نتایج جستجو برای: volcanic breccia

تعداد نتایج: 15341  

2002
Scott E. Bryan

Silicic volcanic rocks are associated with most, if not all, continental ×ood basalt provinces and volcanic rifted margins, where they can form substantial parts of the eruptive stratigraphy and have eruptive volumes >104 km3. Poor preservation of silicic volcanic rocks following kilometer-scale uplift and denudation of the volcanic rifted margins, however, can result in only deeper level struc...

Journal: :Science 1972
M W Higgins A C Waters I Friedman N V Peterson E A Groh

tidal triggering mechanism, ibecause a similar process appears to trigger terrestrial volcanic eruptions (4), and perhaps earthquakes as well (5). The terrestrial situation is somewhat obscured, however, because of the complicating loading effects of oceanic and atmospheric tides, ocean currents, and atmospheric circulation. The moon has provided another clear, albeit luxurious, view of the ear...

2016
Rafael Prieto Curiel Steven Bishop

We introduce here an index, which we call the Rare Event Concentration Coefficient (RECC), that is a measure of the dispersion/concentration of events which have a low frequency but tend to have a high level of concentration, such as the number of crimes suffered by a person. The Rare Event Concentration Coefficient is a metric based on a statistical mixture model, with a value closer to zero m...

2005
Andrew W. Woods Juergen Kienle

In this paper, we present some physical models that can describe the ascent of volcanic ash into the atmosphere during a volcanic eruption. We consider both sustained volcanic eruption columns and discrete volcanic thermal clouds. To test the modeling approach, we compare our predictions of the ascent rate of a model cloud with some observations of the ascent of the ash cloud during the April 1...

Journal: :Remote Sensing 2016
Stefano Corradini Mario Montopoli Lorenzo Guerrieri Matteo Ricci Simona Scollo Luca Merucci Frank S. Marzano Sergio Pugnaghi Michele Prestifilippo Lucy J. Ventress Roy G. Grainger Elisa Carboni Gianfranco Vulpiani Mauro Coltelli

Volcanic activity is observed worldwide with a variety of ground and space-based remote sensing instruments, each with advantages and drawbacks. No single system can give a comprehensive description of eruptive activity, and so, a multi-sensor approach is required. This work integrates infrared and microwave volcanic ash retrievals obtained from the geostationary Meteosat Second Generation (MSG...

Journal: :Computers & Geosciences 2012
Julia K. Howell Scott M. White DelWayne R. Bohnenstiehl

Delineating boundaries of volcanic edifices from surrounding topography is often difficult, timeconsuming and subjective. For large volcanic fields, with hundreds of volcanoes, developing methods to efficiently and consistently identify and isolate volcanoes from surrounding topography is of utmost importance. Advances in technology for collecting and processing digital elevation datasets have ...

Journal: :Science 2003
T C Partridge D E Granger M W Caffee R J Clarke

Cosmogenic aluminum-26 and beryllium-10 burial dates of low-lying fossiliferous breccia in the caves at Sterkfontein, South Africa, show that associated hominid fossils accumulated in the Lower Pliocene. These dates indicate that the skeleton StW 573 and newly discovered specimens from Jacovec Cavern have much the same age: approximately 4 million years. These specimens are thus of an age simil...

2002
K.

Major systems of northwesterly, northerly, and northeasterly trending recurrilig fractures or faults controlled emplacement of various units of the Iron Mask batholith. The batholith was emplaced in a high level volcanic to subvolcanic environment, comagmatic with Nicola volcanic rocks and coeval with part of the upper Nicola succession. The batholith intruded volcanic and sedimentary rocks of ...

Journal: :Advances in geo-energy research 2021

While the well log-based lithology classi?cation has been extensively utilized in reservoir characterization, of carbonate sub-facies remains challenging due to subtle nuances conventional well-logs. The nuclear magnetic resonance (NMR) log provides extra information pore size and geometry features, improving differentiating sub-facies. Here we explore feasibility using ratio between NMR longit...

Journal: :Ore Geology Reviews 2022

The Narusongduo Pb-Zn deposit is located at the northern boundary of Luobadui-Milashan fault zone (LMF) in central Tibet and spatially associated with Linzizong volcanic succession (LVS). Our study indicates that regional structural setting was formed by two-stage tectonic events. first stage, spanning from late Mesozoic to early Paleocene, characterized significant N-S crustal shortening Cordi...

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