Hydrocarbon Generation Evaluation of Permo-Carboniferous Source Rocks in Qinggu-2 Well in Dongpu Depression,China

The Dongpu (东濮) depression is a Mesozoic subsidence and Cenozoic fault basin developed within the North China craton. Since the deposition of Permo-Carboniferous hydrocarbon source rock, the depression has undergone many tectonic disturbances and uplifts. The source rocks have undergone nonuniform uplift, deformation, deep burying, and magmatism, and those led to an interrupted or stepwise evolution of the hydrocarbon source rocks in Qinggu (庆古)-2 well. We have investigated the history of burying, heating, ...     

东北地区中生代岩石圈减薄时间上限的厘定:来自松辽盆地营城组火山岩年代学约束

松辽盆地是我国东北地区一个大型的晚中生代含油气沉积盆地。在盆地发育早期阶段受强烈伸展作用影响形成了大规模的断陷和大量的火山活动。本文以松辽盆地北部徐家围子断陷区火山岩的年代学研究为切入点,通过对徐家围子断陷升深更2井和徐深9-2井营城组(K_1y)火山岩的岩芯样品进行SHRIMP U-Pb定年,获得了营城组火山岩年龄为114～112 Ma,并认为该年龄结果代表了松辽盆地区域晚中生代岩浆作用的上限时间。通过对松辽盆地及邻区的火山年代学的对比发现:中国东北地区晚中生代曾发生过多期的岩浆事件,时间分别为:166～150 Ma;140～130 Ma;130～120 Ma;114～109 Ma。松辽盆地内早白垩世营城组火山岩年龄与我国东北地区中生代最后一期岩浆作用时间一致,指示了东北地区中生代最后一期岩浆事件年龄。松辽盆地营城组火山岩年龄的厘定将为本区中生代岩石圈减薄的上限时间提供进一步可靠的年代学约束。     

东北地区中生代岩石圈减薄时间上限的厘定： 来自松辽盆地营城组火山岩年代学约束

松辽盆地是我国东北地区一个大型的晚中生代含油气沉积盆地。在盆地发育早期阶段受强烈伸展作用影响形成了大规模的断陷和大量的火山活动。本文以松辽盆地北部徐家围子断陷区火山岩的年代学研究为切入点,通过对徐家围子断陷升深更2井和徐深9 2井营城组（K1y）火山岩的岩芯样品进行SHRIMP U Pb定年,获得了营城组火山岩年龄为114～112Ma,并认为该年龄结果代表了松辽盆地区域晚中生代岩浆作用的上限时间。通过对松辽盆地及邻区的火山年代学的对比发现：中国东北地区晚中生代曾发生过多期的岩浆事件,时间分别为： 166～150 Ma; 140～130 Ma; 130～120 Ma; 114～109 Ma。松辽盆地内早白垩世营城组火山岩年龄与我国东北地区中生代最后一期岩浆作用时间一致,指示了东北地区中生代最后一期岩浆事件年龄。松辽盆地营城组火山岩年龄的厘定将为本区中生代岩石圈减薄的上限时间提供进一步可靠的年代学约束。     

Carbon storage and vertical distribution in three shrubland communities in Gurbantünggüt Desert, Uygur Autonomous Region of Xinjiang, Northwest China

This study was carried out in the Gurbantünggüt Desert,Uygur Autonomous Region of Xinjiang,Northwest China in August,2009.To quantify the storage,contribution and vertical distribution patterns of plant biomass carbon (PBC)and soil organic carbon(SOC)in the study area,we investigated the carbon concentrations and its vertical distribution in three different desert shrubland communities dominated by Reaumuria soongorica,Haloxylon ammodendron+R.soongorica and Tamarix ramosissima+R.soongorica,respectively.We analyzed vertical distribution of root biomass carbon and soil carbon contents by excavating soil profiles for each dominated community.The results show that SOC is considerably the larger carbon pool in the soil layers of 1.0-3.0 m(the mean value of three shrubland communities is 38.46%)and 3.0-5.0 m(the mean value is 40.24%).In contrast,70.74%of belowground biomass carbon storage in 0-1.0 m layer,and its content decrease with increasing soil depth.The Haloxylon ammodendron+R. soongorica shrubland community has the highest belowground biomass carbon among three selected communities. This study highlights the importance of SOC stored in deep soil layers(lower than 3.0 m from the surface)in arid shrubland communities in the global carbon balance.In addition,it provides the data support for revealing deep soil solid carbon potential,and offers scientific basis for the further research in the carbon cycle of terrestrial ecosystem.     

深水内波、内潮汐沉积类型及其油气意义

深水内波、内潮汐沉积可归纳为水道型和非水道型两种基本沉积类型。水道型沉积常发育双向递变层序和单向递变层序,单砂层较厚,它不仅是油气的良好储层,而且常与深水重力流沉积和深水背景泥岩沉积一起构成有利的地层或岩性圈闭,应当列为深水沉积区油气勘探的重点目标。非水道型深水内波、内潮汐沉积一般发育由砂泥频繁薄互层所构成的对偶层双向递变层序和对偶层单向递变层序,单砂层很薄,油气勘探意义可能不大。广泛分布的大型沉积物波(分为粗、细粒两种)和水道口附近的内潮汐砂坝,是两种比较特殊的内波、内潮汐沉积建造。根据现有研究实例和沉积成因水流理论分布范围等,建立了深水内波、内潮汐综合沉积模式。