A PETROLOGICAL STUDY ON YOUNGER GRANITIC ROCKS AND REALATED METAMORPHIC ROCKS IN THE ABUKUMA MOUNTAINS.

The Cretaceous Hanawa Granitic Pluton和Neighboring High Grade Metamorphic Rocks在细节中被研究，一张地理地图是制作的。Hanawa Pluton是固定的。在从老到年轻的灌输秩序中，精细的格拉纳的四重奏Diorite和Tonalite，坚定的Tonalite和Granodiorite，以及主要的Granodiortic Rocks。《花岗岩岩石可以被分成四种类型》，那是Porphyritic Potash Feldspar-和Quartz Bearing， Lagre Sphene Bearing，Myronitic和Fine Grained Equigranula类型。第七-一个模式分析独立-那是一般的年轻岩石，波塔什Fedlspar和Quartz，以及黑手党Minerals的富人。13颗花岗岩岩石的化学变体是完美有限的（SiO_2 67- 73%），并且与平均日本花岗岩岩石相似。GM/（MG+FE）Biotite的比率和Plagiocalse Exhibit的内容和Decrease Toward的南部西部片的超级趋势。Mineral Assemblage AND Index Mineral Indicate That A Metamorphic Grade General Decreases to THE Hanawa Pluton， From The Granulite Faces TO THE Amphibolite Faces（2013）这个事实可能会令人惊讶，那是Hanawa Pluton的灵感在Forimg THE High Grade Metamorphic Rocks中并不重要。有两种类型的Metamorphism是Inferred的，它们是High Temperature和Moderate Pressure类型，以及Moderate Temperature和Low Pressure类型。

THE CRETACEOUS HANAWA GRANITIC PLUTON AND NEIGHBORING HIGH-GRADE METAMORPHIC ROCKS WERE STUDIED IN DETAIL, AND A GEOLOGIC MAP IS MADE. THE HANAWA PLUTON IS CONSTITUTED BY. IN ORDER OF INTRUSION FROM OLD TO YOUNG, FINE-GRAINED QUARTZ DIORITE AND TONALITE, FOLIATED TONALITE AND GRANODIORITE, AND MAIN GRANODIORTIC ROCKS. THE GRANODIORITIC ROCKS CAN BE DIVIDED INTO FOUR TYPES; THAT IS PORPHYRITIC POTASH FELDSPAR- AND QUARTZ-BEARING, LAGRE SPHENE-BEARING, MYLONITIC, AND FINE-GRAINED EQUIGRANULA TYPES. SEVENTY-ONE MODAL ANALYSES INDICATE・THAT IN GENERAL THE YOUNGER ROCKS ARE, THE RICHIER IN POTASHI FEDLSPAR AND QUARTZ AND THE POORER IN MAFIC MINERALS. CHEMICAL VARIATION OF 13 GRANODIORITIC ROCKS ARE FAIRLY LIMITED (SiO_2 67-73%), AND ARE SIMILAR TO THOSE OF AVERAGE JAPANESE GRANITIC ROCKS. GM/(MG+FE) RATIO OF BIOTITE AND AN CONTENT OF PLAGIOCLASE EXHIBIT AND OVERALL TREND OF DECREASE TOWARD A SOUTH WESTERN SIDE IN THE GRANODIORITIC PLUTON. MINERAL ASSEMBLAGE AND INDEX MINERAL INDICATE THAT A METAMORPHIC GRADE GENERALLY DECREASES TOWARD THE HANAWA PLUTON, FROM THE GRANULITE FACIES TO THE AMPHIBOLITE FACIES. THIS FACT MAY SUGGEST THAT THE INTRUSION OF THE HANAWA PLUTON WAS NOT IMPORTANT IN FORIMG THE HIGH-GRADE METAMORPHIC ROCKS. TWO TYPES OF METAMORPHISM ARE INFERRED, THAT IS A HIGH TEMPEARTURE AND MODERATE PRESSURE TYPE, AND A MODERATE TEMPERATURE AND LOW PRESSURE TYPE.