Early evolution of Solar System small bodies proceeded through interactions of mineral and water. Melting of water ice accreted with mineral particles to the parent body results in the formation of secondary minerals, the so-called aqueous alteration. Formation of phyllosilicates from anhydrous silicates is a typical alteration effect recorded in primitive meteorites. In addition to mineral and water, organic matter could have been also a significant component in meteorite parent bodies. However, the role of organic matter in the alteration of silicates is not well understood. We conducted a heating experiment of anhydrous silicate (olivine) with a mixture of organic compounds which simulated primordial organic matter in the Solar System. Dissolution and precipitation features were confirmed on the olivine surface after heating at 300 °C for 10 days, and proto-phyllosilicates were formed in the precipitation area. Magnesite was also detected as concomitant mineral phase. These minerals could be the evidence of aqueous alteration and carbonation of olivine induced by water generated through decomposition of the organic compounds with hydroxy groups. Our result showed that the in situ formation of hydrated silicates through a mineral–organic interaction without the initial presence of water. It further implies that formation of phyllosilicates on the olivine surface in contact with organic matter can occur in meteorite parent bodies which formed inside the H 2 O snow line but accreted with organic matter, initially without water. Water formed through decomposition of organic matter could be one candidate for hydrous silicate formation, for example, in ordinary chondrites from S-type asteroids inside the H 2 O snow line. Although the origin of water in ordinary chondrites is under debate, water generation from organic matter may also explain the D-rich water in ordinary chondrites because primordial organic matter is known to be D rich.

中文翻译：

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没有初始水的水蚀变：陨石母体中无水硅酸盐有机诱导水合的可能性

太阳系小天体的早期演化是通过矿物质和水的相互作用进行的。带有矿物颗粒的水冰融化到母体上会导致次生矿物的形成，即所谓的水蚀变。由无水硅酸盐形成页硅酸盐是原始陨石中记录的典型蚀变效应。除了矿物质和水，有机物也可能是陨石母体的重要组成部分。然而，有机物在硅酸盐蚀变中的作用尚不清楚。我们进行了无水硅酸盐（橄榄石）与有机化合物混合物的加热实验，模拟太阳系中的原始有机物质。在300℃加热10天后，橄榄石表面出现溶解和沉淀特征，沉淀区形成原页硅酸盐。菱镁矿也被检测为伴生矿物相。这些矿物质可能是由含羟基的有机化合物分解产生的水引起的橄榄石水蚀和碳酸化的证据。我们的结果表明，水合硅酸盐通过矿物 - 有机相互作用原位形成，而没有最初的水存在。这进一步意味着橄榄石表面与有机物接触的页硅酸盐的形成可能发生在陨石母体中，这些母体在 H 2 O 雪线内形成，但随着有机物的增加，最初没有水。通过有机物分解形成的水可能是形成含水硅酸盐的一种候选物，例如，在 H 2 O 雪线内来自 S 型小行星的普通球粒陨石中。尽管普通球粒陨石中水的来源尚有争议，但有机质产生的水也可以解释普通球粒陨石中富含 D 的水，因为已知原始有机质富含 D。