Textural and geochemical characteristics of late Pleistocene to Holocene fine-grained deep-sea sediment cores (GM6 and GM7), recovered from southwestern Gulf of Mexico

Abstract

Texture, mineralogy, geochemistry, and 14 C ages of two deep-sea sediment cores (GM6 and GM7) recovered in the southwestern Gulf of Mexico were investigated to infer their provenance and depositional condition. The sediments are enriched in fine-grained silt and clay and poor in sand content. Mineralogically, the sediments consist of quartz, calcite, smectite, and kaolinite. Based on the 14 C data, the age of the GM6 and GM7 sediment cores were calculated as 23,615 cal yrs. BP and 19,007 cal yrs. BP, respectively. The weathering indices such as chemical index of alteration (CIA), chemical index of weathering (CIW), and plagioclase index of alteration (PIA) in GM6 (56-69, 60-74, and 61-73, respectively) and GM7 (54-69, 57-76, and 55-74, respectively) cores revealed a moderate-to-high intensity of weathering. The rare earth element (REE) patterns suggested that the sediments were derived mostly by the weathering of intermediate rocks, exposed along the coastal regions of the Gulf of Mexico. The trace elemental ratios like V/Cr (<2), Ni/Co (<2), and Cu/Zn (<1), authigenic uranium content (<1), and Ce anomaly (Ce/Ce * ≤ 1) suggested that the sediments were deposited under an oxic condition, which was also revealed by the benthic foraminiferal assemblages throughout the GM6 and GM7 sediment cores.

Major, trace, and REE geochemistry of the Meghna River sediments, Bangladesh: Constraints on weathering and provenance

“…Garzanti et al () and Hossain et al () documented that detrital heavy minerals such as zircon, allanite, monazite, and ilmenite were omnipresent in the Chittagong–Tripura Folded Belt and the Indo‐Burman Ranges. On the other hand, felsic igneous rock typically contains higher ∑LREE/HREE ratios and marked negative Eu anomalies, while mafic igneous rock commonly contains lower ∑LREE/HREE ratios and no Eu anomalies (Anaya‐Gregorio, Armstrong‐Altrin, Machain‐Castillo, Montiel‐García, & Ramos‐Vázquez, ; Cullers, ; Garbán et al, ; Hossain et al, ). The ∑LREE/HREE ratio for the Meghna River sediments range from 7.00 to 7.99 (average 7.46 ± 0.32), which is close to average UCC (8.68, Rudnick & Gao, ), and display marked negative Eu anomalies (Eu/Eu* 0.57), representing that the investigated sediments were largely originated from felsic source rocks.…”

Texture, mineralogy and geochemistry of Teri sediments from the Kuthiraimozhi deposit, Southern Tamilnadu, India: implications on provenance, weathering and palaeoclimate

“…The bivariate plots ( Fig. 7a; Floyd et al 1989;Anaya Gregorio et al 2018), between TiO 2 vs Ni, further indicate that the teri sediments were mainly derived from felsic or acidic granitoid basement rocks (Fig. 8).…”

“…This comparison also represents that the teri sediment values have coincided within the range of felsic rocks. The La/Th and Th/Sc are quite constant in sedimentary rocks as 2.4 and 0.9, respectively (Taylor and McLennan 1985;Anaya Gregorio et al 2018;Perumal and Udayanapillai 2019). The La/Th and Th/Sc ratios of teri sediments are 2.31 and 1.03, respectively.…”

Detrital zircon U–Pb geochronology and geochemistry of the Riachuelos and Palma Sola beach sediments, Veracruz State, Gulf of Mexico: a new insight on palaeoenvironment

“…Therefore, the combined results obtained from the Pearson's Correlation Coefficient and the Principal Component Analysis indicate the association of major and trace elements with detrital materials rather than biogenic components. Harnois 1988) have been widely used to infer intensity of weathering (e.g., Ota et al 2017;Anaya-Gregorio et al 2018;Raza and Mondal 2018;Tawfik et al 2018;Hossain et al 2018;Kettanah et al 2020). However, a few authors (Cullers 2000;Buggle et al 2011;Garzanti et al 2015) documented that sediments are affected by various factors like sorting, recycling, and having significant proportions of carbonate or phosphate minerals.…”