Session GD05: The Origins of Melting Anomalies

Convenors:
Gill Foulger (g.r.foulger@durham.ac.uk)
Alexander Sobolev

Opinion has recently diversified concerning the origins of “hot spot” volcanism on Earth’s surface. The deep mantle Plume model has been joined by alternatives including the “Plate” model, that advocates shallow causative structures and processes. These developments have re-opened the question of the origins of individual volcanic anomalies, and have influenced thinking on many fundamental generic aspects. These aspects include the temperature, composition and homogeneity of the mantle, the origin of ocean-island-basalt geochemical signatures, the relationship between surface tectonics and magmatism, the interpretation of mantle tomography images, and the relationship between mantle convection models and surface geology. New emphasis has been placed on the need for cross-disciplinary collaboration and interpretations, and “joined-up” science. This multi-disciplinary session will include papers that shed new light on the origins of intraplate or large-volume ridge-centred magmatism, linear volcanic chains and large igneous provinces. It will include observations, case histories, theory, and models covering geophysics, geochemistry, petrology, heat and temperature, tectonics, mantle dynamics and integrated studies, along with syntheses reconciling data from more than one subdiscipline. Oral presentations will include talks advocating the entire spectrum of models, including Plume, Plate and alternatives. Time will be reserved for open discussion and comments. A lively session is anticipated.

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VMSG and the Geological Society of London: Field workshop

Golden Rum! Past, present and future research in the North Atlantic Igneous Province: a celebration of 50 years of Rum research

Convenors:
Dougal Jerram (Durham University)
Valentin Troll (Trinity College, Dublin)
Kathryn Goodenough (British Geological Survey)

The celebration of 50 years of Rum research will mostly take place in the field with a conference day at the end of the workshop. A simple outline for the workshop which will take place on the Isles of Rum and Skye is shown below:

1 May 2007 - Travel to Rum and overnight in the Kinloch Castle hostel.
2, 3 May 2007 - Field visits on Rum
4 May 2007 - Leave Rum and travel to Skye. Accommodation in Portree in chalets and hotel rooms.
5, 6, 7 May 2007 - Field visits on Skye plus a conference day, held at the Aros Centre, with participants giving talks expected to be about 20 mins each.
8 May 2007 - End of trip

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Frontiers in Mineral Science 2007
Symposium 15: The development of the North Atlantic Igneous Province with special reference to the Platinum Group Element concentrations in the magmas

Convenors:
Tony Naldrett (Toronto - ainaldrett@yahoo.com)
Dan Kontak (Nova Scotia - kontakd@gov.ns.ca)
Andrew Kerr (Cardiff - kerra@cardiff.ac.uk)

At present the duration of symposium 15 is unknown, however it is likely to be a single day event. This is because the conference consists of 21 symposia and 3 parallel sessions in total.

Further information on the conference and second circular can be found on the website at: www.minersoc.org/Frontiers2007.html

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Large Igneous Provinces (IAVCEI session)

Convenors:
Richard Ernst (Richard.Ernst@ErnstGeosciences.com)

Ian H. Campbell (Ian.Campbell@anu.edu.au)

Large igneous provinces (LIPs) represent large volume, generally short duration mafic-ultramafic events not associated with 'normal' plate boundary processes. They generally consist of continental flood basalts, volcanic rifted margins, oceanic plateaus, ocean basin flood basalts, submarine ridges and seamount chains. However some LIPs may be dominated by Silicic material and are termed ‘Silicic Large Igneous Provinces’ (SLIPs), they have relatively long durations compared to mafic LIPs, they are dominated by ignimbrite deposits. This sub-division of LIPs has been strongly associated to continental rifting.

In the pre-Mesozoic record their plumbing system of dyke swarms, sill provinces and layered intrusions is typically exposed by erosion. Archean analogues may be represented by greenstone belts of the tholeiite-komatiite association.

Many LIPs are linked to regional-scale uplift, continental rifting and breakup, and climatic crises. They can be useful as precisely dated time markers in the stratigraphic record, and are key targets for mineral exploration (such as Ni-Cu-PGE deposits). LIPs have also become a focus in the debate on the existence and nature of mantle plumes.

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Large Igneous Provinces of Asia, Mantle plumes and metallogeny

For information contact: lip-asia@uiggm.nsc.ru

Sponsors:

• Institute of Geology and Mineralogy (IGM), Novosibirsk

• Presidium of Siberian Branch of Russian Academy of Sciences

Co-Sponsors:

• Russian Foundation for Basic Research (RFBR)

• Centre for Russian and Central Eurasian Mineral Studies (CERCAMS)

• International Association on the Genesis of Ore Deposits (IAGOD)

Other sponsors are welcome to contact the Organizing Committee

The conference is focused on the following topics:

The nature, age, and duration of the formation of large igneous provinces (LIP) of Asia. Modeling of processes involved in the formation and development of mantle plumes, mantle-crust interaction and ore-magmatic systems. Petrologic-geochemical aspects of formation of large igneous provinces (LIP) in Asia. Metallogenic specialization of largest igneous provinces (LIP) and the role of mantle plumes in the formation of large and unique Cu-Ni-Pt, Ni-Co-As, porphyry Cu-Mo, Hg, Au-Hg and rare metal deposits of Asia. Correlation of Permian-Triassic magmatic and ore complexes of Central Asia and Southeastern Asia, their main historic boundaries of formation, and distribution controls of large and unique deposits in the Siberian, Tarim and Emeishan mantle plumes. Interaction of the largest magmatic events, natural disasters and global climate change through time.

There are two related field trips:

1. Pre-conference field trip. Altai-Mongolia: 2–12 August 2007
"Metallogeny of the Southeastern Altai (Russia) and Northwestern Mongolia ore district, Permian-Triassic boundary"
For details contact the field trip leaders:
A.G. Vladimirov, A.S. Borisenko, V.A. Goverdovsky

2. Post-conference field trip. Kuzbas-Minusa: 17-24 August
"Devonian, Permian-Triassic and Cretaceous magmatism (Kolyvan-Tomsk fold area, Kuznetsk and Minusa Depressions)”
For details contact the field trip leaders:
G.S. Fedoseev, A.E. Izokh, I.F. Gertner

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Hotspots and LIPs: Plumes or shallow-mantle sources

Convenors:
Dominique Weis (dweis@eos.ubc.ca)
Conny Class
Cinzia Farnetani.

The origin of hotspots and large igneous processes appears to be as controversial as ever. Points of disagreement extend beyond the current plume debate to questions of the petrologcal nature of the source rocks (peridotite, eclogite, pyroxenite, and their hybrids), the source of geochemical enrichment (metasomatism, recycling of crust), and the "fixity" of hotspots. This symposium will bring together geochemists, petrologists and geophysicists to debate the issues.
 

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Evolution of basaltic provinces

For information contact: jrasmussen@jf.fo

Sponsors:

• Faroe Petroleum plc
• VMSG
• IAVCEI

In the heart of Tórshavn, surrounded by some of the youngest lava flows of the Faroe Islands Basalt Group, new observations and ideas shall be presented covering aspects of how basaltic provinces evolve during their lifetimes. During two days, oral presentations shall be given in a relaxed and informal atmosphere with ample opportunity for discussion. In addition, technical posters shall be on display throughout the conference.

The two days will be separated into four sessions, each with an invited keynote speaker. The following topics have been suggested for presentations, but this is not a definitive list and we welcome other suggestions:

• Weathering, sedimentation and pyroclastic activity
• Tectonic development
• Lava morphologies
• Timing of events
• Geochemical evolution
• Exploration potential of basaltic provinces

Research students are particularly encouraged to attend and present their research in progress.

There are two related field trips:

• Pre-Conference Fieldtrip 28^th August 2007
  The trip shall look at the differing lava flow morphologies, the various volcaniclastic rocks and the stunning Streymoy and Eysturoy sills. There will also be numerous opportunities to take in the beautiful Faroese scenery whilst looking out for comical puffins.
• Post-Conference Fieldtrip 31^st -2nd September 2007
  If there is enough interest, a 2-3 day fieldtrip to the southern island of Suðuroy shall immediately follow the conference. This trip will utilize spectacular views of tabular basalts from the ferry, some of the exposures make cliffs which are 400m in height!! The aim of the trip is to study the small Stapin vent, tuffs and mass flow deposits and the irregular intrusions with their large xenoliths. If we are lucky, we may also get views of passing porpoises and seals.

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AGU special session

Extensional Processes Leading to the Formation of Basins and Rifted Margins, From Volcanic to Magma-Limited

Convenors:
Laurent Gernigon (Laurent.Gernigon@ngu.no)

Jolante W. Van Wijk (jolante@lanl.gov)

Gwen Peron-Pinvidic (Gwenn.Peron-Pinvidic@eost.u-strasbg.fr)

Donna J. Shillingdon (djshill@noc.soton.ac.uk)

New observations and models allow us to investigate the processes responsible for continental extension and lithospheric rupture in unprecedented detail. Key questions that need to be addressed on all rifted margins concern the style of the early phases of extension, delineating the factors that are most important in controlling strain localization and partitioning throughout rifting (e.g., pre-existing weaknesses, detachment and/or rolling hinge faults, syn-rift magmatism, etc.), and understanding how variations in rheology with depth influence the style of rifting and final breakup. Existing datasets indicate that the distribution of strain can vary with depth, but equally show that classic end-member models such as pure and simple shear are often not adequate to account for the observed complexity. Furthermore, rifting can occur over a protracted period of time and/or in multiple phases, and it can result in three-dimensional architectures and distributions of magmatism.

We invite presentations that seek to address these fundamental questions with diverse observations (e.g., geophysical, petrological and geological datasets) and modeling. We would like to subdivide this session into two sub-sessions:

1.  Volcanic Rifted Margins (VRMs) focusing on the relative timing and amount of magmatism and extension, the origin of voluminous magmatism observed on some margins, and their consequences for lithospheric rheology and strain localization require further understanding.
2.  Magma-poor rifted margins (Non-volcanic rifted margins). There are lingering questions which concern the driving forces and extensional mechanisms responsible for rifting cold lithosphere, the role of the lower crust in controlling deformation, the timing and style of mantle denudation and the transition from mantle exhumation to slow-seafloor spreading.

Given the exciting new developments in this field, we also plan to organize a special volume based on contributions to this session.

This conference welcomes contributions on any of the above topics.

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Contributions on any of these themes are welcome.  

(compiled by Sami Mikhail at samikhail@hotmail.co.uk)