Paleoclimatic applications and modern process studies of pedogenic siderite
Paleoclimatic applications and modern process studies of pedogenic siderite
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成土菱铁矿的古气候应用及现代过程研究
DOI：
10.2110/sepmsp.104.01
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
M. Suarez
中科院分区：
文献类型：
--
作者：
G. Ludvigson;L. González;D. Fowle;J. Roberts;S. Driese;Mark A. Villarreal;Jon J Smith;M. Suarez
成土菱铁矿是一种碳酸盐矿物，形成于地带性气候带排水不良的土壤和古土壤的减少地下水中，具有强烈的正降水-蒸发平衡。在水形态古土壤的微形态研究中，通常认识到菱铁矿的微晶和球晶形式。古代古土壤球形菱铁矿通常直径超过1毫米，而现代成土菱铁矿晶体尺寸超过100毫米的很少。成土菱铁矿在晚古生代、中生代和新生代的古土壤中都有广泛的报道。成土菱铁矿的碳氧同位素组成已被广泛用于代表其古土壤的古降水氧同位素组成。对历史成土菱铁矿的现代过程研究使人们对低温菱铁矿的稳定同位素系统有了更精确的认识。这些工作将导致未来对已发表的菱铁矿-水O分馏方程使用的改变。
Pedogenic siderite is a carbonate mineral that forms in the reducing groundwaters of poorly drained soils and paleosols in zonal climatic belts with strongly positive precipitation–evaporation balances. Microcrystalline and spherulitic forms of siderite are commonly recognized in micromorphologic studies of hydromorphic paleosols. Ancient paleosol sphaerosiderites commonly occur with diameters in excess of 1 mm, while modern pedogenic siderite crystal dimensions in excess of 100 lm are rare. Pedogenic siderites have been widely reported from Late Paleozoic, Mesozoic, and Cenozoic paleosols. The carbon and oxygen isotopic compositions of pedogenic siderites have been widely used as proxies for the oxygen isotopic composition of paleoprecipitation for their respective paleosols. Modern process studies of historic pedogenic siderites are yielding a more refined understanding of the stable isotopic systematics of low-temperature siderite. These works will lead to a future change in usage of published siderite–water O fractionation equations.