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1.
The history of Middle to Late Miocene evolution of the Transylvanian Basin was determined by the bordering Carpathian orogen evolution, the tectonic events being well recorded by the sedimentary history. The basin evolved in a back-arc setting, under a regional, compressional stress field. The major tectonic events produced during the Late Sarmatian and Post-Pannonian were related to the reactivation of the pre-Badenian fault systems. The Transylvanian Basin got uplifted after the Late Pannonian (? during the Pliocene), and at least 500 m of sedimentary cover was eroded.
Based on seismic and well-log interpretation, core and outcrop sedimentology, and microfauna, eight sequences were defined. The early Middle Miocene sequences are roughly synchronous to five 3rd order global sea-level cycles. Most of the recognized sequence boundaries are enhanced by regional tectonic events. The sedimentary evolution was also strongly influenced by salt-tectonics, active starting with the Late Sarmatian.
Two sequences were identified in the Lower Badenian deposits. The third sequence (late Early Badenian to early Mid Badenian) preserves information about deeper shelf settings. The lowstand of the following sequence was responsible for the deposition of the salt formation (late Mid Badenian), an important lithostratigraphic marker in the sedimentary record of the basin. In general, the Upper Badenian deposits (parts of the 4th and 5th sequences) belong to deep marine submarine fan systems. The Sarmatian (partially 5th, 6th and partially 7th sequences) was characterized by diverse salinity conditions, stretching from brackish to hypersaline, and by high tectonic instability, which induced several significant relative sea-level falls. During that time, deltaic (north) and fandeltaic (east) systems fed submarine fans, stacked between salt-related submarine heights (“channeled” deep-marine depocenters). Most of the Pannonian deposits (partially 7th and 8th sequences) belong to submarine fan systems, but shallower facies were also found in the western and eastern part of the basin. 相似文献
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新建9个正式岩石地层单位、4个非正式地层单位;将上三叠统日干配错群解体为6个岩石地层单元;解体中上侏罗统雁石坪群;将色哇组分为三段;将班公湖怒江带木嘎岗日群解体为4个岩石地层单元;在西藏首次发现(上三叠统姜钟组)纳拉菁耳羽叶;在羌塘盆地首次发现(下—中侏罗统色哇组)辐鳍鱼类化石;新建8个侵入岩填图单位,时代为晚侏罗世—新近纪末期;在班 怒结合带塔仁本一带首次发现了洋岛型玄武岩;新发现了一系列新生代岩浆岩;在班怒带及南羌塘盆地中发现一些呈串珠状分布的小型斑岩体;发现班 怒带上时代最新的枕状玄武岩。 相似文献
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上世纪70年代以来，由于雨花台组与其他砂砾层之间接触关系未被发现，南京—仪征地区新近纪地层层序及时代一直存在着争议。笔者对仪征大仪集新仪1孔剖面进行了重新整理划分，新近纪各地层叠置关系明显，同时结合其他剖面及岩相古地理分析，在前人工作的基础上，对新近纪地层层序及时代进行了讨论。该地区新近纪地层层序为中新世中期的洞玄观组(N1d)、中新世晚期的六合组(N1l)黄岗组(N1h)及上新世的雨花台组(N2γ)以及非正式岩石地层单位方山玄武岩(fb)。雨花台组沉积是位于六合组之上的另一套砂砾层，其沉积时代为上新世晚期。 相似文献
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四川省盐边县北部稗子田地区的专留系发育良好,牙形刺化石极为丰富,与上覆泥盆系连续沉积,并呈整合接触。该剖面为我国扬子区较为理想的志留纪地层剖面,其代表和反映了扬子区西部一种新的断陷盆地碳酸盐岩沉积类型,丰富了区内志留系的研究内容。笔者详细记述了稗子田专留系至下泥盆统下部剖面的岩性特征和生物化石的垂直分布状部,在此基础上建立和完善区内新的地层系统,提出地层划分的对比依据和建议。新方案除对志留系底的黑 相似文献
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The Fichtelgebirge and Steinwald areas are situated at the western end of the Cenozoic Eger graben. Repeated Neogene fault activity and polyphase morphogenesis created a complex morphotectonic structure. Based on morphotectonic criteria three stages of tectonic activity can be determined: (a) late Oligocene to early Miocene; (b) middle-late Miocene; and (c) late Pliocene to early Pleistocene. Due to the Neogene tectonic movements, the pre-basaltic (preOligocene to Miocene) landscape has been differentially uplifted/downthrown and intensely modified by post-basaltic surface planation (HF). Broad paleovalleys (AT) of late Miocene to early Pliocene age and a system of Pliocene and Quaternary fluvial terraces and pediments (BT and ET) have been incised into the widespread HF relief elements. Due to repeated faulting and erosion, the stratigraphic record of Neogene sediments within the studied area is fragmentary. 相似文献
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通过对山西榆社地区新近纪地层的野外地质调查和实测剖面,对分布于该区的新近纪地层进行了详细的研究和划分,提供了新的ESR测年数据,并结合古地磁年龄、生物地层序列确定了该区新近纪地层顺序为:新近系上新统上部麻则沟组(Naa m)、新近系上新统下部高庄组(N12 g)和中新统马会组(N1m).根据实测剖面,可将这3个组的河湖相地层划分为37层,总厚度达446.5 m.ESR测年结果表明,麻则沟组的形成时间为2.50～3.04 Ma,属新近纪上新世晚期;高庄组形成时间为3.25～5.25 Ma,属新近纪上新世早期;马会组形成时间为5.30～13.10 Ma,属新近纪中新世晚期. 相似文献
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青东凹陷新生代垂向地层序列及展布特征 总被引：3，自引：0，他引：3
针对青东凹陷勘探程度较低、新生代地层发育特征尚不明晰的现状,从岩性、测井、地震、古生物化石等资料入手,结合区域地质背景,对凹陷新生代地层进行了构造层和岩石地层的多重划分,将其划分为古近系和新近系—第四系两个构造层,其中古近系构造层自下而上发育孔店组、沙四段、沙三段、沙二段,地层发育特征与东营凹陷相似,但垂向序列不完整,缺失沙一段和东营组。在此基础上结合钻井标定和地震剖面的解释,重点绘制了古近系四个构造亚层的残留地层等厚图,并对其展布特征进行了分析。结果表明,各构造亚层残留地层在厚度和展布方向上变化较大,且具有一定的规律性,体现了不同地质时期盆地沉积充填和构造演化的差异性。最后对青东凹陷缺失沙一段—东营组的可能原因进行了初步讨论,认为新生代地幔柱高点由渤海湾盆地南部迁移到渤海海域可能造成该地区在古近纪末期未接受沉积,而据垦东地区北部的物源在沙一—东营期来自南部也可推测该时期青东凹陷已抬升遭受剥蚀。 相似文献
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《Geodinamica Acta》2001,14(1-3):31-43
This paper describes the Neogene evolution of northwestern Anatolia based on geological data collected in the course of a new mapping program. The geological history of the region, as recorded by the Neogene sedimentary and magmatic rocks that overlie the Paleozoic–Triassic basement, began after a lake invasion during the Early Miocene period with the deposition of shale-dominated successions. They were accompanied by calc-alkaline intermediate lavas and pyroclastic rocks ejected through NNE trending fractures and faults. The Lower–Middle Miocene successions were deformed under a compressional regime at the end of the Middle Miocene. The deposition of the overlying Upper Miocene–Lower Pliocene successions was restricted to within NE–SW trending graben basins. The graben bounding faults are oblique with a major strike-slip displacement, formed under approximately the N–S extension. The morphological irregularities formed during the Miocene graben formations were obliterated during a severe erosional phase to the end of the deposition of this lacustrine succession. The present E–W graben system as exemplified from the well-developed Edremit graben, postdates the erosional phase, which has formed during the Plio-Quaternary period. 相似文献
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依据丰富翔实的地层古生物资料,首次在内蒙古西部建立了比较完整的第三纪地层层序：命名或厘订了中始新统乌兰乌珠尔组、上始新统查干布拉格组、下渐新统乌兰塔塔尔组、上渐新统、下中新统乌尔图组、上中新统呼和好来组和上新统昂冈浩特组等７个地层单元;区分出了中始新世乌兰乌珠尔、晚始新世查干布拉格、早渐新世早期克克阿木、早渐新世晚期乌兰塔塔尔、晚渐新世因德里沟、早中新世乌尔图、晚中新世呼和好来和上新世昂冈浩特等８个动物群（组合）。 相似文献
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华北地台石炭二叠纪若干地层问题 总被引：5，自引：1，他引：4
以现代地层学理论为指导,以丰富翔实的地质资料为基础,对华北地台石炭二叠纪的若干地层问题进行了剖析并提出：１）修订并论证了华北地台上古生界最底部的一个岩石地层单位——田师傅组,指出这个组的区域分布和穿时性特征,同时对其实用性也进行了论证;２）讨论了华北地台石炭系－二叠系界线,主张以类Ｐｓｅｕｄｏｓｃｈｗａｇｅｒｉｎａ带底作为二叠系的开始,有利于大区域内的相关地层划分对比;３）讨论并厘定了华北地台本溪组、太原组和上石盒子组等岩石地层单位的含义;４）华北地台东北部确切存在早石炭世沉积,传统的有关该区的地质历史结论应予修正。 相似文献
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AbstractThis paper describes the Neogene evolution of north-Western Anatolia based on geological data collected in the course of a new mapping program. The geological history of the region, as recorded by the Neogene sedimentary and magmatic rocks that overlie the Paleozoic-Triassic basement, began after a lake invasion during the Early Miocene period with the deposition of shale-dominated successions. They were accompanied by calc-alkaline intermediate lavas and pyroclastic rocks ejected through NNE trending fractures and faults. The Lower-Middle Miocene successions were deformed under a compressional regime at the end of the Middle Miocene. The deposition of the overlying Upper Miocene-Lower Pliocene successions was restricted to within NE-SW trending graben basins. The graben bounding faults are oblique with a major strike-slip displacement, formed under approximately the N-S extension. The morphological irregularities formed during the Miocene graben formations were obliterated during a severe erosional phase to the end of the deposition of this lacustrine succession. The present E–W graben system as exemplified from the well-developed Edremit graben, postdates the erosional phase, which has formed during the Plio-Quaternary period. © 2001 Éditions Scientifiques et médicates Elsevier SAS 相似文献
14.
上二叠统长兴组分别与飞仙关组、吴家坪组整合接触,在元坝地区为一套稳定的海相碳酸盐岩沉积建造,有利于开展层序地层学研究。通过地震地层学方法、岩石岩相地层学方法以及Daubechies小波分析方法对元坝地区长兴组层序界面、体系域进行识别及特征研究,共划分出2个Ⅲ级层序(旋回)。进一步在单井上进行米兰科维奇旋回的划分及对比,通过岩石学及Daubechies小波方法解释结果可知db5曲线,由此识别出的36个旋回与人工解释的米兰科维奇旋回良好对应。将解释结果绘制Fischer图解,进一步对所得图解进行元坝地区长兴组地层可容空间演化特征分析,再次证实元坝地区长兴组存在的2次可容空间周期变化。最后以本实例为基础对Fischer图解形态特性、影响因素进行讨论。 相似文献
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须家河组二段是川西坳陷中的区域气层。长期以来，地质分层采用岩石地层单位界面。这一界面的穿时性，造成了构造演化分析中的误差。笔者以钻井、测井和地震资料为主要研究对象，在引入地震反射“等时”约束条件的前提下，通过对须家河组长期基准面旋回层序及须二段中期基准面旋回层序的划分和对比，在建立高分辨率时间一地层格架的基础上，经过地震微相特征的仔细分析，确认须二段顶面属Ⅲ级整合界面。 相似文献
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根据"中国地层指南"(2001)关于岩石地层单位的划分,将出露在伊勒呼里山地区的泥鳅河组(S3-D2n)、根里河组(D2-2g),小河里河组(D3x、花达气组(C1h)和查尔格拉河组(C1ch)的一套海相-陆相连续沉积的碎屑岩并组为群,称燎原群(S—C1L).以黑河市查尔格拉河流域为典型地区,并划分燎原群下亚群(S3—C1La)(包括泥鳅河组和根里河组).燎原群上亚群(S3—C1Lb)(包括小河里河组、花达气组和查尔格拉河组).在黑龙江省岩石地层(清理)中,通过横向对比和纵向层序分析等工作认为,燎原群下亚群以海相碎屑沉积岩为主,而燎原群上亚群则以陆相碎屑沉积岩为主,两者之间为整合接触关系,燎原群底以下伏卧都河组上部含砾砂岩消失为界,而顶部不全,时代为晚志留世晚期至早石炭世. 相似文献
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《International Geology Review》2012,54(4):350-362
The Chapala graben forms part of a regional system of intra-arc and half-grabens located along the western and central portions of the Mexican Volcanic Belt. Results of a stratigraphic and tectonic study of the thick, widespread volcano-sedimentary sequence around the Chapala graben are reported. The study has concentrated on the distribution of lacustrine deposits and on the stratigraphy, geochronology, and deformation of the sequence. The volcano-sedimentary record suggests a probable link between the Tepic-Zacoalco and Chapala grabens through a basin system developed during late Miocene and early Pliocene time. The stratigraphic sections show a southward spatial migration of the basin (and lake) system. The main unit of the volcano-sedimentary succession is the Chapala Formation, which has been affected by northeast tilting, unlike the lacustrine deposits to the east in the Chapala plain (e.g., Ixtlan area), where the sequence is essentially flat lying. Two distinct units with different structural attitudes, separated by an angular unconformity, can be distinguished in the Chapala Formation. Based on differences between the stratigraphic sections and structural attitudes, we propose a model for development of the Chapala graben that involves a combination of left-lateral and extensional deformation, together with volcanic and erosional processes, all of which have contributed to shape the basin. Furthermore, we suggest that Lake Chapala is the remnant of a large Jalisco paleo-lake in west-central Mexico. 相似文献
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This study focuses on the detailed provenance evolution of young, syn- to post-orogenic extensional grabens in orogens like the Himalaya to trace the tectonic history of such late-stage basins, using the Neogene Thakkhola-Mustang Graben as a case study. The graben is situated within the Tibetan-Tethys zone and is filled with > 870 m of continental deposits of Miocene to Holocene age-. Based on logged sections within the predominantly alluvial to coarse-grained fluvial fill of the graben we investigated paleocurrent data and the petrology of sandstones and conglomerates including heavy minerals studies to interpret provenance and source areas in detail. Significant changes are recorded by slight differences in heavy mineral and pebble compositions.The sandstones can be classified as lithic greywackes, lithic arkoses and feldspathic litharenites. Sandstone, mudstone, quartzite and some granite clasts are dominant in conglomerates of the central part of the graben. Tetang Formation conglomerates of Miocene age comprise mostly clasts of Mesozoic rocks with an eastern provenance, consistent with measured paleocurrent directions. All paleocurrent data and compositional analyses of imbricated conglomerates of the Miocene–Pliocene Thakkhola Formation in the northeast of the graben suggest that clasts were derived from eastern source areas comprising mainly Mesozoic rocks whereas Paleozoic clasts of a western to northern source area predominate in the centre of the graben.Heavy mineral analysis indicates that tourmaline, staurolite, zircon, garnet and apatite constitute a significant proportion of the assemblages of all formations through time whereas epidote, andalusite, kyanite, chloritoid, hornblende, chrome-spinel, rutile and amphiboles are less common. These assemblages reflect in general stable minerals and low to high-grade metamorphic source rocks, and are principally controlled by reworking of older, passive margin sediments of the Tibetan-Tethys zone as indicated by provenance discrimination diagrams.Three successive stages in provenance evolution were recognized: (1) The Miocene Tetang Formation, characterized by higher kyanite values, corresponding to the Himalayan foreland evolution; (2) the Thakkhola Formation, characterized by granite clasts and significantly higher amounts of andalusite, indicating source area expansion and erosion of the Mustang-Mugu granites to the northwest; (3) the Upper Pleistocene/Holocene Kaligandaki Formation, bearing higher amounts of epidote/klinozoisite and ophiolite and high-pressure/low temperature detritus as indicated by chrome spinel and blue amphiboles, derived from the north-lying Indus-Tsangpo suture zone. The change in source areas from the Miocene/Pliocene to the Late Pleistocene/Holocene is interpreted as a result of the evolution from an initial stage of high-angle normal faulting and collapse basin formation to a low-angle extensional detachment basin system. 相似文献
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Can Ş. Genç Şafak Altunkaynak Zekiye Karacık Metin Yazman Yücel Yılmaz 《Geodinamica Acta》2013,26(1-3):45-55
AbstractField studies on the Neogene successions in south of ?zmir reveal that subsequent Neogene continental basins were developed in the region. Initially a vast lake basin was formed during the early-Middle Miocene period. The lacustrine sediments underwent an approximately N-S shortening deformation to the end of Middle Miocene. A small portion of the basin fill was later trapped within the N-S-trending, fault-bounded graben basin, the Çubukluda? graben, opened during the Late Miocene. Oblique-slip normal faults with minor sinistral displacement are formed possibly under N–S extensional regime, and controlled the sediment deposition. Following this the region suffered a phase of denudation which produced a regionwide erosional surface suggesting that the extension interrupted to the end of Late Miocene–Early Pliocene period. After this event the E–W-trending major grabens and horsts of western Anatolia began to form. The graben bounding faults cut across the Upper Miocene–Pliocene lacustrine sediments and fragmented the erosional surface. The Çubukluda? graben began to work as a cross garden between the E–W grabens, since that period. © 2001 Éditions scientifiques et médicales Elsevier SAS 相似文献