Magmatic nickel–copper–platinum group element (PGE) deposits hosted in mafic–ultramafic intrusions within volcanic arc systems are highly attractive targets for mineral exploration, yet their genesis remains poorly understood. This study investigates metagabbroic intrusions in the Paleoproterozoic Lynn Lake greenstone belt of the Trans-Hudson Orogen to identify the key factors, in the original gabbros, that control the formation of magmatic Ni-Cu-PGE deposits in volcanic arc systems. By examining the field relationships, geochemical and sulfur and oxygen stable isotope compositions, mineralogy, and structural fabrics, this study aims to explain why some intrusions host mineralization (e.g., Lynn Lake and Fraser Lake intrusions), whereas others remain barren (e.g., Ralph Lake, Cartwright Lake, and Snake Lake intrusions). Although both the fertile and barren gabbroic, likewise original, intrusions exhibit metaluminous, tholeiitic to calc-alkaline affinity with volcanic arc geochemical signatures, they differ significantly in shape, ranging from vertical and tube-like to tabular forms, reflecting distinct geological settings and magma dynamics. The gabbroic rocks of fertile intrusions exhibit erratic trace element profiles, lower (Nb/Th)N and higher (Cu/Zr)N ratios, as well as a larger range of δ34S values than those in barren intrusions. Key factors influencing Ni-Cu-PGE mineralization include the degree of partial melting of the mantle, early sulfide segregation, and crustal contamination, particularly from volcanogenic massive sulfide deposits. These processes likely triggered sulfide saturation in the mafic magmas. Geochemical proxies, such as PGE concentrations and sulfur and oxygen stable isotopes, provide critical insights into these controlling factors. The results of this study enhance our understanding of the metallogenic processes responsible for the formation of magmatic Ni-Cu-PGE deposits in the gabbroic intrusions emplaced in an extensional setting due to slab rollback, during the geological evolution of the Lynn Lake greenstone belt, offering valuable guidance for mineral exploration efforts.

Bedrock geological mapping indicates that diverse granitoid intrusions occur closely in space and time in the Paleoproterozoic Lynn Lake greenstone belt of the Trans-Hudson Orogen, Manitoba, Canada. These intrusions display distinct geochemical characteristics of I-type, A-type and adakite-like granitoids as revealed by their respective alkalinity, alumina saturation state, and trace element concentrations and ratios. The ca. 1879 Ma Itype granitoid pluton intruded the 1892 to 1884 Ma supracrustal package of volcanic, volcaniclastic and minor sedimentary rocks that constitute the greenstone belt, which was cut by 1873 Ma A-type granite and then by 1854 Ma adakite-like quartz diorite intrusions. Why the geochemical affinities of these granitoids change so rapidly (within similar to 25 Myr) in orogenic belts, however, is not as well understood. Here we propose using Sm-Nd isotope data and trace element modeling that the compositional variety of the granitoid intrusions likely reflects the mineral assemblages of their source rocks rather than magmatic fractionation. They may have been formed by partial melting of the disparate sources at different depths to respond to the change in tectonic regimes. The timing of the granitoid intrusions tracks a rapid geodynamic transition from subduction to intra-arc extension and to slab break-off due to terrane accretion and collision. This records a crucial piece of history in geodynamic evolution of the Trans-Hudson Orogen, which to date has been overlooked largely in many other orogens.

Representative Nb-bearing minerals in various types of ores in the gaint Bayan Obo Fe-REE-Nb deposit.

The geochemistry of Archean anorthosite-bearing layered intrusions has major implications for the thermal and chemical state of the Archean crust/mantle system, as originally posited by Bowen (1917) as "the anorthosite problem" and expanded on by Ashwal (1993). Debates have centred on the nature of the parental magmas, emplacement mechanisms and geodynamic settings of Archean anorthosites, many of which have megacrystic textures. In this review, we have compiled whole-rock major and trace element and Nd isotope geochemical data from Archean anorthosite-bearing layered intrusions worldwide to address the outstanding questions outlined above regarding the petrogenesis of anorthosites. Archean anorthosite-bearing layered intrusions were not significantly affected by hydrothermal alteration and were derived from depleted mantle sources and most (85%) were emplaced in oceanic settings. Some intrusions were intruded in continental settings or ocean-continent transition zones, reflecting the emergence of continents in the Paleoarchean into the Neoarchean. Based on their petrography and major and trace element geochemistry, Archean anorthosite-bearing layered intrusions mostly crystallised from hydrous Ca- and Al-rich tholeiitic magmas that fractionated from more primitive tholeiitic parental magmas. Archean layered intrusions formed by shallow- and deep-level fractional crystallisation of tholeiitic magmas and predominantly formed in back-arc suprasubduction zone and volcanic arc settings. Archean anorthosite-bearing layered intrusions started forming at ca. 3850 Ma, most of them representing relicts of dismembered Archean subduction-related ophiolites. Modern-style plate tectonic processes have operated at least since the earliest Archean and were the predominant contributor to Archean crustal growth.

Metamorphic devolatilization is thought to be the critical process that can liberate gold from amphibolite facies source rocks to form orogenic gold deposits. However, a growing number of studies demonstrate that orogenic gold deposits are the product of multiple hydrothermal stages over 10 s to 100 s of Myr rather than one metallogenic event. Herein we report new geochronology results for orogenic gold deposits hosted within the Paleoproterozoic Lynn Lake greenstone belt (Manitoba, Canada) to address the knowledge gap. Garnet-hosted xenotime crystals, which occur in a folded pyrite veinlet with gold, yield a weighted average 207Pb/206Pb date at 1827 & PLUSMN; 8 Ma. This new and more precise age demonstrates that the earliest auriferous fluids at the MacLellan gold deposit coincided with the rapid burial of ca. 1836 Ma sedimentary rocks before regional metamorphism. New garnet-biotite geothermometry results further demonstrate that the earliest auriferous veins were preserved despite being metamorphosed to amphibolite facies conditions (505-689 degrees C). The peak metamorphic mineral assemblage is overprinted by: (1) the main xenotime- and gold-bearing deformation fabric (S2; 1790-1827 Ma); (2) an overprinting xenotime- and monazite-bearing S3 fabric that is also associated with gold-rich arsenopyrite (1769-1790 Ma); and (3) chlorite-hosted xenotime and gold (1747 & PLUSMN; 12 Ma) that are coeval with the oldest U-Pb apatite dates (1691-1740 Ma) and a prominent mode of 40Ar/39Ar biotite dates at ca. 1746 Ma. We suggest that the post-orogenic gold events are incompatible with the standard devolatilization model because they post-date subduction and peak-metamorphism by up to 80 Myr. Instead, the new geochronological results suggest that gold deposition at the MacLellan deposit was linked to burial and the subsequent exhumation of chemically reactive trap rocks through favourable temperature windows that allowed gold transport as sulphide complexes. Exhumation and far-field tectonics are interpreted as the most likely drivers of post-orogenic auriferous fluids rather than regional metamorphism and active subduction. This revised mineral systems model provides an explanation for the high prospectivity of high- and low-temperature mineral assemblages and suggests that mineral exploration should focus on the earliest ore-forming structures that are reactivated during multiple stages of orogenesis.

Pressure pipelines use pressure to transport gas, liquefied gas, and steam in the process of use. If there are defects in the pipeline, it is easy to leak or burst, and even cause secondary accidents. To ensure safety, it is necessary to inspect the pressure pipelines in use regularly. However, it is difficult for the pressure pipeline in use to empty the internal medium. Therefore, it is of great significance to inspect the defects of the industrial pressure pipeline under operating conditions. In this paper, X-ray testing experiments are carried out for weld defects of pipelines with the medium. Using the experimental data, multivariate polynomial regression equations of negative blackness and tube voltage, and other variables are established, which provides an effective tool for the formulation of the optimal process route for testing pressure pipelines containing medium.

Hardly any previous studies have focused on the granitic dykes which intrude into the Paleoproterozoic Liaohe Group in the Liaodong Peninsula, northeast of the North China Craton. In situ zircon U-Pb dating, Lu-Hf isotopic and geochemical analyses on three representative monzogranite dykes were taken in this study. These dykes have relatively high content of SiO2 (72.20%–74.78%) and K2O (2.83%–6.37%), and have characteristics of high-K calc-alkaline to shoshonite series. Two dyke samples have I-type granite features and have high Sr/Y ratios and positive Eu anomalies, showing an adakitic feature. Another dyke has a high ratio of Ga/Al, but has a low Zr saturation temperature, which differs from the typical A-type granite. Zircon grains from these three dykes have typical magmatic zoning in CL images and yield consistent U-Pb ages of ~1859–1852 Ma, which are interpreted as the crystallization ages of these dykes. Hf isotopic analyses yield mainly negative εHf(t) values and TDM2 ages of 2782–2430 Ma, similar to those of the 2.2–2.1 Ga granitoids and meta-sedimentary rocks (the Liaohe Group), indicating these monzogranitic dykes may have been sourced from melting of Paleoproterozoic granitoids and meta-sedimentary rocks. The monzogranitic dykes were generated under a post-collisional geological setting after the Jiao-Liao-Ji orogeny process.

The Neoarchean Cross Lake-Pipestone Lake terrain, northwestern Superior Province, consists of the Cross Lake greenstone belt, the Pipestone Lake anorthosite complex, and multiple generations of granitoids. The Cross Lake greenstone belt includes an assemblage of basalt, picrite, gabbro, and sedimentary rocks (Pipestone Lake Group) that formed between 2790 Ma and 2760 Ma, and an assemblage of polymictic conglomerate, sandstone, and siltstone (Cross Lake Group) that were deposited between 2704 Ma and 2691 Ma. The Pipestone Lake anorthosite complex is composed of gabbro, megacrystic anorthosite and leucogabbro, and mafic dykes. The Pipestone Lake Group and the Pipestone Lake anorthosite complex are intruded by ca 2760 Ma and younger granitoids. The trace element systematics of the granitoids suggest that they originated in a volcanic-arc to syn-collisional tectonic setting, whereas the trace element signatures of the basalt, picrite, gabbro, anorthosite and leucogabbro association are consistent with a back-arc setting. Whole-rock initial εNd values, zircon initial εHf values and 207Pb/206Pb zircon ages for the granitoids and the anorthosite complex are consistent with long-term depleted mantle sources and variable degrees of crustal contamination during their interaction with Mesoarchean to Paleoarchean continental crust. Zircon trace element data indicate that the granodiorite and the anorthosite complex formed in a continental crust to oceanic crust transition zone at an arc-related setting. On the basis of the field relationships, and trace element and isotopic data, we suggest that the Pipestone Lake anorthosite complex and the spatially and temporally associated Pipestone Lake Group formed in a continental back-arc setting. During and after the closure of the back-arc basin, both the Pipestone Lake Group and the anorthosite complex were intruded by arc-derived granitoids. Accordingly, we interpret the association of the Pipestone Lake Group and Pipestone Lake anorthosite complex as a Neoarchean suture zone. Following the collision and closure of the back-arc basin, the region was dissected by strike-slip faults resulting in the formation of pull-apart basins and deposition of the Cross Lake Group as Timiskaming-type sedimentary rocks.

This study reports a new dataset of whole-rock geochemistry, biotite chemistry, in situ zircon U-Pb geochronology and Hf isotope for a suite of granite and associated pegmatite samples from the Gubrunde region in the Eastern Nigeria Terrane (ENT), Nigeria. The Gubrunde granitic rocks are weakly ferroan, peraluminous and calcalkalic to alkali-calcic in composition, and show I-type affinity. The zircon U-Pb geochronology gives an age of-580 Ma for the rocks, although the presence of inherited zircons with early Pan-African ages of 696 +/- 12, 647 +/- 7 and 624-613 Ma are evident indicative of a complex history of their source rocks. The Gubrunde granite and the pegmatite yielded similar average Hf crustal model age T-DM2 of 1.9 +/- 0.1 Ga and epsilon Hf(t) values-6.2 +/- 1.2, suggesting that they may have sourced from reworked old crustal rocks with minor contributions from the mantle. The granite and the pegmatite were likely to connect by fractional crystallization under low to moderate pressure (-2.2 to 3.0 kbar) and temperature (similar to 717 ?), and low oxygen fugacity (<delta NNO-1.14). The ca. 580 Ma magmatism may have been triggered by delamination of the lithospheric mantle as a consequence of crustal thinning during waning stage of the Pan-African orogeny.

A suite of Paleoproterozoic syn-orogenic magmatism with distinctive natures in the Jiao-Liao-Ji Belt (JLJB) of North China Craton is studied, including I-type monzogranite, related quartz gabbro, S-type granites, and adakitic granites. The Caiyuan monzogranite and quartz gabbro intrusions yield zircon U-Pb ages of 1881 +/- 31 Ma and 1889 +/- 19 Ma, respectively. They exhibit light rare earth element enriched patterns, and are rich in Rb, Ba, and K, but depleted in Nb, Ta, and Ti. These granites have relatively low (Sr-87/Sr-86)i ratios of 0.701985-0.706703, epsilon Nd(t) values of -13.0 to -0.3 and dominantly negative zircon epsilon Hf(t) values. Two Siping porphyritic granite samples give U-Pb ages of 1877 +/- 11 Ma and 1881 +/- 11 Ma respectively. They display enriched REE patterns, characterized by high Al2O3 and A/CNK ratio (>1.1), similar to S-type granites, with high (Sr-87/Sr-86)i ratios up to 0.711142 and negative epsilon Nd(t) values of -8.0 to -2.2. The Wafang and Xujiapu granites intrusions yield zircon U-Pb age of 1887 +/- 11.0 Ma and 1885 +/- 9.7 Ma and have high Sr/Y, (La/Yb)N and strikingly positive Eu anomalies, likely belonging to adakite. The association of quartz gabbro, I-type, and S-type granites in the Caiyuan region indicate that they were derived from mafic parental magma triggered by slab subduction. Crustal materials mixed in further AFC processes of the magma, before the monzogranite and porphyritic granite crystallized. The Wafang adakitic granite was probably related to the partial melting of a thickened crust. A complex syn-orogenic evolution model is thus proposed in the Late Paleoproterozoic of the JLJB, as slab subduction and partial melting of thickened crust simultaneously occurred at similar to 1885 Ma.

The Mount Douglas Granite (MDG) in southwestern New Brunswick (Canada) consists of three geochemically different intrusive phases, from earlier to late, changing from barren coarse-grained granite (Dmd1) to more fractionated medium- to fine-grained fertile granites (Dmd2 and Dmd3). This provides a unique geological setting to apply different techniques in order to constrain petrogenesis and metallogeny of the system. This study uses biotite chemistry to test its applicability as a mineral exploration tool to discriminate the least evolved non-mineralized Dmd1 from more highly evolved mineralized Dmd2 and Dmd3. Chemical composition of magmatic biotite was determined by EPMA and in situ laser ablation ICP-MS for different phases within the MDG. Applying the reconstruction of trace element contents accompanied with determined minerals-melt partition coefficients, we were able to further constrain the genetic relationship between the Dmd1, Dmd2, and Dmd3 from the composition of biotite. Biotite trace element contents follow a differentiation trend from the least to most evolved phases, indicative of a continuous magmatic evolutionary series. The fact that high degrees of fractional crystallization produced units Dmd2 and Dmd3 associated with endogranitic Sn, W(Mo), Bi, Zn and U mineralization is reflected in the composition of biotite from mineralized units. Remarkably, the biotite from the Dmd2 and Dmd3 is enriched in Zn (<= 879 ppm), Pb (<= 248 ppm), Sn (<= 164 ppm), Ta (<= 163 ppm), Ga (<= 113 ppm), Cu (<= 44 ppm), W(<= 14 ppm), and U (<= 6 ppm); it is also rich in incompatible elements, such as Li, Cs, Rb, Ta, and Nb, as well as substantial contents of F (<= 2.87wt%) and Cl (<= 0.71wt%). The geochemical compositions of biotite not only demonstrate a continuous fractional crystallization of magmas, but also can be used as a fertility indicator. (C) 2020 Elsevier B.V. All rights reserved.

The late Mesoproterozoic geodynamic setting of the Yangtze Block, South China remains largely unknown due to the scarce geological records of this age. This study presents a new dataset consisting of petrology, whole-rock geochemistry, zircon U-Pb geochronology and Hf isotopes of newly identified late Mesoproterozoic diabases in the southwestern Yangtze Block. Two diabase samples give zircon U-Pb ages of 1138 +/- 4 Ma and 1141 +/- 4 Ma. The diabases are tholeiitic in composition and have consistent high TiO2 contents (2.18-2.93 wt%) but low Mg# values (41-47). They are slightly enriched in LREEs with (La/Yb)N ratios of 2.87-3.99 and show E-MORB-like trace element patterns with positive Nb-Ta anomalies. The diabase samples exhibit positive zircon epsilon Hf(t) values from + 9.4 to + 13.7 and whole-rock epsilon Nd(t) values from + 3.4 to + 4.0. These results suggest that they may have undergone negligible crustal contamination during the magma evolution and were most likely generated from partial melting of a depleted asthenosphere mantle source. The diabases possess consistent Nb/Yb (4.87-5.91) and Th/Yb (0.031-0.59) ratios, ruling out the possibility of interaction with subduction-related materials. They have high Ti/V (38-46) and Zr/Y (3.36-5.23) ratios, typical of within-plate basalts. Considering the contemporary A-type granites and alkaline basalts in the same region, intense continental rifting most likely occurred in the southwestern Yangtze Block during the late Mesoproterozoic. Widespread intraplate magmatism of 1.2-1.1 Ga in the Yangtze Block indicates that it may not have been involved in the Rodinia assembly at the time.

天津隶属华北平原区,在大地构造位置上一级分区属于渤海湾裂谷盆地,为典型的多旋回盆地,受不同构造旋回期的发展演化控制,早期地质构造被掩盖,而研究深部构造有利于构造单元划分、资源评价、城市规划、地学研究等.笔者利用区域重磁资料,结合以往地质资料,通过小波变换有效的分离出重磁局部及区域异常信息并利用增强局部相位边界识别技术提取丰富线性构造信息,分析区内主要断裂构造特征,进行定性分析;根据分离出的大尺度重磁异常反演研究区莫霍面、磁性基低起伏特征,莫霍面起伏介于32.5～33.6 km之间,总体上具有西深东浅的特征,磁性基底深度介于7.9～12.4 km之间,为近东西向的带状分布,沧东断裂、宝坻断裂为研究区深部构造主要控制因素,反映了天津市平原区深部构造东西分带、南北分块的特征.

为查明沈白铁路杨树隧道浅层土石分界、深部断层、破碎软弱带及岩体完整性等不良地质情况,选择可控源音频大地电磁测深和浅层地震折射相结合的综合地球物理勘察方法.CSAMT数据处理采用一维反演、地震折射数据处理采用表层剥去法并进行纵波层析成像.在成果解释时采用二者相结合的方式,浅层地层划分重要参考地震折射的解释成果,深部构造、破碎带及软弱岩层划分参考CSAMT测深断面成果.勘察成果表明利用可控源音频大地电磁测深和浅层地震折射相结合的综合地球物理方法可对隧道的浅部地层和深部的不良地质体进行有效划分,并使解释的可靠性得到大大的提高,弥补了单一物探方法解释的缺陷,提高了解释精度,是一种行之有效的综合物探方法.

This study uses selected granite samples to evaluate the effect of redox conditions expressed as molar ferric-ferrous iron oxide ratio, Fe3+# [=Fe2O3/(FeO+ Fe2O3)], on estimation of crystallization pressure (P) of granites using the Qtz-geobarometer. The results indicate that calculated P decreases significantly with increasing Fe3+# for calc-alkaline, metaluminous and peraluminous granites, but much less so for peralkaline and evolved granites. For a calc-alkaline, metaluminous or peraluminous granite sample of a fixed silica content, the calculated P values are a polynomial function of Fe3+#. The difference in P for Fe3+# between 0.1 (reduced) and 1.0 (oxidized) is as high as 437 MPa (or 4.37 kb), much higher than the uncertainty of the geobarometer. However, peralkaline and evolved granite samples display much less difference in P for Fe3+# between 0.1 and 1.0, essentially within the uncertainty. Therefore, redox conditions need to be considered when using Qtz-geobarometry to estimate P of calc-alkaline, metaluminous and peraluminous granites, particularly those bearing hornblende with relatively low silica contents, but such corrections may not be required for peralkaline and highly evolved granites. A practical procedure is proposed to calculate Fe3+# from whole-rock geochemical data to obtain improved P estimation, and a Microsoft Excel spreadsheet program is provided. In addition to constraining the emplacement depth, the program can also be used to evaluate the redox conditions using ferric-ferrous iron oxide ratios, both of which are important for mineralization associated with granite intrusions. (C) 2020 Elsevier B.V. All rights reserved.

天津地处渤海湾盆地北西西向北京—蓬莱断裂带与北东向唐山—河间—磁县新生断裂带交汇部位,盆地内沉积盖层(N1-2-Q)覆盖较厚,新构造运动频繁,为了进一步揭示活动断裂浅部特征,本文利用浅层地震勘探方法查明了天津中部地区部分断裂(杨柳青断裂、杨村断裂)新构造运动背景下的表现形式及展布特征.结果表明,杨柳青断裂(FP3、FP6)在新构造运动时期仍继续活动,形成截切主断裂而反向复活的继续活动断裂(FP4、FP5),且为第四纪活动断裂;杨村断裂(FP2)于新构造运动时期在主断裂上直接复活,为第四纪活动断裂;同时识别出多条发育于新近系明化镇-第四系(N12-Q)沉积盖层中的新生断裂(FP1,FP7 ～ FP10).新构造运动背景下天津中部地区活动断裂发育,既有继承性活动的继续活动断裂,也有具盖层断裂特征的新生断裂.

The Neoarchean (2742.8 +/- 0.8 Ma) megacrystic anorthosite-bearingMayville layered intrusion of the Bird River greenstone belt in the Superior Province of Canada is well preserved and well exposed. Given its good preservation, we studied theMayville Intrusion through a combination of extensive field and petrographic observations, mineral chemistry, and whole-rock major and trace element and Sm-Nd and U-Th-Pb isotopic analyses to unravel its petrogenesis and geodynamic setting, and determine whether its amphibole is of igneous origin and indicative of hydrous magmatism. The Mayville Intrusion intrudes pillow basalts and gabbros of the Mayville Assemblage, which was erupted onto and emplaced into the Mesoarchean phase of the Maskwa Lake tonalite-trondhjemite-granodiorite (TTG) Batholith. Some of the anorthosites and leucogabbros of the Mayville Intrusion have undergone extensive shearing and hydrothermal alteration and had their Sm-Nd and U-Th-Pb isotope systems reset. Despite metamorphism and deformation affecting the Mayville Intrusion, it has largely retained its primary igneous minerals and textures, and trace element and Sm-Nd and Pb isotope compositions. Abundant interstitial magmaticamphibole oikocrysts in the anorthosites and leucogabbros exhibit whole-grain optical continuity and well-preserved igneous grain boundaries with magmatic plagioclase, indicating that the Mayville Intrusion crystallized from a hydrous magma. The Mayville Intrusion has variably positive epsilon(Nd) (2743 Ma) values (+0.7 to +3.9) that are indicative of its derivation from a depleted mantle source. The anorthosites and leucogabbros of the Mayville Intrusion crystallized froma hydrous Ca- and Al-rich tholeiitic parental magma that fractionated from a hydrous primitive arc tholeiitic parental magma. These lithologies were derived by partial melting of a depleted, shallowhydrous sub-arcmantle wedge source. The parental magmas to the gabbros, leucogabbros and anorthosites of the Anorthosite to Leucogabbro Zone subsequently experienced minor contamination by Mesoarchean TTGs (Maskwa Lake TTG Batholith). The field relationships and trace element geochemistry of the Mayville Intrusion and its proximity to the continental arc Maskwa Lake TTG Batholith indicate that it formed in a Chilean-style continental backarc geodynamic setting. The findings of this study demonstrate that hydrous arc magmatism and modern-style plate tectonic processes have been operating since at least the Late Archean. (C) 2020 Elsevier B.V. All rights reserved.

新C-2013-198号航磁异常位于西昆仑造山带东端黄羊滩地区,苏巴什构造结合带南侧.三级查证工作表明,该异常对应地质体为含钴镍矿化超镁铁质岩,由辉橄岩和辉石岩组成.其中辉橄岩Ni含量分布在0.15％ ～0.32％,Co 0.012％ ～0.016％,Ni平均品位0.21％,Co 0.014％;辉石岩Ni含量为0.10％ ～0.19％,Co 0.007％ ～0.010％,Ni平均品位0.14％,Co 0.008％.含钴镍矿化仅赋存于超镁铁质岩石中,具明显岩浆控矿特征.赋矿超镁铁质岩与伴生辉长岩、斜长花岗岩构成蛇绿岩岩石组合,为西昆仑造山带苏巴什蛇绿岩的一部分.综合分析认为,含钴镍矿化成矿类型为与蛇绿岩有关的岩浆硫化物矿床,具煎茶岭式镍矿成矿特征.推断新疆南部西昆仑地区具有寻找煎茶岭式镍矿的找矿前景.

牛东断裂是津保交通廊道上一条重要的北东向断裂.研究该断裂的分布、性质、活动状况可以完善和优化城市规划,减小地质灾害的破坏.高分辨率浅层地震反射勘探方法是一种行之有效的地球物理勘探方法,可以获取断裂浅部构造信息.为了查明牛东断裂中北段浅部构造,该文应用浅层地震反射探测剖面,获取了准确的浅部定位及断裂发肓特征.结果表明:牛东断裂为第四纪活动断裂,正断层性质,视倾角较陡,断距由深至浅逐步减小,并具有明显的分段性;浅层地震勘探在探测牛东断裂中收到了较好效果.