袁河流域强降水的天气背景与回波特征分析

为了更好地监测预警江西袁河流域强降水天气,使用江西雨量资料、欧洲中心格点（1°×1°）再分析资料和江西雷达回波等资料,对袁河流域5次大暴雨过程进行分析,结果表明：（1）袁河流域强降水天气形势场是925～700 hPa切变线、低层辐合高层辐散中心、西南气流达到12～18 m·s-1等因素影响;T-LnP图上整层水汽充沛,可降水量在75 mm以上;降水前低层累积不稳定能量CAPE（1000 J/Kg）和对流抑制能CIN（100 J/Kg）。（2）强降水回波的组合反射率CR在50 dBz左右,回波顶高在13 km左右,垂直积分液态水含量在12 kg·m2左右;40 dBz回波顶高在6～7 km,45 dBz回波顶高在6.5 km以下。（3）强降水和回波强度dBZ成正相关,随降水的增强,回波明显增强;当回波强度≤20 dBz时,雨强几乎不变;当回波强度在20～35 dBz之间,雨强随回波强度增加而缓慢加大;当回波强度在35～50 dBz之间,雨强随回波强度加大明显增加;而当回波强度≥50 dBz时,雨强反而趋于下降或维持。研究结果对袁河流域强降水的监测预警和预报服务有指导意义。     

2000—2021年江西省植被生态质量时空分布及其与气候因子的关系

基于卫星遥感数据和气象数据,采用距平分析、趋势分析、相关性分析等方法,分析了2000—2021年江西省植被生态质量时空变化特征,及其与气温、降水、日照等气候因子的关系。结果表明：1） 自2000年以来江西省植被生态质量整体改善明显,植被净初级生产力和生态质量指数呈明显上升趋势,年平均分别增加3.92 gC/m2和0.4,尤其2011年以后植被净初级生产力和生态质量指数处于较高水平,其中2018年最佳。2） 江西省植被生态指标低值区域位于城区周边,以及由长江和江西五大河流域的泥沙沉积形成的、以鄱阳湖为中心的冲积平原,中值区域位于中南部丘陵,高值区域分布于省境边陲山脉。3） 江西省植被生态指标与年降水量、年平均气温呈显著相关关系,与日照时数相关性不显著。与气候因子的相关性呈现地域差异,南部区域受气温影响较为明显,而中部盆地和东北区域受降水量影响更为明显。     

尼日尔三角洲盆地深水沉积的二元结构特征及层序划分

本文根据测井曲线及地震相特征,建立了深水层序界面划分的5种判别标准,将尼日尔三角洲盆地深水区中中新统一上中新统地层划分了6个三级层序,2个二级层序.根据深水沉积自身沉积旋回所具有的二元结构特征及三角洲与陆架区相对海平面变化之间的关系,将经典的三分体系域划分为二分体系域:异地沉积体系域和原地沉积体系域.其中,异地沉积体系域从基准面下降开始海侵早期,主要发育重力流沉积(块状搬运沉积、浊积扇);原地沉积体系域从海侵中、晚期—基准面上升最大位置结束,主要以原地沉降的泥质披覆沉积为主.本文分析了层序发育的影响因素,综合研究认为:气候条件、海平面变化、构造抬升、沉积物供给、大陆架宽窄等共同制约了研究区深水沉积层序的发育.     

水下分流河道砂体的叠置样式及其储层非均质性变化特征

在研究区目的层进行高分辨率层序地层研究的基础上,对分流河道微相的储层质量非均质性进行分析,应用不同级次基准面旋回成因的沉积学分析和表征储层质量非均质性的各项岩芯化验、统计学数据定量分析,指出基准面旋回因素对不同级次水下分流河道主体储层质量非均质性影响存在差异:单一水下分流河道和单期复合水下分流河道的储层质量非均质性呈正韵律变化,多期复合水下分流河道储层质量非均质性分布呈不规则趋势,多级次的基准面旋回及其伴随的可容纳空间变化所引起的沉积环境的变化影响水下分流河道储层非均质性.     

烷基萘分子稳定碳同位素组成演变的热模拟实验及其意义

萘及烷基萘是原油和沉积有机质的重要组成。目前对于烷基萘单体稳定碳同位素组成随有机质成熟作用加深的演变特征鲜见报道。本研究选取松辽盆地杜601井嫩一段低熟黑色泥岩进行热压模拟生烃实验,采用两步柱色谱层析技术分离烷基萘化合物使其达到稳定碳同位素的在线准确测定,从而厘定有机质不同成熟阶段烷基萘单体稳定碳同位素组成分布面貌。实验结果显示,不同模拟实验温度点排出的一甲基萘(MNs)和二甲基萘(DMNs)各异构体具有相对一致的稳定碳同位素值,分别介于–29.5‰~–29.3‰和–30.9‰~–30.5‰之间,这可能与生烃过程中干酪根的非均一性裂解有关;三甲基萘(TMNs)各异构体之间稳定碳同位素值差异较大,介于–36.8‰~–31.1‰之间,这可能与生源效应有关;其中,1,2,5-TMN稳定碳同位素组成偏轻,介于–36.8‰~–35.6‰之间,可能是细菌来源的藿类化合物降解及其芳构化的产物。实验结果表明,随着有机质热演化作用的加深,烷基萘单体稳定碳同位素组成变化介于0.8‰~1.4‰之间,基本在仪器测试误差范围之内,反映成熟作用所导致的烷基萘单体稳定碳同位素动力学分馏较小。因此,烷基萘单体稳定碳同位素组成可以成为油-源和油-油对比的潜在指标。     

英买力凝析气田群区巴什基奇克组-库姆格列木群 层组划分与对比研究

英买力凝析气田群区层组划分与对比研究是该地区陆相地层油气藏地质和开发工程中最基本和最重要的精细地质研究内容之一,也是急需解决的关键技术难题之一。本次研究采取"取心标准井出发,岩心标定测井,寻找辅助标志层,进行旋回对比、分级控制,将隔夹层纳入到同一沉积旋回进行识别、划分对比,以隔层确定小层,并兼顾‘就近、闭合’的原则"展开层组划分与对比,重新确定出更适用于气田开发的气层组、砂层组、小层等划分单元。而对可以作为层组划分与对比辅助手段的白垩系与古近系不整合界面、库姆格列木群底砂岩段顶界以及层组中的隔夹层等的识别,为层组的精细划分对比提供了重要保证,很好地解决了巴什基奇克组、库姆格列木群的层组划分问题,对英买力地区凝析气藏的后期开发等问题具有积极的指导意义。     

Sequences and biofacies packages in the mid‐Cenozoic Gambier Limestone,South Australia: Reappraisal of foraminiferal evidence

The mid to outer neritic carbonates of the Gambier Limestone (Upper Eocene to lower Middle Miocene) can be divided into seven units by using criteria of sequence stratigraphy and foraminiferal biofacies. The boundaries fall mainly on erosional surfaces, even though the temporal duration of these surfaces appears to be largely beyond the resolution of foraminiferal biostratigraphy. The Eocene/Oligocene contact is distinctively unconformable in several sections, with at least part of the Upper Eocene sediments missing. Chert nodules, common to abundant in most sections, are associated with deep‐ or cool‐water benthic assemblages (> 100–200 m and <15°C), indicating cool, nutrient‐rich bottom conditions probably influenced by the Antarctic Circumpolar Current beginning during the Early Oligocene. The mid‐Oligocene fall in sea‐level was probably coupled with a major local uplift that removed at least part of the Lower Oligocene, an event widely recorded in the Australian‐New Zealand region. In areas weakly affected, this glacioeustatic lowstand is represented by chert‐free limestone and grey to pink dolomites in some sections, with a poorly preserved assemblage comprising few planktonic and deep‐water benthic species. Local unconformities separate regional unconformity‐bounded or allostratigraphic packages of strata to represent third‐order sequences. Although variations in local subsidence might have influenced accumulation space and sediment thickness, glacioeustatic influence on the packaging of the sequences and units of the Gambier Limestone was easily the more effective and concordant with the global patterns.     

Potassium‐argon dates from the Arltunga Nappe complex,northern territory

Twenty‐four mineral separates from the Arunta Complex, four from the metamorphosed Heavitree Quartzite (White Range Quartzite), and one whole rock sample of metamorphosed Bitter Springs Formation, all from the western part of the White Range Nappe of the Arltunga Nappe Complex, and two samples from the autochthonous basement west of the nappe have been dated by the K‐Ar method. The samples from the basement rocks form two groups. Those in the southern or frontal part of the nappe are of Middle Proterozoic (Carpentarian) age (1660–1368 m.y.), determined on hornblende, biotite, and muscovite. In the northern or rear part of the nappe, all but one of the muscovite samples and two biotites are of Middle Silurian to Early Carboniferous age (431–345 m.y.); the remainder of the biotite dates range from 1775 to 548 m.y. (including the two samples from the autochthon), and two hornblendes gave dates of 1639 and 2132 m.y. respectively. All the muscovite samples from the Heavitree Quartzite, and the whole rock sample from the Bitter Springs Formation gave Early to Middle Carboniferous dates (358–322 m.y.). The findings support the identification of the White Range Quartzite as the metamorphosed part of the Heavitree Quartzite, which in turn supports the interpretation of the structure of the area as a large, basement‐cored fold nappe. In addition, they date the time of the Alice Springs Orogeny as pre‐Late Carboniferous, which agrees with fossil evidence from elsewhere in the area. The Alice Springs Orogeny was accompanied by widespread greenschist facies meta‐morphism that progressively metamorphosed the Heavitree Quartzite and Bitter Springs Formation, and retrogressively metamorphosed the Arunta Complex. However, the basement rocks in the southern part of the nappe escaped this metamorphism and retain a Middle Proterozoic age, thus dating the time of the Arunta Orogeny in this region as Carpentarian or older.     

Biological and abiological processes in a simulated sedimentary system

A simulated sedimentary system, capable of being controlled and monitored for a considerable length of time without undue disturbance, has been assembled and applied to specific problems of the genesis of stratiform Pb‐Zn ore deposits. Results have been obtained relevant to: (i) the concentration of Pb and Zn from brines to underlying sediments; (ii) the behaviour of microorganisms in metal‐rich, highly saline environments; (iii) the precipitation diagenesis of calcium and magnesium carbonates; and (iv) the diagenesis of organic matter.

The experiment has demonstrated the feasibility of simulating a complex sedimentary environment in the laboratory and has indicated the potential of such systems for the investigation of geobiological problems.     

A reinterpretation of seismic data in the Laura Basin,Queensland

The results of the seismic surveys recorded during 1963 and 1968 for Marathon Petroleum and Crusader Oil in the Laura Basin, north Queensland, have been reinterpreted. Seismic reflections which dip almost continuously from 0.6 to 4.0 seconds reflection time may come from the base of and within an 8000 m sequence of Permo‐Carboniferous sediments, which may underlie the flat‐lying Mesozoic Laura Basin sediments and overlie the heavily folded Carboniferous‐Devonian sediments in the Hodgkinson Basin. Further seismic investigation of this area is recommended since a thick Permo‐Carboniferous sedimentary section here could be prospective for hydrocarbons.