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DOI	10.1016/j.earscirev.2019.102938
	The hydrochemical evolution of alkaline volcanic lakes: a model to understand the South Atlantic Pre-salt mineral assemblages
	Mercedes-Martín R.; Ayora C.; Tritlla J.; Sánchez-Román M.
发表日期	2019
ISSN	00128252
卷号	198
英文摘要	Understand the origin of the exotic strontium-rich calcite/magnesium-rich clay/silica deposits formed during the Early Cretaceous in the South Atlantic Pre-salt lakes is challenging our ability to comprehend the chemical evolution of alkaline volcanic lakes. Here we present a new hydrochemical model based on an open basin concept, thermodynamic equilibrium, and chemical data from Lake Baringo (East African Rift) to shed light on the mechanisms facilitating carbonate-clay-silica precipitation. This model explores the effects that the leakage to adjacent waterbodies, the combination of lake evaporation and lake recharge (with river, hydrothermal and marine waters), and the bathymetric effects of the partial CO2 pressure have in the stationary precipitation of Pre-salt lacustrine mineral assemblages. Sediment thickness calculations suggest that the facies cyclicity in the Pre-salt and elsewhere are likely reflecting temporal fluctuations in the type of waters sourcing the lake, and in the degree of leakage to aquifers over multiple evaporative-freshening cycles. A plausible link between enhanced strontium uptake into Pre-salt calcite allochems and [Ca2+]/[CO3 2−] lake water stoichiometries allows to infer different scenarios for strontium-rich calcite formation with or without magnesium clays. Our conceptual model allows to quantify the role that hydrology (groundwater charge, discharge to aquifers; evaporation) exert on carbonate-clay-silica precipitation providing with a refined framework to understand the basin-scale chemical sedimentation in alkaline lakes. Furthermore, this model represents a robust template upon which critically test the superimposed kinetic factors likely attached to the genesis of specific mineral factories such as those encountered in the South Atlantic Pre-salt alkaline lakes. © 2019 Elsevier B.V.
关键词	Baringo Calcite Hydrologically open basin Lacustrine Magnesium-rich clay PHREEQC Pre-salt Silica
英文关键词	alkaline water; calcite; clay; lacustrine environment; leakage; magnesium; precipitation (chemistry); saline lake; silica; water chemistry; Atlantic Ocean; Atlantic Ocean (South); Baringo; Kenya; Lake Baringo
语种	英语
来源期刊	Earth Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203506
作者单位	SZALAI Grup S.L., P.O Box 1005, Caimari, 07314, Spain; Departament de Geociències, Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDÆA-CSIC), Barcelona, Spain; REPSOL Exploración S.A, C/Méndez Álvaro 44, Madrid, Spain; Earth Sciences Department, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1086, Amsterdam, HV 1081, Netherlands
推荐引用方式 GB/T 7714	Mercedes-Martín R.,Ayora C.,Tritlla J.,et al. The hydrochemical evolution of alkaline volcanic lakes: a model to understand the South Atlantic Pre-salt mineral assemblages[J],2019,198.
APA	Mercedes-Martín R.,Ayora C.,Tritlla J.,&Sánchez-Román M..(2019).The hydrochemical evolution of alkaline volcanic lakes: a model to understand the South Atlantic Pre-salt mineral assemblages.Earth Science Reviews,198.
MLA	Mercedes-Martín R.,et al."The hydrochemical evolution of alkaline volcanic lakes: a model to understand the South Atlantic Pre-salt mineral assemblages".Earth Science Reviews 198(2019).