Poorly dated large mafic magmatic events

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278 Diamond Springs event

Location: W. USA (Wind River Range, Wyoming Craton)

Age: Archean

Rating: C (possibly 7)

VOLCANIC ROCKS: Diamond Springs Formation (includes meta-ultramafic rocks) Wilks and Harper, 1997[687].

COMMENT: Ultramafic rocks have been variously interpreted as meta-komatiites and meta-cumulates (of an ophiolite) Wilks and Harper, 1997[687].


279 Araras event

Location: Brazil

Size: 80,000 sq. km.

Age: 1.5-0.9 Ga

Rating: B (5)

DIKES: Araras, SE trending, 1500-900 Ma, Teixeira, 1990[688] Ernst et al., 1996[117].


280 Tapajós event

Location: Brazil

Size: 35,000 sq. km.

Age: 1.6-0.9 Ga

Rating: B (5)

DIKES: Tapajós, NE trending, 1600-900 Ma, Teixeira, 1990[688] Ernst et al., 1996[117].


281 Cachorro event

Location: Brazil

Size: 60,000 sq. km.

Age: 1.6-0.9 Ga

Rating: B (5)

DIKES: Cachorro, ENE trending, 1600-900 Ma Teixeira, 1990[688] Ernst et al., 1996[117].


282 Jauru event

Location: WC. Brazil (S. Amazonian Craton)

Age: Early-Middle Proterozoic

Rating: C (possibly 7)

VOLCANIC ROCKS: Pinho et al., 1997[689] Jauru (includes ultramafic volcanic rocks) (part of Alto Jauru greenstone belt).

COMMENT: Geochemistry suggests ocean-floor basalt setting Pinho et al., 1997[689].


283 Piumhi event

Location: Brazil (São Francisco Craton)

Age: Archean

Rating: B (7)

VOLCANIC ROCKS: Piumhi greenstone belt (includes komatiites) Baars, 1997[625].


284 Khopier event

Location: W. Russia (Voronezh Uplift)

Size: 200-km-long mega-dike

Age: ??

Rating: C (possibly 5)

DIKES: Khopier, NNE trending layered intrusion mega-dike Berkovsky and Platunova, 1987[157].


285 Kolmosero-Voronye event

Location: N. Europe (Kola Craton)

Size: 650 sq. km.

Age: >2.8 Ga

Rating: B (7)

VOLCANIC ROCKS: Kolmosero-Voronye greenstone belt (includes komatiites) Kushev, 1997[690].

COMMENT: Amphibolite metamorphism at 2.7-2.8 Ga Kushev, 1997[690].


286 Krasnoyarsk continental flood basalt(C) event

Location: E. Russia

Size: 21,000 sq. km.

Age: 1.6-0.5 Ga

Rating: B (5)

DIKES: Krasnoyarsk, N trending, 1600-550 Ma Soviet Union, 1976[691] Ernst et al., 1996[117].

COMMENT: Is this part of event 81?


287 Timptono-Algamaisky continental flood basalt(C) event

Location: E. Russia (Aldan Shield)

Size: 60,000 sq. km.

Age: 1.7-1.0 Ga

Rating: B (5)

DIKES: Timptono-Algamaisky, SE trending, K 1650-1000 Ma Okrugin et al., 1995[692] Blagovyeshchenskaya, 1973[693] Ernst et al., 1996[117].


288 Kalaro-Nimnyrsky continental flood basalt(C) event

Location: E. Russia (Aldan Shield)

Size: 215,000 sq. km.

Age: 1.7-1.0 Ga

Rating: B (5)

DIKES: Kalaro-Nimnyrsky, NE trending, K 1650-1000 Ma Okrugin et al., 1995[692] Blagovyeshchenskaya, 1973[693] Ernst et al., 1996[117].


289 Seerteng event

Location: N. China (North China craton)

Size: 1200 sq. km.

Age: >2.4 Ga

Rating: B (7)

VOLCANIC ROCKS: Seerteng greenstone belt (<5 komatiites) Yuehua and Wang, 1997[694].


290 North China Craton event Zhao et al., 1999[695]

Location: N. China

Size: 320,000 sq. km.

Age: Archean

Rating: C (possibly 6)

VOLCANIC ROCKS: A-type granulites Zhao et al., 1999[695].

COMMENT: "Two metamorphic continental blocks had formed through the interaction of mantle plumes with pre-existing lithosphere in what subsequently became the eastern and western zones of the North China craton" (p. 237 Zhao et al., 1999[695]). Metavolcanic rocks.


291 Benin-Nigerian schist belt event(s)

Location: West Africa (Benin-Nigerian Shield)

Age: 1.4-0.4 Ga

Rating: C (possibly 7)

VOLCANIC ROCKS: Ife-Ilesha; Maru.

COMMENT: These are schist belts containing komatiite protoliths inferred from geochemistry and mineralogy Attoh and Ekwueme, 1997[516].


292 El Geneina event(s)

Location: Sudan

Size: 48,000 sq. km.

Age: ?

Rating: B (5)

DIKES: El Geneina, SE trending Vail, 1978[255] Vail, 1974a[696] Vail, 1974b[697] Ernst et al., 1996[117].

COMMENT: May include non-diabases Vail, 1978[255].


293 Nepoko event

Location: Congo

Size: 140,000 sq. km.

Age: ?

Rating: B (5)

DIKES: Nepoko, N trending, 1600-900 Ma Thibaut, 1982[362] Ernst et al., 1996[117], possibly 1400-1200 Ma (H. Kapmunzu, 1999, personal communication).


294 Sudan event(s)

Location: Sudan

Size: 1,800,000 sq. km.

Age: ?

Rating: B (5)

DIKES: Sudan, E trending Vail, 1978[255] Vail, 1974a[696] Vail, 1974b[697] Ernst et al., 1996[117].


295 Transvaal-3 continental flood basalt(C) event

Location: South Africa

Size: 120,000 sq. km.

Age: <1.7 Ga

Rating: B (5)

DIKES: Transvaal-3 (Kaapvaal?1), SE trending, <1700 Ma Hunter and Reid, 1987[90] Ernst et al., 1996[117].


296 Tanzania-2 event

Location: Tanzania

Age: >1.8 Ga

Rating: B (5)

DIKES: Tanzania-2, N-NNW trending, >1800 Ma Halls et al., 1987[239] Ernst et al., 1996[117].


297 Tanzania-6 event(s)

Location: Tanzania

Size: 40,000 sq. km.

Age: ?

Rating: B (5)

DIKES: Tanzania-6 (Swarm VI) , SE trending Halls et al., 1987[239] Ernst et al., 1996[117].


298 Techla event(s)

Location: Western Sahara (Morocco), Mauritania, Mali

Size: 520,000 sq. km.

Age: ?

Rating: B (5)

DIKES: Techla, E-ENE trending Mauritane (Afrique Occidentale Mauritane), 1960[698] Maroc, 1985[234] Mali, 1980[233] Ernst et al., 1996[117].


299 Uele event

Location: Zaire

Size: 280,000 sq. km.

Age: ?

Rating: B (5)

DIKES: Uele, SE trending, 2500-550 Ma Thibaut, 1982[362] Ernst et al., 1996[117].


300 Requibat Shield event

Location: West Africa (W. Requibat Shield)

Age: Archean

Rating: C (possibly 7)

VOLCANIC ROCKS: Tasiast greenstone belt Attoh and Ekwueme, 1997[516].

COMMENT: Contains meta-ultramafic rocks Attoh and Ekwueme, 1997[516].


301 Leo-Man Shield event

Location: West Africa (Leo-Man Shield)

Age: Archean

Rating: C (possibly 7)

VOLCANIC ROCKS: Greenstone belts: Sula Attoh and Ekwueme, 1997[516]; Nimini-Kambui Attoh and Ekwueme, 1997[516].

COMMENT: Ultramafic flows are highly metamorphosed Attoh and Ekwueme, 1997[516].


302 Malagasy Shield events

Location: Madagascar

Age: Archean

Rating: C (possibly 7)

VOLCANIC ROCKS: Greenstone belts Rambeloson, 1997[698a]: Maevatanana, Andriamena, Beforona-Alaotra greenstone belts are probably Archean; Dariana-Milanoa may be Proterozoic.

INTRUSIONS: Andriamena complex; Rianila complex.

COMMENT: Some soapstones after ultramafic rocks, may be meta-komatiites Rambeloson, 1997[698a].


303 McArthur Basin-1 event

Location: N. Australia (McArthur Basin)

Plume head center: ~11 S, 135 E

Size: 150,000 sq. km.

Age: ?

Rating: B (5, possibly 3)

DIKES: McArthur Basin 1 SW-S fanning swarm (p. 167 in Tucker and Boyd, 1987[699]) Boyd and Tucker, 1990[126] Ernst et al., 1996[117].


304 Pine Creek event

Location: N. Australia

Size: 45,000 sq. km.

Age: ?

Rating: B (5)

DIKES: Pine Creek, SE trending Parker et al., 1987[216] Ernst et al., 1996[117].