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Magma mixing and evolution at Minna Bluff, Antarctica revealed by amphibole and clinopyroxene analyses.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Magma mixing and evolution at Minna Bluff, Antarctica revealed by amphibole and clinopyroxene analyses./
Author:	Redner, Ellen R.
Description:	1 online resource (214 pages)
Notes:	Source: Masters Abstracts International, Volume: 56-02.
Contained By:	Masters Abstracts International56-02(E).
Subject:	Geology. -
Online resource:	click for full text (PQDT)
ISBN:	9781369488678

Magma mixing and evolution at Minna Bluff, Antarctica revealed by amphibole and clinopyroxene analyses.
Redner, Ellen R.

Magma mixing and evolution at Minna Bluff, Antarctica revealed by amphibole and clinopyroxene analyses. - 1 online resource (214 pages)

Source: Masters Abstracts International, Volume: 56-02.

Thesis (M.S.)

Includes bibliographical references

Lava flows from Minna Bluff, Antarctica, are studied in order to provide insight into magma system dynamics, specifically magma mixing. More than 500 lava/dome and volcaniclastic samples that range in age from ~12 to 4 Ma were collected along the 45 km volcanic peninsula. Lava compositions range from basanite to phonolite. A significant proportion of lavas of all whole rock compositions contain amphibole. This study is focused on the textural and compositional characteristics of amphibole and clinopyroxene as a means to understand open system processes causing fluctuations of temperature, pressure during crystallization.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9781369488678Subjects--Topical Terms:

670379
Geology.
Index Terms--Genre/Form:

554714
Electronic books.

Magma mixing and evolution at Minna Bluff, Antarctica revealed by amphibole and clinopyroxene analyses.
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040 $a MiAaPQ $b eng $c MiAaPQ
099 $a TUL $f hyy $c available through World Wide Web
100 1 $a Redner, Ellen R. $3 1183488
245 1 0 $a Magma mixing and evolution at Minna Bluff, Antarctica revealed by amphibole and clinopyroxene analyses.
264 0 $c 2016
300 $a 1 online resource (214 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Masters Abstracts International, Volume: 56-02.
500 $a Adviser: Kurt Panter.
502 $a Thesis (M.S.) $c Bowling Green State University $d 2016.
504 $a Includes bibliographical references
520 $a Lava flows from Minna Bluff, Antarctica, are studied in order to provide insight into magma system dynamics, specifically magma mixing. More than 500 lava/dome and volcaniclastic samples that range in age from ~12 to 4 Ma were collected along the 45 km volcanic peninsula. Lava compositions range from basanite to phonolite. A significant proportion of lavas of all whole rock compositions contain amphibole. This study is focused on the textural and compositional characteristics of amphibole and clinopyroxene as a means to understand open system processes causing fluctuations of temperature, pressure during crystallization.
520 $a Lavas with amphibole (+/- clinopyroxenes) phenocrysts are texturally diverse and range from porphyritic to glomeroporphyritic. Other phenocrysts consist of olivine, plagioclase, alkali feldspars, magnetite and apatite in a groundmass that varies from holocrystalline to hypohyaline. The amphibole is mostly kaersutite and clinopyroxene is diopside. Compositional zoning in amphibole includes normal, reverse and oscillatory types. The coexisting clinopyroxene is weakly zoned. Amphiboles also exhibit weakly to strongly developed reaction rims, which are produced by decompression and/or increase in temperature.
520 $a Amphibole phenocrysts have higher Fe/Mg ratios than predicted for equilibrium conditions in basanitic magma and lower ratios than predicted for phonolitic magma. The rims of amphibole phenocrysts in intermediate compositions are mostly in equilibrium but cores of the same grain are not. Clinopyroxene phenocrysts show similar relationships. The amphibole and clinopyroxene phenocrysts that are out of equilibrium suggest magma mixing or accidental incorporation of pre-existing crystal 'debris'.
520 $a Geothermobarometric results suggest that amphiboles and clinopyroxenes formed at pressures 4 to 9 kbars (≈ 15-32 km) and 3 to 14 kbars (≈ 11-47 km), respectively. The majority of barometric calculations indicate depths = 22 km, which is at or below the crust-mantle boundary. It is likely that rising melt reached neutral buoyancy at this boundary and pooled, cooled and crystallized to produce more evolved compositions that were, in turn, periodically replenishment by less evolved melts from below. A five stage history is conceived that illustrates the complex nature of magma evolution at Minna Bluff.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Geology. $3 670379
650 4 $a Petrology. $3 783490
655 7 $a Electronic books. $2 local $3 554714
690 $a 0372
690 $a 0584
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a Bowling Green State University. $b Geology. $3 1183489
773 0 $t Masters Abstracts International $g 56-02(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10305533 $z click for full text (PQDT)