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1 Markets I: The Ecosystem and Exchange-Traded Markets市场在线 2 Markets II: Rates, FX and Credit市场在线 3 Markets III: Commodities, Energy and Crypto市场在线 4 Quantitative Methods方法在线 5 Derivatives and Volatility衍生品在线 6 Rates, Credit, XVA and Risk利率、信用与风险在线 7 Research Craft: Predictors, Backtests, Measurement, Portfolios研究在线 8 Strategies I: Equities and Futures策略在线 9 Strategies II: Volatility, Relative Value, Macro and the Bank Desks策略在线 10 Microstructure and Execution交易执行在线 11 Market Making and High-Frequency Trading做市在线 12 Machine Learning for Markets机器学习在线 13 Low-Latency Software技术在线 14 Networks, Hardware and Trading Infrastructure技术在线 15 Research, Data and Risk Platforms技术在线 16 The Desk and the Firm公司运营在线 17 The Industry: Firms, Roles and Careers职业发展在线 18 Interviews I: Maths, Probability and Speed职业发展在线 19 Interviews II: Markets, Trading Games and the Final Round职业发展在线 20 Interviews III: Code职业发展在线

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Earth and Space Sciences · 术语表

什么是 Greenstone belt; komatiite？

又称： greenstone belt · komatiite

Definition 18.2 University Earth and Space Sciences — Year 2 · 第 18 章 — The Precambrian Earth

A greenstone belt is a belt of mafic and ultramafic volcanic rocks, with sediments, metamorphosed at low grade (the green comes from chlorite, actinolite and epidote), lying between bodies of granitoid in Archean and some Proterozoic terrains. A komatiite is an ultramafic lava, far richer in MgO than basalt, erupted as a liquid; its olivine typically grows in long, thin blades, the spinifex texture, as the top of the flow cools fast.

Spinifex texture in a komatiite flow, Pyke Hill, Ontario, part of a Neoarchean greenstone belt about 2.71 billion years old: blades of olivine, now altered, grew across the cooling top of the flow. Photograph James St. John, CC BY 2.0 (Wikimedia Commons).

The komatiite thermometer: the line through the liquidus temperatures measured on two komatiites (dots), extended to the 10 to 13\,\% MgO of the primary basalts of today’s ridges (band). The extension rests on the similar slope of basaltic melts. — The komatiite thermometer: the line through the liquidus temperatures measured on two komatiites (dots), extended to the 10 to $13\,\%$ MgO of the primary basalts of today’s ridges (band). The extension rests on the similar slope of basaltic melts.

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