20:
169:
formed under similar conditions, giving them comparable chemical compositions. The more direct methodology is to observe trends in the chemical makeup of upper mantle peridotites and interpret the hypothetical composition of the primitive mantle based on these trends. This is done by matching the
174:
compositional trends to the distribution of refractory lithophile elements (which are not affected by core-mantle differentiation) in chondritic meteorites. Both methods have limitations based on the assumptions made about inner-earth, as well as statistical uncertainties in the models used to
195:
O, and CaO, and significantly lower concentrations of MgO. More importantly, both approaches show that the primitive mantle has much greater concentrations of refractory lithophile elements (e.g Al, Ba, Be, Ca, Hf, Nb, Sc, Sr, Ta, Th, Ti, U, Y, Zr, and
164:
that represent early Earth chemical composition and creating models using the analyzed chemical characteristics and assumptions describing inner-Earth dynamics. This approach is based on the assumption that early planetary bodies in the
159:
Although the chemical composition of the primitive mantle cannot be directly measured at its source, researchers have been able to estimate primitive mantle characteristics using a few methods. One methodology involves the analysis of
200:. The exact concentrations of these compounds and refractory lithophile elements depends on the estimation method used. Methods using peridotite analysis yield a much smaller primitive mantle weight percentage for SiO
178:
The two approaches detailed above yield weight percentages that follow the same general trends when compared to the depleted (or homogeneous) mantle: the primitive mantle has significantly higher concentrations of
95:
elements accumulated, from the surrounding undifferentiated primitive mantle. Further differentiation would take place later, creating the different chemical reservoirs of crust and mantle material, with
212:
than those estimated using direct chondritic meteorite analysis. The estimated concentrations of refractory lithophile elements obtained from the two methods vary as well, usually 0.1-5 ppm.
758:
253:
674:"Variable refractory lithophile element compositions of planetary building blocks: Insights from components of enstatite chondrites"
60:
24:
139:, geochemists assume there must be a relatively closed and very undifferentiated primitive reservoir somewhere in the
108:
84:
148:
76:
391:"Chemical differentiation of the Earth: the relationship between mantle, continental crust, and oceanic crust"
67:. The chemical composition of the primitive mantle contains characteristics of both the crust and the mantle.
221:
495:"Chemical composition of Earth's primitive mantle and its variance: 2. Implications for global geodynamics"
19:
166:
88:
241:
784:
672:
Yoshizaki, Takashi; Ash, Richard D.; Lipella, Marc D.; Yokoyama, Tetsuya; McDonough, William F. (2021).
673:
446:"Grain size variations in the Earth's mantle and the evolution of primordial chemical heterogeneities"
695:
618:
555:
506:
457:
402:
339:
290:
161:
140:
97:
135:
at hotspots is supposed to have been taken to the surface from the deepest regions of the mantle by
92:
719:
685:
587:
426:
371:
197:
83:
composition through impacts with differentiated planetesimals. During this accretionary phase,
754:
711:
654:
636:
579:
571:
524:
475:
418:
363:
355:
308:
249:
128:
64:
56:
746:
703:
644:
626:
563:
514:
465:
410:
406:
347:
298:
50:
279:"Chemical composition of Earth's primitive mantle and its variance: 1. Method and results"
544:"First-principles constraints on diffusion in lower-mantle minerals and a weak D′′ layer"
699:
622:
559:
510:
461:
343:
294:
28:
649:
606:
390:
778:
723:
414:
124:
591:
430:
375:
136:
104:
40:
745:, Lecture Notes in Earth Sciences, vol. 136, Tokyo: Springer, pp. 9–17,
750:
738:
707:
543:
327:
171:
715:
640:
575:
528:
479:
422:
359:
312:
631:
80:
658:
583:
367:
204:
and significantly larger primitive mantle weight percentages for MgO and Al
519:
494:
470:
445:
303:
278:
567:
351:
240:
Rubie, D. C.; Nimmo, F.; Melosh, H. J. (2015), Schubert, Gerald (ed.),
743:
Arc
Volcano of Japan: Generation of Continental Crust from the Mantle
143:. One hypothesis to describe this assumption is the existence of the
32:
739:"Chemical Composition of Continental Crust and the Primitive Mantle"
690:
144:
75:
One accepted scientific hypothesis is that the Earth was formed by
542:
Ammann, M. W.; Brodholt, J. P.; Wookey, J.; Dobson, D. P. (2010).
132:
107:, resulting in two types of mantle reservoirs: those depleted in
115:
and those composed of "fresh" undifferentiated mantle material (
326:
Wood, Bernard J.; Walter, Michael J.; Wade, Jonathan (2006).
23:
Illustration depicting three proposed processes that drive
35:), thus separating the core from the primitive mantle.
328:"Accretion of the Earth and segregation of its core"
131:
often have a primitive composition, and because the
607:"Chemical composition of Earth, Venus, and Mercury"
611:Proceedings of the National Academy of Sciences
103:Today, differentiation still continues in the
737:Yanagi, Takeru (2011), Yanagi, Takeru (ed.),
8:
499:Journal of Geophysical Research: Solid Earth
450:Journal of Geophysical Research: Solid Earth
283:Journal of Geophysical Research: Solid Earth
493:Lyubetskaya, Tanya; Korenaga, Jun (2007).
277:Lyubetskaya, Tanya; Korenaga, Jun (2007).
689:
648:
630:
518:
469:
302:
605:Morgan, John W.; Anders, Edward (1980).
18:
444:Solomatov, V. S.; Reese, C. C. (2008).
246:Treatise on Geophysics (Second Edition)
232:
59:during the developmental stage between
242:"9.03 - Formation of the Earth's Core"
55:) is the chemical composition of the
7:
272:
270:
248:, Oxford: Elsevier, pp. 43–79,
395:Earth and Planetary Science Letters
14:
678:Geochimica et Cosmochimica Acta
16:Layer in a newly formed planet
1:
389:Hofmann, Albrecht W. (1988).
415:10.1016/0012-821X(88)90132-X
751:10.1007/978-4-431-53996-4_2
100:accumulating in the crust.
63:and the formation of early
61:core-mantle differentiation
25:core–mantle differentiation
801:
708:10.1016/j.gca.2021.05.057
85:planetary differentiation
31:, percolation, and iron
632:10.1073/pnas.77.12.6973
407:1988E&PSL..90..297H
222:Giant impact hypothesis
91:, where heavy metallic
36:
162:chondritic meteorites
121:primitive reservoirs)
113:depleted reservoirs),
98:incompatible elements
22:
520:10.1029/2005JB004224
471:10.1029/2007JB005319
304:10.1029/2005JB004223
198:rare earth elements)
155:Chemical composition
149:core-mantle boundary
700:2021GeCoA.308..173Y
623:1980PNAS...77.6973M
568:10.1038/nature09052
560:2010Natur.465..462A
511:2007JGRB..112.3212L
462:2008JGRB..113.7408S
352:10.1038/nature04763
344:2006Natur.441..825W
295:2007JGRB..112.3211L
175:quantify the data.
79:of material with a
47:(also known as the
37:
760:978-4-431-53996-4
617:(12): 6973–6977.
554:(7297): 462–465.
338:(7095): 825–833.
255:978-0-444-53803-1
65:continental crust
792:
770:
769:
768:
767:
734:
728:
727:
693:
669:
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634:
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386:
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274:
265:
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237:
45:primitive mantle
800:
799:
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761:
736:
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671:
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604:
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599:
541:
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492:
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443:
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388:
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325:
324:
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276:
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268:
260:
258:
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218:
211:
207:
203:
194:
190:
186:
182:
157:
73:
17:
12:
11:
5:
798:
796:
788:
787:
777:
776:
772:
771:
759:
729:
664:
597:
534:
485:
436:
401:(3): 297–314.
381:
318:
266:
254:
231:
229:
226:
225:
224:
217:
214:
209:
205:
201:
192:
188:
184:
180:
156:
153:
125:Volcanic rocks
87:separated the
72:
69:
57:Earth's mantle
15:
13:
10:
9:
6:
4:
3:
2:
797:
786:
783:
782:
780:
762:
756:
752:
748:
744:
740:
733:
730:
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721:
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683:
679:
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624:
620:
616:
612:
608:
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569:
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561:
557:
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549:
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530:
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496:
489:
486:
481:
477:
472:
467:
463:
459:
455:
451:
447:
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437:
432:
428:
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412:
408:
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396:
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385:
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377:
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369:
365:
361:
357:
353:
349:
345:
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333:
329:
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305:
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296:
292:
288:
284:
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273:
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227:
223:
220:
219:
215:
213:
199:
176:
173:
168:
163:
154:
152:
150:
146:
142:
138:
137:mantle plumes
134:
130:
129:hotspot areas
126:
122:
118:
114:
110:
106:
101:
99:
94:
90:
86:
82:
78:
70:
68:
66:
62:
58:
54:
52:
46:
42:
34:
30:
26:
21:
785:Geochemistry
764:, retrieved
742:
732:
681:
677:
667:
614:
610:
600:
551:
547:
537:
502:
498:
488:
453:
449:
439:
398:
394:
384:
335:
331:
321:
286:
282:
259:, retrieved
245:
235:
177:
167:solar system
158:
141:lower mantle
120:
116:
112:
105:upper mantle
102:
89:Earth's core
74:
48:
44:
41:geochemistry
38:
684:: 173–187.
93:siderophile
71:Development
766:2021-11-09
691:2011.13134
261:2021-09-30
228:References
172:peridotite
111:elements (
109:lithophile
81:chondritic
724:227209726
716:0016-7037
641:0027-8424
576:1476-4687
529:2156-2202
480:2156-2202
423:0012-821X
360:1476-4687
313:2156-2202
77:accretion
33:diapirism
779:Category
659:16592930
584:20505725
368:16778882
216:See also
145:D"-layer
117:enriched
51:silicate
696:Bibcode
619:Bibcode
592:4414617
556:Bibcode
507:Bibcode
458:Bibcode
431:3211879
403:Bibcode
376:8942975
340:Bibcode
291:Bibcode
147:at the
757:
722:
714:
657:
650:350422
647:
639:
590:
582:
574:
548:Nature
527:
505:(B3).
478:
456:(B7).
429:
421:
374:
366:
358:
332:Nature
311:
289:(B3).
252:
43:, the
720:S2CID
686:arXiv
588:S2CID
427:S2CID
372:S2CID
133:magma
127:from
53:Earth
49:bulk
29:dikes
755:ISBN
712:ISSN
655:PMID
637:ISSN
580:PMID
572:ISSN
525:ISSN
476:ISSN
419:ISSN
364:PMID
356:ISSN
309:ISSN
250:ISBN
191:, Na
747:doi
704:doi
682:308
645:PMC
627:doi
564:doi
552:465
515:doi
503:112
466:doi
454:113
411:doi
348:doi
336:441
299:doi
287:112
179:SiO
119:or
39:In
781::
753:,
741:,
718:.
710:.
702:.
694:.
680:.
676:.
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643:.
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615:77
613:.
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399:90
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393:.
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346:.
334:.
330:.
307:.
297:.
285:.
281:.
269:^
244:,
183:Al
181:2,
151:.
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749::
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688::
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629::
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566::
558::
531:.
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468::
460::
433:.
413::
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378:.
350::
342::
315:.
301::
293::
210:3
208:O
206:2
202:2
193:2
189:3
187:O
185:2
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