402:
becomes a volcanic rock on the surface of the Earth, reflects the isotopic ratio of the mantle source at the time of melting. The best studied heavy radiogenic isotope systems in ocean island basalts are Sr/Sr, Nd/Nd, Pb/Pb, Pb/Pb, Pb/Pb, Hf/Hf and, more recently, Os/Os. In each of these systems, a radioactive parent isotope with a long half-life (i.e., longer than 704 million years) decays to a āradiogenicā daughter isotope. Changes in the parent/daughter ratio by, for example, mantle melting, result in changes in the radiogenic isotopic ratios. Thus, these radiogenic isotopic systems are sensitive to the timing, and degree, of parent/daughter the changed (or fractionated) parent daughter ratio, which then informs the process(es) responsible for generating observed radiogenic isotopic heterogeneity in ocean island basalts. In mantle geochemistry, any composition with relatively low Sr/Sr, and high Nd/Nd and Hf/Hf, is a referred to as āgeochemically depletedā. High Sr/Sr, and low Nd/Nd and Hf/Hf, is referred to as āgeochemically enrichedā. Relatively low isotopic ratios of Pb in mantle-derived rocks are described as
474:
mantle domains with similar radiogenic isotopic compositions sampled at different hotspot localities are thought to share similar geologic histories. For example, the EM2 hotspots of Samoa and
Society are both thought to have a mantle source that contains recycled upper continental crust, an idea that is supported by stable isotope observations, including Ī“O and Ī“Li. The isotopic similarities do not imply that Samoa and Society have the same physical mantle source, as evidenced by their slightly distinct arrays in radiogenic isotopic multi-space. Thus, hotspots that are categorized as āEM1ā, āEM2ā, āHIMUā, or āFOZOā, may each sample physically distinct, but compositionally similar, portions of the mantle. Furthermore, some hotspot chains host lavas with wide range of isotopic compositions so that the plume source seems to either sample multiple domains which can be sampled at different times in the volcanic evolution of a hotspot.
414:
to an endmember with an extreme composition. The depleted mantle, or DM, is one endmember, and is defined by low Sr/Sr, Pb/Pb, Pb/Pb, Pb/Pb, and high Nd/Nd and Hf/Hf. The DM is therefore geochemically depleted, and relatively unradiogenic. Mid-ocean ridges passively sample the upper mantle and MORBs are typically geochemically depleted, and therefore it is widely accepted that the upper mantle is composed mostly of depleted mantle. Thus, the term depleted MORB mantle (DMM) is often used to describe the upper mantle that sources mid-ocean ridge volcanism. Ocean island basalts also sample geochemically depleted mantle domains. In fact, most ocean island basalts are geochemically depleted, and <10% of ocean island basalts have lavas that extend to geochemically enriched (i.e., Nd/Nd lower than the Earth's building blocks) compositions.
470:
intermediate Pb/Pb, Pb/Pb, Pb/Pb. This central mantle domain has several names, each with slightly different implications. PREMA, or āPrevalent Mantleā was the first term coined by
Zindler and Hart (1986) to describe the most common composition sampled by ocean island basalts. Hart et al. (1992) later named the location of the intersection of ocean island basalt compositions in radiogenic isotopic multi-space as the āFocus Zoneā, or FOZO. Farley et al. (1992) in the same year described a high He/He (a primitive geochemical signature) component in plumes as the āPrimitive Helium Mantleā, or PHEM. Finally, Hanan and Graham (1996) used the term āCā (for common component) to describe a common mixing component in mantle derived rocks.
31:
20:
450:
an Earth material has elevated U/Pb (HIMU), then it will also have elevated U/Pb, and therefore will produce radiogenic Pb compositions for both the Pb/Pb and Pb/Pb isotopic systems (U decays Pb, U decays to Pb). Similarly, Earth materials with high U/Pb also tend to have high Th/Pb, and thus evolve to have high Pb/Pb (Th decays to Pb). Ocean island basalts with highly radiogenic Pb/Pb, Pb/Pb, Pb/Pb are the products of HIMU mantle domains.
151:. Mantle plume conduits may drift slowly, but Earth's tectonic plates drift more rapidly relative to mantle plumes. As a result, the relative motion of Earth's tectonic plates over mantle plumes produces age-progressive chains of volcanic islands and seamounts with the youngest, active volcanoes located above the axis of the mantle plume while older, inactive volcanoes are located progressively farther away from the plume conduit (
1582:
473:
The presence of a particular mantle domain in ocean island basalts from two hotspots, signaled by a particular radiogenic isotopic composition, does not necessarily indicate that mantle plumes with similar isotopic compositions are sourced from the same physical reservoir in the deep mantle. Instead,
413:
These isotopic systems have provided evidence for a heterogenous lower mantle. There are several distinct āmantle domainsā or endmembers that appear in the ocean island basalt record. When plotted in multi-isotope space, ocean island basalts tend to form arrays trending from a central composition out
162:
Not all ocean island basalts are the product of mantle plumes. There are thousands of seamounts that are not clearly associated with upwelling mantle plumes, and there are chains of seamounts that are not age progressive. Seamounts that are not clearly linked to a mantle plume indicate that regional
477:
Isotopic systems help to deconvolve the geologic processes that contributed to, and in some cases the timing of, the formation of these mantle domains. Some important examples include the presence of crustal fingerprints in enriched mantle sources that indicate that material from Earth's continents
449:
Another distinct mantle domain is the HIMU mantle. In isotope geochemistry, the Greek letter Ī¼ (or mu) is used to describe the U/Pb, such that āhigh Ī¼ā (abbreviated HIMU) describes a high U/Pb ratio. Over time, as U decays to Pb, HIMU Earth materials develop particularly radiogenic (high) Pb/Pb. If
490:
isotopic systems, such as He/He, Ne/Ne, and Xe/Xe, have been used to demonstrate that parts of the lower mantle are relatively less degassed and have not been homogenized despite billions of years of mantle convective mixing. Some large, hot mantle plumes have anomalously high He/He. Since He is
401:
are a particularly useful tool for studying the composition of mantle sources because isotopic ratios are not sensitive to mantle melting. According tradition subclassification used Sr-Nd-Pb-Hf-He isotopic ratios. This means that the heavy radiogenic isotopic ratio of a melt, which upwells and
387:
Early conceptual models for the geochemical structure of the mantle argued that the mantle was split into two reservoirs: the upper mantle and the lower mantle. The upper mantle was thought to be geochemically depleted due to melt extraction which formed Earth's continents. The lower mantle was
500:
reservoir in the deep mantle. The timing of the formation of this reservoir is constrained by observed anomalies of Xe/Xe in ocean islands basalts, because Xe was only produced by decay of I during the first ~100 My of Earth's history. Together, high He/He and Xe/Xe indicate a relatively less
469:
The final mantle domain discussed here is the common composition that ocean island basalts trend toward in radiogenic isotopic multi-space. This is also most prevalent mantle source in ocean island basalts, and has intermediate to geochemically depleted Sr/Sr, Nd/Nd, and Hf/Hf, as well as
417:
There are two geochemically enriched domains, named enriched mantle 1 (EM1), and enriched mantle 2 (EM2). Though broadly similar, there are some important distinctions between EM1 and EM2. EM1 has unradiogenic Pb/Pb, moderately high Sr/Sr, and extends to lower Nd/Nd and Hf/Hf than EM2.
1159:
Cabral, Rita A.; Jackson, Matthew G.; Rose-Koga, Estelle F.; Koga, Kenneth T.; Whitehouse, Martin J.; Antonelli, Michael A.; Farquhar, James; Day, James M. D.; Hauri, Erik H. (24 April 2013). "Anomalous sulphur isotopes in plume lavas reveal deep mantle storage of
Archaean crust".
396:
showed subducted slabs passing through the upper mantle and entering the lower mantle, which indicates that the lower mantle cannot be isolated. Additionally, the isotopic heterogeneity observed in plume-derived ocean island basalts argues against a homogenous lower mantle. Heavy,
358:
A source associated with mantle plumes. It is of intermediate composition between DMM and HIMU. The name Focus Zone derives from the apparent fanning out of compositions from this zone when displaying isotope composition data on tetrahedron chart. FOZO contains high contents of
384:(~2900 km deep). The composition of the ocean island basalts at hotspots provides a window into the composition of mantle domains in the plume conduit that melted to yield the basalts, thus providing clues as to how and when different reservoirs in the mantle formed.
363:. The FOZO source is associated with deep mantle plumes. FOZO has been proposed to be either the plume material that rises from the coreāmantle boundary or material that becomes attached to the plume as a sheet as the plume it rises from the coreāmantle boundary.
392:ā. (Primitive, in this case, refers to silicate material that represents the building blocks of the planet that has not been modified by melt extraction, or mixed with subducted materials, since Earth's accretion and core formation.) Seismic
491:
being constantly produced within the Earth via alpha decay (of U, Th, and Sm), but He is not being generated in appreciable quantities in the deep Earth, the ratio of He to He is decreasing in the interior of the Earth over time. The early
486:~2.3 Ga. The presence of recycled material with MIF signatures indicates that some of the recycled material brought is older than 2.3 Ga, formed prior to the Great Oxidation Event and has resurfaced via mantle plume volcanism.
1097:
Jackson, Matthew G.; Hart, Stanley R.; Koppers, Anthony A. P.; Staudigel, Hubert; Konter, Jasper; Blusztajn, Jerzy; Kurz, Mark; Russell, Jamie A. (August 2007). "The return of subducted continental crust in Samoan lavas".
171:
There are various sources identified for ocean island basalt magma in Earth's mantle but the main component is ancient recycled basaltic oceanic crust which has inherited the trace element and isotopic signatures of a
495:
began with high He/He and therefore the Earth first accreted with high He/He. Thus, in plume-derived lavas, high He/He is an āancientā geochemical signature that indicates the existence of a well-preserved
380:
of ocean island basalts is useful for studying the chemical and physical structure of Earth's mantle. Some mantle plumes that feed hotspot volcanism lavas are thought to originate as deep as the
297:
that has not been homogenized with the rest of the mantle. The lack of homogenization could be indebted to the accumulation of subducted oceanic crust in large-scale āmegalithsā at the
863:
Jackson, Matthew G.; Dasgupta, Rajdeep (November 2008). "Compositions of HIMU, EM1, and EM2 from global trends between radiogenic isotopes and major elements in ocean island basalts".
521:
It is premature to be sure that this new clean means of classification will also be useful for intraplate continental basalts and FOZO appears to still need Helium-3 determination
560:
Weaver, Barry L. (October 1990). "Geochemistry of highly-undersaturated ocean island basalt suites from the South
Atlantic Ocean: Fernando de Noronha and Trindade islands".
1344:
Akbari, M; Ghorbani, MR; Cousens, BL; Graham, IT (30 June 2023). "A robust discrimination scheme for ocean island basalts based on Ce/Rb, Tb/La, and Ba/Nb ratios".
976:
Farley, K.A.; Natland, J.H.; Craig, H. (June 1992). "Binary mixing of enriched and undegassed (primitive?) mantle components (He, Sr, Nd, Pb) in Samoan lavas".
808:
131:, Samoa, and Iceland. Over time, however, thermal subsidence and mass loss via subaerial erosion causes islands to become completely submarine seamounts or
438:
are the type localities of EM1. EM2 is defined by higher Sr/Sr than EM1, and higher Nd/Nd and Hf/Hf at a given Sr/Sr value, and intermediate Pb/Pb.
478:
and oceans can be subducted into the mantle and brought back up to the surface in buoyantly rising mantle plumes. Sulfur isotopic analyses have shown
1211:
Graham, David W. (2002). "Noble Gas
Isotope Geochemistry of Mid-Ocean Ridge and Ocean Island Basalts: Characterization of Mantle Source Reservoirs".
482:(MIF) in the sulfur isotopes in some plume-derived lavas. MIF of sulfur isotopes is a phenomenon that occurred in Earth's atmosphere only before the
1011:
Hanan, B. B.; Graham, D. W. (17 May 1996). "Lead and Helium
Isotope Evidence from Oceanic Basalts for a Common Deep Source of Mantle Plumes".
268:
Significant contamination with continental crust, usually upper crust. Likely mantle contaminated with material derived from the recycling of
1228:
623:
672:
French, Scott W.; Romanowicz, Barbara (2 September 2015). "Broad plumes rooted at the base of the Earth's mantle beneath major hotspots".
156:
116:. However, some ocean island basalt locations coincide with plate boundaries like Iceland, which sits on top of a mid-ocean ridge, and
656:
427:
192:(Pb) isotopes but it is now possible to classify usefully and more conveniently on high field strength trace elements alone such as
925:
Hart, S. R.; Hauri, E. H.; Oschmann, L. A.; Whitehead, J. A. (24 April 1992). "Mantle Plumes and
Entrainment: Isotopic Evidence".
1395:
176:
zone dehydration process, with enrichment in high field strength elements. These mantle sources are inferred from differences in
155:). Hotspot chains can record tens of millions of years of continuous volcanic history; for example, the oldest seamounts in the
243:
Significant contamination with continental crust, usually lower crust. Probably mantle contaminated with material derived from
479:
1244:
Mukhopadhyay, Sujoy (6 June 2012). "Early differentiation and volatile accretion recorded in deep-mantle neon and xenon".
341:
30:
139:, which are thought to be the surface expressions of melting of thermally buoyant, rising conduits of hot rock in the
109:
127:, and in some cases, enough material is erupted that the rock protrudes from the ocean and forms an island, like at
1611:
1486:
97:
831:
57:
381:
1481:
298:
148:
69:
19:
163:
mantle composition and tectonic activity may also play important roles in producing intraplate volcanism.
180:
ratios that magmas inherit from their source rock. Sources have been defined from a combined analysis of
483:
320:
Possible formed by mixing of all the other mantle sources or a source formed early in Earth's history.
282:
Less enriched in Nb, Ba, La, and Ce compared to EMI or HIMU but relative enrichment Ba c.f. HIMU or DMM
1302:"The Origin of Intra-plate Ocean Island Basalts (OIB): the Lid Effect and its Geodynamic Implications"
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degassed, primitive noble gas domain that has been relatively well preserved since the early
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993:
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577:
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419:
389:
247:
212:(Tb is chosen as proportion about constant in all IOB). :
1606:
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93:
35:
1317:
1257:
1173:
1111:
1075:
1024:
938:
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573:
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147:. Some such hotspot volcanic chains are believed to have started with the formation of
24:
1600:
1491:
1365:
1197:
997:
709:
589:
294:
49:
1300:
Niu, Yaoling; Wilson, Marjorie; Humphreys, Emma R.; O'Hara, Michael J. (July 2011).
1048:
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455:
451:
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377:
144:
101:
1357:
1083:
639:
Staudigel, Hubert; Koppers, Anthony A.P. (2015). "Seamounts and Island
Building".
1032:
946:
1537:
1062:
White, William M. (December 2015). "Isotopes, DUPAL, LLSVPs, and
Anekantavada".
251:
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884:
1220:
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337:
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53:
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807:
Grand, Stephen P.; Van Der Hilst, Rob D.; Widiyantoro, Sri (1997).
23:
Figure 1. Age-progression of volcanic islands and seamounts at the
809:"Global seismic tomography: A snapshot of convection in the earth"
439:
254:
which could also be contaminated by subducted pelagic sediments.
250:. An alternative explanation is that this source derives from the
132:
117:
61:
29:
18:
1460:
293:
Negligible crustal contamination. Likely derived from subducted
189:
65:
1377:
72:
to produce a range of other volcanic rock types, for example,
847:
752:
731:
606:
Jackson, Matthew Gerard (2016). "Oceanic Island
Basalts".
466:) are the type localities for HIMU ocean island basalts.
340:(MORB) characteristics with low Sr/Sr and high Nd/Nd and
269:
347:
Low Ba, high to moderate Ce/Rb (i.e. low Rb) and low La
610:. Encyclopedia of Earth Sciences Series. pp. 1ā5.
898:
Zindler, A (1 January 1986). "Chemical Geodynamics".
1520:
1474:
1443:
1412:
96:
basalts (MORBs), which erupt at spreading centers (
858:
856:
601:
599:
755:, Section:Origin and genesis of OIB type magmas
123:In the ocean basins, ocean island basalts form
257:Moderate Nb, Ce, Ba, La, Nb. Enrichment of Ba
135:. Many ocean island basalts erupt at volcanic
68:, the basaltic magma is sometimes modified by
1389:
900:Annual Review of Earth and Planetary Sciences
748:
746:
744:
742:
740:
8:
727:
725:
723:
721:
719:
56:in composition, erupted in oceans away from
1339:(2nd ed.). Cambridge University Press.
763:
761:
120:, which is located near a subduction zone.
1396:
1382:
1374:
406:; relatively high ratios are described as
112:), ocean island basalts are the result of
1325:
1127:
775:
773:
562:Contributions to Mineralogy and Petrology
214:
552:
514:
7:
978:Earth and Planetary Science Letters
865:Earth and Planetary Science Letters
446:are the archetypal EM2 localities.
649:10.1016/b978-0-12-385938-9.00022-5
301:or near the coreāmantle boundary.
34:Ocean island basalt formations at
14:
60:. Although ocean island basaltic
1580:
616:10.1007/978-3-319-39193-9_248-1
159:are over 80 million years old.
157:HawaiianāEmperor seamount chain
912:10.1146/annurev.earth.14.1.493
480:mass-independent-fractionation
388:thought to be homogenous and ā
1:
1358:10.1016/j.chemgeo.2023.121486
1084:10.1016/j.chemgeo.2015.09.026
641:The Encyclopedia of Volcanoes
454:, and several islands in the
1033:10.1126/science.272.5264.991
998:10.1016/0012-821X(92)90178-X
947:10.1126/science.256.5056.517
608:Encyclopedia of Geochemistry
299:670 km seismic discontinuity
64:is mainly erupted as basalt
1413:Basalts by tectonic setting
252:sub-continental lithosphere
110:convergent plate boundaries
1628:
1337:Radiogenic Isotope Geology
885:10.1016/j.epsl.2008.09.023
462:volcanic lineament (e.g.,
227:Trace element composition
98:divergent plate boundaries
88:at the intraplate volcano
1576:
1335:Dickin, Alan P. (2005) .
1221:10.1515/9781501509056-010
308:
231:
58:tectonic plate boundaries
46:Ocean island basalt (OIB)
1444:Basalts by form and flow
1327:10.1093/petrology/egr030
779:Dickin 2005, pp. 161ā162
990:1992E&PSL.111..183F
877:2008E&PSL.276..175J
304:Low Ba, high Ce and La
149:large igneous provinces
70:igneous differentiation
1425:Mid-ocean ridge basalt
734:, Section:Introduction
104:lavas, which erupt at
42:
27:
484:Great Oxidation Event
330:Depleted MORB Mantle
33:
22:
1487:Calc-alkaline basalt
1475:Basalts by chemistry
1306:Journal of Petrology
1215:. pp. 247ā318.
643:. pp. 405ā421.
382:coreāmantle boundary
372:Isotope geochemistry
344:as compared to MORB
114:intraplate volcanism
1435:Volcanic arc basalt
1430:Ocean island basalt
1318:2011JPet...52.1443N
1266:10.1038/nature11141
1258:2012Natur.486..101M
1182:10.1038/nature12020
1174:2013Natur.496..490C
1120:10.1038/nature06048
1112:2007Natur.448..684J
1076:2015ChGeo.419...10W
1025:1996Sci...272..991H
939:1992Sci...256..517H
797:Dickin 2005, p. 164
788:Dickin 2005, p. 151
767:Dickin 2005, p. 157
694:10.1038/nature14876
686:2015Natur.525...95F
574:1990CoMP..105..502W
399:radiogenic isotopes
90:Fernando de Noronha
1587:Geology portal
1521:Important minerals
1312:(7ā8): 1443ā1468.
850:, Section:Abstract
848:Akbari et al. 2023
753:Akbari et al. 2023
732:Akbari et al. 2023
582:10.1007/BF00302491
532:subduction erosion
265:Enriched Mantle 2
240:Enriched Mantle 1
178:radiogenic isotope
43:
28:
1612:Hotspot volcanism
1594:
1593:
1482:Tholeiitic basalt
1252:(7401): 101ā104.
1230:978-1-5015-0905-6
1168:(7446): 490ā493.
1106:(7154): 684ā687.
1019:(5264): 991ā995.
933:(5056): 517ā520.
625:978-3-319-12127-7
369:
368:
335:mid-oceanic ridge
317:Prevalent Mantle
309:Depleted sources
279:into the mantle.
277:continental crust
248:pelagic sediments
232:Enriched sources
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915:
895:
889:
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871:(1ā2): 175ā186.
860:
851:
845:
839:
838:
836:
830:. Archived from
813:
804:
798:
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290:High U/Pb ratio
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106:subduction zones
1627:
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1618:
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1451:Columnar basalt
1439:
1408:
1402:
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738:
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680:(7567): 95ā99.
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559:
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94:mid-ocean ridge
36:Rochester Falls
17:
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5:
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1512:Picrite basalt
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1504:
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1229:
1203:
1151:
1089:
1054:
1003:
984:(1): 183ā199.
968:
917:
906:(1): 493ā571.
890:
852:
840:
837:on 2019-07-09.
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781:
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624:
595:
568:(5): 502ā515.
551:
550:
549:
548:
543:
540:
537:
536:
523:
513:
512:
510:
507:
373:
370:
367:
366:
364:
356:
353:
349:
348:
345:
331:
328:
324:
323:
321:
318:
315:
311:
310:
306:
305:
302:
291:
288:
284:
283:
280:
266:
263:
259:
258:
255:
241:
238:
234:
233:
229:
228:
225:
222:
219:
168:
167:Mantle sources
165:
141:Earth's mantle
25:Hawaii hotspot
15:
13:
10:
9:
6:
4:
3:
2:
1624:
1613:
1610:
1608:
1605:
1604:
1602:
1589:
1588:
1583:
1575:
1569:
1566:
1564:
1561:
1559:
1556:
1554:
1551:
1549:
1546:
1544:
1541:
1539:
1536:
1534:
1531:
1529:
1526:
1525:
1523:
1519:
1513:
1510:
1508:
1505:
1503:
1500:
1498:
1495:
1493:
1492:Alkali basalt
1490:
1488:
1485:
1483:
1480:
1479:
1477:
1473:
1467:
1466:Pahoehoe lava
1464:
1462:
1459:
1457:
1456:Pillow basalt
1454:
1452:
1449:
1448:
1446:
1442:
1436:
1433:
1431:
1428:
1426:
1423:
1421:
1418:
1417:
1415:
1411:
1407:
1399:
1394:
1392:
1387:
1385:
1380:
1379:
1376:
1367:
1363:
1359:
1355:
1351:
1347:
1342:
1338:
1333:
1328:
1323:
1319:
1315:
1311:
1307:
1303:
1298:
1297:
1292:
1291:
1283:
1279:
1275:
1271:
1267:
1263:
1259:
1255:
1251:
1247:
1240:
1237:
1232:
1226:
1222:
1218:
1214:
1207:
1204:
1199:
1195:
1191:
1187:
1183:
1179:
1175:
1171:
1167:
1163:
1155:
1152:
1147:
1143:
1139:
1135:
1130:
1125:
1121:
1117:
1113:
1109:
1105:
1101:
1093:
1090:
1085:
1081:
1077:
1073:
1069:
1065:
1058:
1055:
1050:
1046:
1042:
1038:
1034:
1030:
1026:
1022:
1018:
1014:
1007:
1004:
999:
995:
991:
987:
983:
979:
972:
969:
964:
960:
956:
952:
948:
944:
940:
936:
932:
928:
921:
918:
913:
909:
905:
901:
894:
891:
886:
882:
878:
874:
870:
866:
859:
857:
853:
849:
844:
841:
833:
829:
825:
821:
817:
810:
803:
800:
794:
791:
785:
782:
776:
774:
770:
764:
762:
758:
754:
749:
747:
745:
743:
741:
737:
733:
728:
726:
724:
722:
720:
716:
711:
707:
703:
699:
695:
691:
687:
683:
679:
675:
668:
665:
660:
658:9780123859389
654:
650:
646:
642:
635:
632:
627:
621:
617:
613:
609:
602:
600:
596:
591:
587:
583:
579:
575:
571:
567:
563:
556:
553:
546:
545:
541:
533:
527:
524:
518:
515:
508:
506:
504:
499:
494:
489:
485:
481:
475:
471:
467:
465:
461:
457:
453:
447:
445:
441:
437:
433:
429:
425:
421:
415:
411:
409:
405:
400:
395:
391:
385:
383:
379:
371:
365:
362:
357:
354:
351:
350:
346:
343:
339:
336:
332:
329:
326:
325:
322:
319:
316:
313:
312:
307:
303:
300:
296:
295:oceanic crust
292:
289:
286:
285:
281:
278:
274:
267:
264:
261:
260:
256:
253:
249:
246:
242:
239:
236:
235:
230:
226:
223:
220:
217:
216:
213:
211:
207:
203:
199:
195:
191:
187:
183:
179:
175:
166:
164:
160:
158:
154:
150:
146:
145:mantle plumes
142:
138:
134:
130:
126:
121:
119:
115:
111:
107:
103:
99:
95:
91:
87:
83:
79:
75:
71:
67:
63:
59:
55:
51:
50:volcanic rock
47:
41:
37:
32:
26:
21:
16:Volcanic rock
1578:
1563:Cristobalite
1497:Trachybasalt
1429:
1420:Flood basalt
1349:
1345:
1336:
1309:
1305:
1249:
1245:
1239:
1212:
1206:
1165:
1161:
1154:
1103:
1099:
1092:
1067:
1063:
1057:
1016:
1012:
1006:
981:
977:
971:
930:
926:
920:
903:
899:
893:
868:
864:
843:
832:the original
819:
815:
802:
793:
784:
677:
673:
667:
640:
634:
607:
565:
561:
555:
530:Subduction,
526:
517:
493:Solar System
476:
472:
468:
448:
416:
412:
407:
404:unradiogenic
403:
386:
378:geochemistry
375:
170:
161:
153:see Figure 1
152:
122:
102:volcanic arc
45:
44:
1538:Plagioclase
1213:Noble Gases
355:Focus Zone
270:terrigenous
262:EM2 (EMII)
1601:Categories
1352:(121486).
822:(4): 1ā7.
542:References
452:St. Helena
408:radiogenic
394:tomography
237:EM1 (EMI)
174:subduction
52:, usually
1568:Tridymite
1548:Magnetite
1543:Amphibole
1507:Mugearite
1404:Types of
1366:258177656
1198:205233273
1129:1912/2075
1070:: 10ā28.
816:GSA Today
710:205245093
590:128694689
509:Footnotes
488:Noble gas
424:Kerguelen
390:primitive
275:from the
273:sediments
245:subducted
221:Full Name
208:(Nb) and
188:(Nd) and
186:neodymium
182:strontium
143:, called
125:seamounts
92:. Unlike
82:phonolite
40:Mauritius
1553:Ilmenite
1533:Pyroxene
1502:Hawaiite
1274:22678288
1190:23619695
1138:17687322
1049:29813558
963:29042856
955:17787949
828:73626357
702:26333468
420:Pitcairn
361:Helium-3
202:rubidium
137:hotspots
86:trachyte
74:rhyolite
54:basaltic
1528:Olivine
1461:Aa lava
1406:basalts
1314:Bibcode
1293:Sources
1282:8566845
1254:Bibcode
1170:Bibcode
1146:4381042
1108:Bibcode
1072:Bibcode
1041:8662585
1021:Bibcode
1013:Science
986:Bibcode
935:Bibcode
927:Science
873:Bibcode
682:Bibcode
570:Bibcode
464:Mangaia
460:Austral
444:Society
432:Tristan
210:terbium
206:niobium
200:(Ce),
198:caesium
100:), and
78:Iceland
1607:Basalt
1558:Quartz
1364:
1280:
1272:
1246:Nature
1227:
1196:
1188:
1162:Nature
1144:
1136:
1100:Nature
1047:
1039:
961:
953:
826:
708:
700:
674:Nature
655:
622:
588:
503:Hadean
498:helium
430:, and
338:basalt
314:PREMA
224:Source
204:(Rb),
196:(Ba),
194:barium
184:(Sr),
133:guyots
129:Hawaii
80:, and
1362:S2CID
1278:S2CID
1194:S2CID
1142:S2CID
1045:S2CID
959:S2CID
835:(PDF)
824:S2CID
812:(PDF)
706:S2CID
586:S2CID
547:Notes
440:Samoa
436:Gough
428:Heard
352:FOZO
287:HIMU
118:Samoa
62:magma
48:is a
1270:PMID
1225:ISBN
1186:PMID
1134:PMID
1037:PMID
951:PMID
698:PMID
653:ISBN
620:ISBN
534:etc.
456:Cook
442:and
376:The
333:Has
327:DMM
218:Name
190:lead
84:and
66:lava
1354:doi
1350:628
1322:doi
1262:doi
1250:486
1217:doi
1178:doi
1166:496
1124:hdl
1116:doi
1104:448
1080:doi
1068:419
1029:doi
1017:272
994:doi
982:111
943:doi
931:256
908:doi
881:doi
869:276
690:doi
678:525
645:doi
612:doi
578:doi
566:105
342:ĪµHf
76:in
38:in
1603::
1360:.
1348:.
1320:.
1310:52
1308:.
1304:.
1276:.
1268:.
1260:.
1248:.
1223:.
1192:.
1184:.
1176:.
1164:.
1140:.
1132:.
1122:.
1114:.
1102:.
1078:.
1066:.
1043:.
1035:.
1027:.
1015:.
992:.
980:.
957:.
949:.
941:.
929:.
904:14
902:.
879:.
867:.
855:^
818:.
814:.
772:^
760:^
739:^
718:^
704:.
696:.
688:.
676:.
651:.
618:.
598:^
584:.
576:.
564:.
505:.
422:,
410:.
1397:e
1390:t
1383:v
1368:.
1356::
1330:.
1324::
1316::
1284:.
1264::
1256::
1233:.
1219::
1200:.
1180::
1172::
1148:.
1126::
1118::
1110::
1086:.
1082::
1074::
1051:.
1031::
1023::
1000:.
996::
988::
965:.
945::
937::
914:.
910::
887:.
883::
875::
820:7
712:.
692::
684::
661:.
647::
628:.
614::
592:.
580::
572::
458:-
434:-
426:-
108:(
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