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1.
沂沭断裂带大水场剖面断层泥的ESR年代学研究   总被引:6,自引:0,他引:6       下载免费PDF全文
对山东省沂水县大水场断层剖面的断层泥带进行了野外观测和ESR 测年。断层泥的ESR年龄与由其穿插关系等判断出的断层活动次序相符。各断层泥的ESR 年龄显示出大水场断层经历了两个活动较频繁的时段,即0-25~0-28Ma B-P- 和0-45~0-55Ma B.P  相似文献   

2.
潘志龙  张欢  王慧  李庆喆  卜令  石光耀  张金龙 《地震工程学报》2022,44(5):1117-1127,1150
香河—皇庄断裂位于华北盆地北缘,是京津唐地区一条重要的NE向断裂构造。浅层人工地震反射剖面探测发现,香河—皇庄断裂在廊坊市香河县西马家窝地区表现为一条NE-SW走向的NW倾正断层,剖面上呈铲状,上部略陡,向下逐渐变缓;其对大厂凹陷东缘没有明显的控制作用,为一条新近纪以来形成的断裂,切穿了前中生界基底,且第四纪以来仍有活动。通过部署于断层两侧的构造观察孔岩芯对比及测年数据判断,(6.69±5.6) ka以来香河—皇庄断裂无活动,其上断点很可能位于距地表15~30 m范围内,大致相当于晚更新世早期;在中更新世上部地层中,香河—皇庄断裂存在1.5~1.8 m的垂直落差。香河—皇庄断裂现阶段处于不活动状态,未来发生中强地震的可能性较低。  相似文献   

3.
潍坊市主要隐伏断层活动特征研究   总被引:1,自引:0,他引:1  
利用浅层人工地震、电法勘探和工程钻探等多种方法在潍坊市开展了隐伏活断层探测工作,查明了潍坊市城区周围沂水-汤头断裂、鄌郚-葛沟断裂、寒亭断裂和潍县断裂等6条主要断裂的位置;通过释光(TL、OSL)和电子自旋测年(ESR)研究了这些断裂的最新活动时代。结果表明,潍坊市城区范围内无活动断层通过,为土地利用和城市建设规划提供了科学依据。  相似文献   

4.
阐述了断层泥石英颗粒ESR信号达到零化的温度和压力环境,通过4个具体ESR测年实例,论述了测年样品的不同零化程度和测年数据的可靠性。对ESR信号与TL(热释光)信号零化环境的差别及其原因进行了初步的探讨。介绍了断层测年样品ESR信号达到零化的验证的方法。同时,提出了断层测年样品采集时应注意的有关问题  相似文献   

5.
Buried faults in Weifang city and surrounding areas are studied with geophysical surveys such as shallow seismic survey and electrical exploration, and verified with engineering drilling. Six main faults are detected including the Yishul-Tangtou fault, Tangwu-Gegou fault, Hanting fault and Weixian fault, etc. The latest active age is determined by OSL, TL and ESR dating techniques. No active fault has been found so far in the Weifang urban area. Our results provide a scientific basis for land use and urban planning.  相似文献   

6.
Little work has been undertaken on combined dating of sedimentary quartz grains using electron spin resonance (ESR) and optically stimulated luminescence (OSL) techniques in Australia. This study aims to assess the suitability of a combined ESR and OSL dating approach for establishing improved chronologies of Middle-Late Pleistocene deposits within the Naracoorte Cave Complex (NCC), South Australia. Here, we apply ESR and OSL dating in tandem to a series of samples collected from three different NCC sites: Whale Bone, Specimen and Alexandra cave. ESR quartz dating focuses on the multi-centre (MC) approach, which involves comparative evaluations of Al and Ti centre signals, while paired luminescence dating focuses on single-grain OSL analysis and includes examination of multi-grain averaging effects. The comparative ESR-OSL dating results exhibit broad agreement for deposits spanning 50–150 thousand years, with either the Ti–H or Al centre ages overlapping with paired OSL ages at 2σ in nearly all cases. MC ESR evaluations (Al v Ti–Li v Ti–H age assessments) indicate incomplete resetting of the bleachable Al centre signal for a small number of samples. Two-thirds of samples exhibit Ti–Li ages that are significantly older than corresponding Al centre ages, which is unexpected from a bleaching kinetics perspective and may indicate a broader reliability issue for Ti–Li palaeodose evaluation with these particular samples. Our findings: (i) support the applicability of both palaeodosimetric dating methods in this depositional setting; (ii) highlight the merits of applying combined ESR-OSL analyses in tandem, and; (iii) provide one of the first reliable evaluations of quartz ESR MC dating for samples with natural dose ranges as low as only a few tens of Gy. These results show that the Whale Bone, Specimen and Alexandra cave sites are temporally related and can be used to derive multi-site reconstructions of faunal assemblages and palaeoenvironmental history.  相似文献   

7.
深圳市观澜断裂第四纪活动性研究   总被引:2,自引:1,他引:1  
观澜断裂是深圳陆域地区规模最大的北北西向断裂。通过地质地貌调查、联合钻孔探测及地质年代测定等技术方法对观澜断裂的第四纪活动性进行了详细考察与综合研究。结果表明:穿越低丘陵台地地貌区的观澜断裂两侧未见地貌差异或现代构造形变现象;4个典型地质露头和2条钻孔联合剖面显示断裂没有扰动上覆第四系.观澜大布巷钻孔探测剖面还获得了断裂上覆冲洪积砂层底部12.6±2.4Ka的光释光测年数据;断裂物质主要由碎裂岩、构造角砾岩、硅化岩等组成.可见硅质被膜及半固结岩屑或岩粉状物质;7个断层样品的电子自旋共振测试结果显示断裂的最新活动年龄为距今21.1±2.1万年。结合12条浅层地震测线探测未发现断裂错移第四纪覆盖层底界的事实.得出了观澜断裂最新一次活动发生在中更新世晚期.自晚更新世中期以后没有新的近地表活动的结论。  相似文献   

8.
Abstract Electron spin resonance (ESR) analyses of quartz grains in fault gouge were performed for a core sample taken from the Nojima Fault that moved during the 1995 Kobe earthquake (Hyogo-ken Nanbu earthquake). Distribution of radiation-induced defects in the gouge at a depth of 389.4 m was measured by extracting quartz grains from seven discrete positions within 30 mm of the fault plane on the granite side. The decrease in E'1 and Al centers was observed within 2 mm of the fault plane, suggesting partial annealing due to faulting. Partial annealing even at that depth suggested that conventional ESR dating, which is based on the hypothesis of complete annealing during faulting, was not applicable. Theoretical calculations of the temperature rise and of the thermal annealing of defects have been made by assuming a simple annealing model of heat generation on the fault plane. Thermal energy was calculated to have been approximately 8 MJ/m2 to explain the profile of the heat-affected region. Thermal energy was much larger than the one estimated from hydrothermal solution, and corresponded to the frictional heat calculated for a normal stress of 20 MPa, a displacement of 2 m, and a frictional coefficient of 0.2.  相似文献   

9.
Quartz is one of the minerals useful for ESR dating with many applications. Although the study has quite a long history since 1980's, ESR dating of quartz is still in a developing stage. After the basis in physics for the ESR signals in quartz is described, the current status of ESR dating of quartz is summarized for applications to fault gouge, tephra and sediment. Both basic studies for mechanisms and practical applications with independent age controls are still necessary to establish the protocols.  相似文献   

10.
深圳市横岗-罗湖断裂第四纪活动性研究   总被引:3,自引:0,他引:3  
本文在前人研究的基础上,采用地质地貌调查、联合钻孔探测及地质年代测定等技术方法,对深圳横岗-罗湖断裂的第四纪活动性进行了详细考察与综合研究。结果表明:横岗-罗湖断裂最新一次活动发生在中更新世,自晚更新世中期以来没有新的活动证据。  相似文献   

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