{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Vol Lecture Notes 7

L o w e r p a r t u ltim a te ly b e c o m e s d is s

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ltim a te ly b e c o m e s d is s o c ia te d w ith u p p e r p a r t. Cooling during flow Initial temperature (i.e., temperature when the flow “hits the ground”) of ignimbrites are largely a function of initial velocity, and hence water content. Why? Cooling of several hundred Initial temperatures of ignimbrite flows in the Sparks et al. (1978) model. degrees may occur in the “fountain”. In the flow itself, cooling is very limited - perhaps 50°. Welding requires T>625°C (898 K). 12 Other Processes During Flow Grinding and crushing particles in flows, effectively destroying large clasts and creating small ones. P y r o c la s tic d e p o s its r ic h e r in c r y s ta l fr a g m e n ts th a n a s s o c ia te d fa ll d e p o s its Diffusion of remaining magmatic gas out of fine particles Fluidization Fluidization in Flows F lu id iz a tio n o c c u r s w h e n u p w a r d d r a g e x e r te d b y g a s o n p a r tic le s e q u a ls s e ttlin g v e lo c ity . F in e p a r tic l...
View Full Document

{[ snackBarMessage ]}