期刊
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
卷 29, 期 2, 页码 427-438出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jsames.2009.07.005
关键词
Grain size; Mineralogy; Trace elements; Mangrove
资金
- CNPq,
- SelenMerAs [476.874/2001-7]
- Geosedintama [471109/03-7]
- CAPES
The coastline of the state of Pari in the Eastern Amazon is formed by submerged valleys occupied partially with mangroves, such as the estuary of the Marapanim River. The sediments of these mangroves are silty-clays, composed of quartz, kaolinite, illite, smectite, K-feldspar, pyrite, hematite, jarosite and halite with accessory zircon, estaurolite, tourmaline, rarely kyanite, rutile, ilmenite, sillimanite, andaluzite, topaz and anatase. Quartz, kaolinite, hematite and most accessories like zircon, estaurolite, tourmaline, rutile, kyanite, topaz, anatase and opaque minerals are inherited from the surrounding rocks (source area). The smectite, K-feldspar, pyrite, halite and jarosite are authigenic (neoformed). Halite and jarosite are currently and locally formed by intense evaporation. The sediments are formed mainly of SiO2, Al2O3 and Fe2O3, which indicates that they were subjected to intense chemical weathering, like the sediments of the Barreiras Formation. This is reinforced by the trace elements, with concentration of residual elements Zr, Cr, V. Nb, among others, while other trace elements are impoverished. The formation of K-feldspar, illite, smectite, halite and pyrite were linked to the environment of sedimentation of the mangrove, rich in organic matter and under the influence of sea water which contributed SO42-, CI, Na+, K+, Ca2+, and Mg2+ for the formation of these minerals. In conclusion the inherited minerals, chemical composition and concentration of residual trace elements show the Barreiras Formation to be the main source of the land-derived sediments of the Marapanim mangroves. (C) 2009 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据