family:Verdana;">) were analyzed. The samples were processed in an elemental analyzer coupled with a mass spectrometer after the elimination of calcium carbonate. The obtained data were the grain-size, TOM, CaCO</span>_{<span style="font-family:Verdana;">3</span>}<span style="font-family:Verdana;">, elemental (C, N) and the stable isotopic ratios of </span><i><span style="font-family:Verdana;">δ</span></i>^{<span style="font-family:Verdana;">13</span>}<span style="font-family:Verdana;">C e </span><i><span style="font-family:Verdana;">δ</span></i>^{<span style="font-family:Verdana;">15</span>}<span style="font-family:Verdana;">N of SOM. Based on the measured values of carbon and nitrogen, the C/N ratio, associated to </span><i><span style="font-family:Verdana;">δ</span></i>^{<span style="font-family:Verdana;">13</span>}<span style="font-family:Verdana;">C e </span><i><span style="font-family:Verdana;">δ</span></i>^{<span style="font-family:Verdana;">15</span>}<span style="font-family:Verdana;">N, is observed that in the PCS predominates an organic matter of marine origin along its entire length: C < 1%, N < 1%, C/N < 5, </span><i><span style="font-family:Verdana;">

关 键 词：Biogenic Sediments Total Nitrogen δ13C Stable Isotopic Ratio Geochemical Facies PERNAMBUCO 

分 类 号：P73[天文地球—海洋科学]