Since the Neoproterozoic rifting of the supercontinent Rodina, Early Paleozoic entered an active period of plate tectonics. Because plate movement speed became faster, the plate configurations are variable and instabile, the interactions among blocks are complex and changeable. the evolution of orogenic belts are also extremely complex, resulting in that global Early Paleozoic paleo-continent reconstruction today are still ambiguous. In particular, there is a global quasi-simultaneous orogeny at the end of the Early Paleozoic (450-400 Ma), there are three types of global-scale orogenic belts, which are subduction-related acretionary, collisional and intracontinental. This paper focuses on Early Paleozoic collision-type orogenic belts in the globe. It is discussed and summarized for the new geochronological and metamorphic, deformation and magmatism and their temporal and spatial distribution of the typical collisional orogenic belts. Early Paleozoic global collision-type orogenic belts mainly include the Pan-African orogenic belts of the southern hemisphere and the Caledonian orogenic belts of the northern hemisphere, respectively. They are closely related with preliminary assemblies of the Southern Gondwana and the Northern Laurussia. The Early Paleozoic collisional orogeny is mainly characterized by the collisions between large-scale continental blocks. These Early Paleozoic collisional orogenic belts have an approximate collision age, roughly undergoing the same evolutionary process, which the main part of the continent-continent collision for the southern continents completed in 540 Ma, and the main part of the northern continents assembled in 420 Ma. In the global tectonic significance it may means the initial formation of a global supercontinent of 420-400 Ma.

Global Early Paleozoic accretionary orogenic belts extremely developed and mainly distributed in the north and south sides of the Paleo-Asian Ocean, north of Rheic Ocean, south of Iapetus Ocean and peri-Gondwana continent, the accretion related to the proto-Tethyan closing mainly developed within the territory of China, a large amount of micro-continental blocks in the Early Paleozoic may be an important component of the northern margin of the Gondwana subduction-accretionary zone. Accretionary orogenic belt is complex in composition, including the trench-arc-basin system, seamounts, oceanic crust and other relic geological records. Especially eclogite is common. Accretionary orogenic belts are remarkable and unique characteristics of Early Paleozoic Paleo-Asian Ocean and Tethyan tectonic domains. In late Early Paleozoic, the central Asian Orogenic belt was under the accretion of the micro-continental blocks and the trench-arc-basin system developed with the characteristics of the accretionary-weak collisional orogenic processes at the end of the Early Paleozoic. The west and east Kunlun Mountains, north margin of the Qaidam basin, south Altyn Tagh Mountain, north Altyn Tagh, north Qilian and north Qinling, some involved micro-continental blocks in the Proto-Tethyan Ocean as one single linear island arc have the same accretionary orogenic processes in the Early Paleozoic. They overall subducted southward under and accreted to the northern margin of Gondwana. Their curved shape of these accretionary belts was reworked into one orocline by multiple-stage deformation. After 400 Ma, the paleo-Tethyan Ocean to the south and the Mianlue Ocean to the north opened, resulting in the drifting and complex deformation reworking as a giant orocline in Central China. It has very important influence on the tectonic outline in China.

This paper takes South China Early Paleozoic Caledonian intracontinental orogenic belt as an example, analyzing the intracontinental orogenic deformation, magmatic and sedimentary characteristics, the distribution of angular unconformity, fold-thrust belts, and subduction polarity. It was found that E-W-striking Cambrian fold asymmetry and spatial distribution of angular unconformities propagated and became younging towards the north in the Daming Mountain and the Dayaoshan area, indicating that the younging and propagation of north-directed thrusting may resulted from the seuqantially southward collision of the Yunkai block and the Diangui-North Vietanam blocks. Under the global tectonic setting, the deformation may be related to far-field intracontinental effect caused by sequential collision of some blocks in the South China block to the northern margin of Gondwana. The Yuanbaoshan and Yuechengling area in the north Guangxi, and the Hunan-Jiangxi border area developed the Early Paleozoic NE-NNE-trending folds and thrusts of which asymmetry indicates westward propagation, probably resulting from the collision of the Cathaysia block to the Yangtze block along the Chenzhou-Linwu fault in the Late Ordovician and Early Silurian. In the global view, it may be related to the clockwise rotation and comprehensive collision of the South China block to Gondwana. In summary, the Caledonian tectonic movement as a whole was sequentially propagated from south to north, and from east to west, their deformation intensity is from strong to weak toward the north or the west, reflecting that South China intracontinental collisional orogenic event is a far-field effect of its collision to the Gondwana. During about 450-420 Ma the South China block has been a part of the northern margin of Gondwana.

Paleoproterozoic and Phanerozoic plate tectonics and periodic evolutionary processes have obvious difference, reflecting in the geological records developed in two different plate tectonic regimes. The Early Paleozoic is a transition era of these two regimes, the Early Paleozoic tectonic processes and plate reconstructions are the key to understand tectonic mechanism and cycle of the Earth's plate tectonics. This paper summarizes and compares the global geological events of the Early Paleozoic collisional orogenic belts since the rifting of the Supercontinent Rodinia based on the analysis of the evolutions of the Early Paleozoic collisional orogenic belts, summing up seven Gondwana-, Larussia-, Paleo-Chinese blocks-related collisional or accretionary orogenic events: the Brasiliano Orogeny, East African Orogeny, the Kuunga Orogeny, the Caledonian-stage proto-Tethyan- and Paleo-Asian Ocean-related orogeny in East Asia, and classic Caledonian Orogeny, central Eurasian Caledonian suturing, Appalachian Orogeny. After synthesizing seven-stage orogneic events, based on the combination of paleomagnetism, paleontology and paleogeographic data, this paper reconstructs assembly processes of global plates from the Neoproterozoic to Early Paleozoic as follows. Supercontient Rodinia began to experience three stages of rifting since the Neoproterozoic ~950 Ma, developing the Panthalassa, Mozambique and the Paleo-Pacific oceans. The Iapetus ocean opened in 615-560 Ma. In about 560 Ma the dispersal of the Baltica from the West Gondwana resulted in the opening of the narrow Ran Ocean. The Brasiliano Orogeny, the East African orogeny and the Kuunga orogeny in the southern hemisphere completed the final assembly of the Gondwanaland in ~540 Ma. Some terranes in the western segment of the northern margin of the Gondwana locally drifted away to result inthe opening of the Rheic and the Tornquist oceans since ~500 Ma. In ~420 Ma the formation of the classic Caledonian orogenic belt and the Central Eurasian suture zone closed the Iapetus Ocean. Coevally the Svalbard and the United Kingdom may be located in southeast of the Greenland Shield, and some micro-continental blocks such as the North China block docked in the eastern segment of the northern margin of the Gondwanaland. Since 425 Ma the Siberia plate had a trend away from the assembled Larussia Continent, but the South and North American plates were closer and closer in Late Ordovician-Early Devonian, and it resulted in the collision between the North American plate and the terrances on the northern margin of peri-Gondwana. In about 400 Ma, the mixed biota in the South and North America and palaeogeographic reconstruction shows the South and North America were very closer, so we speculated that one supercontinent may existed and called the Supercontinent Carolina in this paper, because the Carolina orogenic belt is the potential final collisional zone. Based on this supercontinent, this paper proposes that the supercontinent cycle is 700 Myr.

NE China has traditionally been considered as the eastern part of the Central Asian Orogenic Belt (CAOB), located between the Siberia and North China cratons. They constitute Paleozoic accretionary margins to the Siberia and the North China cratons, terminated to the east by the Paleo-Pacific orogens. In detail, NE China is the key area for understanding the geodynamics between the CAOB and Paleo-Pacific subduction. The tectonic units of the combined NE China blocks (NEC) include the Jiamusi-Khanka blocks in the northeast, the Xing'an and Songliao blocks in the central area, and the Erguna block in the northwest. The basement rocks in NEC constitute a common khondalitic sequence of Neoproterozoic with high grade metamorphism occurred at ~500 Ma. The Paleozoic sediments also show slimier sequences in most blocks in the NE China, suggesting that the combined NE China blocks (NEC) might be have similar or same tectonic evolutions during that time. The boundary between these blocks show following new evidences: 1)the suture zone between the Eerguna and Xing'an blocks is the Early Paleozoic Toudaoqiao-Xinlin suture and not the Mesozoic Derbugan fault. 2)the emplacement time of the Hegenshan-Heihe suture between the Xing'an and Songlao blocks is the Late Carboniferous and not the Mesozoic as recently reported. 3)the Paleo-Asian Ocean between the combined NE China blocks (NEC) and North China block is along the Xar Moron-Changchun suture and the collision timing is the Triassic. 4)the collision timing of the Jilin-Heilongjiang high pressure metamorphic belt (Ji-Hei HP belt) between the Jiamusi-Khanka and Songliao blocks is the switch time when end of the CAOB and beginning the Paleo-Pacific subduction at sometime between 210 and 180 Ma, and 5)the Nadanhada accretionary complex is the only records for the Paleo-Pacific subuduction from Late Triassic to Early Cretaceous in NE China. In addition, we also focus on the evidences of the both typical tectono-magmatic events and Paleontologic signatures, and reconstruction of the NEC from Gondwana to Pangea supercontinent.

Rock's classification has long been an intriguing task for geologists all over the world. With the development of volcanic reservoir exploration, volcanic classification buried in petroliferous basins has become increasingly needed work recently. Based on comprehensive summarization of the available classification scenarios of volcanic rocks, we proposed a so called structure-composition-origin volcanic classification for the Junggar basin focusing on the volcanic reservoir evaluation and exploration. The related data base includes 3 outcrops of 4.2 km accumulative thickness and 21 wells of 474 m volcanic core sections. Geochemical data and thin sections work have been done on these samples. 8 categories and 45 types are classified for the volcanogenic successions. Volcanic lavas, breccia-bearing lavas, pyroclastic rocks, sedimentary pyroclastic rocks, pyroclastic-bearing sedimentary rocks, hypabyssal rocks and subvolcanic rocks, and platonic rocks are described in detail. Paleozoic volcanic rocks interested have generally been suffered from alterations which can change the petrochemical compositions, and affect the result of the chemical classification using the TAS diagram. Methods were provided for the precise naming of the altered volcanic rocks in the paper. Correlations have been well established between volcanic lithology and reservoir features in the basin. The results would be useful for similar basins concerning volcanic classification and reservoir evaluation and exploration.

Pluvial seasonal river sandstones are characterized by high content of detrital clays. According to petrofabric, detrital clays can be divided into mud intraclast, mechanically infiltrated clays and pedogenic mud aggregates. Mud intraclast is distributed mainly in the bottom of the river sandstone. The textures of mechanically infiltrated clays include ridges and bridges, geopetal fabrics, loose aggregates, anisopachous coatings of tangentially-accreted lamellae and massive aggregates. And spatial distribution of mechanically infiltrated clays is controlled by the fluctuating water table, the shifting and the incising of drainageways. Pedogenic mud aggregates are often distributed in sandstones and siltstones with texture or cross-bedding, in basal channel lags, trough fills of megaforms, and at the tops of channel-fill sequences. Mechanically infiltrated clays is one of the most important factors of causing the heterogeneity of river-facies sand reservoir. The erosion vulnerability of the "Pisha" sandstones is probably related with its high value of content of detrital smectite.

The fracturing of shale is one of the keys to determine whether the shale oil and gas can be effectively developed. The differences of deposition and diagenesis usually cause significant shale heterogeneity in composition, structure, construction, diagenesis, etc. Fracturing is an essential comprehensive reflection of lithological characteristics of shale, therefore these different aspects of shale lithology are critical to its fracturing properties. We analyzed and summarized the influence mechanism of shale lithologyon fracturing. The content of brittle mineral is a qualitative judgmentfor shale fracturing; Althoughfelsic minerals is regarded as a brittleness index, the conclusionshould also build on the basis of middle-strong diagenesis. Large felsic particles or authigenic mineralgrains are usually in complex shape and possess high degree oforder, which improves the fracturing property of shale. Shale fracturing will be reduced withwell-developed and strongly continued laminae, but enhanced with diagenesis and consolidation. In the process of shale oil and gas exploration and development, we must pay attention to the difference in lithology; as it can affect the fracturing of shale.

Several oil shale-bearing basins are distributed in the Dunhua-Mishan fault zone in Northeast China. The characteristics of tectonic and sedimentary filling evolution, sedimentary association, the occurrences of oil shale and coal indicated that oil shale deposited in the heyday of the lakes, while the sedimentary age of oil shale layers was the Paleogene Eocene Lutetian Stage. While oil shale have displayed certain differences among these basins, from southwest to northeast direction of this fault zone, the thickness of oil shale becomes smaller, and sedimentary environment changed from deep lake to semi-deep lake, and limnetic finally. Meanwhile, the organism sources was dominated by aquatic organism in the southwest part basins, and it became a mixture of terrestrial and aquatic organic matter in the middle part of this fault zone, whereas organic matter of northeast part basins in the fault zone originates mainly from land plants. Combined oil shale layers developed in the same age and similar paleoclimate, tectonic subsidence and sedimentary filling were the key factors on controlling the differences of oil shale in these basins. Perpetual underfilled sedimentary environment and large accommodation promoted huge thick high quality oil shale developed. With the decreasing of accommodation and increasing terrigenous debris supply, the thickness of oil shale thinned and distributed sparsely, while grade of deep lake and limnetic oil shale was high and semi-deep lake oil shale was low.

The southern segment poly-metal metallogenic belt of the Da Hinggan Mountains (DHM) is located at the area between the Hegenshan fault and the Xilamulun fault in eastern Central Asia Orogenic belt, and also situated the superposition area caused by the paleo-Asia ocean tectonic system and paleo-Pacific ocean tectonic system. The southern segment poly-metal metallogenic belt of DHM is characterized by the bilayer structure (Permian basement,Jurassic-Early Cretaceous covers), poly-stage tectonic-magma activities and numerous poly-metal deposits. The metal deposits are characterized by the associated poly elements. The metal deposits can be classified to four ore-forming system by the mineralization features: porphyry, skarn, hydrothermal vein and alkaline granite ore-forming systems. Porphyry ore-forming system includes Mo-poly metal and Sn-poly metal subsystems, skarn ore-forming system includes Fe-Sn and Pb-Zn-Ag subsystems, hydrothermal vein ore-forming system includes Ag-poly metal, Cu-poly metal and Sn-poly metal subsystems. Alkaline granite ore-forming system is the rare and rare earth metal ore-forming system. The metal deposits in southern segment of DHM were mainly formed in two periods: Late Permian to Triassic and Late Jurassic to Early Cretaceous. Both periods mineralization is related to the granitic magmatism. The ore-forming materials were derived from multi-sources which including deep and strata sources. The Late Permian and Triassic poly metal deposits were formed in the paleo-Asia tectonic setting, the Late Jurassic and Early Cretaceous poly metal deposits were formed in the paleo-Pacific tectonic setting. The favorable metallogenic geological conditions, the good geophysical and geochemical anomalies indicate that the southern segment has still huge exploration potential.

Island arc and back-arc basin systems are the important seafloor environments for the development of hydrothermal sulfide resources. In this study, we reviewed the results of international investigations and numerous studies on the hydrothermal activities and the accompanying sulfide mineralization processes in the arc and back-arc basin systems over the past few decades. We summarized geographical distributions, tectonic environments, water depths, vent fluid temperatures and phase separation process for the hydrothermal activities, and the sulfide types, element accumulation characteristics, ore body scales and the main ore-forming control factors for the hydrothermal sulfides in the systems. We suggested that, the variation trendy for the water depth of vents in the systems is the same as that for maximum vent fluid temperatures, and both of them are related to the phase separation process. Hydrothermal sulfides are mainly dominated by Fe-Zn-Pb type, and significantly enriched in the metal elements such as Zn, Pb, Au, Ag, etc. Hydrothermal mineralization is mainly controlled by the following five factors, island arc and back-arc magmatism, phase separation, basement rock, back-arc spreading rate and sediment.

Hot dry rock (HDR) is a kind of high temperature rock in depth without or with a small amount of water. A conservative estimation of the HDR thermal energy in the earth's crust (depth of 3-10 km) is equivalent to the 30 times of the total energy contained in the oil, gas and coal all over the world. Enhanced geothermal system (EGS) is an engineered reservoirs that has been created to extract economical amounts of heat from low permeability and/or porosity geothermal resources. The history of study and development of EGS has been about 40 years, but only a small number of countries in the world have conducted EGS research and demonstration, such as the United States, Britain, France, Japan, Australia, etc. In recent years, we have started the research and development. Currently, the exploitation of HDR faces many challenges, such as the creation of the massive artificial fractured thermal reservoir, and implementing EGS commercialization needs further research and technological development. This paper reviewed the experiences and lessons learned from international typical EGS demonstration projects, and discussed the research progress of China in recent years. The purpose of the paper is to offer reference for future scientific research and field demonstration of the EGS in China.

Ravines & gullies crisscrossed that makes hydropower resources abundant at the up reaches of Jinsha River, north slope of Hengduan Mountain. Since the Middle and the Late Pleistocene, rapidly uplift neotectonic activity gives rise to gravitational deformation and disasters occurrence due to the complexed structural rock mass in this river section. Basic geological background due to high geostress and the basic features of the complicated structural rock mass for ophiolite suite developed in Jinsha River plate tectonics joint belt of this river section were stated. A new concept of rapid uplift river section is put forwarded, annul uplift value up to ≥5 mm/a is recommended to be the threshold of rapid uplift river section. Evidences and basic features related to four events of huge landslide dams originated from defferent time and different scale were enumerated, the relationship between the rapid uplift river section and four landslide dams was expressed. Genetic mechanism of four huge landslide dams developed in the reach of 21.4 km river section was disccussed and analyzed based on geological process mechanism method, and earlier landslide dam residual might be a potential harzadous for the future human activities is pointed out.

Debris flow is a kind of nature hazard which can produce serious consequences, and the accuracy of debris flow risk classification is important for the early warning and disaster prevention.Now there are a lot of algorithms used to evaluate the risk of debris flow. Fuzzy c means (FCM) algorithm is one of the widely used algorithms. Compared with general classification method, FCM does not need to determine risk boundaries artificially, and it outputs membership degree matrix for each risk degree. Support vector machine (SVM) is a machine algorithm based on structure risk minimization. It establishes classification model by support vectors and has better Robustness. It is well applied to small samples. In this paper, the SVM method based on FCM is used for debris flow risk evaluation, which gets a good classification performance.

Environmental endocrine disrupting chemicals have become a global concerned environmental problem, whose distribution, transport and fate of estrogens in groundwater and soils closely relate to human and ecological health. Based on the summary of properties, classification, analytical methods and other aspects of environmental estrogens, it reveals the variety of hazards and risks to organisms and wider environment. Their migration and transformation processes in groundwater and soil environment were characterized then, and understanding of their control and remediation techniques and methods were further reviewed, to provide guidance for reducing the ecological and environmental risks of estrogens. Based upon the significance of the estrogen study, further potential research areas and prospects were highlighted in this field.

The present work investigates the treatment of polyvinyl alcohol (PVA) wastewater by using ozone/ultrasound(US) oxidation process. The effects of initial PVA mass concentration, the flow rate of ozone, initial pH, ultrasonic power, ultrasonic frequency, and raction time have been studied. The optimal treatment conditions for PVA and COD removal were obtained using orthogonal experiments. The results showed that ultrasonic frequency has a remarkable influence on the removal efficiency,the initial PVA mass concentration plays an important role, while reaction time, ultrasonic power, the flow rate of ozone and initial pH have minor effects in order. The maximum removal of COD and PVA could be reached under the following conditions: initial PVA mass concentration was 100 mg/L, initial pH was 9, ozone dosage was 4 g/h, ultrasonic power was 320 W, ultrasonic frequency was 40 kHz, and the reaction time was 20 minutes. Under these conditions,the removal efficiency of COD and PVA was 86.4% and 99.3%,respectively. Compared O₃ with O₃/US, different types of technology were operated at the same final condition to show the difference between them, the PVA removal efficiency of O₃/US was 5.1% higher than O₃, the COD removal efficiency of O₃/US was 19.4% higher than that with the treatment of only O₃ under the same optimal conditions.

The biochar was produced by pyrolyse process under 450 ℃ using soybean stem waste materials. The elemental analyzer,electron microscope scanning (SEM),transform infrared spectroscopy(FTIR),x-ray photoelectron spectroscopy (XPS) were applied to analyze the physical and chemical characteristics of biochar. The effects of four factors (initial pH, doge of adsorbent, concentration of atrazine and temperature) on the removal efficiency of atrazine were investigated using central composite design (CCD) under response surface methodology (RSM). Creating a 2-order equation, and then the ANOVA was employed to verify the validity of the quadratic model. The results showed that the surface of biochar was full of pore structures and C=C、C-C、CHx、-C-OR、-COOR functional groups. A new adsorption peak appeared on the -OH position after adsorption of atrazine by biochar. So we speculated that the hydroxyl groups played an important role in the process of adsorption. The optimum adsorption removal (92.18%) by RSM obtained at pH=6.67, the doge of adsorbent 7.75 g/L, initial atrazine concentration 5 mg/L, T=35 ℃. The research will provide references for the migration regularity of atrazine in biochar-applied soil and the remediation of atrazine polluted water.

The conventional hydrocarbon exploration program is approximately reconnaissance, detail survey, detailed survey, prospecting, geology and logging etc. Based on predecessors' studies and applications, the research team has gradually formed a theory of pluralistic exploration for oil and gas resources through years of practice. The theoretical system covers several parts as follows: 1)a multi-tectonic unit under the superimposition of the controlled regional structure and tectonic movements in different geologic times; 2)a target unit with different characteristics of oil and gas properties; 3)a geophysical unit with multi-geophysical properties and multi-scales; 4)a unit with different geophysical methods and technology. This paper demonstrates the theory of pluralistic exploration using an exploration example at Tangyuan-Yitong graben on Jiayi fault in northern Songliao basin. Songliao basin is controlled by compressional stress field with superimposition in the clockwise from the tectonic domain of Paleo-Asian Ocean, Mongol-Okhotsk Ocean and Western Pacific from Paleozoic to Mesozoic-Cenozoic. Combined regional geophysics, petroleum geology, petrophysics, with computational geophysics, multi-scale geophysical techniques are applied in the deep zone and zones with low level. Finally, the new understanding and target zones of oil and gas are obtained in the new strata and new regions. The proposed theory can extend the ideas of exploration for oil and gas and improve the existing exploration programme. Moreover, the theory can be used for the exploration of solid minerals.

Magnetic resonance sounding (MRS) for groundwater investigation has received much attention of geophysicists due to its higher resolution, more efficiency, more information and unique interpretation for hydrogeological investigations. It has shown continuous development towards a frequently used geophysical technique over the last decades. There has been significant improvements in forward modeling, inversion and interpretation during the last years. These improvements extended the application range of the method concerning solutions to hydrogeological tasks. But the applicability of MRS is highly limited due to bad signal-to-noise (S/N) ratio. In many cases, the expected MRS signals are only few tens of nanovolts and therefore often contaminated by significant high-level electromagnetic noise. MRS group of Jilin University has studied the noise and its characteristics, and found that Power-line harmonic noise and spike noise are the most disturbing noises. The purpose of this paper is to give an overview of noise cancelling in MRS signal processing. We report the recent researches, including noise cancelling in real time, independent component analysis, spikes removal of MRS data based on energy calculation, as well as synchronous compression wavelet transform and self-optimizing nonlinear threshold compensation. By introducing several case studies, we prospect the developing trends of MRS noise cancelling.

To bring out the essentials of high-frequency asymptotic scattering theories and their applications in numerical modeling and imaging of geophysical fields, we give a brief overview of the corresponding research histories and the state-of-the-art. Also, we present some new developments that we have achieved in the last five years in the investigation of the high-frequency asymptotic scattering theories. Considering some problems in the literature, we first give a brief review of the basic concepts and formulas in the scattering theory; and reaffirm and underline the mathematical physics intensions of the concepts and formulas. Next, we give an overview of the research history and the state-of-the-art of the high-frequency asymptotic scattering theories, and make some comments on some related topics. Moreover, we present some new developments that we have achieved in the last five years in the corresponding studies, including the quasi-analytical approximation of the surface integral equation of the scattered waves, the generalized Beam-Born and Beam-Rytov type approximations, and so on. Finally, we give some prospects for the road ahead of the development of the high-frequency asymptotic scattering theories themselves and their application in numerical modeling and imaging of geophysical fields. Not only in history but also at present, play the asymptotic scattering theories an irreplaceable role in numerical modeling and imaging of geophysical fields, especially in migration of reflection seismic data and in full waveform inversion. In author's point of view, the further development of the high-frequency asymptotic scattering theories depends on the investigation of the Green's function. Along with the uninterrupted deep-going of the corresponding studies, the high-frequency asymptotic scattering theories will play a much more important role in numerical modeling and imaging of geophysical fields in future.

The analytic solution of the magnetotelluric fields for an idealized 2-D model which is composed of two segments with diagonal anisotropy underlain by a perfect insulator basement is considered using a quasi-static analytic approach. The analytic magnetotelluric responses for a particular model are presented. The resulting analytic solution could be used to check the numerical solutions given by numerical algorithms before more complex situations are investigated.