变质地质学飞变地14

1、第四章、超高压变质作用1、概述2、矿物学标志及岩石学特征3、大陆型超高压变质带4、大洋型超高压变质带Ultrahigh pressure Metamorphism (UHP)超高压变质作用是近20年间固体地球科学领域中取得的最具有突破性的成果：1、拓宽了变质作用研究范畴，由地壳压力到地幔压力。2、推动了板块构造理论的发展：岩石圈在软流圈之上运动，到岩石圈和软流圈之间的相互作用。2、矿物学标志及岩石学特征柯石英 （coesite）金刚石 (diamond)矿物多型：金红石II 锆石II矿物的出溶结构矿物组合石英 柯石英28 kbar ; 800 OC在Raman 分析谱图上出现521525 cm

2、-1特征峰金刚石石墨 金刚石，36 kbar; 800 OC极高突起，Raman光谱具有1331cm-1峰Xu et al., 2005Schertl et al., 2013, JAESOgasawara, 2005, Element金刚石包体在石榴石中与流体包裹体在一起II型金红石 40 kbarK-cymrite: KAlSi3O8 nH2OMajorite(富硅石榴石): Mg3MgSiSi3O12 P16GPaSkiagite(富铁石榴石): Fe3Fe2Si3O12 P9GPaMg2+ + Si4+ = 2Al3+石榴石中出熔辉石Nature Ye et al., 2000Ti+N

3、a=Ca+Al; P+Na=Si+Ca; Na+Si=Ca+AlSong and Zhang et al., 2004, Am. Min.Song and Zhang et al., 2004, Am. Min.SiO2在榍石中的溶解度UHPM minerals (3)Zhang et al., 2005Am. Min.Raman Analyses of relict coesite exsolution in omphaciteUHP (3)：柯石英出溶Zhang et al., 2005Am. Min.Kfd in Cpx, K+Al = Ca+Mg斜顽辉石多型的转化Am. Min. Zh

4、ang et al., 2002Possible Metamorphic reaction of magnesite + aragonite (calcite) = dolomite: MgCO3+CaCO3=CaMg(CO3)2aragoniteUHPM minerals (5)P：5GPaT： 100 km)? Creation vs preservation B. What exhumation rates and other special conditions are required to preserve UHP mineralogy? C. Why there is no re

5、port of in-situ identification of microdiamond?D. What are the protoliths of UHP rocks; can these be correlated withlithologies on unsubducted parts of the same tectonic plate? D. How are mantle-derived peridotites introduced into a UHP supracrustal collage?E. What are the unusual textural features

6、suggesting that some garnet peridotites derived from mantle depths 200 km? F. How common are the inclusions of nanophases in the UHP rocks? What are the role of dense hydro-Mg-silicates for fluid transport to the mantle?G. What kinds of slab/mantle interaction take place when continentalmaterials ar

7、e subducted to great depths, and how do such processes affect global geochemical recycling? Major Petrochemical QuestionsEclogites and Eclogite-facies Rocks (Smith ed., 1988) Eclogite Facies Rocks (Carswell ed., 1990)Ultrahigh Pressure Metamorphism(Coleman & Wang, eds., 1995) UHP Metamorphic Rocks i

8、n the Dabieshan-Sulu Region of China (Cong ed., 1996)Subduction Top to Bottom (Bebout et al. eds., 1996)When Continents Collide: Geodynamics and Geochemistry of UHP Rocks (Hacker & Liou, eds., 1998). UHP Metamorphism and Geodynamics in Collision-type Orogenic Belts (Ernst & Liou, eds., 2000). The Di

9、amond-bearing Kokchetav Massif: Petrochemistry and Tectonic Evolution of an Unique UHP Metamorphic Terrane (Parkinson, Katayama, Liou & Maruyama, eds., 2002).UHP-HP BOOKSSpecial UHP Journal IssuesUltrahigh-pressure Metamorphism and Tectonics (Island Arc, v. 4 pp. 233 383; Liou et al. eds., 1995) Hig

10、h Pressure Metamorphism in Nature and Experiments (Lithos, v. 41 pp. 1 266; Schreyer & Stockhert eds., 1997) Geodynamics for High- and Ultrahigh-Pressure Metamorphism (Island Arc, v. 7; Liou et al. eds., 1998) Ultra-High Pressure Metamorphic Rocks(Lithos, v. 52, pp. 1-278; Carswell ed., 2000)Petrotectonic Characteristics of the Kokchetav Massif, northern Kazakhstan(Island Arc, v. 9, pp. 259-263; Liou & Banno, 2000) Garnet Peridotites and Ultrahigh-Pressure Minerals (J. Metamorphic Geology, 121- 219; Liou & Carswell, 2000) Petrochemical and Tectonic Processes of UHP/HP