| Autor: |
Baird AK, Toulmin P 3rd, Clark BC, Rose HJ Jr, Keil K, Christian RP, Gooding JL |
| Jazyk: |
angličtina |
| Zdroj: |
Science (New York, N.Y.) [Science] 1976 Dec 11; Vol. 194 (4271), pp. 1288-93. |
| DOI: |
10.1126/science.194.4271.1288 |
| Abstrakt: |
Chemical results from four samples of martian fines delivered to Viking landers 1 and 2 are remarkably similar in that they all have high iron; moderate magnesium, calcium, and sulfur; low aluminum; and apparently very low alkalies and trace elements. This composition is best interpreted as representing the weathering products of mafic igneous rocks. A mineralogic model, derived from computer mixing studies and laboratory analog preparations, suggests that Mars fines could be an intimate mixture of about 80 percent iron-rich clay, about 10 percent magnesium sulfate (kieserite?), about 5 percent carbonate (calcite), and about 5 percent iron oxides (hematite, magnetite, maghemite, goethite?). The mafic nature of the present fines (distributed globally) and their probable source rocks seems to preclude large-scale planetary differentiation of a terrestrial nature. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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