Five new small theropod teeth and one manual ungual have recently been recovered from the
Upper Cretaceous Nenjiang Formation in the Songliao Basin. The specimens were examined for their
morphological characteristics, leading to the identification of four distinct taxa. The first taxon consists of
three foliodont teeth characterized by a pronounced basal constriction and large hook-like distal denticles,
which can be attributed to Troodontidae. The second taxon is represented by an elongated tooth featuring
prominent longitudinal ridges, allowing for its assignment to Paronychodon. The third taxon is a bladelike tooth with notably small distal denticles, corresponding to Richardoestesia. The fourth taxon comprises
a manual ungual characterized by a transversely wide and nearly symmetrical proximal articular surface,
fully enclosed ventral foramina, a flattened ventral surface, and the absence of a flexor tubercle, resembling
Alvarezsauridae. These specimens significantly enhance the known dinosaur diversity of the Nenjiang
Formation and provide crucial insights for understanding the terrestrial ecosystem in Northeast Asia during
the Late Cretaceous.
Previous studies have shown that the Eocene oil shale sequences in the Green River Basin contain
long-period astronomical age information. The fine-scale chronological characteristics of the oil shale laminae
remain largely unexplored.We selected finely laminated oil shales formed in deep-water environments
characterized by stable water column stratification as the primary focus of this study, using microscopy and
micro-area X-ray fluorescence (μ-XRF) techniques. By integrating high-resolution elemental data with timeseries analysis, we identified significant periodic signals associated with solar activity (Hale and Schwabe
cycles) and ENSO. The results indicate that the alternations of light and dark laminae in the Green River
Formation oil shale correspond to alternating dry and wet climate regimes: the light laminae are dominated by
carbonate minerals, reflecting drier and milder conditions, while the dark laminae are enriched in terrigenous
clastics and organic matter, indicating periods of increased precipitation and warmer temperatures. The
detected periodicities (23.5 years, 13.3 years and 5.8 years) are highly consistent with modern observations,
demonstrating that the lower Eocene Green River oil shale effectively records short-term solar activity and
climate variability. Furthermore, our findings confirm that a persistent "permanent El Niño" state did not
develop under Early Eocene greenhouse conditions, providing a refined chronological framework for highresolution paleoclimate studies during greenhouse intervals.
In recent years, significant breakthroughs have been achieved in the exploration of deep volcanic
rocks in the Junggar Basin, highlighting their substantial exploration potential. The complex distribution of
volcanic reservoirs is attributed to the multi-phase tectonic evolution within the basin, with their superior
reservoir properties playing a crucial role in natural gas formation. However, due to the combined effects of
multi-cyclic volcanic eruptions and tectonic activities, predicting volcanic facies distribution and favorable
reservoirs remains highly challenging. This study focuses on the third member of the Jiamuhe Formation in
the Zhongguai Uplift. By integrating drilling and petrophysical data with well-seismic analysis techniques,
a seismic identification model for volcanic reservoirs has been established. The findings reveal that different
facies exhibit distinct seismic response characteristics. Andesite, rhyolite, volcanic breccia, and volcanic
clastic rocks show variability in amplitude, frequency, and continuity. Using structural-guided filtering,
high-resolution coherence analysis, and 3D body carving techniques, the locations of volcanic craters and
eruption centers were successfully identified, further clarifying the distribution patterns of volcanic facies.
By combining multi-attribute clustering analysis and seismic attribute extraction, a volcanic facies zone
distribution map was generated, and favorable exploration directions for volcanic reservoirs were proposed.
The study provides technical guidance for the exploration of deep volcanic oil and gas reservoirs in the
Junggar Basin and holds significant application value.
The Solonker Suture records the termination of the Central Asian Orogenic Belt (CAOB), but
its eastward extension beneath the Songliao Basin has not been clear. The Yaduwula ophiolite is one of
the significant fragments within the Solonker Suture. LA–ICP–MS U–Pb dating of zircon grains from
metamorphic basalts yield ages of 263±4 Ma and 274±3 Ma, constraining the Yaduwula ophiolite in the late
Cisuralian and Guadalupian age. This might indicate that the subduction of Paleo-Asian Ocean continued
until at least the Guadalupian (middle Permian). Geochemical analysis of the metamorphic basalts revealed
enrichment in large ion lithophile elements (LILEs) and depletion in high field strength elements (HFSEs)
and show the characteristics of a supra-subduction zone. The results provide the evidence for the closure
time of the Paleo-Asian Ocean after the middle Permian and also suggest that the Yaduwula ophiolite may be
considered the eastern extension of Solonker Suture. Our study provides further insights on the evolution of
the southeastern Central Asian Orogenic Belt.
The Mailong gold deposit is located in the eastern section of the East Kunlun orogenic belt and is
one of the recently discovered important gold polymetallic deposits in the Qinhai Gouli region. The primary
host rocks of the Mailong gold deposit consist of intermediate-acid intrusive rocks from the Varisian and
Indosinian periods, as well as the Precambrian Jinshuikou Group, with mineralization controlled by northeast
and northwest faults. The alteration of the host rocks is mainly characterized by silicification, sericitization,
chloritization, and carbonatization. Based on the cross-cutting relationships of the veins, the hydrothermal
mineralization of the gold deposit can be categorized into three stages: the quartz-pyrite stage, the quartzpolymetallic sulfide stage, and the quartz-carbonate stage. Microthermometry of fluid inclusions indicates that
the Mailong gold deposit belongs to a low-density (0.73–0.86 g/cm3
), medium-temperature (240–340 ℃), and
medium-salinity (4.01–10.74 wt% NaCl) NaCl-CO2-H2O fluid system. The C-H-O isotopic analysis suggests
that the mineralizing fluids is derived from magmatic water, with later contributions from atmospheric
precipitation. In-situ S isotopic results indicate that the mineralizing materials mainly derive from igneous
rocks. A comprehensive analysis concludes that the Mailong gold deposit is a mesothermal hydrothermal
vein-type gold deposit controlled by structural factors.
The Jiao-Liao-Ji Belt within the North China Craton had undergone a complex tectonic evolution,
marked by extensive Paleoproterozoic magmatism that produced a diverse range of mafic to felsic magmatic rocks. These events provide valuable geological records for understanding the tectonic evolution of
the Jiao-Liao-Ji Belt. This study focuses on the Paleoproterozoic Chibaisong meta-gabbro in southern Jilin,
investigating the source of mafic magma, petrogenesis, and tectonic setting through systematic petrological
analysis, zircon U-Pb dating, and geochemical studies. The findings contribute to constraining the dynamic
mechanisms of Paleoproterozoic extensional rifting in the Jiao-Liao-Ji orogenic belt. Geochemical data indicate that the samples exhibit low SiO₂(47.99–50.66 wt.%), TiO₂(0.75–3.20 wt.%), Nb(3.22–8.09 ppm), and
Ta(0.22–0.51 ppm) contents, along with high TFeO₃(11.97–15.82 wt.%) and MgO(5.67–12.66 wt.%) concentrations. They also show low Nb/La ratios and high (Th/Nb)N values, consistent with the geochemical characteristics of tholeiitic basalts. The samples display low total rare earth element concentrations, weak or absent
Eu anomalies, slight enrichment in light rare earth elements, relatively flat heavy rare earth element patterns,
and depletion in Nb, Ta, and Ti. The meta-gabbro from southern Jilin exhibits geochemical similarities to Paleoproterozoic metamafic rocks from other regions of the Jiao-Liao-Ji Belt, resembling enriched mid-ocean
ridge basalts (E-MORB) with Nb, Ta, and Ti depletion. Integration of previous studies and geochemical data
suggests that the 2.16–2.10 Ga metamafic rocks in the Jiao-Liao-Ji Belt experienced contamination by older
crustal material. These results indicate that the 2.16–2.10 Ga metamafic rocks are unlikely to be associated
with island arc, continental arc, or mid-ocean ridge settings. Instead, they are more likely related to intraplate
magmatism associated with continental rifting
Slope units are divided according to the real topography and have clear geological characteristics,
making them ideal units for evaluating the susceptibility to geological disasters. Based on the results of
automatically and manually corrected hydrological slope unit division,the Longhua District, Shenzhen
City, Guangdong Province, was selected as the study area. A total of 15 influencing factors,namely
Fluctuation,slope, slope aspect, curvature, topographic witness index (TWI),stream power index
(SPI),topographic roughness index (TRI), annual average rainfall,distance to water system, engineering rock
group,distance to fault, land use,normalized difference vegetation index (NDVI),nighttime light, and distance
to road, were selected as evaluation indicators. The information volume model (IV) and random points were
used to select non-geological disaster units, and then the random forest model (RF) was used to evaluate the
susceptibility to geological disasters. The automatic slope unit and the hydrological slope unit were compared
and analyzed in the random forest and information volume random forest models. The results show that the
area under the curve (AUC) values of the automatic slope unit evaluation results are 0.931 for the IV-RF
model and 0.716 for the RF model, which are 0.6% (IV-RF model) and 1.9% (RF model) higher than those
for the hydrological slope unit. Based on a comparison of the evaluation methods based on the two types of
slope units, the hydrological slope unit evaluation method based on manual correction is highly subjective, is
complicated to operate,and has a low evaluation accuracy, whereas the evaluation method based on automatic
slope unit division is efficient and accurate, is suitable for large-scale efficient geological disaster evaluation,
and can better deal with the problem of geological disaster susceptibility evaluation.