2000年退变质作用研究的展望

变质作用的研究是变质岩石学的主要部分之一。世界各地古老地块中麻粒岩和片麻岩区的变质作用深入研究,又结合其它学科的综合研究成果,大大提高了早前寒武纪地壳演化的研究程度。退变质作用属变质作用的一种类型,过去对进变质作用已进行了广泛的研究,而对退变质作用则研究较少。近二十年来各国地质学者在世界各地重视和研究了退变质作用,不断发表他们的研究成果,取得了迅速的进展。

Prospects for the Year 2000 Retrograde Metamorphism Researches

Since last two decades, Geologists of each country have devoted much attention to and studied retrograde metamorphism all over the world, pub- lisped many articles continuously, and made a considerable headway. In the United States of America, for example, the retrogression of philadelphia area, pennsylvania has early been discussed; afterwards retrograde metamorphism for Broken Hill district, Australia; Saleix area (French pyrenees);Almklo- vdalen, and western coast, Norway; western Veporides in the Soviet Union; Hida area, central Japan and soforth have also been studied, publisb.ing con- tinuously works. Especially, retrograde metamorphism of Lewisian Complex, NW Scotland was investigated thoroughly. At present, retrograde study make progress in the following several aspects; (1) tectonization, rock deformation&retrograde metamorphism, (2) Causing retrograde metamorphism, following decreasing temperature, (3) retro- gressive geochemistry study, (4) retrograde metamorphism and minerogenesis, (5) Regional metamorphic thermal metamorphism. The prograde metamorphic study should not be overemphasized at the expense of the retrograde metamorphic. For highly raising the retrograde metamorphism level of our country in end of the century, I make some sug- gestions; 1 .Pay great attention to tectonization, and tectonic framework in the field, and try to fine which tectonization is related to the retrogression more seriously. Deformation domain is more usually a place retrogressive. Both sides of plate collision indicate a gradually retrogressive belt in an extensive region. These aspects at home have not yet been noticed. 2. The retrogressive reaction study must be strengthened, although started. When we make an experiment in the progressive reaction, retrogressive reac- tion test must be added to some extent. 3. Studies of the retrogressive geochemistry and fluids controlling retro- gressive activity law, following height of level in isotope assay and microarea measurement, should achieve good results. 4. Attach importance to ore deposit related to the retrograde metamor- phism, pay attention to the retrogressive shear zones controlling ore-bearing property and information of ore shoot near the ore body. 5. We not only study retrograde metamorphism of early precambrian but also look fixedly at that of proterozoic, Palaeozoic and mesozoic. We expect that in the year 2000, using new determinative techniques, deformational ret- rogression, retrogressive reaction, retrogressive geochemistry, retrogression & ore deposit, retrogressive thermodynamics, ect, should be modernized to create a branch of the metamorphic petrology-retrograde metamorphism.