남원지역에 분포하는 화강암류에 대한 Rb-Sr 동위원소 연구 = Rb-Sr isotopic study on the granitoids in the Namweon area

다국어 초록 (Multilingual Abstract)

In the Namweon area Ogcheon geosyncline SE zone exist two kinds of igneous rocks. One type is mylonitic foliated granites which are developed metamorphic or in some cases have a deformation of texture. The other is Namweon granite(which does not deform).
Granitoids of the Namweon area consist of hornblende biotite granodiorite, biotite granite and two mica granite. Two-mica granite is partly developed by alteration.
According to the variation diagram of AMF, trace elements, and REE, granitoids show calk-alkali rock series, and the Na_(2)O versus K_(2)O ratio of the granitoids indicate that they belong to I-type, differentiated from mantle.
The initial Sr isotope ratios of the Namweon granitoids vary from 0.706 to 0.716, when the emplacement age is assumed to be 210 Ma from studies of Rb-Sr whole rock and concentrated biotite. The observation of the lowest initial ^(87)Sr/^(86)Sr ratio shows that the Namweon granitoids were formed by mantle magma. Beside the lowest initial ^(87)Sr/^(86)Sr ratio, initial ^(87)Sr/^(86)Sr ratios of whole rock and concentrated biotite show relatively high values. These isotopic data indicate that at least two distinct origins of magma are required for the Namweon granitoids.
The geochronological data of concentrated biotite from the Namweon granitoids Rb-Sr method are 201 Ma to 220 Ma. Initial ^(87)Sr/^(86)Sr ratios of concentrated biotite show relatively high values. These values indicate the magma of biotite generated from melting of lower crust or contamination of upper mantle magma. So, geochronological data of concentrated biotite suggest that Namweon granitoids might be a product of intrusion and crystallization at the early Jurassic to middle Triassic.

목차 (Table of Contents)

• 목차
• LIST OF TABLES = ⅰ
• LIST OF FIGURES = ⅱ
• ABSTRACT = ⅴ
• 제1장 서론 = 1
• 제2장 일반지질 = 3
• 제3장 남원화강암류에 대한 암석기재 = 7
• 3.1. 각섬석흑운모화강섬록암 = 7
• 3.2. 흑운모화강암 = 8
• 3.3. 복운모화강암 = 9
• 제4장 화강암체의 암석화학 = 10
• 4.1. 주성분 원소와 미량성분원소 = 10
• 4.2. 희토류원소 = 20
• 제5장 Rb-Sr 동위원소 분석 = 23
• 5.1. 동위원소분석 시료준비 = 23
• 5.2. Sr의 분리 = 25
• 5.3. Rb-Sr 동위원소 분석실험 = 25
• 제6장 Rb-Sr 동위원소 자료에 의한 지질시 대 = 27
• 6.1. 전암 및 혹운모 농집시료에 의한 Rb-Sr 동위원소 분석 = 27
• 6.2. 흑운모 농집시료에 의한 Rb-Sr 지질시대 = 38
• 제7장 결론 = 47
• 參考文獻 = 49
• Appendix 1. Major(wt.%) elements and normative analyses of granitoids in the Namweon area = 54
• Appendix 2. Trace(ppm) elements of ganitoids in the Namweon area = 58
• Appendix 3. BASIC program for ^(87)Rb/^(86)Sr ratio = 62