Study on Pull-Apart Basin along Median Tectonic Line

沿正中构造线拉分盆地研究

• 批准号: 01540629
• 负责人: MIYATA Takao
• 金额: $ 0.96万
• 依托单位: Kobe University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01540629/
• 关键词: Median Tectonic Line; strike-slip duplex; Izumi sedimentary basin; pull-apart basin; disharmonic fold; en echelon fault; 横ずれ複合断層; 和泉層群堆積盆地; プル・アパ-ト型堆積盆; 雁行状断層構造

The Izumi Sedimenatry Basin (ISB) along the Median Tectonic Line (MTL) has become of major interest lately as a typical strike-slip basin. The purpose of this study is to become clear formative mechanism for the ISB and deformational style in the ISB, attaining to about 300 km in length. A summary of the results obtained is shown below.1. Division of ISB : A tectonic map showing the MTL fault system and the distribution of the Izumi Group (Upper Cretaceous) was compiled. According to this map, the ISB is divisible into at least 5 segments (A-E). The possibility of a basin having liked with each segment (subbasin) is envisioned, though the distribution of the Izumi Group is continuous from segment A (west Shikoku) to segment D (Izumi Mountains). This study has hence tried to determine ages of some segments : Until now, the fission track age of 77-72 Ma from the western part of the segment D, and Radioralia (Archeodictyomitra Sp, etc.) from the segment E (far east of Gojo) were obtained. … More (will be submitted)2. Formative mechanism for ISB : A tectonic map in the segment D, west of a fault bend (Gojo bend) of the MTL, was also compiled. At this releasing bend of the MTL, duplex structures produced by left-slip movement have become clear (Geology, v. 18, p. 392-394, 1990 ; Structural Geology, no. 35, p. 65-70, 1990). The ISB can be regarded as a pull-apart basin formed by the duplexing at the MTL bend. The mechanism of pull-apart basin was further discussed (Structural Geology, no. 36, 1991, in press).3. Deformational style in ISB : Deformation structures, such as disharmonic folds and small-scale echelon faults, produced by gravity-induced bedding-plane slippages, are well developed in the turbidite facies of the Izumi Group in the segment D. By measuring for them, the shear stranin (gamma= 0.3--1.4) along the bedding plane was obtained. Using a scanning electron microscope, the slip direction on slickensides was determined. Judging from their evidence and the migration of depocenter, the tilting of the filling Izumi Group in the basin is thought to have been caused by strike-slip duplexing along the MTL (Geological Society of Japan, Kansai Branch Proceedings, no. 109, p. 7, 1990 ; Geological Society of Japan, Annual Meeting, 97th, Abstracts, p. 346, 1990 ; will be submitted). Less

沿中位构造线（MTL）的泉沉积盆地（ISB）作为典型的走滑盆地近年来引起了人们的广泛关注。本研究的目的是明确ISB的形成机制和ISB的变形样式，长度达到约300公里。所获得的结果总结如下： 1． ISB划分：绘制了显示MTL断层系统和泉群（上白垩统）分布的构造图。根据该图，ISB 至少可分为 5 个部分 (A-E)。尽管和泉群的分布从 A 段（西四国）到 D 段（和泉山脉）连续，但每个段（子流域）都有可能形成一个盆地。因此，本研究试图确定一些段的年龄：到目前为止，从D段的西部获得了77-72 Ma的裂变径迹年龄，并从E段（五条远东）获得了Radioralia（Archeodictyomitra Sp等）。 …更多（将提交）2。 ISB的形成机制：还编制了MTL断层弯曲（Gojo弯曲）以西D段的构造图。在 MTL 的释放弯曲处，左滑运动产生的复式结构已变得清晰（Geology，v. 18，第 392-394 页，1990；Structural Geology，第 35 期，第 65-70 页，1990）。 ISB可以看作是MTL弯道处双工形成的拉分盆地。对盆地拉分机理进行了进一步探讨（《构造地质学》，1991年第36期，待出版）。 3． ISB变形样式：D段和泉群浊积岩相中重力诱发层理面滑移产生的不和谐褶皱、小规模梯次断层等变形构造十分发育，通过对其进行测量，得到了沿层理面的剪切应变（gamma=0.3--1.4）。使用扫描电子显微镜确定光滑面上的滑移方向。从他们的证据和沉积中心的迁移来看，盆地中充填泉群的倾斜被认为是由沿 MTL 的走滑复式引起的（日本地质学会关西分会论文集，第 109 期，第 7 页，1990 年；日本地质学会年会，第 97 届，摘要，第 346 页，1990 年；将提交）。较少的

项目成果

宮田 隆夫: "横ずれ断層運動に伴う堆積盆の形成" 構造地質. 35号. 65-70 (1990)

Takao Miyata：“与走滑断层运动相关的沉积盆地的形成”《构造地质学》35, 65-70 (1990)。

宮田 隆夫: "和泉横ずれ堆積盆の堆積・変形様式" 構造地質. 36号. (1991)

Takao Miyata：“和泉走滑盆地的沉积和变形模式”，《构造地质学》第36期。（1991）

Miyata, T.: "Sedimentary and deformational styles of Izumi strike-slip basin" Structural Geology. no. 36. (1991)

Miyata, T.：“泉走滑盆地的沉积和变形样式”构造地质学。

Miyata,T.: "Cretaceous Izumi Sedimentary Basin:pullーaparts with duplex structure along Mdian Tectonic Line.Southwest Japan" 28th International Geological Congress.Washington D.C.Abstracts. 2. 447 (1989)

Miyata, T.：“白垩纪泉沉积盆地：沿 Mdian 构造线的双相构造拉断。日本西南部”第 28 届华盛顿特区地质大会摘要 2. 447 (1989)。

Miyata,T.: "Slump strain indicative of paleoslope in Cretaceous Izumi sedimentary basin along Median tectonic line.soutwest Japan" Geology. 18. 392-394 (1990)

Miyata,T.：“指示白垩纪和泉沉积盆地沿中位构造线古斜坡的滑落应变。日本西南部”地质学。