Division Features of Coal-Bearing Tectonic Units in North China

2015 ◽  
Vol 737 ◽  
pp. 827-830
Author(s):  
Kang Liu ◽  
Guo Hong Qin ◽  
Zhi Kai Ma
Keyword(s):  
North China ◽  
Tectonic Structure ◽  
Tectonic Zone ◽  
Coal Resources ◽  
Tectonic Zones ◽  
Potential Evaluation ◽  
Basic Characteristics

Based on the new round of national potential evaluation on coal resources, and reference to the latest achievements about regional geological and energy basins, this article analyzed the main features of North China coalfield structure. According to the main features of North China coalfield structure and the distribution of North China coal series, the boundary of North China coal-bearing tectonic region and the division of North China coal-bearing tectonic units were identified. North China coalfield tectonic region can be divided into 5 coal-bearing tectonic sub-regions and 22 coal-bearing tectonic zones. The basic characteristics of the tectonic structure and its influence upon coal series distribution in each coal-bearing tectonic zone were systemically discussed.

Analysis on spatial distribution characteristics and geographical factors of Chinese National Geoparks

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Fang Wang ◽  
Xiaolei Zhang ◽  
Zhaoping Yang ◽  
Fuming Luan ◽  
Heigang Xiong ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Pearson Correlation ◽  
Geological Structure ◽  
Distributional Pattern ◽  
Tectonic Zone ◽  
The Pacific ◽  
Spatial Distribution Characteristics ◽  
Geological Conditions ◽  
Tectonic Zones ◽  
National Geoparks

AbstractThis study presents the Pearson correlation analyses of the various factors influencing the Chinese National Geoparks. The aim of this contribution is to offer insights on the Chinese National Geoparks by describing its relations with geoheritage and their intrinsic linkages with geological, climatic controls. The results suggest that: 1) Geomorphologic landscape and palaeontology National Geoparks contribute to 81.65% of Chinese National Geoparks. 2) The NNI of geoparks is 0.97 and it belongs to causal distributional patternwhose regional distributional characteristics may be best characterized as’ dispersion in overall and aggregation in local’. 3) Spatial distribution of National Geoparks is wide. The geographic imbalance in their distribution across regions and types of National Geoparks is obvious, with 13 clustered belts, including Tianshan-Altaishan Mountain, Lesser Higgnan-Changbai, Western Bohai Sea, Taihangshan Mountain, Shandong, Qilianshan-Qinling Mountain, Annulus Tibetan Plateau, Dabashan Mountain, Dabieshan Mountain, Chongqing-Western Hunan, Nanling Mountain, Wuyishan Mountain, Southeastern Coastal, of which the National Geoparks number is 180, accounting for 82.57%. 4) Spatial distribution of National Geoparks coincide with latitudinal tectonic zone and longitude tectonic zone of geological structure features, which is consistent with the areas around the Pacific Rim of volcanic tectonic zones. The coupling relationships are obvious between the spatial distributional pattern and the natural and geological conditions.

2-D P-wave velocity structure of lithosphere in the North China tectonic zone: Constraints from the Yancheng-Baotou deep seismic profile

2015 ◽  
Vol 58 (9) ◽  
pp. 1577-1591 ◽  
Author(s):  
YongHong Duan ◽  
BaoJin Liu ◽  
JinRen Zhao ◽  
BaoFeng Liu ◽  
ChengKe Zhang ◽  
...  
Keyword(s):  
Wave Velocity ◽  
North China ◽  
Velocity Structure ◽  
Seismic Profile ◽  
P Wave ◽  
Tectonic Zone ◽  
The North ◽  
P Wave Velocity ◽  
P Wave Velocity Structure

Geochemical constraints on the petrogenesis of the Proterozoic granitoid gneisses from the eastern segment of the Central Tianshan Tectonic Zone, northwestern China

2007 ◽  
Vol 144 (2) ◽  
pp. 305-317 ◽  
Author(s):  
QIUGEN LI ◽  
SHUWEN LIU ◽  
ZONGQI WANG ◽  
QUANREN YAN ◽  
ZHAOJIE GUO ◽  
...  
Keyword(s):  
Partial Melting ◽  
Minor Amount ◽  
Tectonic Zone ◽  
Depleted Mantle ◽  
Eastern Segment ◽  
Tectonic Zones ◽  
Granitoid Gneisses ◽  
A Minor ◽  
T Values ◽  
Ree Patterns

The Tianshan orogen is divided into the Northern, Central and Southern Tianshan tectonic zones by the northern and southern sutures on both sides of the Central Tianshan Tectonic Zone. The eastern segment of the Central Tianshan Tectonic Zone is characterized by the presence of numerous Precambrian metamorphic blocks and is unconformably overlain by Ordovician–Silurian and late Palaeozoic strata. The Precambrian Kumishi and Pargantag metamorphic blocks are the largest older blocks in the eastern segment of the Central Tianshan Tectonic Zone, consisting mainly of metamorphic granitoids and sedimentary rocks in greenschist to amphibolite facies. There are two major lithological assemblages of the metamorphic granitoids: (1) quartz dioritic gneisses, and (2) granodioritic–monzogranitic gneisses with a minor amount of tonalitic and syenogranitic gneisses in both the Kumishi and Pargantag blocks. The quartz dioritic gneisses are characterized by low Sr/Ce (<5.3) and Sr/Y (<28), relatively high Mg no. (51.0–57.0), K2O (2.65–4.04 wt %) contents and εNd(t) values (−2.37–5.84), and negative Nb and Zr–Hf anomalies, as well as relatively flat chondrite-normalized REE patterns with slightly negative Eu anomalies, suggesting that the quartz dioritic gneisses were derived from partial melting of a depleted mantle source enriched by fluids and sedimentary melts from the subducted slab. However, most of granitic gneiss samples display high K2O contents, low Al2O3/(FeO* + MgO + TiO2) values, and relatively flat chondrite-normalized REE patterns with intensively negative Eu anomalies. Integrated low εNd(t) values and older TDM model ages suggest that crustal materials played a significant role in the petrogenesis of these granitoid gneisses and that they were mainly derived from the partial melting of calc-alkaline mafic to intermediate rocks in the crust. Also, variations in geochemical features between the Kumishi–Gangou and Pargantag regions, such as Zr and Hf, may reflect geographic variability in the development of coeval granitic magmas. Tectonic discrimination for granitoid, using trace elements, together with Nd isotopic data, demonstrates that these granitoid gneisses in the eastern segment of the Central Tianshan Tectonic Zone formed in a continental margin arc during late Mesoproterozoic times.

Geochemistry of Paleozoic granitoid plutons from contrasting tectonic zones of northeast Newfoundland

1978 ◽  
Vol 15 (1) ◽  
pp. 145-156 ◽  
Author(s):  
D. F Strong ◽  
W. L. Dickson
Keyword(s):  
Sedimentary Rocks ◽  
Metamorphic Rocks ◽  
Close Correspondence ◽  
Calc Alkaline ◽  
Tectonic Zone ◽  
Crustal Rocks ◽  
Metasedimentary Rocks ◽  
Tectonic Zones ◽  
Tectonic Settings ◽  
Devonian Age

Granitoid plutons of similar (Silurian–Devonian) age intrude four of the tectono-stratigraphic zones of northeastern Newfoundland, and show systematic petrographic and chemical differences corresponding to the tectonic zone in which they occur. Those intruding the dominantly mafic volcanic and sedimentary rocks of the Botwood and Exploits Zones are dominated by calc-alkaline hornblende–biotite bearing granodiorite, quartz diorite and granite. Those intruding the metamorphic rocks of the Gander Zone are two-mica garnet-bearing 'leucogranites' mainly in metasedimentary rocks, and microcline – megacrystic biotite granites and quartz monzonites, mainly in gneissic terrains. The Gander Zone plutons are more silicic and have lower Na/(Na + K) and K/Rb ratios than those of the Botwood and Exploits Zones, although the Rocky Bay pluton, close to the boundary between them, shows some transitional features. This close correspondence between granitoid plutons and crustal rocks of different tectonic settings is taken as evidence for their formation by partial melting of the crustal rocks.

scholarly journals Geology, structure and metamorphism of the Lesser Himalayan metasedimentary sequence in Pokhara region, western Nepal

1998 ◽  
Vol 18 ◽  
Author(s):  
L. P. Paudel ◽  
K. Arita
Keyword(s):  
Low Grade ◽  
Lesser Himalaya ◽  
The South ◽  
Main Central Thrust ◽  
Tectonic Zone ◽  
Chemical Zoning ◽  
The North ◽  
Tectonic Zones ◽  
Thrust Zone ◽  
Uplift And Erosion

The Lesser Himalaya in the Pokhara region, western Nepal, comprises low grade metamorphic rocks of the Nawakot Complex in the south and mylonitic rocks of the Main Central Thrust Zone in the north. It is delimited in the north by the Main Central Thrust (MCT), which brings the kyanite gneisses of the Higher Himalayan Crystallines over the Lesser Himalayan metasediments. Cross-cutting pegmatite veins injected prior and posterior to the main deformation event are reported for the first time from the MCT Zone. The Phalebas Thrust, Lumle Thrust and the MCT are the major structural discordances, which divide the area into various tectonic zones with different style and intensity of deformation. At least three deformation events are recognised in each tectonic zone. Sense of shearing is always top to the south in the MCT Zone. The Higher Himalayan Crystallines and the Lesser Himalayan metasediments show marked differences both in history and grade of metamorphism. The gneisses of the Higher Himalayan Crystallines exhibit polyphase metamorphism. The older high grade (kyanite-grade) metamorphism formed pyrope-rich cores in garnets and plagioclase with An>20%. The younger retrograde metamorphism caused to recrystallise phengitic muscovite and to form retrograde chemical zoning in garnets. The Lesser Himalaya shows syn- to post-tectonic, garnet-grade, inverted prograde metarnrophism. The grade of metamorphism increases from chlorite zone in the south to the biotite zone below the Lumle Thrust and the garnet zone in the MCT Zone. The garnets show prograde zoning pattern, muscovite gradually becomes poor in celadonite component, biotite becomes rich in Ti-content, and Ca-amphiboles become rich in Na and K from south towards the MCT. Both the Lesser Himalayan metasediments and the Higher Himalayan Crystallines have experienced the late-stage weak regression due to uplift and erosion.

scholarly journals GEODYNAMICS

GEODYNAMICS ◽  
2021 ◽  
Vol 1(30)2021 (1(30)) ◽  
pp. 65-77
Author(s):  
Liudmyla Shtohryn ◽  
Keyword(s):  
Magnetic Fields ◽  
Regional Scale ◽  
Fault Zones ◽  
Distribution Area ◽  
Tectonic Structure ◽  
Tectonic Zone ◽  
Gravitational Fields ◽  
Landslide Processes ◽  
Lithological Composition ◽  
The Impact

Purpose. The aim of the research presented in this article is to analyze the features of the reflection of the damage to the territory of the Transcarpathian region by landslide processes based on the anomalies in the magnetic and gravitational fields, taking into account tectonic zoning. The study is an important stage in predicting the landslide processes and it is aimed at reducing their negative effects on the environment. The relevance of the research is due to the growing intensification of landslides in the Carpathian region of Ukraine. Methodology. The development of landslides in each structural-tectonic zone is associated with its tectonic structure, and therefore these processes can have different intensity, dynamics, tendencies for further development and distribution area. Lithological-facies composition and bedding conditions of rocks form the physical and mechanical properties of rocks, determining the rate and mechanism of the development of landslides. The spatial confinedness of landslide processes in the fault zones is reflected in the gravitational and magnetic fields. Results. With the help of GIS MapInfo tools, a number of landslides in each tectonic zone, anomalies in the gravitational and magnetic fields, areas affected by landslides, the distance to the fault zones were calculated. The important result of the research is to prove a direct correlation between the spatial distribution of landslides and fault zones, tectonic structure, the lithological composition of rocks, which are reflected in gravimagnetic anomalies. Scientific novelty. The peculiarities of the reflection of the tectonic structure, zones of decompression, fragmentation of rocks and lithological composition in gravimagnetic fields on a regional scale are examined, and their association with landslide processes is evaluated for the first time. Practical significance. The theoretical substantiation of the peculiarities of the behaviour of gravimagnetic fields in the zones of distribution of landslide processes makes it possible to assess the natural conditions for the formation and development of landslides in a given region. The connection between the impact of the fault zones on landslide processes by their reflection in gravimagnetic fields is established, which can be used in the future for spatial forecasting of the development of landslides in territories with related structural-tectonic conditions.

scholarly journals Geological Controls on Mineralogical Characteristic Differences of Coals from the Main Coal Fields in Shaanxi, North China

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7905
Author(s):  
Wei Yuan ◽  
Jing Li ◽  
Xinguo Zhuang ◽  
Guanghua Yang ◽  
Lei Pan
Keyword(s):  
Middle Jurassic ◽  
North China ◽  
Ordos Basin ◽  
Shaanxi Province ◽  
Late Triassic ◽  
Sediment Provenance ◽  
Coal Resources ◽  
Mineral Characteristics ◽  
Lagoon Environment ◽  
Coal Fields

Shaanxi is among the provinces with abundant coal resources in North China. These enormous coal resources (approx. 4143 Gt) are widely distributed in the Ordos Basin and its marginal fold belts. The main coal-bearing strata consist of the late Carboniferous Taiyuan Formation, the early Permain Shanxi Formation, the late Triassic Wayaobao Formation, and the middle Jurassic Yan’an Formation, which were respectively deposited in coastal plains and a lagoon environment, a continental environment, an inland open lake and a confined lake environment. The Permo-Carboniferous coals are low volatile bituminous and characterized by relatively high vitrinite content, which decreases from south to north, and from the lower coal seams upwards. By contrast, the late Triassic and middle Jurassic coals are highly volatile bituminous, but are respectively characterized by relatively high vitrinite and high inertinite content. Minerals in the Permo-Carboniferous coals, the late Triassic coals, and the middle Jurassic coals, are respectively dominated by kaolinite and calcite, quartz and kaolinite, and quartz and calcite. Furthermore, contemporary coals deposited in different coal fields or even different mines of the same coal field present different mineral characteristics. The Permain Shanxi Formation coals from the Shanbei C-P coalfield in the north of Shaanxi Province are characterized by higher kaolinite and lower carbonate contents compared to those from the Weibei C-P coalfield in the south of Shaanxi Province. The distinctive mineralogical characteristics of coals formed in different coalfields and different geological ages were ascribed to integrated influences of different terrigenous detrital input from sediment provenance, sedimentary settings (e.g., subsidence rate, sea transgression, and regression process), and hydrothermal activities.

Contrasting seismic characteristics of three major faults in northwestern Canada

2005 ◽  
Vol 42 (6) ◽  
pp. 1223-1237 ◽  
Author(s):  
David B Snyder ◽  
Brian J Roberts ◽  
Steven P Gordey
Keyword(s):  
Fault Zone ◽  
Strike Slip ◽  
Depth Of Penetration ◽  
Tectonic Zone ◽  
Reflection Data ◽  
Vertical Fault ◽  
Tectonic Zones ◽  
Fault Trace ◽  
Major Strike ◽  
Depth Extent

The Lithoprobe Slave – Northern Cordillera Lithospheric Evolution (SNORCLE) profiles crossed three major tectonic zones of the northwestern Canadian Shield and northern Canadian Cordillera that are diverse in age and in depth of penetration. The oldest (2630–2590 Ma), the Yellowknife River fault zone, formed as a strike-slip fault in a tensional strain regime. Reflector attenuation or truncations align vertically beneath the fault trace through much of the crust, implying a near-vertical fault plane. The youngest (60–10 Ma), the Tintina fault zone, produced cumulative dextral strike-slip displacements of 425 km, perhaps 800 km. Tomographic velocity and ray-trace models of reflection data indicate that several fault splays form a tectonic zone 30 km wide at the surface, but truncations of deeper crustal reflections suggest that the zone thins in the mid-crust and widens near the Moho. This apparent variable width versus depth of the Tintina fault is atypical of major strike-slip faults worldwide. The Teslin fault was an active terrane boundary during accretion of terranes onto North America. Observed reflection geometries indicate that the juxtapositions of highly contrasting metamorphic grades across the Teslin fault are confined to the upper crust along SNORCLE line 3, implying that the fault soles eastward into a mid-crustal detachment at the interpreted top of North American crust. The limited depth extent of the Teslin fault zone is similar to some models of the San Andreas fault and may result from their similar histories as convergent margin structures.

scholarly journals Gravity Anomalies And Crustal Structure Of The Eastern Part Of The Verkhoyansk Fold-And-Thrust Belt, NE Russia: Evidence From The Junction Area Of The Adycha-Elga And Allakh-Yun Tectonic Zones

2021 ◽  
Vol 906 (1) ◽  
pp. 012039
Author(s):  
Evgeny Solovyov ◽  
Valery Fridovsky ◽  
Denis Savvin ◽  
Vadim Kychkin
Keyword(s):  
Deep Structure ◽  
Gravity Anomalies ◽  
Crystalline Basement ◽  
Thrust Belt ◽  
Tectonic Zone ◽  
Upper Carboniferous ◽  
Junction Area ◽  
Fold And Thrust Belt ◽  
Tectonic Zones ◽  
Middle Carboniferous

Abstract The results of geophysical studies of the junction area of the Adycha-Elga and Allakh-Yun tectonic zones of the Verkhoyansk fold-and-thrust belt located on the submerged eastern margin of the Siberian craton are presented. Three structural-mineral complexes are recognized: Archean-Paleoproterozoic, Mesoproterozoic-Middle Carboniferous, and Upper Carboniferous-Early Mesozoic. The Early Jurassic plume-related basaltic volcanism and suprasubduction Late Jurassic-Early Cretaceous granitoids, regional Brungadin and Suntar faults are identified. The goal of the research is to identify deep heterogeneities and clarify the structure of the Earth’s crust in the junction area of the Adycha-Elga and Allakh-Yun tectonic zones of the Verkhoyansk fold-and-thrust belt. The analysis of gravitational anomalies is carried out, their transformations are performed – distinguishing the medium and low-frequency components, the vertical derivative Vzz, and calculating the equivalent distribution of sources of density masses at depth. It is determined that the hidden granitoids of the Adycha-Elga tectonic zone are located mainly in linear zones of decompaction at a depth of about 3.5 km. In the Allakh-Yun zone, a large gravitational minimum has been identified, where it is assumed that there is a magma granitoid chamber occurring at a depth of about 9 km. The model of the deep structure of the territory is based on the analysis of materials on the reference seismic profile 3-DV with the use of gravimetric data and the regional structure of the territory. According to the results of the wave pattern interpretation, the thickness of the lithosphere varies from 41 to 44 km. The thickness of the Upper Carboniferous-Triassic terrigenous rocks is 8-12 km, Mesoproterozoic - Middle Carboniferous carbonate-terrigenous complex is up to 12 km. The Archean-Paleoproterozoic crystalline basement occurs at a depth of 19-21 km. The Conrad discontinuity is assumed at a depth of about 30 km. Intense deformations of the crystalline basement are recognized, and trans-crust faults are identified.

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