The breakdown of diopside to(Ca,Mg)SiO3 perovskite–(Mg,Ca,Fe)SiO3 glass–(Mg,Ca)SiO3 glass–(Mg,Ca)SiO3 majorite in a melt vein the Suizhou L6 chondrite

The Suizhou meteorite is a heavily shocked and melted vein-containing L6 chondrite. It contains a minor amount of diopside with a(Ca_0.419Mg_0.466Fe_0.088)SiO₃ composition, and a shock-metamorphosed diopside grain associated with ringwoodite and lingunite was found in a melt vein of this meteorite. Our electron microprobe,transmission electron microscopic and Raman spectroscopic analyses revealed four silicate phases with different compositions and struct...     

Geochemistry and zircon U–Pb ages of the Paleoproterozoic ultramafic rocks of the Mbi Valley,Boali area,Central African Republic

This paper investigates the geochemistry of bulk rock and infers the petrogenesis of ultramafic rocks in the Boali Precambrian terrane in Mbi Valley, in the North of the Central African Republic(CAR). The studied rocks comprise coarse primary olivine and orthopyroxene relics(dominant phase), magnesio-hornblende, magnetite, and antigorite. Whole-rock analysis indicates low SiO₂(average of 43.14 wt%) and high MgO(19.84–26.98 wt%)contents and their Mg number(Mg#) ranges from 74 to 82.The...     

Geochemistry,zircon U–Pb geochronology,and Hf isotopes of S-type granite in the Baoshan block,constraints on the age and evolution of the Proto-Tethys

Geochemistry, zircon U–Pb geochronology, and Hf isotope data for the Early Paleozoic granites in the Baoshan Block reveal the Early Paleozoic tectonic evolution of the Proto-Tethys. The samples are high-K, calcalkaline, strongly peraluminous rocks with A/CNK values of 1.37–1.46, are enriched in SiO₂, K₂O, and Rb, and are depleted in Nb, P, Ti, Eu, and heavy rare earth elements,which indicates the crystallization fractionation of the granitic magma. Zircon U–Pb dating indica...     

Interactions between hydrocarbon-bearing fluids and calcite in fused silica capillary capsules and geological implications for deeply-buried hydrocarbon reservoirs

During the burial processes of deep/ultra-deep hydrocarbon reservoirs,the interactions between hydrocarbon-bearing fluids and reservoirs significantly affect the quality evolution of hydrocarbons and reservoirs;thus,this topic requires further investigation.In this study,the continuous evolution and the coupling mechanisms in various anhydrous and hydrous nC₁₆H₃₄-(water)-(calcite)systems in fused silica capillary capsules(FSCCs)were investigated using laser Raman spectroscopy,fluorescence color analysis,and fluorescence spectroscopy,and the mineral alterations were analyzed using scanning electron microscopy(SEM).The experimental results show that extensive organic-inorganic interactions occur in the systems if water is present,and different inorganic components have different effects on hydrocarbon degradation.Distilled water promotes freeradical thermal cracking and steps oxidation,forming more low-molecular-weight hydrocarbons,CO₂,and organic acids(e.g.,acetic acids)but suppresses the free-radical cross-linking,generating less high-molecular-weight hydrocarbons.However,in the presence of CaCl₂ water,the yields of hydrocarbon gases are lower than in the distilled water system because high concentrations of Ca ions inhibit the generation of free radicals.Calcites,which exhibit different surface reactivities in different fluid conditions,affect hydrocarbon degradation in different ways.In the anhydrous nC16H34-calcite system,calcites promote the generation of both hydrocarbon gases and high-molecular-weight hydrocarbons.In contrast,in the hydrous nC16H34-distilled(CaCl₂)watercalcite system,calcites promote the generation of hydrocarbon gases and suppress the generation of high-molecular-weight hydrocarbons.Calcite also reacts with organic acids via surface reactions to form secondary pores.Therefore,except for the formation temperature and pressure,organic-inorganic interactions are controlled by multiple factors,such as the water saturation,water type,water salinity,and the mineral content,resulting in different evolutions of the hydrocarbon degradation and reservoir properties.     

TiO2 nanoparticles in aquatic environments: impact on heavy metals distribution in sediments and overlying water

The extensive application of TiO₂ nanoparticles(NPs) highlights the importance of investigating their influence on aquatic systems. In this work, the effect of TiO₂NPs on heavy metals speciation was studied on a lab scale. For this goal, a series of aquaria containing water,sediment, and TiO₂NPs with various concentrations were set up. The study results revealed that TiO₂NPs caused(copper) Cu,(mercury) Hg,(titanium) Ti, and(zinc) Zn to be adsorbed by s...     

Geochemical and Pb-Sr-Nd isotopic compositions of Indosinian granitoids from the Bikou block,northwest of the Yangtze plate:Constraints on petrogenesis,nature of deep crust and geodynamics

This paper reports geochemical and Pb-Sr-Nd isotopic compositions of the Indosinian Yangba (215 Ma),Nanyili (225 Ma) and Mopi granitoids from the Bikou block of the northwestern margin of the Yangtze plate. These granitoids are enriched in Al (Al2O3:14.56%―16.48%) and Sr (352 μg/g―1047 μg/g),and depleted in Y (<16 μg/g) and HREE (e.g. Yb<1.61 μg/g),resulting in high Sr/Y (36.3―150) and (La/Yb)N (7.8―36.3) ratios and strongly fractionationed REE patterns. The Indosinian granotoids show initial Sr isotopic ratios (ISr) from 0.70419 to 70752,εNd(t) values from-3.1 to -8.5,and initial Pb isotopic ratios 206Pb/204Pb=17.891-18.250,207Pb/204Pb=15.494-15.575,and 208Pb/204Pb=37.788-38.335. Their geochemi-cal signatures indicate that the granitoids are adakitic. However,they are distinct from some adakites,generated by partial melting of subducted oceanic slab and/or underplated basaltic lower crust,be-cause they have high K (K2O: 1.49%―3.84%) and evolved Nd isotopic compositions,with older Nd iso-topic model ages (TDM=1.06―1.83 Ga). Geochemical and Sr-Nd isotopic compositions suggest that the magmas of the Insoninian adakitic rocks in the Bikou block were derived from partial melting of thick-ened basaltic lower crust. Combined with regional analyses,a lithospheric delamination model after collision between the North China and South China plates can account for the Indosinian adakitic magma generation. On the other hand,based on the Pb-Sr-Nd isotopic probing to the magma sources of the adakitic rocks,it is suggested that there is an unexposed continent-type basement under the exposed Bikou Group volcanic rocks. This can constrain on the Bikou Group volcanic rocks not to be MORB-or OIB-type.     

An EXAFS investigation of the mechanism of competitive sorption between Co(Ⅱ) and Ni(Ⅱ) at γ-alumina/solution interface

Co(Ⅱ)and Ni(Ⅱ)are two common toxic heavy metals,and may simultaneously exist in contaminated water,soil,and sediment systems in Earth’s surface environment.Under this circumstance,competitive adsorption between the two metals may influence their migration,toxicity,and bioavailability.In this research,the competitive sorption of Co(Ⅱ)and Ni(Ⅱ)on γ-Al_2O_3was studied using both macroscopic sorption experiments and extended X-ray absorption fine structure(EXAFS)spectroscopy.Results suggest that Ni(Ⅱ)reduced the amount of Co(Ⅱ)sorption in a binary-solute system at pH 6.0.This is because both Co(Ⅱ)and Ni(Ⅱ)form inner-sphere surface complexes during sorption on γ-Al_2O_3and compete for the surface reactive sites.However,Co(Ⅱ)exhibited a negligible influence on sorption amount of Ni(Ⅱ)under the same conditions,which suggests Ni(Ⅱ)has a stronger affinity to alumina surface.At pH 7.5,Co(Ⅱ)and Ni(Ⅱ)sorption density were much higher than that at pH 6.0,but there no mutual competitive effect was observed.EXAFS analysis further revealed that formation of layered double-hydrated precipitates was the dominant sorption mechanism for both Co(Ⅱ)and Ni(Ⅱ)at pH 7.5.Because this type of sorption does not rely on surface reactive sites,there was no competition between Co(Ⅱ)and Ni(Ⅱ).This finding sheds light on risk assessment and remediation of Ni/Co pollution.     

Geochemistry and mineralogy of the Late Permian coals from the Songzao Coalfield, Chongqing, southwestern China

Mineralogy and geochemistry of the four main workable coal seams (No.6, No.7, No.8, and No.11) of Late Permian age from the Songzao Coalfield, Chongqing, Southwest China, were examined using in- ductively coupled plasma-mass spectrometry (ICP-MS), X-ray fluorescence spectrometry (XRF), cold-vapor absorption spectrometry (CV-AAS), ion-selective electrode (ISE), scanning electron mi- croscopy equipped with an energy-dispersive X-ray spectrometer (SEM-EDX), and X-ray diffraction analysis (XRD). The results showed that the main workable No.8 Coal that accounts for about 60% of the total coal reserves in the Songzao Coalfield was not enriched in hazardous trace elements. The No.11 Coal has high concentrations of alkaline elements, Be (9.14 μg/g), Sc (12.9 μg/g), Ti (9508 μg/g), Mn (397 μg/g), Co (23.7 μg/g), Cu (108 μg/g), Zn (123 μg/g), Ga (32 μg/g), Zr (1304 μg/g), Nb (169 μg/g), Hf (32.7 μg/g), Ta (11.4 μg/g), W (24.8 μg/g), Hg (0.28 μg/g), Pb (28.1 μg/g), Th (24.1 μg/g), and rare earth elements (509.62 μg/g). The concentration of Nb and Ta in the No. 11 Coal is higher than the industrial grade, and their potential utilization should be further studied. Besides pyrite, quartz, calcite, and clay minerals, trace minerals including chalcopyrite, marcasite, siderite, albite, mixed-layer clay minerals of illite and smectite, monazite, apatite, anatase, chlorite, and gypsum were found in the No.11 Coal. It should be noted that alabandite of hydrothermal origin and anatase occurring as cement were identi- fied in coal. In addition, the clayey microbands derived from alkaline volcanic ashes were identified in the coal. The dominant compositions of these clayey microbands were mixed-layer clay minerals of illite and smectite, which were interlayered with organic bands. The modes of occurrence of alkaline volcanic ash bands indicate that the volcanic activities were characterized by the multiple eruptions, short time interval and small scale for each eruption during peat accumulation. The alkaline volcanic ashes were the dominant factors for the enrichment of alkaline elements, Nb, Ta, Zr, Hf, and rare earth elements, and the sulfide minerals are the main carriers of Ga, Cu, and Hg in the No. 11 Coal.     

Crustal electric structure of Haiyuan arcuate tectonic region in the northeastern margin of Qinghai-Xizang Plateau, China

Through the analysis and 2-D inversion for the 5 profiles in Haiyuan arcuate tectonic region (105°～107°E,36°～37.5°N) in the northeastern margin of Qinghai-Xizang Plateau, we have obtained the electric structure within a range of 160 km in width (east-west) and 60 km in depth in the studied area. The results show that the crustal electric structure can be divided into 6 sections, corresponding respectively to Xiji basin (Ⅰ), Xihuashan-Nanhuashan uplift (Ⅱ), Xingrenbu-Haiyuan basin (Ⅲ), Zhongwei-Qingshuihe basin (Ⅳ), Zhongning-Hongsibu basin (Ⅴ) and west-margin zone of Ordos (Ⅵ) from the southwest to the northeast. The crustal electric structure is characterized by a broom-shaped pattern, which scatters to the northwest and shrinks to the southeast. The structures in the top part of Haiyuan arcuate tectonic region are complete and large, however, they diminish from the arc top to the northwest and southeast ends. In the depth from 0 km to 10 km, the resistivity is high in the sections Ⅱ and Ⅵ, but relatively low in the other four sections, showing a similar pattern of basin depression. The electrical basement in the section Ⅲ is the deepest, displaying a "dustpan" shape that is deep in the southwest and shallow in the northeast. A series of discontinuous zones with high conductivity exist in the middle-lower crust in Haiyuan arcuate tectonic region, which is possibly related to the moderate and strong earthquakes in the region. The resistivity distribution in the focal area of the 1920 Haiyuan earthquake is significantly heterogeneous with an obviously high conductivity zone near the hypocenter regime.     

ULF electric and magnetic anomalies accompanying the cracking of rock sample

The anomalies of electric-magnetic field and self-potential before earthquakes are important precursory phenom-ena.A simulating experiment study on the variations in ultra-low frequency(ULF)magnetic field and self-poten-tial during rock cracking was carried out in a magnetic field-free space.The results revealing in detail the whole process of the occurrences of electric and magnetic anomalises are significant for understanding the microscopic mechanism of ULF electric and magnetic signals.The experiment indicated that at the initial stage the slow changes in strain.self-potential and magnetic field with small amounts appeared firstly near the source of initial cracking,and then extended as the crack developed on.In the time domain,the self-potential anomaly emerged first and ULF magnetic field changes arose then.The shape of the ULF electric and magnetic anomaly varied ob-viously in early-,mid-and late-term of the test.The authors attributed the pulse-like changes of self-potential to the generationj and movement of the accumulated electric charges during the cracking caused by charge separation on the crack tips within the sample.While the magnetic pulses of shorter-period at the last stage of the test,may be induced by instantaneous electric current of the accumulated charege during the cracking acceleration.The technical method and the observational results of this experiment are given in detail and the microscopic mechanism of elec-tric and magnetic precursors before earthquake are discussd in the present paper as well.     

Comparison of Pb(Ⅱ) and Cd(Ⅱ) micro-interfacial adsorption on fine sediment in the Pearl River Basin,China

The complex micro-interfacial interaction theories of heavy metal ions such as Pb(Ⅱ)and Cd(Ⅱ)adsorption on fine sediment in aqueous solution were not systematically investigated.The aim of this work was to reflect the micro-interfacial adsorption characteristics.Sediment samples were collected from an estuary.The Isothermal and kinetics adsorption experiment were done to acquire the data.Isothermal,kinetics,film diffusion and intraparticle diffusion models were adopted to fit the adsorption experimental data.The results indicated that the Langmuir,Freundlich and Temkin models were suitable for analyzing the isothermal experimental data.The maximum adsorption capacities of Pb(Ⅱ)and Cd(Ⅱ)on the sediment were 1.1377 and 0.9821 mg·g-1,respectively.The qm and KL of the Langmuir model,Kf and nF of the Freundlich model,and b and A of the Temkin model all exhibited a power function relationship with the initial adsorbate concentration.The pseudo-second-order model provided a better fit for the experimental kinetics data compared with the fit of the pseudo-first-order and Elovich models.The pseudo-second-order parameters k2 and qe of Pb(Ⅱ)and qe of Cd(Ⅱ)both had a power function relationship with adsorption time,additionally,the k2 of Cd(Ⅱ)had an exponential function relationship with adsorption time.The liquid-film diffusion parameters kfd of Pb(Ⅱ)and Cd(Ⅱ)were 0.0569 and 0.1806 min
1,respectively.The intraparticle diffusion parameter kid values of Pb(Ⅱ)and Cd(Ⅱ)were 0.0055 mg$g
1$min1/2 and 0.0049 mg$g
1$min1/2,respectively.The physical significance of the model parameters showed that Pb(Ⅱ)adsorption on sediment was stronger than Cd(Ⅱ).The results of this study provided a theoretical reference for the micro-interfacial mechanism of heavy metal ion adsorption on sediment.     

Petrological, geochemical and chronological constraints for the tectonic setting of the Dongco ophiolite in Tibet

The Dongco ophiolite occurred in the middle-western segment of the Bangong-Nujiang suture zone. The thickness of the ophiolite suite is more than 5 km, which is composed, from bottom to top, of the mantle peridotite, mafic-ultramafic cumulates, basic sills (dykes) and basic lava and tectoni- cally emplaced in Jurassic strata (Mugagongru Group). The Dongco cumulates consist of dunite- troctolite-olivine-gabbro, being a part of DTG series of mafic-ultramafic cumulates. The basic lavas are characterized by being rich in alkali (Na2O K2O), TiO2, P2O5 and a LREE-rich type pattern dip- ping right with [La/Yb]=6.94―16.6 as well as a trace elements spider-diagram with normal anomaly of Th, Nb, Ta, Hf. Therefore, the Dongco basic lavas belong to ocean-island basalt (OIB) and dis- tinctly differ from mid-ocean ridge basalt (MORB) and island-arc basalt (IAB) formed in the plate convergence margin. The basic lavas have higher 87Sr/86Sr (0.704363―0.705007), lower 143Nd/144Nd (0.512708―0.512887) and εNd(t ) from 2.7― 5.8, indicating that they derive from a two-components mixing mantle source of depleted mantle (DM) and enriched mantle (EMI). From above it is ready to see that the Dongco ophiolite forms in oceanic island (OIB) where the mantle source is replaced by a large amount of enriched material, therefore it distinctly differs from these ophiolites formed in island-arc and mid-oecan ridge. Newly obtained SHRIMP U-Pb dating for zircon of the cumulate troctolite is 132 ± 3 Ma and whole-rock dating of ~(39)Ar/~(40)Ar for the basalt is 173.4 ± 2.7 Ma and 140.9 ± 2.8 Ma, indicating that the Dongco ophiolite formed at Early Cretaceous and the middle-western segment of the Bangong-Nujiang oceanic basin was still in the developing and evolving period at Early Cretaceous.     

Changes in the patterns of inorganic nitrogen and TN/TP ratio and the associated mechanism of biological regulation in the shallow lakes of the middle and lower reaches of the Yangtze River

The changes of NH3-N, NO3-N, NO2-N and TN/TP were studied during growth and non-growth season in 33 subtropical shallow lakes in the middle and lower reaches of the Yangtze River. There were significant positive correlations among all nutrient concentrations, and the correlations were better in growth season than in non-growth season. When TP>0.1 mgL-1, NH3-N increased sharply in non-growth season with increasing TP, and NO3-N increased in growth season but decreased in non-growth season with TP. These might be attributed to lower dissolved oxygen and low temperature in non-growth season of the hypereutrophic lakes, since nitrification is more sensitive to dissolved oxygen and temperature than antinitrification. When 0.1 mgL-1>TP>0.035 mgL-1, TN and all kinds of inorganic nitrogen were lower in growth season than in non-growth season, and phytoplank-ton might be the vital regulating factor. When TP<0.035 mgL-1, inorganic nitrogen concentrations were relatively low and NH3-N, NO2-N had significant correlations with phytoplankton, indicating that NH3-N and NO2-N might be limiting factors to phytoplankton. In addition, TN/TP went down with decline in TP concentration, and TN and inorganic nitrogen concentrations were obviously lower in growth season than in non-growth season, suggesting that decreasing nitrogen (especially NH3-N and NO3-N) was an important reason for the decreasing TN/TP in growth season. The ranges of TN/TP were closely related to trophic level in both growth and non-growth seasons, and it is apparent that in the eutrophic and hypertrophic state the TN/TP ratio was obviously lower in growth season than in non-growth season. The changes of the TN/TP ratio were closely correlated with trophic levels, and both declines of TN in the water column and TP release from the sediment were important factors for the decline of the TN/TP ratio in growth season.     

The in situ spectral methods for examining redox status of c-type cytochromes in metal-reducing/oxidizing bacteria

The membrane-associated c-type cytochromes(c-Cyts) have been well known as the key enzymes mediating extracellular electron transfer to terminal electron acceptors, resulting in biogeochemical elemental transformation, contaminant degradation, and nutrient cycling. Although c-Cyts-mediated metal reduction or oxidation have been mainly investigated with the purified proteins of metal reducing/oxidizing bacteria, the in vivo behavior of c-Cyts is still unclear, given the difficulty in measuring the proteins of intact cells. Fortunately, the in situ spectroscopy would be ideal for measuring the reaction kinetics of c-Cyts in intact cells under noninvasive physiological conditions. It can also help the establishment of kinetic/thermodynamic models of extracellular electron transfer processes, which are essential to understand the electron transfer mechanisms at the molecular scale. This review briefly summarizes the current advances in spectral methods for examining the c-Cyts in intact cells of dissimilatory metal reducing bacteria and Fe(Ⅱ)-oxidizing bacteria.     

Mixing processes and patterns of fluids in alkane-CO2-water systems under high temperature and high pressure——Microscopic visual physical thermal simulations and molecular dynamics simulations

Various types of geofluids exist in deep and ultra-deep layers in petroliferous basins.The geofluids are much more active under high-temperature and high-pressure (HTHP) conditions,but their properties are unclear.We simulated the mixing of different fluids in CH₄/C₃H₈/C₆H₁₄/C₈H₁₈-water systems and C₆H₁₄/C₈H₁₈-CO₂-H₂O systems at temperatures of 25℃ to 425...     

New equation to decipher the relationship between carbon isotopic composition of methane and maturity of gas source rocks

The identification of the origin and source of natural gas is always a difficult and hot issue.Hereinto,the maturity identification is one of the most important scientific problems.Many empirical equations have been established to decipher the relationship between the maturity of gas source rocks and the carbon isotopic composition of natural gas.However,these equations proposed often fail to identify the maturity of the source rocks correctly,which in turn prevents the identification of genetic types and source rocks of the natural gas because the petroliferous sedimentary basins in China are complex and diverse,with multiple sets of source rocks and different thermal history.In this paper,the oil-associated gas from the Permian lacustrine source rocks and the coal-derived gas from the Jurassic source rocks in Junggar and Turpan-Hami basins have been investigated to decipher the relationship between the maturity(vitrinite reflectance)of gas source rocks and the carbon isotopic composition of methane.The equations established areδ¹³C₁=25lgR_o-42.5 for oil-associated gas,andδ¹³C₁=25lgR_o-37.5 for coal-derived gas.These new equations are suitable for the maturity identification of source rocks in most petroliferous basins,and favorable for the identification of the genetic type and source of natural gas,which is very important to improve the geological theory of natural gas.     

Evolution of the 2015/16 El Nio and historical perspective since 1979

The 2015/16 El Nio developed from weak warm conditions in late 2014 and NINO3.4 reached 3℃ in November 2015. We describe the characteristics of the evolution of the 2015/16 El Nio using various data sets including SST, surface winds,outgoing longwave radiation and subsurface temperature from an ensemble operational ocean reanalyses, and place this event in the context of historical ENSO events since 1979. One salient feature about the 2015/16 El Nio was a large number of westerly wind bursts and downwelling oceanic Kelvin waves(DWKVs). Four DWKVs were observed in April-November 2015 that initiated and enhanced the eastern-central Pacific warming. Eastward zonal current anomalies associated with DWKVs advected the warm pool water eastward in spring/summer. An upwelling Kelvin wave(UWKV) emerged in early November 2015 leading to a rapid decline of the event. Another outstanding feature was that NINO4 reached a historical high(1.7℃), which was 1℃(0.8℃) higher than that of the 1982/83(1997/98) El Nio . Although NINO3 was comparable to that of the 1982/83 and 1997/98 El Nio , NINO1+2 was much weaker. Consistently, enhanced convection was displaced 20 degree westward, and the maximum D20 anomaly was about 1/3.1/2 of that in 1997 and 1982 near the west coast of South America.     

The influence of silica on reaction rates and molecular hydrogen (H2) generation during olivine hydrothermal alteration

Hydrothermal alteration of olivine greatly influences geodynamics and the recycling of volatiles (such as water and carbon) in subduction zones.Silica is an important component of geological fluids,and its influence on the hydrothermal alteration of olivine remains poorly constrained.In this study,we performed experiments at 300–515℃ and 3.0 kbar (1 bar=10⁵Pa) by reacting well homogenized mixtures of olivine and silica powders with saline solutions (0.5 mol L^-1Na Cl).Silica...     

Characteristics and dynamics of the soil seed bank at the north edge of Taklimakan Desert

In order to understand the potential of revegetation of halophytic community at the north edge of Taklimakan Desert, the species structure, storage capacity, the vertical distribution pattern and seasonal dynamics of soil seed bank and their interrelationship with community structure of above-ground plants were investigated. The results show that (i) 9 species were identified from seed bank in different seasons indicating that plant composition in this area was simple. (ii) The seed density in soil was 222±10.79 grain/m2 on average, and showed a seasonal variation range from 132±8.16 grain/m2 in summer to 303±12.70 grain/m2 in autumn. (iii) The similarity coefficient between soil seed bank and above-ground vegetation was 0.778. (iv) Vertically, seed densities declined with soil depth. 82.4% of total seeds were found in the top 3 cm of soil profile. No active seeds were found in soil profile below 6 cm. It is concluded that the seed bank at the north edge of Taklimakan Desert contains active seeds of all plant species observed on above ground, and is able to supply potential contribution to reconstruction of vegetation.     

Study on Self-Affine Fractal and Multi-Fractal Features of Geomorphic System in the Tianshan Area of Xinjiang Region, China

In this paper, we use the standard deviation method and the fixed mass method to study the self-affine fractal and multi-fractal features along two topographic profiles across different tectonic-geomorphic elements in the Tianshan area of Xinjiang region, China. The results show that in the studied scaling range, the two profiles display different scaling fractal features, and the form and value range of multi-fractal spectra Dq also show different characteristics. The study suggests that the landforms are not completely random, but are deterministically random. The fractal dimension values in different scaling ranges express the mode, intensity and spatial dimension of the endogenic and exogenic processes. Meanwhile, a boundary point between the macroscopic and microscopic scales of geomorphic process is suggested to be about 5km. These results are of significance in quantitative study of geomorphic dynamics.