Discovery of a new Proterozoic paleo-reservoir and its oil source in the Jianchang Sag,Yanliao Faulted-Depression Zone,North China

The discovery of many Proterozoic primary oil and gas reservoirs around the world testifies that the Meso-Neoproterozoic petroleum is an energy resources realm worthy of attention.This paper firstly reports the occurrence of hydrocarbon accumulations in the Neoproterozoic Luotuoling Formation in the Jianchang Sag,the Yanliao Faulted-Depression Zone.Petrography observation shows that the lower sandstone member of the Luotuoling Formation contains yellow fluorescent liquid hydrocarbons,while the upper sandstone member is rich in solid bitumen.Further analysis of the biomarkers and isotopic compositions reveals that the upper and lower reservoirs have different oil sources.The bitumen in the lower reservoir is rich in C_(19)-C_(20)tricyclic terpanes(TTs),13α(n-alkyl)-tricyclic terpanes and rearranged hopanes,but lacks gammacerane and steranes and depletes ^(13)C isotope(-33.4‰to-30.6‰).This is consistent with the properties of the Hongshuizhuang Formation source rocks.The upper reservoir bitumen has C_(23)TT as the major peak among C_(19)-C_(23)TTs,lacks 13α(n-alkyl)-tricyclic terpanes,has a low abundance of rearranged hopanes,obvious distribution of gammacerane and steranes,and depletion of the^(13)C isotope;essentially the same as the Gaoyuzhuang Formation source rocks.The discovery of oil seepage in the Luotuoling Formation of the Han-1 well is a promising indicator of the Precambrian oil and gas exploration potential of the Jianchang Sag.

Early Cretaceous precious fossil-bearing beds in Weijialing—Yaolugou of Jianchang Basin,western Liaoning

The Jianchang Basin is one of the main localities of the precious fossils of Jehol Biota in western Liaoning.The fossil-bearing horizons are mainly in the Yixian-and Jiufotang formations.In the Weijialing--Yaolugou of southwest Jianchang Basin,many precious fossils have been found at Luojiagou Bed of the 2nd Member of the Yixian Formation and at Xidian Bed of the 1st member of the Jiufotang Formation.The geologic setting,sedimentary environment and paleogeography of the precious fossil-bearing beds were also studied.

Characteristics of Thermal Climate Resources Changes of Agricultural Production during Frost Period in Jianchang County

[Objective] The characteristics of thermal climate resources changes of agricultural production during frost period in Jianchang County were studied. [Method] By dint of Jianchang climate resources and routine numerical statistics method, the sunlight and temperature changes trend from 1960 to 2009 in Jianchang County were analyzed. [Result] The sunshine hours and sunshine percentages during frost period in Janchang County from 1960 to 2009 tended to decrease. The climate tendency rates were -55.556 h/10 a and -2.39%/10 a respectively, 287 h and 12% of deduction in recent 50 years. There were climate transition in 1981 and 1982. And there were a shortage of 161 h and 7% of sunshine hours and sunshine percentages before and after the transition. The temperature during the frost period generally was increasing. The average temperature, average maximum and lowest temperature tendency rate were 0.386, 0.392 and 0.567 ℃/10 a. There was a growth of 1.93, 1.96 and 2.84 ℃ in recent 50 years. There were temperature transition in 1987 and 1988. The average temperature, average maximum and lowest temperature increased 1.3, 1.2 and 1.7 ℃. In recent 50 years, the sunshine resources during frost period in Jianchang were decreasing, while the thermal resources were strengthening, forming complementary of light and heat. [Conclusion] The study provided climate accordance to the development of local facility agriculture during frost period.