¹Ahrens, L. H.

¹Department of Geology and Geophysics, Massachusetts Institute of Technology, USA

Frequency distribution plots of K, Rb, Sc, V, Co, Ga, Cr, and Zr in Ontario diabase, Sc, V, Ga, Cr, La, and Zr in Canadian granite, K, Rb, and Cs in New England granite and F and Mo in granite from various localities are regular, but assume decided positive skewness when dispersion is large, hence, distribution of concentration is not normal. All distributions become normal, or nearly so, provided the variate (concentration of an element) is transformed to log concentration: this leads to a statement of a fundamental (lognormal) law concerning the nature of the distribution of the concentration of an element in specific igneous rocks.
A subsidiary law concerning the relationship between averages and most prevalent concentrations follows as a direct consequence of the fundamental law.
Dispersions of different elements can be compared and predictions may be made on the basis of the lognormal law. A comparison of the dispersions of elements in igneous rocks and chondrites emphasizes the strikingly high uniformity of abundance of many elements in these meteorites. A given element may show a totally different magnitude of dispersion in different igneous rocks, for example, dispersion of scandium is small in diabase and extreme in granite.
“The linear scale, since it was first cut on the wall of an Egyptian temple, has come to be accepted by man almost as if it were the unique scale with which Nature builds and works. Whereas, it is nothing of the sort”—(Bagnold, 1941)

Reference
Ahrens LH (1954) The lognormal distribution of the elements (A fundamental law of geochemistry and its subsidiary). Geochimica et Cosmochimica Acta 5,49-73.
Link to Article [DOI: 10.1016/0016-7037(54)90040-X]

Copyright Elsevier

^1,2,3 Robert A. Wittenmyer et al. (>10)*
*Find the extensive, full author and affiliation list on the publishers website.

¹School of Physics, UNSW Australia, Sydney, NSW 2052, Australia
²Australian Centre for Astrobiology, UNSW Australia, Sydney, NSW 2052, Australia
³Computational Engineering and Science Research Centre, University of Southern Queensland, Toowoomba, Queensland 4350, Australia

We report the detection of GJ 832c, a super-Earth orbiting near the inner edge of the habitable zone of GJ 832, an M dwarf previously known to host a Jupiter analog in a nearly circular 9.4 yr orbit. The combination of precise radial-velocity measurements from three telescopes reveals the presence of a planet with a period of 35.68 ± 0.03 days and minimum mass (m sin i) of 5.4 ± 1.0 Earth masses. GJ 832c moves on a low-eccentricity orbit (e = 0.18 ± 0.13) toward the inner edge of the habitable zone. However, given the large mass of the planet, it seems likely that it would possess a massive atmosphere, which may well render the planet inhospitable. Indeed, it is perhaps more likely that GJ 832c is a “super-Venus,” featuring significant greenhouse forcing. With an outer giant planet and an interior, potentially rocky planet, the GJ 832 planetary system can be thought of as a miniature version of our own solar system.

Reference
Wittenmyer RA et al. (2014) GJ 832c: A Super-Earth in the Habitable Zone. The Astrophysical Journal 791, 114.
Link to Article [doi:10.1088/0004-637X/791/2/114]