Earth-prints repository, logo   DSpace

About DSpace Software
|earth-prints home page | roma library | bologna library | catania library | milano library | napoli library | palermo library
Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/8161

Authors: Mollo, S.*
Putirka, K.*
Iezzi, G.*
Scarlato, P.*
Title: The control of cooling rate on titanomagnetite composition: implications for a geospeedometry model applicable to alkaline rocks from Mt. Etna volcano
Title of journal: Contributions to Mineralogy and Petrology
Series/Report no.: /165 (2013)
Publisher: Springer Verlag Germany
Issue Date: 2013
DOI: 10.1007/s00410-012-0817-6
Keywords: Titanomagnetite; cooling rate
Abstract: In this study, we have investigated the control of cooling rate on the composition of titanomagnetite formed from a trachybasaltic melt. Results show that disequilibrium growth conditions exert a primary control on the abundance, texture, and composition of the crystals. As the degree of cooling is increased, titanomagnetites show immature textures and are progressively enriched in Al ? Mg and depleted in Ti. Thus, early-formed titanomagnetite nuclei do not re-equilibrate with the melt over faster cooling rates; instead, their compositions are far from equilibrium. On the basis of the different intra-crystal redistribution rates for Ti, Al, and Mg, we have calibrated a geospeedometer that represents the first quantitative description of the effect of cooling rate on titanomagnetite composition. This model was tested using the compositions of titanomagnetites in lava and dike samples from Mt. Etna volcano whose crystallization conditions resemble those of our experiments. Cooling rates calculated for lava samples are comparable with those measured in several volcanic complexes. At Mt. Etna, compositional variations of titanomagnetite grains from the innermost to the outermost part of a dike testify to progressively higher degrees of cooling, in agreement with numerical simulations of thermal gradients in and around magmatic intrusions.
Appears in Collections:Papers Published / Papers in press
04.04.05. Mineralogy and petrology

Files in This Item:

File SizeFormatVisibility
01_Mollo et al._2012_CMP.pdf927.56 kBAdobe PDFonly authorized users View/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


Share this record
Del.icio.us

Citeulike

Connotea

Facebook

Stumble it!

reddit


 

Valid XHTML 1.0! ICT Support, development & maintenance are provided by CINECA. Powered on DSpace Software. CINECA