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1.
1981年,我队肖伟民、王洪第、康沛泉、沈邦耀等在贵州六枝郎岱洒志一带,测制了早二迭世地层剖面。化石发育较全,尤以(竹蜓)类化石极为丰富,属种繁多,保存甚好;次为珊瑚、腕足及少量其他化石。其中(竹蜓)类化石经笔者研究,发现茅口组第一段上部深灰色厚层夹中厚层泥晶生物屑灰岩中,保存一类旋壁具纤维状构造之层,壳形与南京(竹蜓)十分相似,初房特大的(竹蜓),定名为Sazhiella gen.nov.,归于史塔夫(竹蜓)科。 相似文献
2.
西藏羌北地区石炭纪(竹蜓)类动物群是笔者等于2004年首次发现的,并将动物群所在层位建立了瓦垄山组,该套地层中产大量的(竹蜓)类化石,种属多,分布连续.经研究,自下而上建立6个(竹蜓)类化石带:(1)Eostaffella mosquensis带,(2)Millerella-Eostaffella带,(3)Pseudostaffella-Eostaffella带,(4)Profusuliena带,(5)Fusulina-Fusulinella带,(6)Protriticites-Triticites带.该套含(竹蜓)类化石地层的发现,为研究羌北地区晚古生代构造活动提供了信息,也为研究该区石炭纪地层、古生物、生物古地理、区域性地层划分和对比提供了依据. 相似文献
3.
4.
Nie Zetong Song Zhimin 《地球科学》1990,(3)
本文通过对西藏二叠系(竹蜓)类及非(竹蜓)有孔虫的研究认为,早二叠世早期(竹蜓)类以冷温型的Monodiexodina动物群为主,属冈瓦纳—特提斯生物区,冈瓦纳大陆与欧亚太陆及扬子地块的分界分别为昆仑山南坡断裂和金沙江断裂。早二叠世晚期(竹蜓)类Neoschwagerina-Polydiexodina动物群仍限于冈瓦纳北缘区,其生物区系以及扬子地块的分界与早二叠世早期相同,而冈瓦纳大陆北缘西部首先与欧亚大陆塔里木等地块接近,该动物群才越过了昆仑山北坡。晚二叠世晚期(竹蜓)类以Palaeofusulina动物群为主,与扬子地块相似属华夏—特提斯生物区,冈瓦纳与欧亚大陆的界线转为班公湖—怒江断裂,而冈底斯带与喜马拉雅带至今未见Palaeofusulina,该二带仍属冈瓦纳—特提斯生物区。 相似文献
5.
陈旭字旦初,浙江乐清人.著名的古生物学家、地质教育家.1925年毕业于北京大学地质系,留校任教.1927～1936年任中央研究院地质研究所助理研究员.先后发表《(竹蜓)科化石之研究》(1929)、《黄龙灰岩及其动物群》(与李四光合作,1930)、《扬子江下游石炭纪及二叠纪灰岩中(竹蜓)科化石之分布与重要化石带》(1931)、《二叠纪(竹蜓)科之研究》(1934)、《广西黄龙灰岩及马平灰岩之 相似文献
6.
太原西山上石炭统太原组的(竹蜓)类分带 总被引：9，自引：3，他引：9
<正> 太原西山是华北晚石炭世海陆交替相含煤沉积之一——太原组的层型剖面建立地区。李四光教授(1927—1931)曾于《中国北部之(竹蜓)科》等专著中,记述产于区内太原组中的若干(竹蜓)类,为华北区石炭纪的(竹蜓)类研究及地层的划分对比,奠定了重要基础。盛金章、李星学(1965)亦曾记载过太原西山太原组的部份(竹蜓)类名单。但区内太原组的(竹蜓)类尚缺乏系统的研究。近年来,山西区调队在太原西山的玉门沟—北岔沟—前火山一带,重新测 相似文献
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8.
一、引岩吉林省延边地区属于华力西晚期地槽褶皱区,晚古生代地层发育,经杨启伦、李西昆等于1962～1963年在区域地质调查中进行了较为详细的划分,建立了晚石炭世山秀岭组。标准剖面位于延吉县开山屯镇西南十公里的山秀岭。1980年李莉、谷峰在古生物学报上描述了该剖面的腕足类化石13属20种,同年,韩建修在东北地区古生物图册中研究和描述了(竹蜓)类化石6属9种,但对(竹蜓)类化石的分带尚未涉及。笔者根据对该剖面(竹蜓)的研 相似文献
9.
在醴陵县大障煤矿的当冲组中、上部发现了较多的(竹蜓)类化石。它对确定地层时代、划分与对比,以及古生物等方面的研究都具有一定意义。作者对化石进行了系统描述 相似文献
10.
1979年,在江西省西云山矿区的乐平煤系中发现了Neomisellina等(竹蜓)化石,长期来虽然有不少人设想江西的乐平组下部也存在茅口阶,但是缺少明确的化石证据。西云山位于莲花县北部,该处的乐平组与安福、 相似文献
11.
I.McDermid J.C.Aitchison Badengzhu A.M.Davis Liu Jianbing Luo Hui Wu Hiyun S.V.Ziabrev WT ”BX 《地学前缘》2000,(Z1)
ZEDONG TERRANE, A MID CRETACEOUS INTRA-OCEANIC ARC, SOUTH TIBET 相似文献
12.
《Australian Journal of Earth Sciences》2013,60(6):1035-1041
In its type area around Narooma, the Narooma Terrane in the Lachlan Orogen comprises the Wagonga Group, which consists of the Narooma Chert overlain by the argillaceous Bogolo Formation. Conodonts indicate that the lower, largely massive (ribbon chert) part of the Narooma Chert ranges in age from mid-Late Cambrian to Darriwilian-Gisbornian (late Middle to early Late Ordovician). The upper Narooma Chert consists of shale, containing Eastonian (Late Ordovician) graptolites, interbedded with chert. Where not deformed by later faulting, the boundary between the Narooma Chert and Bogolo Formation is gradational. At map scale, the Narooma Terrane consists of a stack of imbricate thrust slices caught between two thrust faults that juxtaposed the terrane against the coeval Adaminaby Superterrane in Early Silurian time. These slices are best defined where Narooma Chert is thrust over Bogolo Formation. The soles of such slices contain multiply foliated chert. Late extensional shear bands indicate a strike-slip component to the faulting. The Narooma Terrane, with chert overlain by muddy ooze, is interpreted to be an oceanic terrane that accumulated remote from land for ～50 million years. The upward increase in the terrigenous component at the top of the Wagonga Group (shale, argillite, siltstone and sandstone of the upper Narooma Chert and Bogolo Formation) records approach of the terrane to the Australian sector of the Gondwana margin. Blocks of chert, argillite and sandstone reflect extensional/strike-slip disruption of the terrane as it approached the transform trench along the Gondwana-proto-Pacific plate boundary. Blocks of basalt and basalt breccia represent detritus from a seamount that was also entering the trench. There is no evidence that the Narooma Terrane or the adjacent Adaminaby Group formed in an accretionary prism/ subduction complex. 相似文献
13.
Kurosegawa Terrane in Southwest Japan: Disrupted Remnants of a Gondwana-Derived Terrane 总被引：1，自引：0，他引：1
The Kurosegawa Terrane is an anomalous, disrupted, Paleozoic and Mesozoic lithotectonic assemblage characterized by fragments of continent and continental margins. It is located in Southwest Japan where it lies between two Mesozoic subduction complex terranes. The Kurosegawa Terrane is an exotic and far-travelled geologic entity with respect to its present position. Limestones of the Kurosegawa Terrane formed along a continental margin yield fusulinacean fossils Cancellina, Colania and Lepidolina. Accordingly, the Kurosegawa Terrane was once situated within the Colania-Lepidolina territory in the East Tethys-Panthalassa region at a palaeo-equatorial latitude, possibly close to the eastern margin of the South China and/or Indochina-East Malaya continental blocks. These blocks had rifted from Gondwana by late Devonian. They drifted northwards, passing through the Colania-Lepidolina territory in mid-Permian time, and amalgamated with the proto-Asian continent during the late Triassic. Subsequently, during the Cretaceous, parts of the allochthonous continental blocks and their associated tectonic collage were transpressed, dispersed, and displaced from the southeastern periphery of Asia towards the north. As a result, the Kurosegawa Terrane is formed as a disrupted allochthonous terrane, characterized by a serpentinite melange zone, lying between the adjoining Mesozoic subduction complex terranes. 相似文献
14.
Summary The Lanterman Fault Zone, a major terrane boundary in northern Victoria Land, displays a polyphase structural evolution. After
west-over-east thrusting, it experienced sinistral strike-slip shearing. Sheared metabasites from the Wilson Terrane (inboard
terrane) preserve a record of retrograde metamorphic evolution. Shearing took place under amphibolite-facies metamorphic conditions
(roughly comparable to those reached during regional metamorphism) which later evolved to greenschist-facies conditions. In
contrast, the Bowers Terrane (outboard terrane) preserves a prograde metamorphic evolution which developed from greenschist-facies
to amphibolite-facies metamorphism during shearing, followed by greenschist-facies metamorphism during the late deformational
stages. Laser step-heating 40Ar–39Ar analyses of syn-shear amphibolite-facies amphiboles yielded ages of 480–460 Ma, in agreement with a ∼480-Ma age obtained
from a biotite aligned along the mylonitic foliation. These ages are younger than those (∼492 to ∼495 Ma) obtained from pre-shear
amphibole relics linked to regional metamorphism of the Wilson Terrane. Results attribute the structural and metamorphic reworking
during shearing to the late stages of the Cambrian-Ordovician Ross Orogeny and to the Middle-Late Ordovician probably in relation
to the beginning of deformation in the Lachlan Orogen, thus precluding any appreciable impact of the Devonian-Carboniferous
Borchgrevink event in the study area. 相似文献
15.
A hitherto unknown terrane and its bounding sutures have been revealed by a combined study of normal-incidence and wide-angle seismic data along the BABEL profile in the Baltic Sea. This Intermediate Terrane is situated between a Northern Terrane of Svecofennian age and a Southwestern Terrane of Gothian age. It is delimited upwards by two low-angle and oppositely dipping sutures and occupies mainly middle and lower crustal levels with a width of 300 km at Moho level. The 1.86 Ga suture against the Northern Terrane is imaged by a prominent almost continuous NE-dipping crustal reflection from 3.5 to 14 s twt over 175 km. Where it downlaps on the Moho, sub-Moho velocities change from 8.2 to 7.8 km/s (±0.2) over less than 25 km. A relatively strong, NE-dipping normal-incidence and wide-angle reflection at 19–23 s twt indicates that the suture extends into the upper mantle. The pervasive NE-dipping reflection fabric of the Intermediate Terrane is interpreted as shear zones that developed during collision and possibly were reactivated by later events. High Poisson's ratios suggest a mafic composition or high fluid content. The 1.86 Ga collision was probably succeeded by continental break-up and removal of an unknown continent, except for the Intermediate Terrane. Subsequent formation of an east-dipping subduction zone further to the west led to the emplacement of 1.81-1.77-Ga-old granitoids in the southern part of the Transscandinavian Igneous Belt. The 1.65-1.60 Ga suture against the Southwestern Terrane is defined by a semi-continuous band of strong SW-dipping reflections between 3 and 8 s twt over 65 km, which are interpreted as a low-angle thrust zone along which Gothian crust overrode the Intermediate Terrane. The identification of three individual seismic terranes in the southeastern part of the Baltic Shield provides new evidence for Palaeoproterozoic plate tectonic processes. 相似文献
16.
This paper reviews recent progress on the geotectonic evolution of exotic Paleozoic terranes in Southwest Japan, namely the Paleo-Ryoke and Kurosegawa terranes. The Paleo-Ryoke Terrane is composed mainly of Permian granitic rocks with hornfels, mid-Cretaceous high-grade metamorphic rocks associated with granitic rocks, and Upper Cretaceous sedimentary cover. They form nappe structures on the Sambagawa metamorphic rocks. The Permian granitic rocks are correlative with granitic clasts in Permian conglomerates in the South Kitakami Terrane, whereas the mid-Cretaceous rocks are correlative with those in the Abukuma Terrane. This correlation suggests that the elements of Northeast Japan to the northeast of the Tanakura Tectonic Line were connected in between the paired metamorphic belt along the Median Tectonic Line, Southwest Japan. The Kurosegawa Terrane is composed of various Paleozoic rocks with serpentinite and occurs as disrupted bodies bounded by faults in the middle part of the Jurassic Chichibu Terrane accretionary complex. It is correlated with the South Kitakami Terrane in Northeast Japan. The constituents of both terranes are considered to have been originally distributed more closely and overlay the Jurassic accretionary terrane as nappes. The current sporadic occurrence of these terranes can possibly be attributed to the difference in erosion level and later stage depression or transtension along strike-slip faults. The constituents of both exotic terranes, especially the Ordovician granite in the Kurosegawa-South Kitakami Terrane and the Permian granite in the Paleo-Ryoke Terrane provide a significant key to reconstructing these exotic terranes by correlating them with Paleozoic granitoids in the eastern Asia continent. 相似文献
17.
The Kurosegawa Terrane intervening in the Jurassic-Early Cretaceous accretionary complexes along the Pacific side of the SW Japanese Islands is a serpentinite mélange zone. It contains various kinds of exotic rocks, for example, granitoids, metamorphic rocks, Siluro-Devonian deposits and is intimately associated with Cretaceous forearc basin deposits. The terrane is regarded as a key to clarify the Mesozoic geotectonic history of the western circum-Pacific orogenic belts. The current model, in which the formation of the Kurosegawa Terrane is attributed to nappe-movement or sinistral strike-slip faulting, can explain neither the mode of occurrence of the Kurosegawa Terrane we observed in eastern Kii Peninsula nor the array of evidence obtained from the Ryoke Terrane southward to the Shimanto Terrane. We suggest a new hypothesis in which the Kurosegawa Terrane was a transform fault zone that originated because of oceanic ridge subduction along the southern margin of the coeval accretionary prism (Butsuzo T.L.) in the late Early Cretaceous. Our model is mainly based on new geological evidence from the Kurosegawa Terrane in eastern Kii Peninsula where the deepest erosion level is exposed due to neotectonic uplift. 相似文献
18.
S. D. Velikoslavinskii A. B. Kotov V. P. Kovach E. V. Tolmacheva A. A. Sorokin E. B. Sal’nikova A. M. Larin N. Yu. Zagornaya K. L. Wang S.-L. Chung 《Geotectonics》2017,51(4):341-352
Based on the results of Sm–Nd isotopic geochemical and U–Th–Pb geochronological LA–ICP–MS studies, it has been established that the formation of metamorphic rock protoliths of the Stanovoi Complex in the western Dzhugdzhur–Stanovoi Superterrane of the Central Asian Foldbelt took place over the following time spans: 2750–2860 Ma (Ilikan Group of the Ilikan Zone), 1890–1910 Ma (Bryanta Group of the Bryanta Zone), and ~2.0 Ga (Kupuri and Zeya groups of the Kupuri and Zeya zones, respectively). It has been shown that the western part of the Dzhugdzhur–Stanovoi Superterrane was formed ~1.9 Ga ago, as a result of collision of the Neoarchean Ilikan Terrane, the Paleoproterozoic island arc, and the Paleoproterozoic Kupuri–Zeya Terrane. The data make it possible to consider the Kurul’ta, and Zverevo blocks of the Stanovoi Structural Suture and the Ilikan Terrane of the Dzhugdzhur–Stanovoi Superterrane of the Central Asian Foldbelt as constituents of a common terrane. 相似文献
19.
地层特征对比研究在地体解析中的意义 总被引：2，自引：0，他引：2
不同地区地层特征的对比研究,是地体解析的重要方法之一。在对中国那丹哈达地区和日本美浓地区出露的地层、岩石等进行对比研究后认为,在老第三纪日本海尚未形成之前它们是连在一起的统一的地体。三叠纪时它们在赤道附近生成,侏罗纪—白垩纪时随板块运动增生于亚洲东部大陆边缘,白垩纪—老第三纪时左行剪切北移,新第三纪时因日本海的扩张而分裂移动到现今的位置。 相似文献
20.
Guido Meinhold Dimitrios Kostopoulos Dirk Frei Felix Himmerkus Thomas Reischmann 《International Journal of Earth Sciences》2010,99(4):813-832
The Pirgadikia Terrane in northern Greece forms tectonic inliers within the Vardar suture zone bordering the Serbo-Macedonian
Massif to the southwest. It comprises Cadomian basement rocks of volcanic-arc origin and very mature quartz-rich metasedimentary
rocks. U–Pb laser ablation sector-field inductively-coupled plasma mass spectrometry analyses of detrital zircons from the
latter reveal a marked input from a Cadomian–Pan-African source with minor contribution from Mesoproterozoic, Palaeoproterozoic
and Archaean sources. The metasedimentary rocks are correlated with Ordovician overlap sequences at the northern margin of
Gondwana on the basis of their maturity and zircon age spectra. The Pirgadikia Terrane can be best interpreted as a peri-Gondwana
terrane of Avalonian origin, which was situated close to the Cadomian terranes in the Late Neoproterozoic–Early Palaeozoic,
very much like the Istanbul Terrane. The second unit investigated is the Vertiskos Terrane, which constitutes the major part
of the Serbo-Macedonian Massif in Greece. It comprises predominantly igneous rocks of Silurian age and minor metasedimentary
rocks of unknown age and provenance. U–Pb analyses of detrital zircons from a garnetiferous mica schist of the Vertiskos Terrane
indicate derivation from 550 to 1,150 Ma-old source rocks with a major Cadomian peak. This, combined with minor input of >1,950 Ma-old
zircons and the absence of ages between ca. 1.2 and 1.7 Ga suggests a NW Africa source. The protolith age of the garnetiferous
mica schist is presumably Early Ordovician. One sample of garnet-bearing biotite gneiss, interpreted as meta-igneous rock,
comprises predominantly subhedral zircons of igneous origin with late Middle Ordovician to Silurian ages. We suggest that
the rock association of the Vertiskos Terrane is part of an ancient active-margin succession of the Hun superterrane, comparable
to successions of the Austro- and Intra-Alpine Terranes. The new data of this study provide evidence of occurrences of Avalonia-
and Armorica-derived terranes in the Eastern Mediterranean and moreover help to clarify palaeogeographic reconstructions for
the peri-Gondwana realm in the Early Palaeozoic. 相似文献