IGCP 510 – A-TYPE GRANITES AND RELATED ROCKS THROUGH TIME
	GLOBAL CORRELATION OF A-TYPE GRANITES AND RELATED ROCKS, THEIR MINERALIZATION, AND SIGNIFICANCE IN LITHOSPHERIC EVOLUTION

September 1-7, 2008: Field trip ”The Permian-Triassic A-type volcanic-plutonic igneous suite of Corsica”, Corsica, France

This was the eight scientific field trip of IGCP-510. The trip was arranged by Bernard Bonin (Université de Paris-Sud) and it focused on the volcanic and plutonic A-type suites of Corsica. These suites constitute a classic and outstandingly varied collage of A-type granitoid and related rocks: volcanic calderas, layered mafic chambers, and a complete set of felsic rock types ranging from monzonite to syenite to alkali feldspar granite, with hypersolvus to transsolvus to subsolvus alkali feldspar mineralogy, and metaluminous to peraluminous or peralkaline compositions. The trip was a joint venture with the Eurogranites and it was attended by 37 individuals from 16 countries (Belgium, Canada, Czech Republic, Estonia, Finland, France, Ireland, Italy, Norway, Poland, Romania, Slovakia, Spain, Sweden, the United Kingdom, and the United States). The following targets were examined:

Day 0: Assembly at Ajaccio airport, ground transport to Ajaccio hotel.

Day 1: The Tana-Peloso complex: a mafic layered igneous complex, monzonite and syenite intrusions, subsolvus granite dyke.

Day 2: The Cauro-Bastelica ring complex: camptonite dykes, hypersolvus granites, transsolvus granite, subsolvus granite, rhyolite breccias and domes.

Day 3: The Ota-Porto ring complex: gabbro, biotite subsolvus granite, biotite transsolvus granite, hybric rocks.

Day 4: The Evisa ring complex: classic locality of peralkaline alkali feldspar granite (cupola-forming), an early subsolvus syenogranite, and late bimodal dykes.

Day 5: The Scandola and Seninu calderas: intra-caldera ignimbrites (K-rich rhyolite) and sedimentary rocks, complex set of concentric caldera ring faults and other cauldron subsidence structures. Mafic lavas (basalt, hawaiite).

Day 6: Departure from Corsica.

The Permo-Triassic A-type suites of Corsica are a classic occurrence of Phanerozoic high-level alkali granite complexes and associated dyke and volcanic rocks and the trip offered an excellent opportunity to examine these rocks with one of the pioneers in the field as the field trip leader. The interplay of magmatic diversity (mafic-felsic assemblages), existense of two magmatic episodes (275±10 Ma, 245±10 Ma) with distinct tectonic lineages (post-orogenic and early anorogenic, respectively), and caldera-related volcanic processes are the main characteristics of the Corsican A-type granite assemblage. The Corsican A-type granites have also been the subject of a pioneer study of Fe isotopes in granite and they have turned out to contain especially heavy iron (delta-57Fe values up to 0.5‰, as opposed to the average mantle value of ~0.1‰).

A field trip guide

B. Bonin, B. Platevoet, F. Poitrasson, M.R. Renna (2008) Eurogranites-IGCP510 2008 Joint field-meeting – Alkaline The Permian-Triassic A-type volcanic-plutonic igneous suite of Corsica. Université de Paris-Sud, Paris, 54 p.

was published.

IGCP-510 September 1-7, 2008 field trip participants examining the Permo-Triassic A-type granite suites of Corsica (in particular, the Porto and Evisa ring complexes) with Bernard Bonin as the guide (at center, at Tolla dam). Photos courtesy of Matti Kurhila. (Click the Photo to Enlarge)

 

August 7-8, 2008: Meeting ” Granite Classification – a Never-ending Problem”, 33^rd IGC, Norway Convention Centre, Lillestrøm, Norway

This was the fourth Annual (fifth technical) Meeting of IGCP-510. It was arranged in conjunction with the 33rd International Geological Congress that was held in the Oslo area, Norway on August 6-14, 2008. This was a joint session of IGCP-510 and the IUGC Subcommission of Systematics of Igneous Rocks (SSIR). As the classification of granite is currently woven around several controversial issues, including the significance of chemical diagrams, the alphabet genetic classification, generation of migmatites vs. granites, and relationships of granites with volcanic rocks, contributions were solicited in the fields of rock-forming minerals, igneous petrology, experimental petrology, and elemental and isotope geochemistry, in order to provide a more robust frame for granite classification. The session was convened by Bernard Bonin (Université de Paris-Sud), Tapani Rämö (University of Helsinki), and Tom Andersen (University of Oslo), and gathered together ~40 researchers representing 9 countries (Brazil, Canada, Finland, France, Iran, Israel, Norway, Russia, and the United States). Fourteen presentations (6 oral, 8 poster) on granite typology and A-type granites and related rocks in general were given.

The International Geological Congress is arranged every four years and now provided the project with an audience wider than usual. The joint symposium with the IUGC Subcommission of Systematics of Igneous Rocks was tailored to this end to draw colleagues also from more distant sectors of the field. Specific topics related to classification of granites included A-saturation, overall alkalinity, the TAS space, and redox budget as typological criteria. The salient traits in distinguishing alkaline and calc-alkaline granitic suites were outlined as well. Furthermore, the given presentations also covered Archean A-type granites, Proterozoic A- and I-type volcanism in northern South America (Guyana shield), as well as A-type granites of Siberia and Iran.

An IGCP-510 Business Meeting was held on August 8, 2008 at the Norway Convention Centre in Lillestrøm to review the achievements and plan the future activities of the project. The meeting was chaired by O.T. Rämö and R. Dall’Agnol and it was attended by 14 individuals representing Brazil, Cameroon, Finland, France, and Iran.

The abstracts of the IGCP-510 symposium were published in the 33IGC Abstract Volume [CD-ROM].

The King of Norway, HM King Harald V addressing the Opening Ceremony of the 33rd IGC on August 6, 2009. Photos courtesy of O.T. Rämö. (Click the Photo to Enlarge)

August 1-5, 2008: Field trip: ”Alkaline rocks of the Oslo Rift, SE Norway: A field trip with emphasis on felsic to intermediate intrusive rocks and their associated mineralizations”, Oslo region, southern Norway

This was the seventh scientific field trip of IGCP-510. The trip was arranged by Tom Andersen (University of Oslo) and it focused on the classic alkaline Paleozoic anorogenic rocks of the Oslo rift. The trip was also a joint venture with the Eurogranites and preceded the Oslo 33IGC. Targets covered both saturated and undersaturated plutonic and volcanic rocks of the rift and their tectonic evolution and associated mineralization. The trip was attended by 27 individuals from 8 countries (Brazil, Estonia, Finland, France, Norway, Russia, Switzerland, and the United States). The following program was carried out:

Day 0: Rendez-vous and introductory lecture for the field trip at the Department of Geosciences, University of Oslo. Ground transport to Asker.

Day 1: General geology of the Oslo rift: basement gneisses (~1.6 Ga), Cambrian basal conglomerate, Silurian sandstones, Oslo rift basalts and rhomb-porphyries (latites).

Day 2: Various intrusive phases (rapakivi, biotite granite, aplite) of the subvolcanic Drammen granite. Skarns in the contact aureole of the granite, Mo and Bi mineralization (intraplutonic) associated with the granite.

Day 3: The ~280 Ma Siljan-Mykle plutonic complex with larvikite, gabbro/diorite, nepheline syenite, nordmarkite (saturated miarolitic syenite), and miarolitic alkali granite.

Day 4: The Larvik pluton (a composite ring intrusion) was examined at the ”Blue Pearl” quarry in the southern part of the rift. This exposed a spectacular nepheline syenite pegmatite with microcline, nepheline, sodalite, ferrokentbrookite, wöhlerite, and leucophane as the main constituents. Layered larvikite in shore cliffs at Ula were also examined. Return to Oslo.

The field trip offered the participants a good look at an undoubtedly rift-related, Phanerozoic A-type granite suite that also includes a wealth of undersaturated silicate rocks. This promoted a lively petrologic discussion on saturated vs. undersaturated magmatic lineages. The examined plutons are all high-level structures and their relationships to the volcanic rocks of the rift and supracrustal rocks preceding the onset of rifting (as well as the local Precambrian basement) could be easily observed. Skarn-type Pb-Zn-Cu deposits and late-magmatic Mo-W mineralization associated with these A-type rocks were also examined.

A field trip guide

T. Andersen, R.G. Trønnes, O. Nielsen, A.O. Larsen (2008) Eurogranites 2008/IGCP 510 field trip 2008 – Alkaline rocks of the Oslo Rift, SE Norway: A field trip with emphasis on felsic to intermediate intrusive rocks and their associated mineralizations. August 1st to 5th, 2008. University of Oslo, Oslo, 54 p.

was published.

 

IGCP-510 August 1-5, 2008 field trip participants examining the saturated and undesaturated plutonic and volcanic alkaline igneous suites in the Phanerozoic Oslo Graben and the surrounding Precambian bedrock. The quarry photo shows a spectacular nepheline syenite pegmatite at the “Blue Pearl” site. Photos courtesy of O.T. Rämö. (Click the Photo to Enlarge)

May 26-28, 2008: Meeting ” Anorthosites to Rapakivi Granites: a Tribute to the Career of Ronald F. Emslie” in Québec City Convention Centre, Québec City, Québec, Canada

This was the fourth technical meeting of IGCP-510. The meeting (symposium SS16) was arranged in conjunction with the the GAC-MAC-SEG-SGA Joint Annual Meeting in Quebec, Canada. The symposium honored the late Ronald F. Emslie, one of the pioneers of A-type granite research and, among many other things, co-leader of the rapakivi granite IGCP project (#315, 1991-1996). The symposium was convened by Mike Hamilton (University of Toronto), James Scoates (University of British Columbia), and Tapani Rämö (University of Helsinki) and it gathered together ~40 researchers representing 9 countries (Belgium, Brazil, Canada, Colombia, Finland, Poland, South Africa, Sweden, and the United States). Thirty-one presentations (26 oral, 5 poster) on A-type granites and related rocks (in particular, massif-type anorthosites) were given.

The symposium offered an excellent opportunity to discuss the bimodal aspects of A-type granite suites, the relation of these granites to the mid-Proterozoic massif-type anortosites in particular. A quite varied set of topics on the subject was covered, both thematically (isotope geochemistry, geochronology, magnetic susceptibility, petrologic evolution, tectonic setting, typology, origin of associated Fe-Ti-P ore deposits) and in terms of the geographic distribution of A-type granite–massif-type anothosite suites (new data were presented for magmatic suites in the Grenville province, Labrador, Wyoming, Brazil, central Africa, the Fennoscandian and Ukrainian shields, Poland).

The program and abstracts of the symposium were published in the GAC-MAC-SEG-SGA Joint Annual Meeting Program Volume (#33, ISBN 978-1-897095-36-2) and Abstract Volume (#33, ISBN 978-1-897095-35-5), respectively. A proceedings volume based on the presentations given at the SS16 symposium will be published as a special issue of the Canadian Mineralogist, guest-edited by M.A. Hamilton, J.S. Scoates, and O.T. Rämö. The issue will be completed in 2009/2010.

IGCP-510 May 26-28, 2008 symposium was arranged in Quebéc City, Quebéc, Canada. Photos courtesy of Aku Heinonen and O.T. Rämö. (Click the Photo to Enlarge)

November 1-4, 2007: Field trip ”Coeval Miocene Magmatism and Crustal Extension in the Colorado River and Death Valley Extensional Terrains” in southern Nevada and southeastern California

The trip offered an excellent opportunity to examine a thoroughly studied, young A-type granite terrain within an undoubtedly extensional tectonic regime (Basin and Range Province). In the Colorado River extensional corridor and the Death Valley half graben area, Miocene bimodal A-type magmatism was obviously synchronous with extension. The field trip targets also provided an interesting comparison to the supracrustal A-type suites that were examined on the first scientific field trip of IGCP-510 in 2005 (Yellowstone hot spot tractand the Snake River Plain). A field trip guide article [J.P. Calzia, S. Luddington, C.F. Miller, O.T. Rämö (in press) Miocene magmatism and Coeval Crustal Extension in the Colorado River and Death Valley Extensional Terrains (IGCP-510). In: B. Reynolds (Ed.), Field trips associated with the 2007 Annual Meeting of GSA.] will appear in the Geological Society of America Field Guide vol. 6.

IGCP-510 November 1-4, 2007 field trip participants examining the Miocene (18-5 Ma Ga) A-type granites and associated volcanic rocks in the grossly extended terrains of the Colorado River extensional Corridor (southernmost Nevada) and Death Valley (southeastern California). The close-up photo shows Proterozoic (~1.38 Ga) carbonatite from the Mountain Pass Mine that was also visited on the trip. Photos courtesy of O.T. Rämö. (Click the Photo to Enlarge)

July 7-10, 2007: Field trip ”Bushveld Granites and Associated Mineralization” in the Bushveld Igneous Province, South Africa

The participants had an excellent opportunity to examine several of the Paleoproterozoic A-type granites associated with the classic Bushveld mafic layered igneous complex. These granites are also associated with a great variety of mineralization types: polymetallic Cu-Pb-Zn-Ag-U-F concentrations in quartz-hematite veins in granite apical facies; late magmatic tabular, disseminated, and pipe-form Sn-W-REE mineralizations; and a world-class fluorite deposit (Vergenoeg) related to Paleoproterozoic explosive volcanic activity. A field trip guide [J. Kinnaird, L. Robb (2007) Excursion guide to the Bushveld Granites and associated mineralization; post Hutton conference field trip 2007. Economic Geology Research Institute, School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa, 46 p.] was published.

IGCP-510 July 7-10, 2007 field trip participants examining the Paleoproterozoic (~2.05 Ga) A-type granites and associated mineralization in the east-central Bushveld Igneous Province. The close-up photos display hydrothermal tourmaline pipes in the Klipkloof granite and fluorite ore from the Vergenoeg breccia pipe. Photos courtesy of O.T. Rämö. (Click the Photo to Enlarge)

July 2-6, 2007: Sixth International Hutton Symposium; Origin of Granites and Related Rocks at the Stellenbosch University, Stellenbosch, South Africa (http://academic.sun.ac.za/geology/hutton/hutton2007.htm)

This was the third annual meeting of IGCP-510 and it was arranged in conjunction with the Sixth International Hutton Symposium on the origin of granites and related rocks. The symposium gathered together ~90 researchers, 20 of them with A-type granites and related rocks as principal expertise, representing 13 countries (Australia, Brazil, Canada, China, Finland, Germany, Iran, Israel, Russia, Sweden, Turkey, and the United States). The symposium was organised by the Department of Geology, University of Stellenbosch, IAVCEI, and the Geological Society of South Africa (John Clemens, Chairman of the Organizing Committee), and IGCP-510 was one of the main sponsors of the symposium. 18 presentations (one of them keynote) on A-type granites and related rocks were given.

An abstract volume [J.A. Miller, A.F.M. Kisters (Comps. and Eds.) (2007) 6th International Hutton Symposium, Abstract Volume & Program Guide. Department of Geology, Geography and Environmental Sciences, Stellenbosch University, Stellenbosch, South Africa, 236 p.] was released. A proceedings volume based on the presentations given at the 6th Hutton Symposium will be published as a volume of the Transactions of the Royal Society of Edinburgh: Earth Sciences. C.D. Frost, co-leader of IGCP-510, has been invited as one of the guest editors of the volume. The volume will be completed in 2008/2009.

IGCP-510 July 2-6, 2007 Hutton Symposium in Stellenbosch, South Africa. Photo courtesy of O.T. Rämö. (Click the Photo to Enlarge)

August 10-15, 2006: Field trip ”Archean and Paleoproterozoic Granitoids of the Carajás Metallogenic Province, Eastern Amazonian Craton” Serra dos Carajás, Pará, Brazil

The participants had a chance to examine the truly anorogenic, oxidized A-type granites (the classic Jamon suite) that were emplaced into the late Archean Rio Maria granite-greenstone terrain at ~1.88 Ga. The role of these oxidized A-type granites (A-type granites are usually reduced, not oxidized) in the petrogenesis of A-type granites was lively discussed. Some of the Archean granites examined (e.g., the Planalto and Estrela granites) have an A-type character and add on to the few known examples of Archean A-type granites. A field trip guide [R. Dall'Agnol, , M.A. de Oliveira, J.A.C. de Almeida, F.J. Althoff, A.A.S. Leite, D.C. de Oliveira, and C.E.M. Barros (2006) Archean and Paleoproterozoic Granitoids of the Carajás Metallogenic Province, Eastern Amazonian Craton – Geological Setting and Field Trip Program. In: R. Dall’Agnol, L.T. Rosa-Costa, E.L. Klein (Eds.), Symposium on Magmatism, Crustal Evolution, and Metallogenesis of the Amazonian Craton. Abstracts Volume and Field Trips Guide. Belém, PRONEX-UFPA/SBG-NO, p. 98-150] was released.

IGCP-510 August 10-15, 2006 field trip to the Archean and Paleoproterozoic bedrock of Carajás, southeastern Amazonian craton. Close-up photo shows the rapakivi-textured, oxidized A-type Redenção granite of the Jamon suite (1.88 Ga). Photos courtesy of R. Dall’Agnol and O.T. Rämö. (Click the Photo to Enlarge)

August 6-9, 2006: Symposium “A-type Granites and Related Rocks through Time” at Hotel Sagres, Belém, Pará, Brazil

A proceedings volume based on the presentations given at the A-type granite workshop will be published as a special issue of The Canadian Mineralogist. The issue will be edited by R. Dall’Agnol, O.T. Rämö, and R. Martin and will be published in 2008.

July 2-6, 2007 Symposium on Magmatism, Crustal Evolution, and Metallogenesis of the Amazonian Craton in Belém, Pará, Brazil. Photos courtesy of R. Dall'Agnol. (Click the Photo to Enlarge)

 

August 2-5, 2006: Field trip to the Pitinga Mine and surrounding bedrock in Pitinga, Amazonia, Brazil (60°00'W, 0°50'S)

This was a rare occasion (realized via excellent collaboration with and generous support from the Paranema Group, Mineração Taboca S/A) to examine the world-class tin-deposit, large xenotime reserves, and cryolite mineralization associated with the A-type Madeira pluton at the Pitinga Mine. The A-type granites and cassiterite-siderophyllite-quartz greisens associated with the consanquineous Madeira pluton northeast of the mine were also examined. These granites (and the mineralization) comprise an economically and petrologically extremely interesting A-type granite suite. A field trip guide [H.T. Costi, J.M.T.M. Ferron, M. Prado (2006) Pitinga mine – geological setting and field trip program. In: R. Dall’Agnol, L.T. Rosa-Costa, E.L. Klein (Eds.), Symposium on Magmatism, Crustal Evolution, and Metallogenesis of the Amazonian Craton. Abstracts Volume and Field Trips Guide. Belém, PRONEX-UFPA/SBG-NO, p. 81-96] was published.

IGCP-510 August 2-5, 2006 field trip participants examining the Madeira granite ans its Proterozoic country rocks in the Pitinga Mine are in equatorial Brazil. A 4-m paython was encountered in the field. Photos courtesy of O.T. Rämö. (Click the Photo to Enlarge)

September 11-17, 2005: The Eurogranites 2005 field conference to southern and central Finland (http://www.fmnh.helsinki.fi/eurogranites)

IGCP-510 also co-sponsored the Eurogranites 2005 field conference to southern and central Finland. The conference brought together 47 individuals from 15 countries (Belgium, Estonia, Finland, France, Germany, Ireland, Italy, Japan, Norway, Poland, Romania, Slovakia, Spain, United Kingdom, United States) to examine the origin and significance of Proterozoic and Archean granitoid rocks along a traverse from the southern to east-central Finland. Specific targets included (i) the classic A-type ~1.64 Ga rapakivi granites and related mafic rocks of southeastern Finland; (ii) the orogenic granitoids of the ~1.9 Ga Svecofennian orogen; and (iii) the sanukitoids, TTG suites, and A-type granites of the late Archean Karelian craton.

A field trip guide (O.T. Rämö, J. Halla, M. Nironen, L.S. Lauri, M. Kurhila, A. Käpyaho, P. Sorjonen-Ward, O. Äikäs, 2005, EUROGRANITES 2005 - Proterozoic and Archean Granites and Related Rocks of the Finnish Precambrian. Eurogranites 2005 Field Conference, September 11-17, 2005. Publications of the Department of Geology A1, 130 pp. (Download PDF) was published.