Hydrocarbon accumulation characteristics in basement reservoirs and exploration targets of deep basement reservoirs in onshore China

Based on the global basement reservoir database and the dissection of basement reservoirs in China,the characteristics of hydrocarbon accumulation in basement reservoirs are analyzed,and the favorable conditions for hydrocarbon accumulation in deep basement reservoirs are investigated to highlight the exploration targets.The discovered basement reservoirs worldwide are mainly buried in the Archean and Precambrian granitic and metamorphic formations with depths less than 4500 m,and the relatively large reservoirs have been found in rift,back-arc and foreland basins in tectonic active zones of the Meso-Cenozoic plates.The hydrocarbon accumulation in basement reservoirs exhibits the characteristics in three aspects.First,the porous-fractured reservoirs with low porosity and ultra-low permeability are dominant,where extensive hydrocarbon accumulation occurred during the weathering denudation and later tectonic reworking of the basin basement.High resistance to compaction allows the physical properties of these highly heterogeneous reservoirs to be independent of the buried depth.Second,the hydrocarbons were sourced from the formations outside the basement.The source-reservoir assemblages are divided into contacted source rock-basement and separated source rock-basement patterns.Third,the abnormal high pressure in the source rock and the normal–low pressure in the basement reservoirs cause a large pressure difference between the source rock and the reservoirs,which is conducive to the pumping effect of hydrocarbons in the deep basement.The deep basement prospects are mainly evaluated by the factors such as tectonic activity of basement,source-reservoir combination,development of large deep faults(especially strike-slip faults),and regional seals.The Precambrian crystalline basements at the margin of the intracontinental rifts in cratonic basins,as well as the Paleozoic folded basements and the Meso-Cenozoic fault-block basements adjacent to the hydrocarbon generation depressions,have favorable conditions for hydrocarbon accumulation,and thus they are considered as the main targets for future exploration of deep basement reservoirs.

Discovery and Significance of the Triassic–Late Paleozoic Double-layered Basement in the Songliao Basin:Based on the Complete Coring Data from ICDP Borehole SK2

The Songliao Basin(SLB)covers an area of approximately 260,000 km2in northeastern Asia and preserves a continuous and complete Cretaceous terrestrial record(Wang et al.,2021).The region is the most important petroliferous sedimentary basin in China because of its continual annual oil and gas equivalent production of tens of millions of tons(ca.220–440 million barrels per year)since 1959.The SLB was previously thought to have developed on Hercynian basement and accumulated continuous sedimentary deposits during the Late Jurassic and Cretaceous(Wan et al.,2013;Wang et al.,2016).

Characterization of Aquifers in Crystalline and Crystallophyll Basement Zones Using the Electrical Resistivity Method (Trails and Electrical Soundings) in the Gagnoa Region, (Central-Western Côte d’Ivoire)

Introduction: Located in the central-western part of Côte d’Ivoire, the subsoil of the Gagnoa region is made up of sedimentary volcano formations and granitoids with developed fracturing. This complex Precambrian basement contains most of the region’s water resources. This is at the origin of the high failure rate during the various hydrogeological prospecting campaigns. Methodology: The database consists of resistivities from 42 holes and 51 trails drilled as part of the implementation of high-throughput drilling in the study area. The objective of this study is to deepen the knowledge of the fissured basement by interpreting profile curves and electrical soundings. It will be a question of classifying the different types of anomalies obtained on the profiles and their shapes. The orientation of the lineaments observed on the profiles was determined. Results: The interpretation of the geophysical data revealed various anomalies, the main ones being of the CC (Conductor Compartment) and CEDP (Contact between two bearings) types. These types of anomalies are mainly expressed in various forms: the “V”, “W” and “U” shapes. From these anomalies and the appearance of the electrical profiles, lineaments and their orientations were identified with N90-100, N130-140, N170-180 as major orientations. Conclusion: These results could contribute to a better understanding of the fractured environment of the Gagnoa region.

Early Paleozoic basement diorite of arc-magmatism from Kutch basin, Western India

In this study,we report for thefirst time an Early Palaeozoic basement diorite from the drilled well Nirona-A in the Banni Half-Graben of the Kutch basin,western India.The 40Ar–39Ar dates provided a plateau age of 441.84±2.66 Ma and another pseudo plateau of 441.28±5.82 to 388.08±16.65 Ma for the basement diorite.These ages constrain the basement formation age to the Late Ordovician-Early Silurian period.The obtained basement ages are correlatable with the later part of Cambro-Ordovician alkaline magmatism that has been reported from the Huqf area in Central Oman,whereas their lithological and petrographic correlativity with base-ment diorites occurring in the Dinsi Body of Nagar Parkar igneous complex in Pakistan can also be envisaged.The geochemical studies characterized the diorite with enrich-ment of LILE(Rb,Ba,and K)and LREE(La,Ce,Nd),strong depletion of HFSE(Nb,Sr,P,and Ti),along with weakly negative Eu anomalies.The geochemical signatures indicate their petrogenetic affiliation with mantle-derived magmas,as well as their tectonic setting to be arc-related,having post-collisional continental-arc type affinity.The*440 Ma basement of Kutch,therefore,appears to rep-resent the later thermal event associated with the reworked Neoproterozoic subduction-related suite from Greater India’s northwest edge,which has implications for Gond-wana assembly in the northwest Indian subcontinent.

Water Quality on the Basement Areas in Kouba-Adougoul and Its Surroundings, Guera Province, Chad

Water is an essential element for all forms of life. The quantity and quality of water are a problem in places. In Kouba Adougoul and its surroundings in south guera, water-related health problems are reported. That is why this study focuses on the quality of water in the basement areas, of Kouba Adougoul. Our objective is to contribute to a better understanding of water of human consumption in these areas for this, we carried out a physicochemical and bacteriological control on a number water point. Ten water points were collected during May 2022 for analysis. To achieve this objective, we made the in-situ analysis of physical parameters such as pH, electrical conductivity, and temperature. These measurements were made using the multi-parameter kit. The result shows that, the water temperatures vary from 24.4˚C to 27.4˚C proving that the waters are from deep depths. For the use of these waters, it is necessary to take certain precautions. The pH values varied between 6.15 and 7.78, an average of 6.77 giving some waters an aggressive character. It was low mineralized, with electrical conductivity averages ranging from 182.1 to 2100 μS/cm−1 an average of 586.36 μS/cm−1. For the chemical parameters, it is by hydrometric titration that the content of the ions was determined. The determination of the various coliforms in these waters was carried out by its various methods which led to detecting that the waters of Kouba Adougoul are turbid, and present high proportions of nitrates, iron and ammonium. The presence of pathogenic germs, such as total coliforms and thermo-tolerant coliforms in these waters, has been demonstrated. For their consumption, these waters deserve treatment beforehand. In the study area, the anthropogenic activities are considered the most serious sources of groundwater.

Analysis on the basement constitution of the southern Okinawa Trough

Based on the data of seismic reflection, seismic refraction and magnetism collected in the research area and geology obtained from adjacent areas, this paper deals with the issue of basement constitution of the southern part of the Okinawa Trough. In the shelf basin of the East China Sea, Taiwan folded belt and Ryukyu Islands folded belt which surround the trough, outcrop Later Paleozoic, Mesozoic and Eogene strata. In the southern trough, multichannel seismic reflection data indicate that the overlying strata are composed of Neogene and Quaternary deposits, and the acoustic basement consists of Eogent and even older strata. Seismic refraction profiles show that there are Eogene and Mesozoic velocity layers with longitudinal velocities of 4.7 - 5.3 km/s and 6.3 km/s respectively beneath the Quaternary-Miocene Layers. Qualitative analysis and forward and reversed calculation of magnetic data show that the magnetic basement is mainly formed by metamorphic rocks, the Yanshanian neutral-acid magmatic rocks and the Himalayan neutral-basic magmatic rocks being the next components, and the magnetic basement is mostly corresponding to the acoustic basement. Comprehensive analyses demonstrate that the basement of the southern Okinawa Trough is mainly formed by Eogene system and Mesozoic and Upper Paleozoic groups metamorphosed in varying degrees, and the basic magmatic rocks of Himalayan epoch have been formed in some parts of the basin.

基底膜相关基因在类风湿关节炎不同中医证型中的转录组学分析及药物预测

背景:基底膜基因与类风湿关节炎的发生发展密切相关,但不同中医证型下基底膜相关基因在其发病机制中的作用尚不明确。目的:基底膜基因联合转录组学分析探讨类风湿关节炎5种不同中医证型的发病机制差异,并进行潜在治疗药物预测。方法:基于GEO数据库整理类风湿关节炎相关中医证型芯片数据以及基底膜相关基因,利用R-limma包筛选差异表达基因,Mfuzz包进行表达趋势分析。借助STRING数据库构建PPI网络,UPset筛选关键基因,通过R-clusterProfiler包对差异表达基因进行GSEA及富集分析,同时绘制ROC曲线评估基底膜相关核心靶点对5种证型分别的诊断价值。基于CIBERSORT核心算法计算每种证型的免疫浸润情况。最后,利用SymMap和COREMINE数据库预测可靶向基底膜相关核心基因治疗类风湿关节炎不同证型的潜在中药及小分子药物。结果与结论:①在5种类风湿关节炎中医证型中(风湿痹阻证、寒湿痹阻证、肝肾亏虚证、气血两虚证及血瘀阻络证)分别筛选出67,47,59,57,55个基底膜相关差异表达基因,其中关键靶点分别为5,7,5,3,5个。③各证型中富集最多的为细胞基质黏附、免疫细胞迁移及胶原代谢等生物过程以及细胞外基质受体相互作用、PI3K-Akt、局灶性粘连和Rap1信号通路等。④药物预测结果显示,土茯苓、川乌、绵马贯众及黄精是通过影响基底膜基因治疗5种类风湿关节炎中医证型最具潜力的中药。⑤结果证实,基底膜相关基因的异常表达可能是通过调控细胞附着、免疫细胞迁移及炎症反应等多个途径影响类风湿关节炎的发生和发展,在不同证型中有着差异表现,其中ITGA6可作为5种类风湿关节炎证型中共同的诊断标志物。清热解毒类中药可能是类风湿关节炎不同证型治疗中可以贯穿始终的潜在有效药物。

Ages and Compositions of the Precambrian High-grade Basement of the Qilian Terrane and Its Adjacent Areas

Based on geological, chronological, geochemical and Nd isotopic studies of the high-grade basement of the Qilian terrane, the authors have drawn the following main conclusions: (1) the high-grade basement of the Qilian terrane consists mainly of meta-argillo-arenaceous rocks and granites and its bulk part was formed in the period of 0.8–1.0 Ga (the Jinningian period); (2) most of the meta-argillo-arenaceous rocks and granitic rocks have strong negative Eu and Ba anomalies (Eu/Eu*= 0.47–0.71 and Ba/Ba*=0.16–0.64), with fDM and ENd (1.0 Ga) ranging from 1.87 to 2.26 Ga and from ?8.54 to ?4.06 respectively, showing relatively high maturity; and (3) the Jinningian granitic rocks are a typical product of continent-continent collision, being probably related to the formation of the supercontinent Rodinia. These studies, combined with the study of high-grade basement rocks near the Qilian terrane, suggest that before the Jinningian period, the Qilian-Qaidam northern-margin terrane and Dunhuang-Alxa terrane were separated from each other, belonging to different plate systems of the North China craton and Yangtze platform respectively. The Qilian orogenic belt was the same as or similar to the Qiling orogenic belt in terms of the geological evolution history at least before the Jinningian period.

Basement of the South China Sea Area:Tracing the Tethyan Realm

The basement of the South China Sea（SCS）and adjacent areas can be divided into six divisions（regions）-Paleozoic Erathem graben-faulted basement division in Beibu Gulf,Paleozoic Erathem strike-slip pull-apart in Yinggehai waters,Paleozoic Erathem faulted-depression in eastern Hainan,Paleozoic Erathem rifted in northern Xisha（Paracel）,Paleozoic Erathem strike-slip extending in southern Xisha,and Paleozoic-Mesozoic Erathem extending in Nansha Islands（Spratly）waters.The Pre-Cenozoic basement in the SCS and Yunkai continental area are coeval within the Tethyan tectonic domain in the Pre-Cenozoic Period.They are formed on the background of the Paleo-Tethyan tectonic domain,and are important components of the Eastern Tethyan multi-island-ocean system.Three branches of the Eastern Paleo-Tethys tectonic domain,North Yunkai,North Hainan,and South Hainan sea basins,have evolved into the North Yunkai,North Hainan,and South Hainan suture zones, respectively.This shows a distinctive feature of localization for the Pre-Cenozoic basement.The Qiongnan（i.e.South Hainan）Suture Zone on the northern margin of the South China Sea can be considered the vestige of the principal ocean basin of Paleo-Tethys,and connected with the suture zone of the Longmucuo-Shuanghu belt-Bitu belt-Changning-Menglian-Bentong-Raub belt,the south extension of Bitu-Changning-Menglian-Ching Mai belt-Chanthaburi-Raub-Bentong belt on the west of South China Sea,and with the Lianhua-Taidong suture zone（a fault along the east side of Longitudinal Valley in Taiwan）-Hida LP/HT（low pressure-high temperature）metamorphic belt-Hida -marginal HP/LT metamorphic belt in southwestern Honshu of Japan,on the east of the South China Sea.The Qiongbei（North Hainan）suture zone may eastwards extended along the Wangwu-Wenjiao fault zone,and connects with the Lufeng-Dapu-Zhenghe-Shangyu（Lianhuashan）deep fault zone through the Pearl River Mouth Basin.The Meso-Tethys developed on the south of the South China Sea.The Nansha Trough may be considered the vestige of the northern shelf of the Meso-Tethys. The oceanic crust of the Meso-Tethys has southwards subducted along the subduction-collision-thrust southern margin of the Nansha Trough with a subduction-pole opposite to those of the Yarlung Zangbo-Mytkyina-Bago zone on the west of the South China Sea,and the Meso-Tethyan（e.g.Northern Chichibu Ocean of the Meso-Tethys）suture zone＂Butsozo tectonic line＂in the outer belt of the Jurassic-Early Cretaceous terrene group in southwest Japan,on the east of the South China Sea.

Timing of Metamorphism and Provenance of the Metamorphic Basement of the Xiangshan Uranium Orefield, Jiangxi Province, China

The origin, age and evolution of the Precambrian metamorphic basement of southern China provide useful insights into early crustal development. Here, we present new laser ablation-inductively coupled plasma-mass spectrometry （LA-ICP-MS） U-Pb age data for detrital zircons from five samples of the Precambrian metamorphic basement of the Xiangshan uranium orefield. Two of these samples, from the northern Xiangshan volcanic basin, yielded a total of 140 U-Pb ages that cluster within the Neoproterozoic （773-963 Ma; 79.3% of data points）, with the rest being scattered through the Paleoproterozoic and Mesoproterozoic, along with a single Archean age. These ages indicate that this basement material is associated with the Cathaysia Block. In comparison, the 172 concordant ages from the other three samples from the southern part of the Xiangshan volcanic basin cluster within the Neoproterozoic （767-944 Ma; 59.8%） as well as the Proterozoic （37.8%） and the Archean （2502-2712 Ma; 14.5%）. These samples are also free of zircons with Grenvillian ages, indicating that these units are associated with the southeastern Yangtze Block. Combining these data with the geochemistry of these units, which suggests that the metamorphosed sedimentary rocks within the northern and southern parts of the Xiangshan basin have a common component from a magmatic island arc that formed during the early Neoproterozoic, we infer that the basin was located along the boundary between the Cathaysian and Yangtze blocks. In addition, the zircons within the samples from the southern and northern parts of the Xiangshan basin show different pre-Neoproterozoic （963 Ma） age populations but similar post- Neoproterozoic zircon populations, indicating that the amalgamation of the Cathaysian and Yangtze blocks occurred after the Neoproterozoic （960 Ma）, with magmatism peaking at 830 Ma and rifting starting at -770 Ma, leading to the subsequent deposition （from bottom to top） of the Shenshan, Kuli, and Shangshi formations.

Estimating Moho basement and faults using gravity inversion in Yushu-earthquake area,China

A gravity survey was conducted one month after the 2010 Yushu earthquake in the epicenter area. The cross-fauh survey line was 500 km long, from Langqian county to Qingshuihe county, in a transition zone between Bayan Har block and Qiangtang block, in an area of high elevation, large undulating terrain, and complex geological features. An interpretation of the data was carried out together with other kinds of data, such as seismic exploration and magnetic exploration. The result shows that gravity is sensitive to fault bounda- ry ; the geologic structure of the region is complex at middle and upper depths, and the density profile reveals an eastward-pushing fault movement.

Ordovician Basement Hydrocarbon Reservoirs in the Tarim Basin, China

Ordovician marine carbonate basement traps are widely developed in the paleo-highs and paleo-slopes in the Tarim Basin. Reservoirs are mainly altered pore-cavity-fissure reservoirs. Oil sources are marine carbonate rocks of the Lower Paleozoic. Thus, the paleo-highs and paleo-slopes have good reservoiring conditions and they are the main areas to explore giant and large-scale oil reservoirs. The main factors for their reservoiring are: (1) Effective combination of fenestral pore-cavity-fracture reservoirs, resulting from multi-stage, multi-cyclic karstification (paleo-hypergene and deep buried) and fracturing, with effective overlying seals, especially mudstone and gypsum mudstone in the Carboniferous Bachu Formation, is essential to hydrocarbon reservoiring and high and stable production; (2) Long-term inherited large rises and multi-stage fracture systems confine the development range of karst reservoirs and control hydrocarbon migration, accumulation and reservoiring; (3) Long-term multi-source hydrocarbon supply, early reservoiring alteration and late charging adjustment are important reservoiring mechanisms and determine the resource structure and oil and gas properties. Favorable areas for exploration of Ordovician carbonate basement hydrocarbon reservoirs in the Tarim Basin are the Akekule rise, Katahe uplift, Hetianhe paleo-high and Yakela faulted rise.

High matrix metalloproteinase-9 expression induces angiogenesis and basement membrane degradation in stroke-prone spontaneously hypertensive rats after cerebral infarction

Basement membrane degradation and blood-brain barrier damage appear after cerebral infarc- tion, severely impacting neuronal and brain functioning; however, the underlying pathogenetic mechanisms remain poorly understood. In this study, we induced cerebral infarction in stroke- prone spontaneously hypertensive rats by intragastric administration of high-sodium water （1.3% NaC1） for 7 consecutive weeks. Immunohistochemical and immunofluorescence assays demonstrated that, compared with the non-infarcted contralateral hemisphere, stroke-prone spontaneously hypertensive rats on normal sodium intake and Wistar-Kyoto rats, matrix metalloproteinase-9 expression, the number of blood vessels with discontinuous collagen IV expression and microvessel density were significantly higher, and the number of continuous collagen IV-positive blood vessels was lower in the infarct border zones of stroke-prone sponta- neously hypertensive rats given high-sodium water. Linear correlation analysis showed matrix metalloproteinase-9 expression was positively correlated with the number of discontinuously collagen IV-labeled blood vessels and microvessel density in cerebral infarcts of stroke-prone spontaneously hypertensive rats. These results suggest that matrix metalloproteinase-9 upregula- tion is associated with increased regional angiogenesis and degradation of collagen IV, the major component of the basal lamina, in stroke-prone spontaneously hypertensive rats with high-sodi- um water-induced focal cerebral infarction.

Characteristics of the crystalline basement beneath the Ordos Basin:Constraint from aeromagnetic data

Aeromagnetic anomaly zonation of the Ordos Basin and adjacent areas was obtained by processing high-precision and large-scale aeromagnetic anomalies with an approach of reduction to the pole upward continuation. Comparative study on aeromagnetic and seismic tomography suggests that aeromagnetic anomalies in this area are influenced by both the magnetic property of the rock and the burial depth of the Precambrian crystalline basement. Basement depth might be the fundamental control factor for aeromagnetic anomalies because the positive and negative anomalies on the reduction to the pole- upward-continuation anomaly maps roughly coincide with the uplifts and depressions of the crystalline basement in the basin. The results, together with the latest understanding of basement faults, SHRIMP U-Pb zircon dating of metamorphic rock and granite, drilling data, detrital zircon ages, and gravity data interpretation, suggest that the Ordos block is not an entirety of Archean.

Cambro-Silurian magmatisms at the northern Gondwana margin(Penninic basement of the Ligurian Alps)

The Early Paleozoic evolution of the northern margin of Gondwana is characterized by several episodes of bimodal magmatism intruded or outpoured within thick sedimentary basins. These processes are well recorded in the Variscan blocks incorporated in the Ligurian Alps because they experienced low temperature Alpine metamorphism. During the Paleozoic, these blocks, together with the other Alpine basements, were placed between the Corsica-Sardinia and the Bohemian Massif along the northern margin of Gondwana. In this framework, they host several a variegated lithostratigraphy forming two main complexes(Complexs I and II) that can be distinguished by both the protoliths and their crosscutting relationships, which indicate that the acidic and mafic intrusives of Complex II cut an already folded sequence made of sediments, basalts and granitoids of Complex I. Both complexes were involved in the Variscan orogenic phases as highlighted by the pervasive eclogite-amphibolite facies schistosity(foliation II). However, rare relicts of a metamorphic foliation at amphibolite facies conditions(foliation I)is locally preserved only in the rocks of Complex I. It is debatable if this schistosity was produced during the early folding event e occurred between the emplacement of Complex I and II e rather than during an early stage of the Variscan metamorphic cycle.New SHRIMP and LA ICP-MS Ue Pb zircon dating integrated with literature data, provide emplacement ages of the several volcanic or intrusive bodies of both complexes. The igneous activity of Complex I is dated between 507 ± 15 Ma and 494 ± 5 Ma, while Complex II between 467 ± 12 Ma and 445.5 ± 12 Ma.The folding event recorded only by the Complex I should therefore have occurred between 494 ± 5 Ma and 467 ± 12 Ma. The Variscan eclogite-amphibolite facies metamorphism is instead constrained between ~420 Ma and ~300 Ma. These ages and the geochemical signature of these rocks allow constraining the Early Paleozoic tectono-magmatic evolution of the Ligurian blocks, from a middleeupper Cambrian rifting stage, through the formation of an Early Ordovician volcanic arc during the Rheic Ocean subduction, until a Late Ordovician extension related to the arc collapse and subsequent rifting of the PaleoThetys. Furthermore, the ~420-350 Ma ages from zircon rims testify to thermal perturbations that may be associated with the Silurian rifting-related magmatism, followed by the subduction-collisional phases of the Variscan orogeny.

Reinterpretation of the northern South China Sea pre-Cenozoic basement and geodynamic implications of the South China continent: constraints from combined geological and geophysical records

The pre-Cenozoic northern South China Sea(SCS)Basin basement was supposed to exist as a complex of heterogeneous segments,divided by dozens of N-S faulting.Unfortunately,only the Hainan Island and the northeastern SCS region were modestly dated while the extensive basement remains roughly postulated by limited geophysical data.This study presents a systematic analysis including U-Pb geochronology,elemental geochemistry and petrographic identification on granite and meta-clastic borehole samples from several key areas.Constrained from gravity-magnetic joint inversion,this interpretation will be of great significance revealing the tectono-magmatic evolution along the southeastern margin of the Eurasian Plate.Beneath the thick Cenozoic sediments,the northern SCS is composed of a uniform Mesozoic basement while the Precambrian rocks are only constricted along the Red River Fault Zone.Further eastern part of the northern SCS below the Cenozoic succession was widely intruded by granites with Jurassic-to-early Cretaceous ages.Further western part,on the other hand,is represented by meta-sedimentary rocks with relatively sporadic granite complexes.To be noted,the western areas derived higher-degree and wider metamorphic zones,which is in contrast with the lowerdegree and narrower metamorphic belt developed in the eastern region.Drastic collisions between the Indochina Block and South China continent took place since at least late Triassic,resulting in large-scale suturing and deformation zones.At the westernmost part of the northern SCS,the intracontinental amalgamation with closure of the Meso-Tethys has caused fairly stronger and broader metamorphism.One metamorphic biotite granite is located on the suturing belt and yields a Precambrian U-Pb age.It likely represents the relict from the ancient Gondwana supercontinent or its fringes.Arc-continental collision between the Paleo-Pacific and the southeast China Block,on the other hand,results in a relatively narrow NE–SW trending metamorphic belt during the late Mesozoic.Within the overall geological setting,the Cenozoic SCS oceanic basin was subsequently generated from a series of rifting and faulting processes along the collisional-accretionary continental margin.

Heparanase expression,degradation of basement membrane and low degree of infi ltration by immunocytes correlate with invasion and progression of human gastric cancer

AIM： To disclose the mechanisms that accelerate or limit tumor invasion and metastasis in gastric cancer patients. METHODS： The heparanase expression, continuity of basement, degree of infiltration by dendritic cells and lymphocytes in gastric cancer tissues from 33 the early and late stage patients were examined by immunohistochemistry, in situ hybridization and transmission electron microscopy. RESULTS： Heparanase mRNA expression in the late stage patients with gastric cancer was stronger than that in the early stage gastric cancer patients. In the early stage gastric cancer tissues, basement membrane （BM） appeared intact, whereas in the late stage, discontinuous BM was often present. The density of Sl00 protein positive tumor infiltrating dendritic cells （TIDC） in the early stage gastric cancer tissues was higher than that in the late stage. The infiltrating degree of tumor infiltrating lymphocytes （TIL） in the early stage patients whose tumor tissues contained a high density of TIDC was significantly higher than that in the late stage gastric cancer tissues patients with a low density of TIDC. There were few cancer cells penetrated through the continuous BM of cancer nests in the early stage gastric cancers, but many cancer cells were found outside of the defective BM of cancer nests in the late stage. CONCLUSION： Our results suggest that strongheparanase expression is related with the degradation of BM which allows or accelerates tumor invasion and metastasis. However, high density of TIDC and degree of infiltration by TIL are associated with tumor progression in human gastric cancers.

Hydrochemical and Isotopic Characteristics of the Basement Aquifer in the Wadi Fira Area, Eastern Chad

The Wadi-Fira region in eastern Chad is facing dramatic water supply problems, related to the climatic semi-arid context and the reception of refugees from the Darfour, which has increased the local population by 22% these last years. Expansion of agglomerations (temporary new towns), development of agricultural and pastoral practices together with the augmentation of the population have led to dramatic water needs. The basement aquifer of Wadi-Fira constitutes the main source of water supply. However, little is known about this system. Within this context, this work aims at better understanding and identifying hydrogeochemical processes and their relations to groundwater quality within this complex environment, and groundwater recharge mechanisms. 31 groundwater samples were collected at two sites, Am Zoer and Guereda-Iriba, from hand dug wells and deep wells. Major chemical elements were analyzed on all samples and stables isotopes (oxygen-18 and deuterium) on 17 samples. Various methods were used to interpret the hydrochemical data (descriptive and multivariate statistics, Piper and Schoeller diagrams, scatter plots, minerals saturation indices). The stable isotopes were interpreted using conventional IAEA methods. The results permitted to differentiate the laterite reservoir from the deep fractured reservoir. The main process controlling groundwater mineralization is water-rocks interaction and natural minerals dissolution. Ion exchanges, evaporation and anthropogenic activities have also a moderate impact on groundwater quality. Based on isotopes data, it is concluded that groundwater in the basement aquifer is related with modern rainfall. These results provide further insights into this basement aquifer, which is a vital resource for the region of Wadi-Fira.

Oldest Basement(ca.462 Ma)in Indonesian Borneo and its Implication for Early Paleozoic Tectonic Evolution of SE Asia

The lack of preserved basement results in uncertain placements of many terranes in Southeast Asia.Here,we flag the first evidence of the oldest basement in Indonesian Borneo,which can help locate terranes in Borneo on the northern margin of Gondwana in the early Paleozoic and explain the regional tectonic setting of the island.Two schist samples from the Embuoi Complex in the Semitau Block,Northwest Kalimantan yielded zircon U-Pb dates of 453.3±1.9 Ma and 462.4±2.6 Ma,respectively,representing the formation time of the protolith.Petrographic,internal structural and high Th/U ratios of zircons indicate that the protolith of schists is of magmatic origin.The zircons haveεHf(t)values of−4.1 to+1.1 and Hf model ages of 1.37–1.69 Ga,indicating they were derived from a mixed source of juvenile crust with old components.By comparison of zircon age distribution,two-stage Hf model ages andεHf(t)variations of the early Paleozoic igneous rocks from Semitau with those of South China,Tengchong–Baoshan,and Indochina,the Semitau Block was most likely a part of or placed next to the Indochina Block of northern Gondwana during the early Paleozoic.Such a similar tectono-magmatic pattern on northern Gondwana formed a prolonged early Paleozoic arc-related belt associated with subduction of the Proto-Tethyan Ocean.

Zircon U-Pb geochronology,Hf isotopes,and geochemistry constraints on the age and tectonic affinity of the basement granitoids from the Qiongdongnan Basin,northern South China Sea

Studies in the northern South China Sea(SCS)basement remain important for understanding the evolution of the Southeast Asian continental margin.Due to a thick cover of sediments and scarce borehole penetration,little is known about the age and tectonic affinity of this basement.In this study,an integrated study of zircon U-Pb geochronology,Hf isotopes,and whole-rock major and trace elements on seven basement granitoids from seven boreholes of Qiongdongnan Basin has been carried out.New zircon U-Pb results for these granitoids present middle-late Permian((270.0±1.2)Ma;(253±3.4)Ma),middle to late Triassic((246.2±3.4)Ma;(239.3±0.96)Ma;(237.9±0.99)Ma;(228.9±1.0)Ma)and Late Cretaceous ages((120.6±0.6)Ma).New data from this study,in combination with the previous dataset,indicates that granitoid ages in northern SCS basement vary from 270 Ma to 70.5 Ma,with three age groups of 270–196 Ma,162–142 Ma,and 137–71 Ma,respectively.Except for the late Paleozoic-Mesozoic rocks in the basement of the northern SCS,a few old zircon grains with the age of(2708.1±17)Ma to(2166.6±19)Ma provide clues to the existence of the pre-Proterozoic components.The geochemical signatures indicate that the middle Permian-early Cretaceous granitoids from the Qiongdongnan Basin are I-type granites formed in a volcanic arc environment,which were probably related to the subduction of the Paleo-Pacific Plate.