CAJ | 학술논문

1：25万常德市幅和岳阳市幅区域地质调查项目在详细的野外地质调查、大量的钻孔资料和分析测试工作基础上，对洞庭盆地第四纪地质特征及演化进行了重点研究，取得以下重要进展：①厘定了洞庭盆地及周缘隆。凹构造格局；重新建立了露头区及覆盖区地层系统。②分别对洞庭盆地各次级构造单元及其周缘地区的第四纪构造活动、沉积特征及环境演化等进行了详细解剖，从而揭示出盆地第四纪构造．沉积作用的横向差异。③查明洞庭盆地早更新世一中更新世中期处于断陷阶段，盆地及周缘的构造活动表现主要有多组方向正断裂活动、盆内次级凹陷区的差异性和幕式构造沉降、盆地周缘及盆内隆起区的脉动式抬升等；中更新世晚期以来盆地处于坳陷阶段，其中中更新世晚期发生抬升、掀斜及褶皱作用，晚更新世．全新世盆地主体处于坳陷沉降中。提出了新的不同阶段构造活动动力机制模式，较好地解释了构造活动的各种特征。④通过两护村ZKCl孔孢粉组合、化学蚀变指数和微量元素含量等变化，重塑了第四纪气候演化过程。⑤通过ZKCl孔重矿物分析，探讨了洞庭盆地南部早．中更新世沉积环境暨河湖变迁以及构造沉降过程。⑥研究发现津市黄牯山泥砾混杂堆积为泥石流产物，而非前人所认为的冰川成因。⑦提出构造．沉积地貌类型的概念，于图区划分出10种构造．沉积地貌类型，提供了直观表达不同地区地貌状况，以及第四纪地层和构造特征及其反映的地质与环境演化过程的有效途径。
1：25만상덕시폭화악양시폭구역지질조사항목재상세적야외지질조사、대량적찬공자료화분석측시공작기출상，대동정분지제사기지질특정급연화진행료중점연구，취득이하중요진전：①전정료동정분지급주연륭。요구조격국；중신건립료로두구급복개구지층계통。②분별대동정분지각차급구조단원급기주연지구적제사기구조활동、침적특정급배경연화등진행료상세해부，종이게시출분지제사기구조．침적작용적횡향차이。③사명동정분지조경신세일중경신세중기처우단함계단，분지급주연적구조활동표현주요유다조방향정단렬활동、분내차급요함구적차이성화막식구조침강、분지주연급분내륭기구적맥동식태승등；중경신세만기이래분지처우요함계단，기중중경신세만기발생태승、흔사급습추작용，만경신세．전신세분지주체처우요함침강중。제출료신적불동계단구조활동동력궤제모식，교호지해석료구조활동적각충특정。④통과량호촌ZKCl공포분조합、화학식변지수화미량원소함량등변화，중소료제사기기후연화과정。⑤통과ZKCl공중광물분석，탐토료동정분지남부조．중경신세침적배경기하호변천이급구조침강과정。⑥연구발현진시황고산니력혼잡퇴적위니석유산물，이비전인소인위적빙천성인。⑦제출구조．침적지모류형적개념，우도구화분출10충구조．침적지모류형，제공료직관표체불동지구지모상황，이급제사기지층화구조특정급기반영적지질여배경연화과정적유효도경。
On the base of detailed geologic mapping, a great deal borehole data and systemic analyses, the regional geological survey of 1：250 000 Changde and Yueyang sheets studied the Quaternary geological and environmental characteristics and evolution of the Dongting basin. The main progresses are shown as follows： ①The writers found the Quaternary uplift-depression tectonic framework of the Dongting basin and peripheral area, and re-founded the Quarternary stratum system of outcropped and covered areas. The authors studied amply the Quaternary tectonic and sedimentary characteristics and environmental evolution of every secondary tectonic unit of the Dongting basin, and revealed the lateral variations of Quaternary tectonic activities and sedimentations of the Dongting basin. ③Dongting basin was a rift basin during Early Pleistocene-middle of Middle Pleistocene, when there were tectonic movements such as the movements of multi-directional normal faults, differential and episodic subsidences of the secondary sags of the basin, and pulsative rises of the uplifts around and inside the basin. Dongting basin entered into a depressional phase since late Middle Pleistocene, which was characterized by rise, tilt and folds in late Middle Pleistocene, and by depressional subsidence of most areas during Late Pleistoncene-Holocene. Geodynamic mechanisms of the different tectonic periods were advanced, which explained satisfactorily the genesis of the tectonic movemental characteristics of Dongting basin.④The climatic evolution of the Dongting basin was revealed through sporopollen assemblages, chemical alteration index （CIA） and contents of some trace elements. ⑤Through analysis of heavy minerals from the core of the ZKC 1 borehole, evolutions of sedimentary environment and tectonic subsidence of southern Dongting basin during Early and Middle Pleistocene are traced. ⑥Muddy gravel deposits in Huanggushan, Jinshi, Hunan province were debris flow deposits but not moraines as former cognition. ⑦The studies brought forward the concept of tectonic-sedimentary landforms, and defined ten types of tectonic-sedimentary land- forms in the study area. The concept of tectonic-sedimentary landforms can not only indicate geographic environments, but also provide the information of Quaternary stratum, tectonic features, and the geological and environmental evolution process.