Terrestrial planet compositions controlled by accretion disk magnetic field

Progress in Earth and Planetary Science

Table 1 Composition of the terrestrial planets

Atomic%	Mercury ^a	Venus ^a	Earth ^b	Mars ^c	CI chondrite ^d
					(volatile-free)
O	27.5	49.0	49.0	55.3	48.2
Mg	11.1	16.7	16.7	15.3	15.1
Si	11.1	15.1	15.1	15.1	14.7
Fe	41.2	15.1	15.1	10.3	12.8
Ni	2.25	0.82	0.82	0.57	0.70
Al	1.03	1.56	1.56	1.41	1.20
Ca	0.75	1.13	1.13	1.03	0.88
S	5.07	0.52	0.52	0.92	6.43
Fe/O	1.50	0.31	0.31	0.19	0.27
Fe/Si	3.71	1.00	1.00	0.69	0.87
Mg/Si	0.99	1.11	1.11	1.02	1.03
Al/Si	0.093	0.103	0.103	0.093	0.082
Fe/Al	40.0	9.7	9.7	7.3	10.7
Mg/Al	10.7	10.8	10.8	10.9	12.6
mean Z	17.5	12.7	12.7	11.8	12.6
wt%	Mercury	Venus	Earth	Mars	CI (volatile-free)
O	12.0 (± 2.1)	29.7	29.7	36.3	29.1
Mg	7.31 (± 1.3)	15.4	15.4	15.3	13.9
Si	8.50 (± 1.0)	16.1	16.1	17.4	15.6
Fe	62.6 (± 4.5)	32.0	32.0	23.7	26.9
Ni	3.60 (± 0.25)	1.82	1.82	1.36	1.54
Al	0.76 (± 0.14)	1.59	1.59	1.56	1.22
Ca	0.82 (± 0.15)	1.71	1.71	1.69	1.33
S	4.42 (± 1.50)	0.64	0.64	1.21	7.78
Uncompressed ρ^e	5200 ± 200	4100	4200	3800	2430 ^f
Metal mass fraction	74/100 (± 5)	1/3	1/3	1/5	0
H distance (AU)	0.39	0.72	1.00	1.52	>15^g
h (pW kg ⁻¹) ^h	2.0	3.6	3.3	4.0	–
h (TW) ^h	0.7	18	20	2.5	–

^aThis study. The ± values (1 standard deviation) are calculated as the differences between the high and low uncompressed density models
^bMcDonough (2014).
^cYoshizaki and McDonough (2020).
^dAlexander (2019a).
^eUncompressed ρ, density, in kg/m³ (Lewis 1972; Lodders and Fegley Jr. 1998; Stacey 2005).
^fMacke et al. (2011).
^gDesch et al. (2018).
^hHeat production in the bulk silicate planets are calculated from chondritic (Al/Th) _mass = 2.81 ×10⁵ and (Th/U) _mass = 3.7, planetary (K/Th) _mass = 7000, 3700, and 5300 for Mercury, Earth, and Mars, respectively (Peplowski et al. 2011; Arevalo Jr. et al. 2009; Taylor et al. 2006), and an equation from McDonough et al. (2020). pW = 10⁻¹² W; TW = 10¹² W.