The compositions of the minerals : calcic plagio, Al rich Cpx gr-alm rich
garnet, fe sp a
> Dear Colleagues,
> I have gotten a rock showing the assemblage An98 +Cpx (>10 wt% Al2O3) +
> garnet (Grs58-65Alm32-33Pry8-10) + Spinel (XMg= 0.2-0.4) + amphibole
> (Magnesiohastingsite) with minor titanite and zoisite. The rock occurs as
> a
> raft (100 X 3 sq feet) within felsic orthogneiss. The rock shows cm-dm
> thick compositional layers rich in plagioclase and mafic phases. My first
> impression is the rock could be a fragment of a troctolite dyke that was
> metamorphosed to spinel-grarnet-CPx bearing assemblage. I solicit your
> valuable opinion on this. I shall be thankful to have some references that
> publish high aluminous clinopyroxene in metamorphic rock.
> Thanking you in advance,
> Cheers,
> Pulak
>
> N.B. I append a field photograph.
>
>
> On Fri, Aug 2, 2013 at 4:02 PM, Michael Brown <[log in to unmask]> wrote:
>
>> Abstract deadline - next Tuesday, Aug 6
>>
>> Topical Session T258, GSA Meetings Oct 27-30, 2013
>>
>> Title: The Pulse of the Earth: Episodic and Periodic Events on
>> Timescales
>> of ≥ 10 million years
>>
>> Co-chairs: Kent Condie, Michael Brown, Stephen Meyers
>>
>> It has been over 60 years since the publication of Umgrove's "The Pulse
>> of
>> the Earth". The 125th Anniversary of the GSA seems an appropriate time
>> to
>> recognize this book as well as the numerous papers published later
>> related
>> to episodic and periodic events in Earth history. This session will
>> address possible common links between terrestrial, oceanic, atmospheric
>> and
>> biologic events, and connections between surficial and deep earth
>> processes
>> including the supercontinent cycle. Papers on any aspect of the theme
>> are
>> welcome, including isotopic dating methods and problems related to
>> resolution and interpretation of episodic and periodic geologic events.
>>
>> Invited speakers are: Nick Arndt (Université Joseph Fourier, Grenoble,
>> France), Craig O'Neill (GEMOC Macquarie University, Sydney, Australia),
>> Bjarte Hannisdal (University of Bergen, Bergen, Norway)
>>
>> Abstract deadline is August 6, see: http://community.geosociety.**
>> org/2013AnnualMeeting/**Sessions/Abstracts<http://community.geosociety.org/2013AnnualMeeting/Sessions/Abstracts>
>>
>> We hope you will submit an abstract for our session.
>>
>> --
>> ______________________________**____________________________
>>
>> Michael Brown, Professor of Geology
>>
>> Department of Geology
>> Geology Building (#237)
>> University of Maryland
>> College Park
>> MD 20742-4211
>> USA
>> [log in to unmask]
>> http: www.geol.umd.edu
>> Dept. office: 301 405 4082; Direct line: 301 405 4080
>> Direct fax: 301 314 7970; Dept. fax: 301 314 9661
>>
>> LABORATORY FOR CRUSTAL PETROLOGY (Information at:
>> http:
>> www.geol.umd.edu/pages/**faculty/BROWN/LCP/lcp.htm<http://www.geol.umd.edu/pages/faculty/BROWN/LCP/lcp.htm>
>> )
>> ______________________________**____________________________
>>
>
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