Fractures, fluid flow and inherited structures in geothermal systems: inputs from the Fe-ore deposits of eastern Elba Island (Northern Apennines, Italy)
Fractures, fluid flow and inherited structures in geothermal systems: inputs from the Fe-ore deposits of eastern Elba Island (Northern Apennines, Italy)
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地热系统中的裂缝、流体流动和继承结构：厄尔巴岛东部（意大利北亚平宁山脉）铁矿床的输入
DOI：
10.1017/s0016756822000310
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发表时间：
2022
影响因子：
2.3
通讯作者：
P. Matera
中科院分区：
文献类型：
--
作者：
M. Zucchi;A. Brogi;D. Liotta;A. Caggianelli;A. Dini;G. Ventruti;G. Ruggieri;P. Matera
在受多相变形影响的地形中，地热系统的储层具有三维几何形状，通常难以预测。本文描述了在厄尔巴岛东部暴露的一个多期褶皱和断裂环境下发育的化石地热系统，这有助于我们了解地热流体在具有继承构造的地质体中是如何循环的。厄尔巴岛的地热循环使铁矿床（赤铁矿/磁铁矿和黄铁矿）的沉积和蚀变岩石体积成为古流体流动的示踪剂。正滑断层和斜滑断层切割了多相褶皱的变质硅碎屑序列，形成了5 × 10−13 ~ 5 × 10−16 m2的次生渗透率。地热流体从可渗透断裂带作为输水管道，渗透到经两代褶皱变形的水力连接的变质硅碎屑岩体中。地热流体遵循已经确定的几何形状，从而产生明显的褶皱矿化层。变质硅酸碎屑岩具有化学侵蚀作用，有利于石英的溶蚀和再沉淀，有利于铁氧化物和硫化物的沉积。更新后的液体保持了其化学性质（主要是pH值和温度）。这一结论为重建地热概念模型和评价类似地质环境下可开发地区的地热潜力提供了参考。
Abstract Geothermal systems in terrains affected by polyphase deformation have reservoirs with a 3D geometry that is always difficult to predict. In this paper we describe a fossil exhumed geothermal system exposed in eastern Elba Island that developed in a polyphase folded and faulted setting, which can help us to understand how geothermal fluids circulate in geological bodies with inherited structures. Geothermal circulation at Elba allowed the deposition of Fe-ore deposits (haematite/magnetite and pyrite) and altered rock volumes, which represent tracers of the palaeo-fluid flow. Normal and oblique-slip faults dissected a polyphase folded metasiliciclastic succession and produced a secondary permeability in the range of 5 × 10−13 to 5 × 10−16 m2. From the permeable fault zones acting as feeder conduits, geothermal fluids permeated the hydraulically connected metasiliciclastic rock bodies previously deformed by two generations of folds. Geothermal fluids followed the already defined geometry, thus giving rise to apparent folded mineralized levels. Fluid migration into the metasiliciclastic rocks was possible due to their chemical aggression, which favoured the dissolution and reprecipitation of quartz, and Fe-oxide and sulphide deposition. Renewed fluids maintained their chemical properties (pH value and temperature, mostly). This conclusion provides inputs for reconstructing geothermal conceptual models and evaluating the geothermal potentiality of exploitable areas developing in similar geological settings.
第勒尼安海盆地北部的早期裂谷：广角和多道地震联合研究的结果
影响因子：
3.7
作者：
Moeller;I. Grevemeyer;C. R. Ranero;C. Berndt;D. Klaeschen;V. Sallares;N. Zitellini;R. de Franco
通讯作者：
R. de Franco