變質(zhì)地質(zhì)學飛變地14

1、第四章、超高壓變質(zhì)作用1、概述2、礦物學標志及巖石學特征3、大陸型超高壓變質(zhì)帶4、大洋型超高壓變質(zhì)帶Ultrahigh pressure Metamorphism (UHP)超高壓變質(zhì)作用是近20年間固體地球科學領域中取得的最具有突破性的成果：1、拓寬了變質(zhì)作用研究范疇，由地殼壓力到地幔壓力。2、推動了板塊構造理論的發(fā)展：巖石圈在軟流圈之上運動，到巖石圈和軟流圈之間的相互作用。2、礦物學標志及巖石學特征柯石英 （coesite）金剛石 (diamond)礦物多型：金紅石II 鋯石II礦物的出溶結(jié)構礦物組合石英 柯石英28 kbar ; 800 OC在Raman 分析譜圖上出現(xiàn)521525 cm

2、-1特征峰金剛石石墨 金剛石，36 kbar; 800 OC極高突起，Raman光譜具有1331cm-1峰Xu et al., 2005Schertl et al., 2013, JAESOgasawara, 2005, Element金剛石包體在石榴石中與流體包裹體在一起II型金紅石 40 kbarK-cymrite: KAlSi3O8 nH2OMajorite(富硅石榴石): Mg3MgSiSi3O12 P16GPaSkiagite(富鐵石榴石): Fe3Fe2Si3O12 P9GPaMg2+ + Si4+ = 2Al3+石榴石中出熔輝石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斜頑輝石多型的轉(zhuǎn)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