نتایج جستجو برای: pyroclastic units

تعداد نتایج: 172732  

2014
L. Wilson J. W. Head

Introduction: Lunar pyroclastic deposits can be subdivided into several modes of occurrence [1], suggesting different modes of emplacement. For example, some smaller pyroclastic deposits have been interpreted to have erupted during strombolian/hawaiian activity [2], while others are linked to vulcanian activity related to dike and sill emplacement below crater floors [3,4]. The largest pyroclas...

Iraj Rasa, Mohammad reza Janesari, Mohammad Yazdi, Sahar Sadeghi,

    Introduction Epithermal deposits are usually found in association with near-surface magmatic-hydrothermal environments with volcanic rocks. According to studies, their formation depth is less than 1.5 km and the temperature for their formation is less than 300 ° C. Epithermal deposits are usually rich in gold to gold-silver and rich in silver and include low sulfide, medium sulfide and hig...

2009
Lynn M. Carter Bruce A. Campbell B. Ray Hawke Donald B. Campbell Michael C. Nolan

[1] We use polarimetric radar observations to study the distribution, depth, and embedded rock abundance of nearside lunar pyroclastic deposits. Radar images were obtained for Mare Vaporum and the southern half of Mare Serenitatis; the imaged areas contain the large Rima Bode, Mare Vaporum, Sulpicius Gallus, and Taurus-Littrow pyroclastic deposits. Potential pyroclastic deposits at Rima Hyginus...

2001
P. De Vita V. Piscopo

The paper illustrates some results of research carried out to assess factors triggering debris flows which involve the pyroclastic overburdens covering carbonate mountains around Vesuvius. The aims of the research were to reconstruct a relationship between rainfall and debris flow occurrence and to highlight empirical hydrological thresholds through rainfall pattern analysis. The research was a...

Jalali Khalil Abadi, Mohammad, Mohebi, Ayda, Sadati, Seyedeh Narges, Yazdi, Mohammad,

The Grouh area is located about 19 km north-east of Sarduyeh city in Kerman Province. The major lithological units in this area include Eocene andesite and andesitic basalt. Oligo-Miocene intrusive units include diorite, quartz diorite and granodiorite; while pyroclastic units include tuff and breccia. The alteration in the Grouh area is remarkable due to the penetration of the intrusive masses...

2017
Ralph E. Milliken Shuai Li

Laboratory analyses of lunar samples provide a direct means to identify indigenous volatiles and have been used to argue for the presence of Earth-like water content in the lunar interior. Some volatile elements, however, have been interpreted as evidence for a bulk lunar mantle that is dry. Here we demonstrate that, for a number of lunar pyroclastic deposits, near-infrared reflectance spectra ...

Mazloumi Bajestani, , Malekzadeh Shafaroudi, , Sahebi Khader, ,

Fadiheh copper-gold prospect area in northwest of Torbat-e Heydariyeh in Khorasan Razavi Province is located in the central part of the Khaf-Kashmar-Bardaskan magmatic belt. This area includes outcrops of Eocene volcanic-pyroclastic units with felsicـintermediate nature. The lavas are andesite and latite, and pyroclastic units include rhyodacitic tuff, andesitic lithic tuff and ignimbrite. Intr...

2017
Sarah E. Ogburn Eliza S. Calder

Citation: Ogburn SE and Calder ES (2017) The Relative Effectiveness of Empirical and Physical Models for Simulating the Dense Undercurrent of Pyroclastic Flows under Different Emplacement Conditions. Front. Earth Sci. 5:83. doi: 10.3389/feart.2017.00083 The Relative Effectiveness of Empirical and Physical Models for Simulating the Dense Undercurrent of Pyroclastic Flows under Different Emplacem...

2003
William I. Rose

Multiple volcanic eruptions occurred between 8500 and 9000 yr. B.P. from the central crater of CitiaitCpetl Volcano generating a series of pyroclastic flows that formed a deposit with a total volume of about 0.26 km3 (D.R.E.). The flows descended in all directions around the crater, but they were mostly controlled by topography and deposited in valleys or local topographic depressions up to abo...

2014
L. M. Carter R. R. Ghent J. L. Bandfield B. A. Campbell

Introduction: Lunar volcanism creates a wide variety of features such as domes, rilles, and large pyroclastic deposits. Mapping the subsurface column structure of the upper part of these deposits can provide key information about how they were formed and how the surface regolith developed through subsequent weathering. In addition, many possible lunar landing sites (e.g., the Constellation site...

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