RE: Celebration of the Career Contributions of Ron Vernon: The "Ron Vernon
Symposium" at the 15th Australian Geological Convention, Sydney, 3-7 July
2000
Dear Friends and Colleagues,
By now you may have heard about the "Ron Vernon Symposium", which has been
organised to coincide with the 15th Australian Geological Convention, to be
held in Sydney on 3-7 July, 2000 (two months before the Sydney Olympics).
Below is a detailed description of the Symposium, which has associated with
it pre-conference and post-conference field trips; complete information can
be found at the AGC web site at::
http://www.science.uts.edu.au/agc/agchome.html
In the Technical Program, go to Theme 3, Symposium 3D for a description of
the meeting. For information about the field trips, they are FP3 and FA4.
The Symposium was organised to celebrate Ron's wonderful career, and to
encompass the full range of his contributions, four sessions on successive
days of the Convention are planned. These will be: microstructural
processes, metamorphic processes, igneous processes and magma emplacement
processes. Two convenors have been appointed to each session, one national
and one international, representing those who have worked closely with Ron
at some stage. In addition, a one-day workshop will be run in central
Australia by Bruce Hobbs, Win Means & Paul Williams, as part of the
post-conference field trip. The workshop is titled "Melt Generation and
Transport in Middle-to-Lower Crustal Environments".
Speakers for the four sessions are by invitation only, and our intention
has been to attract mainly those residing outside of Australia to fill
these positions (to maximise the likelihood of their participation). In
choosing these speakers, we have included many who know or have worked with
Ron at some point in his career. As the speaker positions are now mostly
full, we would now like to invite you to consider giving a poster
presentation in one of the four sessions, listed below. This is going to be
a great celebration with a great line-up of speakers and events, and we
want to encourage you to attend. We would like to see the poster sessions
be as large and diverse as possible, bringing together the largest possible
groups of workers in each of the four fields of research.
If you would like to contribute a poster to the Ron Vernon Symposium, and
participate in celebrating his contributions to a wide range of geological
sciences, please contact the convenors of the appropriate session. The
coordinator of the whole activity is Bill Collins (University of Newcastle,
Australia), and the convenors of the individual sessions in Sydney are:
Microstructural Processes
Scott Johnson (University of Maine, USA; [log in to unmask])
Mike Williams (University of Massachusetts, USA; [log in to unmask])
Metamorphic Processes
Geoff Clarke (Sydney University, Australia; [log in to unmask])
Mike Brown (University of Maryland, USA; [log in to unmask])
Igneous Processes (Magma chamber controls on granite petrogenesis)
Dick Flood (Macquarie University, Australia; [log in to unmask])
Bob Wiebe (Franklin & Marshall College, USA; [log in to unmask])
Magma Emplacement Processes
Bill Collins (University of Newcastle, Australia;
[log in to unmask])
Scott Paterson (University of Southern California, USA; [log in to unmask])
PLEASE NOTE:
Abstracts must be submitted through the 15th AGC technical committee by
March 31 (this can be done on-line through the above web address). Also,
this is the deadline for early-bird registration. We hope to hear from you
soon!
A celebratory reception and dinner will be held in Ron's honour after the
Metamorphic Processes session. The cost will be 40 Australian dollars per
person, with drinks subsidised by the Journal of Metamorphic Geology.
MORE INFORMATION ABOUT THE RON VERNON SYMPOSIUM
Everyone who knows Professor Ron Vernon is aware of his cutting-edge
research in a variety of geological fields, including his contributions to
microstructural analysis, the origin of microgranitoid enclaves, K-feldspar
megacrysts and orbicular granitoids, aspects of low P, high T metamorphic
terranes, P-T-t paths and magma emplacement mechanisms, and more recently,
recognition of magmatic versus solid-state fabrics in igneous rocks. Ron
has always combined astute observations with logical, incisive analysis to
understand igneous, metamorphic and structural processes. Also, he has
been heavily involved in editorial work, particularly with Australian
Journal of Earth Sciences and Journal of Metamorphic Geology. As
recognition of his career contributions, the "Ron Vernon Symposium" has
been organised to coincide with the 15th Australian Geological Convention,
to be held in Sydney on 3-7 July, 2000 (two months before the Sydney
Olympics).
Two 5-day field trips have been organised: a pre-conference excursion
through the Lachlan Fold Belt (LFB) of eastern Australia and a
post-conference trip to the Early Proterozoic Arunta Block of central
Australia. The general theme is to examine granite emplacement processes
at different crustal levels (upper/middle crustal in the LFB and
middle/lower in the Arunta) and how these interrelate with metamorphic and
structural process.
To summarize, the "Vernon Symposium" package involves a three-week
"boondoggle" through Proterozoic central Australia, Paleozoic eastern
Australia, and contemporary Sydney. The pre-conference trip will begin
early in the morning of the Tuesday before the Conference (27 June, 2000),
so you will need to arrive in Sydney at least the day before. You can stay
at various hotels, all of which are detailed at the AGC web site. Most of
these accommodations are within walking distance of the Convention Centre,
but Mercure is directly opposite, so is probably the best option. This is
appropriate for pre-conference participants, as we will congregate at the
Centre on Monday night (26 June) for Icebreaker, possibly with a briefing
session. Also, all of these accommodations will hold baggage for people
travelling out on excursions, provided you are returning for at least a
night.
The post-conference trip will begin on Sunday (9 July), which gives people
the opportunity to travel to Alice Springs on Saturday morning 8 July (at
~9 a.m. with either Qantas or Ansett Australia - note in the web site that
Qantas offers special deals to ACG participants), and participants will be
back in Alice Springs on Friday morning (14 July) to connect with outward
bound flights (to Sydney, Perth, Darwin, - leaving 11-12 noon with both
Qantas and Ansett Australia). Overseas participants will be given
preference for the field trips, particularly the Lachlan excursion, but you
have the option of staying one, two or the full three weeks.
PROPOSED ITINERARY (Please see web site for additional details regarding
transport, costs, etc).
Pre-conference Excursion
27 June (Tuesday) - Tuross Head Tonalite
28 June - Kameruka/Candelo suites
29 June - Basal contact /Kameruka pluton
30 June - Wog Wog Complex/Kameruka pluton
1 July - Cooma Complex
2 July (Sunday) - Cooma-Sydney (5-6 hours)
15th Australian Geological Convention
3-7 July
Post-conference Excursion
8 July (Saturday morning) - Travel to Alice Springs
Chewings Range traverse???
9 July - Workshop ("Melt generation and transport in the mid- to lower-crust"
(Bruce Hobbs, Win Means and Paul Williams)
10 July - Redbank Shear Zone/Mt Hay
11 July - Wuluma Hills/ kyanite-staurolite shear zone?
12 July - Anmatjira Range
13 July - Mt Stafford
14 July (Friday) - Alice Springs - outward bound
Details of Excursions
Pre-conference: Lachlan Fold Belt
Initially, we will view stratigraphic sections and way-up criteria in a
high-level pluton (Tuross Head Tonalite, Moruya Batholith), which is a
sequence of "Mafic and silicic layered intrusions (MASLI)". Then we
examine the internal structure of sheeted/layered plutons of the
Kameruka/Candelo suites, Bega Batholith, before examining
emplacement/hybridisation processes recorded in migmatites at the base of
Kameruka. Special features of these days include (1) sedimentary features
in granites, such as giant load casts and "flame-structures", from which
"way-up" in plutons and "pluton stratigraphy" can be determined; (2)
synplutonic mafic dykes which fountain into zones of crystal-poor magma;
(3) mafic enclave settling/accumulation zones in magma chambers; (4)
termination of granite feeder dykes at the top of crystal mushes in
granitic magma chambers; (5) intricate pipe-structures/magmatic diapirs at
sites of felsic/mafic dyke intersections, (6) skyscraper-sized blocks that
have slid through mush-magma interfaces to produce "bow-wave" currents,
characterised by cross-bedded laminations in the overlying crystal-poor
chamber; (7) "elephants' graveyards" of country-rock xenoliths; (8) flow
zones and sense-of-shear recorders in migmatites at the base of plutons;
(9) hybridisation zones between mafic synplutonic dykes and host granite
magma; (10) hybridisation zones between migmatites and host granite magma;
and finally (11), beneath the migmatites and the overlying plutons, the
ultimate cause of the batholith!
The Lachlan field trip will also include a one-day visit and re-evaluation
of the classic Cooma complex. We will traverse the complex from low- to
high-grade, then focus on outcrops that explain why the Cooma granite
(really a diatexite) has such a large aureole. A clue is that we will also
examine its relation with the adjacent (S-type) Murrumbidgee Batholith.
Post-conference: Arunta and central Australia
The central Australian trip will begin with a one-day workshop, organised
by Bruce Hobbs, Win Means and Paul Williams as part of the post-conference
excursion to Alice Springs. A traverse through the Chewings Range (we
think), looking at 1600 Ma old structures overprinted by thrusts associated
with the Alice Springs Orogeny (400-300 Ma) follows. Next, we investigate
granite magma-transfer through the middle-lower (7-8 kbar) crust at Mt Hay,
which occurred (we think) during non-coaxial compressive deformation, then
through the middle-upper (4-5 kbar) crust in the Anmatjira Range. MASLI
systems have been identified at both crustal levels, and criteria for
recognition of way-up structures in these deep-crustal plutonic systems
will be evaluated. At Wuluma Hills, we will see melt segregation and
emplacement processes in granulite facies rocks. We will show how
leucosomes are expelled from the hinge and synformal region of folds, and
collect in antiformal hinges during compressional deformation. The K-rich
leucosomes of this location are identical in chemistry and age to the
Wuluma granite, which is the inferred leucosome sink; so we will look at
that as well. Finally, the characteristics and origin of a high-T, very
low-P (2.5±1 kbar) granulite facies terrane at Mt Stafford, will be
examined. This terrane has not undergone intense deformation, so it is an
ideal location to study the prograde metamorphic reactions associated with
migmatite formation and migmatite/granite magma hybridisation.
****************************************************
Scott E. Johnson
Department of Geological Sciences
5790 Bryand Global Sciences Center
University of Maine
Orono, ME 04469-5790
USA
email: [log in to unmask]
phone: (207) 581-2142
Fax: (207) 581 2202
www: http://www.geology.um.maine.edu/user/scott_johnson/HM.html
****************************************************
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
