Sediment provenance, routing, and tectonic linkages in the nankai forearc region, Japan

2021 ◽  
Author(s):  
S. G. Ramirez ◽  
N. W. Hayman ◽  
S. P. S. Gulick ◽  
K. L. Milliken ◽  
D. F. Stockli ◽  
...  
Keyword(s):  
Sediment Provenance ◽  
Forearc Region

SEDIMENT PROVENANCE AND DISPERSAL DURING FORELAND BASIN UPLIFT: LOWER CRETACEOUS MANNVILLE GROUP, ALBERTA BASIN, CANADA

2017 ◽  
Author(s):  
Benjamin G. Daniels ◽  
◽  
Stephen M. Hubbard ◽  
William A. Matthews ◽  
Garrett M. Quinn ◽  
...  
Keyword(s):  
Lower Cretaceous ◽  
Foreland Basin ◽  
Sediment Provenance ◽  
Alberta Basin

scholarly journals Water contents of nominally anhydrous orthopyroxenes from oceanic peridotites determined by SIMS and FTIR

2021 ◽  
Author(s):  
Kirsten T. Wenzel ◽  
Michael Wiedenbeck ◽  
Jürgen Gose ◽  
Alexander Rocholl ◽  
Esther Schmädicke
Keyword(s):  
Upper Mantle ◽  
Secondary Ion Mass Spectrometry ◽  
Spinel Peridotite ◽  
Structural Water ◽  
Major Element Composition ◽  
Mantle Peridotites ◽  
History Of ◽  
Polarized Ftir ◽  
Water Contents ◽  
Forearc Region

AbstractThis study presents new secondary ion mass spectrometry (SIMS) reference materials (RMs) for measuring water contents in nominally anhydrous orthopyroxenes from upper mantle peridotites. The enstatitic reference orthopyroxenes from spinel peridotite xenoliths have Mg#s between 0.83 and 0.86, Al2O3 ranges between 4.02 and 5.56 wt%, and Cr2O3 ranges between 0.21 and 0.69 wt%. Based on Fourier-transform infrared spectroscopy (FTIR) characterizations, the water contents of the eleven reference orthopyroxenes vary from dry to 249 ± 6 µg/g H2O. Using these reference grains, a set of orthopyroxene samples obtained from variably altered abyssal spinel peridotites from the Atlantic and Arctic Ridges as well as from the Izu-Bonin-Mariana forearc region was analyzed by SIMS and FTIR regarding their incorporation of water. The major element composition of the sample orthopyroxenes is typical of spinel peridotites from the upper mantle, characterized by Mg#s between 0.90 and 0.92, Al2O3 between 1.66 and 5.34 wt%, and Cr2O3 between 0.62 and 0.96 wt%. Water contents as measured by SIMS range from 68 ± 7 to 261 ± 11 µg/g H2O and correlate well with Al2O3 contents (r = 0.80) and Cr#s (r. = -0.89). We also describe in detail an optimized strategy, employing both SIMS and FTIR, for quantifying structural water in highly altered samples such as abyssal peridotite. This approach first analyzes individual oriented grains by polarized FTIR, which provides an overview of alteration. Subsequently, the same grain along with others of the same sample is measured using SIMS, thereby gaining information about homogeneity at the hand sample scale, which is key for understanding the geological history of these rocks.

scholarly journals Provenance of sediments from Barra del Tordo and Tesoro beaches, Tamaulipas State, northwestern Gulf of Mexico

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Mayla A. Ramos-Vázquez ◽  
John S. Armstrong-Altrin
Keyword(s):  
Gulf Of Mexico ◽  
Age Groups ◽  
Source Area ◽  
Detrital Zircons ◽  
Sediment Provenance ◽  
Geochemical Composition ◽  
Chemical Index ◽  
Beach Sediments ◽  
Chemical Index Of Alteration ◽  
Ree Patterns

AbstractThe mineralogy, bulk sediment geochemical composition, and U–Pb ages of detrital zircons retrieved from the Barra del Tordo (Tordo) and Tesoro beach sediments in the northwestern Gulf of Mexico were analyzed to determine their provenance. The beach sediments are mainly composed of quartz, ilmenite, magnetite, titanite, zircon, and anorthite. The weathering proxies such as the Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA), reveal a moderate-to-high intensity of weathering in the source area. The chondrite-normalized rare earth element (REE) patterns are similar to felsic igneous rocks, with large negative europium anomaly (Eu/Eu* = ~ 0.47–0.80 and ~ 0.57–0.67 in the Tordo and Tesoro beach sediments, respectively).Three major zircon U–Pb age groups are identified in the Tordo and Tesoro beach sediments, i.e., Proterozoic (~ 2039–595 Ma), Mesozoic (~ 244–70.3 Ma), and Cenozoic (~ 65.9–1.2 Ma). The differences of the zircon age spectrum between the Tordo and Tesoro beach sediments are not significant. The comparison of zircon U–Pb ages in this study with ages of potential source terranes suggests that the Mesozoic and Cenozoic zircons of the studied Tordo and Tesoro beach sediments were derived from the Eastern Alkaline Province (EAP) and Mesa Central Province (MCP). Similarly, the likely sources for the Proterozoic zircons were the Sierra Madre Oriental (SMOr) and Oaxaquia in the northwestern Gulf of Mexico. The results of this study further indicate that the sediments delivered to the beaches by rivers and redistributed by longshore currents were crucial in determining the sediment provenance.

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