scholarly journals Sedimentary provenance of the Plio-Pleistocene Nicobar Fan: Complex sourcing revealed through Raman spectroscopy heavy mineral analysis

2021 ◽  
Vol 125 ◽  
pp. 104874
Author(s):  
Max Webb ◽  
Amy Gough ◽  
Paola Vannucchi ◽  
Nils K. Lünsdorf ◽  
Joseph McNeil
Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 385 ◽  
Author(s):  
Lünsdorf ◽  
Kalies ◽  
Ahlers ◽  
Dunkl ◽  
von Eynatten

A significant amount of information on sedimentary provenance is encoded in the heavy minerals of a sediment or sedimentary rock. This information is commonly assessed by optically determining the heavy-mineral assemblage, potentially followed by geochemical and/or geochronological analysis of specific heavy minerals. The proposed method of semi-automated heavy-mineral analysis by Raman spectroscopy (Raman-HMA) aims to combine the objective mineral identification capabilities of Raman spectroscopy with high-resolution geochemical techniques applied to single grains. The Raman-HMA method is an efficient and precise tool that significantly improves the comparability of heavy-mineral data with respect to both overall assemblages and individual compositions within solid solution series. Furthermore, the efficiency of subsequent analysis is increased due to identification and spatial referencing of the heavy minerals in the sample slide. The method is tested on modern sediments of the Fulda river (central Germany) draining two Miocene volcanic sources (Vogelsberg, Rhön) resting on top of Lower Triassic siliciclastic sediments. The downstream evolution of the volcanic detritus is documented and the capability to analyze silt-sized grains has revealed an additional eolian source. This capability also poses the possibility of systematically assessing the heavy-mineral assemblages of shales, which are often disregarded in sedimentary provenance studies.


2021 ◽  
pp. 1-13
Author(s):  
Jasper Verhaegen ◽  
Hilmar von Eynatten ◽  
István Dunkl ◽  
Gert Jan Weltje

Abstract Heavy mineral analysis is a long-standing and valuable tool for sedimentary provenance analysis. Many studies have indicated that heavy mineral data can also be significantly affected by hydraulic sorting, weathering and reworking or recycling, leading to incomplete or erroneous provenance interpretations if they are used in isolation. By combining zircon U–Pb geochronology with heavy mineral data for the southern North Sea Basin, this study shows that the classic model of sediment mixing between a northern and a southern source throughout the Neogene is more complex. In contrast to the strongly variable heavy mineral composition, the zircon U–Pb age spectra are mostly constant for the studied samples. This provides a strong indication that most zircons had an initial similar northern source, yet the sediment has undergone intense chemical weathering on top of the Brabant Massif and Ardennes in the south. This weathered sediment was later recycled into the southern North Sea Basin through local rivers and the Meuse, leading to a weathered southern heavy mineral signature and a fresh northern heavy mineral signature, yet exhibiting a constant zircon U–Pb age signature. Thus, this study highlights the necessity of combining multiple provenance proxies to correctly account for weathering, reworking and recycling.


1965 ◽  
Vol S7-VII (2) ◽  
pp. 327-333
Author(s):  
P. Juignet

Abstract A heavy mineral analysis of sands reveals differences between Sequanian (upper Jurassic) and Albian (lower Cretaceous) formations of the Lisieux area, France. The heavy mineral suite in the horizontal well-sorted Sequanian Glos sands shows a predominance of tourmaline, zircon, rutile, and brookite. The Albian green sands differ from the Glos sands by the presence of glauconite, oblique stratification, and poor sorting at the base. A thin sandy bed intermediate between the Albian and Sequanian shows heavy mineral affinities for the Albian suite.


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