【作者】 王书琴；

【导师】 孙晓猛；

【作者基本信息】 吉林大学 ， 构造地质学， 2010， 硕士

【摘要】 郯庐断裂带从三叠纪以来经历了长期而复杂的演化历史,发生多期不同性质活动,形成各具特色的构造样式。本文通过对郯庐断裂带北段各分支断裂出露的构造样式进行野外性质判断、要素分析,利用各种构造样式和地层间切割或覆盖关系的匹配研究,限定了断裂带活动期次及时代,建立了郯庐断裂带北段变形序列。为最终达到揭示西太平洋板块对东北地区中、新生代构造演化规律制约的目的提供了第一手资料。不同构造样式反映了断裂带由老至新经历了以下6个重要的变形事件:①密山县知一镇韧性剪切带黑云母40Ar/39Ar等时线年龄为161±3Ma,是郯庐断裂带再次发生大规模左旋走滑活动并扩展到东北地区的产物;②四平市石岭子镇碎裂花岗岩形成于晚侏罗世晚期,是继左旋韧性剪切活动后挤压作用的结果;③四平市叶赫乡负花状断层系以及早白垩世早期东北断陷盆地群的形成,是郯庐断裂带北段在早白垩世早期发生了强烈的走滑-伸展作用的重要依据;④四平市石岭子镇佳伊断裂大型走滑-逆冲断褶带、桦甸县敦密断裂“逆地堑”、沈阳-哈尔滨逆冲断裂是郯庐断裂带北段特征最明显、分布最广泛的构造样式,它们形成于晚白垩世嫩江运动-晚白垩世末期,反映了这一时期郯庐断裂带北段遭受到广泛而又强烈的右旋走滑-逆冲作用;⑤佳伊、敦密古近纪地堑是右旋走滑、伸展双重机制控制的产物;⑥渐新世末期古近纪地堑的构造反转结束了地堑的演化;中新世郯庐断裂带北段上地幔剪切控制了新生代含幔源包体火山口沿断裂有规律的分布。上述6个重要的变形事件由老至新组成了郯庐断裂带北段较为完整的构造演化序列,它们是不同地球动力学机制的产物,其演化历史主要受控于滨太平洋构造域的构造作用。更多还原

【Abstract】 Tancheng-Lujiang fault zone was a large fault zone of longitudinal east China ,which had undergone a long evolutionary history since the Triassic.From west to east the northern segment of the Tancheng-Lujiang fault zone included Shenyang - Harbin fault,Jiamusi-Yitiong fault and Dunhua-Mishan fault. The direction of the general distribution was NE 40°-50°, the northern segment of the fault zone acrossed the eastwest part of Jilin、Heilongjiang small plate group and the North China Block with different evolutionary history .Because of the Quaternary and vegetation covering, the less exposed of the northern segment of Tancheng-Lujiang fault zone, seriously restricted on in-depth study , its level was significantly lower than the study of the southern segment, there were many problems failed to solve. Such as when a large-scale sinistral ductile slip? When large-scale extensional activities occurred? When thrusting the main activities? How many terms of extension activities and extrusion activities? and so on. No resolved of the basic geological problems, we can not set up correctly the northern segment of Tancheng-Lujiang fault zone tectonic evolution sequence, can not compare with the southern segment of Tancheng-Lujiang fault zone, also not reveal structural response of the fault to the Western Pacific tectonic plate movement. At the same time, these issues are the important bottleneck of the prototype basin in the Meso-Cenozoic basin group restoring of Jilin and the east part of Heilongjiang . Therefore, the study of the nature and the activities times both tracing Western Pacific tectonic systematic impacting on the construction of the Northeast region,and predicting oil & gas resources in Northeast China、earthquakes、volcanic activity is of great significance. The solution to these problems must rely on system researching structural styles of different stages of the fault. I conducted more detailed field investigation and desk studies in the northern segment of Tancheng-Lujiang fault zone in the recent years, and acquired the first-hand information about a large number of different structural styles, Increasing new evidence for the activities times,properties in different times and evolution sequence of the fault zone.Sinistral strike-slip is characteristic of Dunhua-Mishan ductile shear zone near Zhiyi town, Mishan county, ductile shear zone is mylonitized granite, protolith with Neoproterozoic granite.deformation extent of ductile shear zone was uneven,it can be divided in strong deformation zone and weak deformation domain. General wide 1cm-10cm about strong deformation zone,which distrubuted in weak deformation domain with reticular. Mylonitic foliation advantage strike to the NE 45°,mainly southward steep dip, angle of inclination with 50°-75°. Mineral stretching lineation SSW gently dipping, angle of inclination about 20°.Microscopic deformation structures are well developed of strong deformation zone, Quartz drawing structure and Feldspar rotation porphyroclast developed widely, Mineral stretching lineation of field and S-C fabric、rotation porphyroclast of interior orientation slices all directed ductile shear zone with sinistral strike-slip characteristics.Getting the biotite40Ar/39Ar isochron age is 161±3Ma by dating, indicateing that later period of J2 was sinistral strike-slip age of the northern segment Tancheng-Lujiang fault zone,which is the product of Tancheng-Lujiang fault zone recurrence of large-scale sinistral strike-slip that extended to the Northeast region.About 300 meters Cracked granite belt developed in Shiling town , Shiping city in Jiamusi-Yitong fault zone,which trend towarded to the extension of NE. Cataclastic rock belt were focused on structural breccia and Cataclasite, more irregular shapes of tectonic breccia,edges and corners clear, vary in size, diameter of particle was generally between 2mm-5mm, angle the phenomenon of non-aligned gravel,which belong to squeezing action.Did not break-deformed granite U-Pb age of 150-162.5Ma, in the vicinity of cracked granite,Shahezi-Denglouku formation of Early Cretaceous has no fracture deformation closed to cracked granite. These characteristics limited that cracked granite formed in the late of J3 which was the result of compression following the left-lateral ductile shear activity.The negative flower faults exposed in Yehe town,Siping city , which formed by the five normal fault.These faults tend from north slope to south slope, angle of inclination from gently to slope to gently again,indicating external cast of the negative flower faults, the five normal fault down to merged together to form "Dried flowers".By analysing occurrence of brand fault,coming to trend of Dried flowers about NE,which was similar to trend of Jiamusi-Yitong fault.Shahezi formation was cutting by the negative flower faults,but Denglouku formation was not disturbed. By cutting relationship between stratigraphic and faults figured out the negative flower faults forming in Yingcheng epoch between Shahezi epoch and Denglouku epoch. The negative flower faults and the formation of the northeastern fault basin group in the early period of K1 were the important basis for the northern segment Tancheng-Lujiang fault zone suffering from strong strike-slip and stretch in the early period of K1.Large-scale strike slip-thrust fold belt was found in Jiamusi-Yitong fault, including thrust faults and fault-related fold.Thrust faults mainly distributed in areas near the main boundary of the Jiamusi-Yitong fault zone,which has similar occurrence,trend about NNE, angle of inclination about 20°-30°,section shape exhibited characteristics of steep, angle of inclination of fault about 70°~85°, structural lenticular body and extrusion schistosity of faults well developed.In plane Jiamusi-Yitong fault zone was NE 45°direction of extension, The branches thrust faults were ususlly 20°-30°direction,and almost all features with steep, showed an acute angle intersection with the main fault, This feature reflects strong right-lateral strike-slip thrusting nature.Yaojiazu formation and Nenjiangzu formation of later period of K2 was cutting by thrust faults,but the thrust faults was been cover unconformity by Ganyaozu of PaleogeneFault detachment fold in East boundary of Jiamusi-Yitong fault zone was composed of alternate arrangement a series of synclines and anticlines, the west side of fold formation was askew closed fold in section shape ,for the NW of the tilt axis, which was similar to the trend of thrust faults; gradient for the vertical fold to the SE, angles between the two wings were larger to open fold,then increase angle between the two wings to SE,to upright gentle fold. This fold system variation along the profile shown by the not exposed to the surface of the detachment fault-controlled. Fault bend fold in East of fault detachment fold, thrust fault was composed of flat and ramp, thrust rock of fault on the plate climb along ramp,in the end turn of flat and ramp form wide slow anticline, angle of inclination about anticline wings roughly equal. Folds occured as fine gray conglomerate of Denglouku formation.Form Dunhua city of Northern Jilin province to Meihekou city of Southern Dunhua-Mishan fault was mainly composed of arranged parallel of two high-angle thrust fault. these two main boundaries fault was 15- 20km apart general, Cenozoic basin were distributed in intermediate.tendency of main fault was contrary, angle of inclination of fault about 50°-80°,on southeast the hanging wall of main fault was composed of supracrustal rocks in the Archean such as variable biotite granulite、amphibolites magnetic quartzite rock folder,on northwest the hanging wall of main fault was composed of Hercynian,Yanshan granite and Jurassic– Cretaceous, the hanging wall of fault hedge in the opposite over Jiuda formation coal measures of Late Jurassic-Dashata formation of Early Cretaceous、Xiaonangou formation of Late Cretaceous, formed a "reverse Graben" fault system. In addition to surface rendering "reverse Graben" outside the structural style, also in deep underground reflected opposite thrust of the tectonic framework. In Tangyuan Graben DB04 profile MT interpretation maps perpendicular to Jiamusi-Yitong fault, proved "reverse Graben" formed of two main thurst faults in deep underground,which indicating consistent of deep detection and surface observations.along the fault zone trend, alternating with each other pattern about rift composed of the Paleogene and uplift composed of Cretaceous exist,in the uplift, for the absence of Paleogene graben coverage, Surface mainly as a "reverse Graben" structural style,in the lift, covered by Graben sedimentary on the surface ,the deep underground showed "reverse graben".Large-scale strike slip-thrust fold belt and the"obsequent graben"in Dunhua-Mishan faulted zone of Huadian City were the most obvious and wide-distributed structural styles in the northern segment of Tancheng-Lujiang fault zone formed in the Nenjiang movement of later period of K2 and last stage of K2 ,which reflects the northern segment of the Tancheng-Lujiang faulted zone subjected to the extensive and strong right-lateral strike-slip thrusting activity.Paleogene graben of Jiamusi-Yitong and Dunhua-Mishan asymmetry in the cross section in the structural style.Basin side faults was steep and deep and controled large sediment thickness,the other side faults cut shallow and control small sediment thickness,indicating that a side faults had a main action in the formation of the graben. which was the product of the northern segment of Tancheng-Lujiang fault zone controlled by right-lateral strike-slip and extensional double machanism in PaleogeneLate Oligocene pre-thrusting normal faults in Paleogene graben transform into reverse faults, to form the structural framework right on thrust ,that reversal structure,Which ended the early evolution of the graben, in this issue thrusting a relatively small, the formation of small-scale thrust faults, the number of small, very limited displacement;the upper mantle shearing in the northeast segment of Tancheng-Lujiang faulted zone in Miocene controls the Cenozoic volcanic crater containing mantle enclave regularly distributed along the fault.Over these different times, different types of structural styles, formed in different deformation events, The above six major deformational events from the old to the new formed a relatively complete tectonic evolutionary sequence of the northern segment of Tancheng-Lujiang faulted zone.①sinistral strike-slip ductile stage (the last stage of J2)②Compression strike-slip stage (in the late of J3)③left-lateral tenso-shear stage(the earlier-mid period of K1)④right-lateral compression shear stage (of later period of K2-last stage of K2)⑤right-lateral strike-slip fault depression stage(E)⑥structural inversion and upper mantle shearing ( the end of E3 and N1)These are the products of the different geodynamic machanism.The evolutionary history of the northern segment of Tancheng-Lujiang faulted zone was mainly controlled by circum-Pacific tectonic domain.更多还原