New prospecting progress using information and big data of coal and oil exploration holes on sandstone-type uranium deposit in North China

1.Objective A series of Mesozoic-Cenozoic continental sedimentary basins exist in North China,coexisting with coal,oil/gas,and salt resources.Many previous drilling projects have been conducted within these basins to explore coal,petroleum,and mineral resources,however,these data have not been integrated due to different industries owners.In order to efficiently explore the large-sized,easily extracted,and environmentally friendly,sandstone-type uranium deposits,previous coal and oil exploration drilling-hole data are systematically collected, processed,and analyzed to improve the sandstone-type uranium prospecting exploitation.At the same time,we also discussed the uranium source,ore-forming process and model for the sandstone-type uranium deposits.

Lithium Resources in Brine of China's Sea Salt Field Operations

Objective With the rapid development of mobile power and electronic vehicles, the application of lithium is in the ascendant, and the contradiction between its supply and demand is prominent.

Risk Assessment and Treatment Countermeasures for the Barrier Lakes of Wenchuan Earthquake on May 12^(th),2008

This paper introduced the first hand investigation results of the risk and treatment measures for the barrier lakes triggered by the earthquake of Wenchuan. Characteristics of 10 barrier lakes were investigated and analyzed; procedure and methods for barrier lake treatment were brought forward. The dams of the barrier lakes can be classified as two classes： block rock in the south and loose deposit in the north. All the barrier dams were stable at the time of investigation, but water drainage channel needed to be constructed and to be protected from blockage or collapse. After the rain season of 2008, some dams needed to be consolidated, and change the barrier lakes to reservoirs.

Report of LA-ICP-MS zircon U-Pb dating(272 Ma) of gabbros in Yagan area, northern Alxa, Inner Mongolia: Insights into the tectonic evolution of the southern Paleo-Asian Ocean

1.Objective The northern margin of the Alxa Block in Inner Mongolia is located in the middle part of the southern margin of the Central Asian Orogenic Belt.It serves as a key position that connects the eastern and western tectonic units of the Central Asian Orogenic Belt and is an ideal site for the research on the final closing process of the Paleo-Asian Ocean.

Using time series analysis to assess tidal effect on coastal groundwater level in Southern Laizhou Bay, China

Sea water intrusion is an environmental problem cause by the irrational exploitation of coastal groundwater resources and has attracted the attention of many coastal countries.In this study,we used time series monitoring data of groundwater levels and tidal waves to analyze the influence of tide flow on groundwater dynamics in the southern Laizhou Bay.The auto-correlation and cross-correlation coefficients between groundwater level and tidal wave level were calculated specifically to measure the boundary conditions along the coastline.In addition,spectrum analysis was employed to assess the periodicity and hysteresis of various tide and groundwater level fluctuations.The results of time series analysis show that groundwater level fluctuation is noticeably influenced by tides,but the influence is limited to a certain distance and cannot reach the saltwater-freshwater interface in the southern Laizhou Bay.There are three main periodic components of groundwater level in tidal effect range(i.e.23.804 h,12.500 h and 12.046 h),the pattern of which is the same as the tides.The affected groundwater level fluctuations lag behind the tides.The dynamic analysis of groundwater indicates that the coastal aquifer has a hydraulic connection with seawater but not in a direct way.Owing to the existence of the groundwater mound between the salty groundwater(brine)and fresh groundwater,the maximum influencing distance of the tide on the groundwater is 8.85 km.Considering that the fresh-saline groundwater interface is about 30 km away from the coastline,modern seawater has a limited contribution to sea-salt water intrusion in Laizhou Bay.The results of this study are expected to provide a reference for the study on sea water intrusion.

A^2.5 Ga magmatic event at the northern margin of the Yangtze craton:Evidence from U-Pb dating and Hf isotope analysis of zircons from the Douling Complex in the South Qinling orogen

The poorly studied Douling Complex is a crystalline basement that developed in the Neoproterozoic-Paleozoic weakly metamorphosed to non-metamorphosed strata at the South Qinling tectonic belt.Five banded dioritic-granitic gneiss samples from the Douling Complex were chosen for LA-MC-ICPMS U-Pb zircon dating,which yielded protolith emplacement ages of 2469±22Ma,2479±12 Ma,2497±21 Ma,2501±17 Ma and 2509±14 Ma,respectively.An important peak age of^2.48 Ga was also obtained for a metasedimentary rock in the same region.These discoveries suggest the occurrence of magmatic activity of2.51–2.47 Ga at the northern margin of the Yangtze craton.The age-correctedεHf(t)values obtained from in situ zircon Hf isotopic analysis are mainly between 5.5 and+0.3,and the two-stage zircon Hf model ages range from 3.30 to 2.95 Ga.Considering two important periods of^3.3–3.2 Ga and^2.95–2.90 Ga for the continental crustal growth in the Yangtze craton,we infer that the dioritic-granitic gneisses from the Douling Complex are the products of reworking of Paleo-to Mesoarchean crust at the northern margin of the Yangtze craton at^2.5 Ga.In addition,metamorphic ages of 837±8 Ma and 818±10 Ma were obtained for zircon overgrowth rims from a dioritic gneiss and a metasedimentary rock,indicating that the main phase amphibolite facies metamorphism of the Doulng Complex occurred during the Neoproterozoic,although its geological meaning remains ambiguous.