Identification of Hydrovolcanism and Its Significance for Hydrocarbon
Xian et al. Journal of Palaeogeography (2018) 7:11 https://doi.org/10.1186/s42501-018-0010-6 Journal of Palaeogeography REVIEW Open Access Identification of hydrovolcanism and its significance for hydrocarbon reservoir assessment: A review Ben-Zhong Xian1,2*, Yan-Xin He1, Hua-Peng Niu1,2, Jun-Hui Wang1,2, Jian-Ping Liu1 and Zhen Wang1 Abstract Investigations of modern volcanic eruptions have demonstrated that ancient volcanic eruptions widely involved water, which was thus named as hydrovolcanic eruptions. Hydrovolcanisms are distinctive in many aspects, such as dynamics, eruptive pattern, texture and structure of rock, and vesicularity. First, normal sediments covered directly by volcanic rocks are the indicators of eruption environments. In addition, microfeatures, special structures, lithofacies or facies associations, and geochemical index of volcanic rocks can also provide significant evidences. Moreover, perlitic texture, quenching fragmentation, surface feature, cementation type, vesicularity, and pillow structure, parallel bedding, large-scale low-angle cross-bedding, antidune cross-bedding of pyroclast are keys to indicating hydrovolcanisms. Clearly, these marks are not equally reliable for identifying eruption environments, and most of them are effective and convincible in limited applications only. For explosive eruptions, the most dependable identification marks include quenching textures, vesicularity in pyroclasts and special large-scale cross-bedding. However, for effusive eruptions, useful indicators mainly include pillow
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