In Jurassic sediments of Siberia，remains of Lycopodites are rare in occurrence． They are represented by two species: Lycopodites tenerrimus Heer，and L． (?) trichiatus Pryn． This paper presents an emended diag- nosis of the species L．(?) trichiatus Pryn．，and the descriptions of two new species: Lycopodites subulifolius sp． nov．，and L． baikalensis sp． nov． from the Early--Middle Jurassic sediments of the Irkutsk coal basin，Eastern Siberia，Ｒussia． As part of the research effort，it was found that the ecological preference of the new species was different: Lycopodites subulifolius sp． nov． grew in wet and open spaces，while Lycopodites baikalensis sp． nov． preferred to colonize young growth of bog forests．

Through a sampling analysis of trace elements and ＲEE in the section of Middle Permian Zhesi For- mation in Solon area of Inner Mongolia，it is found that the overall sandstone and mudstone samples are charac- terized by LＲEE-enrichment． By analysis of the discriminant index of the sedimentary environment，the tectonic setting of Zhesi Formation is determined to be a continental island arc environment． Meanwhile，according to the sedimentary structure and lithology combination，Zhesi Formation is divided into the neritic-bathyal reten- tion-reduction environment as well as the delta front and prodelta sedimentary systems．

Factors of shale gas accumulation can be divided into the external and internal factors，according to accumulation mechanism and characteristics of shale gas． The internal factors mainly refer to parameters of or- ganic geochemistry，mineral components and physical parameters． Six factors were presented in this study，i．e． organic matter，maturity，quartz，carbonate，clay mineral and pore． The external factors mainly refer to geolog- ic environment of shale gas reservoir，including four factors: temperature，pressure，depth and thickness． Based on the experiment results of 26 samples of drilling cores from Wuling fold belt in Lower Paleozoic Silurian of the Upper Yangtze Basin，combined with the integrated analysis of geology，logging and test，the correlation of the gas content of shale gas to the above-mentioned ten factors was concluded． Six important evaluation indi- cators were preliminarily established in the gas-bearing core area of marine shale in the Upper Yangtze Basin．

The authors studied the geochemistry，zircon U-Pb ages，Hf isotope of the granite porphyry and its petrogenesis and tectonic setting in the studied area． The zircon U-Pb dating indicates the formation of the gran- ite porphyry is in Early Cretaceous (125． 1 ±1． 5 Ma)． The granite porphyry has high-SiO2and alkali-rich fea- tures，which belongs to high-K calc-alkaline series rocks (A/CNK = 0． 95%--1． 25%)． The analyses of trace elements show the characteristics of a swallow-shaped ＲEE distribution pattern with enrichment in LＲEEs and most of LILEs and HFSEs，depletion in Ba，Sr，Nb，P and Ti，and especially strong depletion in Eu，which indicates the granite porphyry belongs to the aluminous A-type granite． Their εHf(t)range from 5． 94 to 8． 80 with Hf two-stage model ages (TDM2) of 620 Ma to 803 Ma． Combining with the regional tectonic background， we conclude that the source of the rocks is the new crust materials accreted from depleted mantle in Neoprotero- zoic and is the product of partial melting of middle and lower crustal rocks，which may be suffered from the dual impact of the subduction of the Palaeo-Pacific Ocean and the closure of the Mongol-Okhotsk Ocean．

In order to discover the relation between rock-soil thermal properties and strata during the process of engineering investigation，the authors studied the measuring principle of Thermal Conductivity Scanner (TCS) and measured the thermal properties of 45 drilling samples from Qinghai with TCS in the laboratory． The results show that the specific heat capacity (SHC) decreases while the thermal conductivity (TC) increases with the increase of the depth． With the lithological change，the specific heat capacity and thermal conductivity have the opposite trend． The depth and lithology have a greater influence on the thermal conductivity than the specific heat capacity．

The study of artificial slope stability has been a key item of geological engineering projects． Though more evaluation methods are available，result of stability evaluation simulation does not explain the actual prob- lem owing to the diversified geological engineering factors and complexity． The author made a detailed study based on surveys of large amount of geological engineering research on Donggang Power Plant slope project，dis- cussed the comprehensive factors influencing the project，and gave analytical calculation and evaluation to the improved response surface of the slope project． The study result shows that the slope is stable，which can pro- vide scientific basis for designing the slope．

With the increasing researches on geotechnical properties of the diesel contaminated soil (DCS)，the water content measured is indispensable part during the early period． In this study，the relative error of water content measurement using the traditional method is as high as 20． 78%，which is no longer suitable for contam- inated soil． Through a series of tests to measure the loss coefficient of diesel in the drying time，the authors fi- nally proposed a modified calculation formula for test samples． The results show that the maximum relative error calculated by using the modified formula is 0． 96%，far lower than that of traditional formula，which can pro- vide accurate data for further study of diesel contaminated soil．

Ice cores contain an abundance of information about the Earth's climate in the past，and recovered from shallow drilling down to 300--350 m give sufficient information for reconstructing of the last climatic chan- ges and for monitoring of pollution from human being． Cable-suspended core auger drills use an armored cable with a winch to provide power to the down-hole motor system and to retrieve the down-hole unit． Because of their lightweight，convenient transportation and installation，high penetration rates and low power consumption， core auger drills are widely used for shallow drilling in ice． Nowadays at least 14 types of auger electromechani- cal drills were designed and tested in different foreign and national glaciological laboratories． However，auger options were usually determined by experience，and the main parameters (helix angle of the fights and rotational speed) are varied in a wide range from drill to drill． If parameters of auger are not chosen properly，poorly en- gineered drills had troubles with low efficiency of cuttings transportation，jam of ice cuttings，repeated fragmen- tation，cutters icing and stop penetration，abnormal power consumption，high rotation torques，and so on． Thus，this paper presents the method of optimization of ice cuttings transportation of cable-suspended core auger drill on the base of the theory of rotary auger． As the result，the optimal helix angle was determined correspond- ing to the rotational speed from the transportation efficiency point of view．

The authors studied the potential field boundary identification of the new technology in order to find out the possible fractures or contact zones using the following methods such as tilt derivative，horizontal deriva- tive of tilt derivative，normalized standard deviation and normalized differential method． Combined with Euler deconvolution and small subdomain filtering，the actual data processing results show that these methods are all a- ble to identify wider range extending fractures and obtain abundant geological information． The horizontal deriva- tive of tilt derivative and normalized differential method have a better resolution for the small cutting fractures and lacunae in the studied area． They provide a reliable basis for study of the cutting relationship between fractures．

Focusing inversion is accomplished by the iterative of abnormal source to make the image gradually focused． It can better reflect the underground geological geometry and physical parameters． The model experi- ments in the study show that gravity focusing inversion allows inversion image stabilization and polymerization， which solves the multiple solutions and instability of inversion and so on． The method is applied to measured gravity data processing of certain region of Changbai Mountain，compared to Euler deconvolution，the results show that the method for determining the horizontal position and depth of underground anomalies has good ef- forts．