Zircon Hf Isotope of Yingfeng Rapakivi Granites from the Quanji Massif and ～2.7 Ga Crustal Growth

The Quanji （全吉） Massif is located in the Northwest China, which is interpreted as a micro-continent that is composed of metamorphic basement and stable cover strata. There are some controversies of genetic relationship between the Quanji Massif and the major cratons in China. In this study, we obtained in situ zircon U-Pb and Hf isotopic compositions of the Yingfeng （鹰峰） rapakivi granites from the northwest Quanji Massif by application of LA-MC-ICP-MS technique. Twenty U-Pb age measurements points are concordant or near concordant, and their weighted mean 207pb/206pb age is 1 793.9±6.4 Ma （MSWD= 1.09）, yields an upper intercept age of 1 800±17 Ma （MSWD=0.41）; 19 Hf isotope measurements yield a two-stage Hf model ages （TDM2） of 2.63 to 2.81 Ga, with a weighted average age of about 2.70±0.02 Ga and till（t）values variate between -8.91 to -5.35. This indicates that magma source of the Yingfeng rapakivi granites were produced from partial melting of late stage of Neoarchean juvenile crust, and suggests a significant crustal growth event occurred in the Quanji Massif at that time. The Quanji Massif might be an ancient continental segment detached from the Tarim Craton based on the crustal growth history and other geological records. The Tarim Craton （including the Quanji Massif） and the North China Craton had a similar or homological early crustal evolution around -2.7 Ga, which implies that Tarim Craton might be one of the component parts of North China Craton. of the Yingfeng rapakivi granites were produced from partial melting of late stage of Neoarchean juve- nile crust, and suggests a significant crustal growth event occurred in the Quanji Massif at that time. The Quanji Massif might be an ancient continental segment detached from the Tarim Craton based on the crustal growth history and other geological records. The Tarim Craton （including the Quanji Massif） and the North China Craton had a similar or homological early crustal evolution around -2.7 Ga, which implies that Tarim Craton might be one of the component parts of North China Craton.

Granulite Facies Metamorphic Age and Tectonic Implications of BIFs from the Kongling Group in the Northern Huangling Anticline

We report preliminary results of a geochemical study on banded iron formations （BIFs） in the Zhaojiayangpo （赵家阳坡） area from the Kongling （崆岭） Group in the northern Huangling （黄陵） anticline, on the northern margin of the Yangtze craton. The CL （cathodoluminescence） images of zircons mostly have sector zoning, fir-tree zoning and patched zoning, and a few show core-rim tex-tures with rims having patched zoning. The calculated formation temperatures using the Ti-in-zircon thermometer are 660-808 ℃ （714 ℃C in aver-age）, all indicating that the BIFs underwent granulite facies metamorphism. The age of zir-cons with granulite facies metamorphism is 1 990±14 Ma by LA-ICP-MS U-Pb dating, indi-cating that there was a significant granulite fa-cies tectonothermal event in the northern Huangling anticline in the Paleoproterozoic, which may be related with tectonic thermal events of the metamorphism caused by the as-sembly of the Columbia supercontinent with South China. Moreover, the REE pattern ischaracterized by depletion in LREE while relatively flat in HREE, LaN/YbN=0.26, with a positive Eu anomaly （Eu/Eu^＊---1.59）, which reveals its hydrothermal sedimentation origin and it may have formed in the environment of submarine exhalation.

The Neoarchean Ophiolite in the North China Craton:Early Precambrian Plate Tectonics and Scientific Debate

Archean greenstone belts and their possible inclusion of fragments of ophiolites is an im-portant research subject, since it is correlated with the nature of early oceanic crust, and can yield in-formation on the nature of early planetary lithospheres, the origin of TTG （tonalite-trondhjemite-granodiorite） continental crust, the formation of early cratons and continents, and is related to when plate tectonics started in the Earth＇s evolutionary history. This article briefly reviews the North China craton＇s Archean ophiolite argument and proposes further studies aimed at understanding the genera- tion of greenstone belts and Archean ophiolites, and suggests some key scientific questions that remain to be answered.

Geological Features and Deformational Ages of the Basal Thrust Belt of the Miaowan Ophiolite in the Southern Huangling Anticline and Its Tectonic Implications

The stratigraphic, structural and metamorphic features of the basal thrust belt of the ca. 1.0 Ga Miaowan （庙湾） ophiolite in the southern Huangling （黄陵） anticline, show that it can be divided into three tectono-lithostratigraphic units from north to south： mélange/wildflysch rock units, flysch rock units, and sedimentary rock units of the autochthonous （in situ） stable continental margin. The three units underwent thrust-related deformation during emplacement of the Miaowan ophiolitic nappe, with kinematic indicators indicating movement from the NNE to SSW, with the metamorphic grade reaching greenschist-amphibolite facies. LA-ICP-MS U-Pb geochronology of zircons from granite pebbles in the basal thrust-related wildflysch yield ages of 859±26, 861＋12 and 871±16 Ma; whereas monzonitic granite clasts yield an age of 813±14 Ma. This indicates that the formation age of the basal thrust belt is not older than 813±14 Ma, and is earlier than the earliest formation time of the majority of the Neoproterozoic Huangling granitoid intrusive complex, which did not experience penetrative ductile deforma-tion. These results suggest that the northern margin of the Yangtze craton was involved in collisional tectonics that continued past 813 Ma.This may be related to the amalgamation of the Yangtze craton with the Rodinia supercontinent. Through comparative study of lithology, zircon geochronology, REE patterns between granodiorite and tonalite pebbles in the basal thrust-zone conglomerate, it can be concluded that the pebbles are the most similar to the Huanglingmiao （黄陵庙） rock-mass （unit）, implying that they may have come from Huanglingmiao rock-mass. Zircon cores yield xenocrystic ages of 2 074±120 Ma, suggesting that the protolith of the Neoproterozoic Huangling granitoid intrusive complex may have originated from par-tial melting of older basement rocks, that is to say there may be Paleoproterozoic crystalline basement in the southern Huangling anticline. The ages of xenocrystic zircons in the granite pebbles in the basal-thrust congiomerate/wildflysch show a correlation with the age spectra from Australia, implying that the terrain that collided with the northern margin of the Yangtze craton and emplaced the Miaowan ophiolite at ca. 813 Ma may have been derived from the Australian segment of Rodinia.

Sea-Floor Metamorphism Recorded in Epidosites from the ca.1.0 Ga Miaowan Ophiolite,Huangling Anticline,China

The epidosites are interpreted to form in upflow zones at the base of ore-forming oceanic hydrothermal systems that vent as black smokers on the sea floor. This study presents new field, major and trace element, and oxygen isotope data for the recently discovered epidosites in the ca. 1.0 Ga Miaowan （庙湾） ophiolite located near the northern margin of the Yangtze craton. The ep-idosites occur mainly in the cores of strongly de-formed, lensoidal amphibolites. Field observations, major and trace elements and oxygen isotopes sug-gest that the epidosites were formed by metasoma-tism of ocean floor basalts, diabase dykes, and gabbros during seafloor hydrothermal alteration.

Origin and Emplacement of Archean Ophiolites of the Central Orogenic Belt, North China Craton

Understanding Archean crustal and mantle evolution hinges upon identification and characterization of oceanic lithosphere. We report and update here more than 10 years work on a complete, yet dismembered and metamorphosed Archcan ophiolite sequence in the North China craton, in the Dongwanzi （东湾子）-Zunhua （遵化） structural belt and correlatives in the Wutaishan （五台山） area. Banded iron formation structurally overlies several tens of meters of variably deformed pillow lavas, mafic flows, and picritic amphibolites. These are in structural contact with a 2 km thick mixed gabbro and dike complex with gabbro screens, exposed discontinuously along strike for more than 20 km. The dikes consist of metamorphosed diabase, basalt, Hb-Cpx-gabbro, and pyroxenite. The dike/gabbro complex is underlain by several kilometers of mixed isotropic and foliated gabbro, which preserve compositional layering approximately 2 km below the dike complex, and then over several hundred meters merge into strongly compositionally layered gabbro and olivine-gabbro. The layered gabbro becomes mixed with layered pyroxenite/gabbro marking a transition zone into emulate ultramaflc rocks including serpentinzed dunite, pyroxenite and wehrlite, and finally into strongly deformed and serpentinized olivine and orthopyroxene-bearing ultraInafic rocks interpreted as depleted mantle harzburgite tectoultes. A U/Pb zircon age of 2.505 Ga from gabbro of the Dongwanzi ophioUte makes it one of the world＇s oldest recognized, laterally. extensive complete ophiolite sequences, though older dismembered ophiolites are recognized in South Africa and Greenland, extending back to 3.8 Ga. This age is confirmed by a ca. 2.6 Ga Re-Os isochron from chromites from the belt, and a number of dated 2.5-2.4 Ga cross-cuttlng younger igneous units. The Dongwanzi ophiolite is one of the largest well-preserved greenstone belts in the central orogenic belt that divides the North China craton into eastern and western blocks. More than 1 000 other fragments of gabbro, pillow lava, sheeted dikes, harzburgite,and podiform-chromite bearing dunite occur as tectonic blocks （tens to hundreds of meters long） in a biotite-gneiss and BIF matrix, intruded by tonalite and granodiorite, in the Zunhua structural belt. Blocks in this metamorphosed Archcan ophiolitic melange preserve deeper levels of oceanic mantle than the Dongwanzi ophiolite. The ophiolite-related melange marks a suture zone across the North China craton, traced for more than 1 600 km along the central orogenic belt. Many of the chromitite bodies are localized in dunite envelopes within harzburgite tectonite, and have characteristic nodular and orbicular chromite textures, known elsewhere only from ophiolites. The chromites have variable but high chrome numbers （Cr/（Cr＋Al）=0.74-0.93） and elevated P, also characteristic of suprasubduction zone ophiolites. The high chrome numbers, coupled with TiO2〈0.2 wt.% and V2O5〈0.1 wt.% indicate high degrees of partial melting from a very depleted mantle source and primitive melt for the chromite. A Re-Os isochron from the chromites indicates an age of 2.6 Ga, showing that they are the same age as the Dongwanzi ophiolite. The range in initial Os isotopic compositions in the chromites in these ophiolitic blocks is small and well within the range seen in modern ophiolites. The ultramafic and ophiolitic blocks in the Zunhua melange are therefore interpreted as dismembered and strongly deformed parts of the Dongwanzi ophiolite. We suggest the name ＂Dongwanzi-Zunhua ophiolite belt＂ for these rocks. Geochemical and structural features of the Dongwanzi ophiolite suggest that it formed in a forearc environment and was incorporated in an accretionary prism soon after it formed. Neoarchean and Paleoproterozoic （2.50 and 1.90 Ga） high-pressure granulites form a belt more than 700 km long along the western side of the central orogenic belt. Several Neoarchean sedimentary basins consisting of conglomerate, greywacke, and shale are located along the eastern side of the central orogenic belt, and are interpreted as remnants of a foreland basin. The three belts record the Neoarchcan subduction and collision between an arc terrane and eastern blocks of the North China craton in the Neoarchean, and further deformation and metamorphism in the Paleoproterozoic related to collisions on the northern margin of the already amalgamated North China craton.

Mapping of Planation Surfaces in the Southwest Region of Hubei Province,China——Using the DEM-Derived Painted Relief Model

Planation surfaces （PS） play a major role in reconstruction of the evolutionary history of landforms in local areas. Thus, objective and consistent mapping of planation surfaces from remotely sensed data （e.g., satellite imagery, digital elevation models （DEMs）） is paramount for interpreting the geomorphological evolution. Due to the lack of dated sedimentary covers and the difficulties of com-prehensive field work, the number and age of planation surfaces in the Southwest Hubei （湖北） Prov-ince of China are still controversial. In order to map the PS in the study area, four data visualization techniques including ETM＋ false color composite, grey-scale DEM, shaded relief model （SRM） and painted relief model （P M） were examined. It is found that the PRM is the most optimal technique for planation surface mapping. The study area was successfully mapped by visual interpretation of a PRM derived from ASTER GDEM. The mapped PS was divided into five classes in terms of elevation ac-cording to previous studies, varying from 1 700-2 000 （PS1）, 1 300-1 500 （PS2）, 1 000-1 200 （PS3）, 800-900 （PS4） to 500-600 （PS5） m. The results were partially compared with the published works. It is revealed that this method of mapping enjoys a higher accuracy and can reduce the time and ef- fort required in the traditional mapping to a large extent. The results also demonstrated that the PRM is an effective tool for geomorphological fea-ture mapping with considerable accuracy. The pre- liminary results can serve to facilitate locating rep-resentative samples for the planation surfaces dating, thus to determine the ages of PS in the study areas.

Focusing Seismic Energy along Faults through Time-Variable Rupture Modes: Wenchuan Earthquake, China

Field analysis and differential interferometry derived from Synthetic Aperture Radar （PALSAR） of the epicentral area of the May 12 2008 Mw 8.0 Wenchuan （汶川） earthquake zone reveal details about fault ruptures and ground displacements, with field-documented vertical offsets reaching 12 m along the trace of the main fault rupture, and PALSAR-measured horizontal displacements reaching 12.3 m. We document slip indicators on the fault scarp that show initially sub-horizontal then progressively steeper slip increments with time along the same fault during the 2 min earthquake, suggesting that the rupture propagated as a mixed Mode Ⅱ-Ⅲ fracture, with strike-slip movement at the tip directing energy from the initial rupture to points north of the epicenter, followed by vertical displacement in the interior of the slipped region. Field, seismic, and PALSAR-measured displacements are dominantly thrust near the epicentral region, and dextral in northeasterly areas, showing that slipwas partitioned along the fault in space and time during the earthquake. The changing slip directions may correlate with three main pulses of energy release at 0, 23, and 57 s during the earthquake as recorded by seismograms. The earthquake generated massive landsfides 〉100 km north of the epicenter along the trace of the fault. These massive sturzstroms formed where entire mountainsides collapsed and moved at high velocity down populated mountain valleys, jumping smaller mountains and ricocheting off steep canyon walls. These avalanches rode on cushions of water and compressed air that generated air blasts from beneath the debris, knocking down trees high on opposing mountain slopes. The concentration of massive landslides and ground deformation so far north of the epicenter was related to the Mode Ⅱ-Ⅲ fracture propagation focusing seismic energy along the fault towards the north, explaining why so much devastation occurred 〉100 km from the epicenter, such as in the destroyed city of Beichuan （北川）. Understanding near-surface earthquake processes and geological hazards associated with massive earthquakes in populated mountainous areas has the potential to save many lives in the future.

Comparison of Results of Recent Seismic Profiles with Tectonic Models of the North China Craton

The geometry and timing of amalgamation of the North China craton（NCC） have been controversial,with three main models with significantly different interpretations of regional structure,geochronology,and geological relationships.The model of Zhao G C et al.suggests that the eastern and western blocks of the NCC formed separately in the Archean,and an active margin was developed on the eastern block between 2.5 and 1.85 Ga,when the two blocks collided above an east dipping subduc-tion zone.The model of Kusky et al.presumes that the eastern block rifted from an unknown larger continent at circa 2.7 Ga,and experienced a collision with an arc（perhaps attached to the western block） above a west-dipping subduction zone at 2.5 Ga,and the 1.85 Ga metamorphism is related to a collision along the northern margin of the craton when the NCC joined the Columbia supercontinent.The model of Faure et al.suggests two collisions in the central orogenic belt,at 2.1 and 1.88 Ga.Recent seismic results support both the models of Kusky et al.and Faure et al.,showing that subduction be-neath the central orogenic belt（COB） was west-directed,and that there is a second,west-dipping pa-leosubduction zone located to the east of the COB dipping beneath the western block（Ordos craton）.The boundaries identified through geophysics do not correlate with the boundaries of the Trans-North China orogen suggested in the Zhao et al.model,and the subduction polarity is opposite that predicted by that model.The seismic profiles are consistent with an Archean collision above a west-dipping sub-duction zone beneath the COB predicted by the models of Kusky et al.,and the second west-dipping subduction zone is consistent with the two events suggested in the Faure et al.model.

Structural and Tectonic Evolution of El-Faiyum Depression,North Western Desert,Egypt Based on Analysis of Landsat ETM+,and SRTM Data

False color Landsat ETM＋ （bands 7, 4, 2 in RGB） and SRTM images of the EI-Faiyum depression, Egypt, highlights major NE-SW faults and other lineaments trending NW-SE and N-S. Airborne magnetic data reveal some E-W subsurface faults which are not recognized on Landsat ETM＋ and SRTM images. Ratio images （5/7, 3/1, 4/3） and （5/7, 5/1, 4） were used for lithological discrimination of different rock types. The EI-Faiyum area is occupied by sedimentary rocks of Middle Eocene, Upper Eocene, Oligocene, Lower Miocene, Pliocene, Pleistocene and Holocene. Understanding the structural regime of EI-Faiyum depression in the Western Desert of Egypt is significant in relation to the neotectonics of the Nile Delta and to the development of new communities west of the delta. The area is covered by Late Cretaceous, Middle to Late Eocene deposits, Oligocene deposits （comprising fluviatile sediments and basalt sheets） and Pliocene and Quaternary alluvium and sand deposits. New geological and structural maps were prepared at a scale of 1 ： 100 000 using Landsat ETM＋ and SRTM images coupled with extensive field work. The major structural trends are E-W, ENE, NS and NW--the same trends observed elsewhere in North Africa from NW Sudan to NE Egypt including north and central Sinai. EI-Faiyum depression is a structurally-controlled tectonic basin, marked by northeast-striking faults along its northern margin. These faults are parallel to similar faults of the Syrian arc fold belt, which includes a group of related faults, folds, push-up structures, and basins. Qarun Lake is located in the northern part of EI-Faiyum depression, at a right-step between two strands of the NE striking fault system. We have suggested elsewhere that EI-Faiyum depression is a pull-apart basin related to extension between these mismatched strands of strike-slip faults. The E-W structures are probably related to the relative motion between south Europe and north Egypt and closure of the Neotethys. The continuation of these faults in the present area is only detected from magnetic and seismic studies. The question that needs to be raised is why these old structural features have been reactivated in recent times. Thus, the presence of these fault zones must be heeded in all development plans for EI-Faiyum region.

Discovery of a Sheeted Dike Complex in the Northern Yangtze Craton and Its Implications for Craton Evolution

The Miaowan （庙湾） ophiolite is a highly dismembered ophiolitic complex cropping out near the northern margin of the Yangtze craton. The rocks of this complex consist of, from bottom to top, harzburgite tectonite locally containing podiform chromite, dunite, layered and isotropic gabbro, a sheeted dike complex （SDC）, meta-pillow lavas with chert pods and layers, and tectonically intercalated marble. The SDC is a very important and significant part of the Miaowan ophiolitic sequence, and grades downward into gabbro and ultramafic rocks, and upward into meta-pillow lavas. Some dikes preserve one-way chilled margins, typical of extensional ophiolitic settings, whereas most preserve dou-ble chilled margins, in cases where the chilling direction can be determined. The SDC is mainly com-posed of meta-diabase （dolerite）, meta-plagiogranite, and small amounts of meta-gabbro and ultramafic rocks. LA-ICP-MS zircon dating yields an upper intercept age of 1 026±79 Ma for one meta-plagiogranite, 1 043±23 Ma for a second meta-plagiogranite and I 096±32 Ma for one meta-gabbro at the bottom of the SDC, suggesting formation of the SDC at circa 1 026-1 096 Ma, consistent with the recently determined formation age of the Miaowan ophiolite. Sparse geochemical data on the meta-diabase indicate that the protolith was a sub-alkaline, low-potassium tholeiite similar to mid-ocean ridge basalt （MORB）. The chondrite-normalized rare earth element （REE） patterns of the meta-diabase are generally flat （（La/Yb）N=0.56-0.94）, with a slight depletion in LREE, but no obvious Eu anomalies. Given that the meta-plagiogranites show evidence of formation in a suprasubduction zone environment, we suggest that the basalts were originally island arc tholeiites, perhaps formed in an extensional forearc setting. The geochemistry of the meta-diabase and plagiogranite from the sheeted dikes, together with regional relationships, all agree with the previous interpretations that the Miaowan ophiolite formed in a suprasubduction zone setting.

Environmental Monitoring of Bombetoka Bay and the Betsiboka Estuary,Madagascar,Using Multi-temporal Satellite Data

The causes and consequences of soil erosion in Madagascar have been the focus of recent environmental debates. The Betsiboka, Madagascar＇s largest river stretching 600 km from the high central plateau to the northwest coast on the Mozambique Channel, is a major conduit for transporting lateritic soils and sediments derived from the highlands of Central Madagascar to the sea. These en- trained lateritic sediments color the river a blood-red hue, as if the life of the island is being drained away. In this study, Landsat visible and near infrared spectral bands are used to map the underwater sediments especially under the sea and in the interface between seawater and freshwater. Band color composites, single bands and band ratios are used to improve the detection of underwater sediments including sand bars and delta lobes. We show the evolution of the bay, coastline, delta, and change detection results derived from Landsat satellite images recorded in 1973, 1989, 1999, 2000 and 2003, respectively. Results indicate that sedimentary transport and suspension in Bombetoka Bay has significantly changed during the past 30 years, with a dramatic increase in the amount of sediment moved by the river, and deposited in the estuary and in offshore delta lobes. These changes have adversely affected agriculture, fisheries, and transportation for one of Madagascar＇s largest ports. The changes are attributed to increased erosion following large-scale deforestation, bush fires, and overgrazing in the river basin.

Lithospheric Structure in the North China Craton Constrained from Gravity Field Model(EGM 2008)

A detailed knowledge of the thickness of the lithosphere in the North China craton（NCC） is important for understanding the significant tectonic reactivation of the craton in Mesozoic and Ce-nozoic.We achieve this goal by applying the newly proposed continuous wavelet transform theory to the Gravity Field Model（EGM 2008） data in the region.Distinct structural variations are identified in the scalogram image of profile Alxa-Datong（大同）-Qingdao（青岛）-Yellow Sea（profile ABC）,trans-versing the main units of NCC,which we interpret as mainly representing the Moho and lithosphere-asthenosphere boundary（LAB） undulations.The imaged LAB is as shallow as 60-70 km in the south-east basin and coastal areas and deepens to no more than 140 km in the northwest mountain ranges and continental interior.A rapid change of about 30 km in the LAB depth was detected at around the boundary between the Bohai（渤海） Bay basin（BBB） and the Taihang（太行） Mountains（TM）,roughly coincident with the distinct gravity decrease of more than 100 mGal that marks the North-South Grav-ity Lineament（NSGL） in the region.At last we present the gravity modeling work based on the spectral analysis results,incorporating with the observations on high-resolution seismic images and surface to-pography.The observed structural differences between the eastern and western NCC are likely associ-ated with different lithospheric tectonics across the NSGL.Combined with seismic tomography results and geochemical and petrological data,this sug-gests that complex modification of the litho-sphere probably accompanied significant litho-spheric thinning during the tectonic reactivation of the old craton.

On the Role of Dual Active Margin Collision for Exhuming the World's Largest Ultrahigh Pressure Metamorphic Belt

ABSTRACT： A wide variety of tectonic models have been invoked to explain the exhumation of the world＇s largest ultrahigh pressure （UHP） orogenic belt, the Qinling Dabieshan Sulu belt in China, and its correlatives in Korea. Most of these models assume that the orogen contains one main collisional suture between the North and South China cratons that collided in the Mesozoic. New field data reveal that this model is too simplistic, and that the collision involved an additional mi- croplate, which initially rifted off the Yangtze craton. This continental microplate was partially sub- ducted beneath an active margin on the North China craton, and subsequently an additional active Andean-style margin developed on the southern margin of the Qinling microplate after collision, leav- ing the near-vertical microplate wedged between the two thickened and thermally softened margins. The thermo-mechanical environment of collision thus left a cold, thick, and buoyant microplate wedged between two easily deformed margins, which acted as power-law creep channels, accommodating rapid buoyancy-driven rise of a 2 000 km long wedge of the subducted microplate, which became intimately involved with the collisional process. An addi- tional segment of the northern Yangtze craton was subducted to ~100 kin, and formed a separate wedge that rose alongside the thermally softened margin of the Qinling mieroeontinent, and was bordered on the south by the recently thermally- softened rift zone where the Qinling mieroeonti- nent broke off the Yangtze eraton between Late Devonian and Permian times. Recognizing the dual active margins in Qinling-Dabieshan-Sulu orogen and the thermally-softened power-law creep channels sheds new light on understanding exhumation of the world＇s largest ultrahigh pressure belt. We propose that this model is generally applicable to other UHP belts worldwide.

Geological Evolution of Longhushan World Geopark in Relation to Global Tectonics

The South China fold belt has experienced a complex series of tectonic events that span 1.0 billion years of earth history. Longhushan （龙虎山） World Geopark is located on the Proterozoic suture between the Yangtze craton and Cathyasia block and highlights the long history of this belt. Collision of the Cathyasia and Yangtze cratons 1.0 billion years ago was associated with the formation of the Rodinian supercontinent where most of the planet＇s landmasses were amalgamated into one block. Jurassic through Early Cretaceous magmatism was associated with the inland migration of the continental margin arc associated with the penetration of a flat slab after subduction of the Kula-Farallon ridge. Slab roll-back in the Early to Middle Cretaceous opened many extensional basins across the South China fold belt, including the Xinjiang （信江） basin in which Longhushan is located, and these were filled largely with continental red beds deposited by fluvial systems in the hot torrid climate. The beds are richly fossiliferous, including remains of many dinosaurs and dinosaur eggs. Subduction of the Kula-Pacific plate in the Middle Cretaceous caused a short magmatic pulse, and then, the basins subsided slowly through the remainder of the Cretaceous. Cenozoic uplift of the red bed basins was initiated by the India- Asia collision. The uplift was associated with the formation of many faults, joints, and brittle structures that dissected the red bed deposits. Fluvial erosion of the red beds was enhanced along the brittle structures, and different locations have developed very distinctive and structuraliy controlled geomorphological features including mesas, kopjies, and isolated stone peaks that are known in China as Danxia （丹霞） land-forms. Together, these features form Danxia landscapes, and Longhushan World Geopark exhibits a complete range of the Danxia landscapes from juvenile, to mature and to old stages of development. The United Nations Educational, Scientific, and Cultural Organization （UNESCO） World Geopark program ensures that these features and geologic history will be preserved in their pristine state and be available for study and appreciation for generations to come.

New Research Progress on the Pre-Sinian Tectonic Evolution and Neotectonics of the Huangling Anticline Region,South China

In this paper the authors briefly introduce and review the new progress of the newly dis-covered Proterozoic Miaowan （庙湾） ophiolite and Neoproterozoic HuangUng （黄陵） granitoids in the southern Huangling anticline in the Yangtze craton, and the tectonic evolution significance of assemblage and breakup of Rodinia and Columbia supereontinent in South China.