基于多源数据的湘北地区春季一次冰雹过程的观测分析

新型探测资料在强对流短临预报中发挥着重要作用.该文以2020年3月22日湘北地区春季一次冰雹过程为研究对象,运用多普勒天气雷达、风廓线雷达和地基微波辐射计等新型探测资料对该过程观测分析。结果表明：①此次过程发生在冷空气南下与南支槽前暖湿空气交汇背景下,受中低层切变线与急流影响,冰雹风暴生成前回暖明显,环境垂直风切变大;风暴由地面辐合线触发产生。②此次超级单体降雹过程在雷达回波中表现出“三体散射”、“V型缺口”、中气旋等特征;VIL、低仰角大风速核对冰雹、大风预警有很好的指示。③风廓线雷达探测到,风暴影响前超低空急流加强,中层有干侵入,低层垂直速度出现波动,风暴临近时超低空急流减弱。④地基微波辐射计监测发现,风暴影响前高空湿度增大,K指数、TT指数呈同趋势变化,而K指数预警灵敏度高于TT指数;风暴影响阶段,高空温度、相对湿度和大气不稳定指数出现不同程度跃升和突降。     

西秦岭西段光盖山-迭山断裂带坪定-化马断裂的新活动性与滑动速率

位于西秦岭西段的光盖山-迭山断裂带是由3条近平行的断裂所组成,其中坪定-化马断裂是该断裂带的主断层.坪定-化马断裂以宕昌岷江为界分为东、西两段,西段的新活动性明显强于东段.断裂西段线性特征明显,可见清晰的断层崖,不同期次的洪积扇上均有断层陡坎发育,晚第四纪以来有过明显的活动,最新一次活动的离逝时间约为1kaB.P.左右.通过对断错地貌研究得到断裂晚第四纪以来的垂直滑动速率为0.49±0.08 ～1.15±0.28mm/a,左旋滑动速率为0.51±0.13mm/a.而断裂东段由多条斜交或近于平行的断裂所组成,活动性明显减弱,没有发现最新活动的证据.在地貌上多表现为线性沟谷,向东逐渐被褶皱所替代,从基岩断面及相关地貌特征来看断裂活动性质主要表现为逆冲兼具左旋走滑运动.     

THE RELATIONSHIP BETWEEN ENVIRONMENTAL CHANGES AND HUMAN ACTIVITIES DURING THE MEDIEVAL WARM PERIOD AND THE LITTLE ICE AGE IN OTINDAG SANDLAND BY OSL DATING

为了深入了解中世纪暖期和小冰期浑善达克沙地环境变迁与人类活动的关系,对沙地5个具有代表性的风成砂——砂质土剖面序列进行了光释光测年研究.结合粒度、磁化率、烧失量等气候替代性指标及地层中的文化遗存分析,得到了浑善达克沙地近2ka来的环境变迁记录:距今1.45～1.10ka和0.83 ～0.58ka,浑善达克沙地发育砂质土层,气候温暖湿润,与中国唐朝暖期和元朝暖期相对应,欧洲此时经历了中世纪暖期,该地自然环境条件比较优越,旱作农业文化发展.距今1.10～0.83ka和0.58 ～0.20ka,浑善达克沙地发育浅黄色砂层,气候干旱寒冷,沙丘活化,分别与我国宋辽和清朝冷期相对应,其中宋辽冷期是中世纪暖期的气候波动,清朝冷期则对应千欧洲小冰期,游牧文化发展.浑善达克沙地地层序列、气候替代性指标及其所保存的人类文化遗存揭示了自然环境与人类活动的相互关系.2ka以来,气候经历了暖湿与冷干的交替变化,自然环境变化影响了人类生产生活方式.沙地气候事件可能对我国相应时期朝代的兴亡产生过重大影响.     

Holocene palaeoflood events recorded by slackwater deposits along the lower Jinghe River valley,middle Yellow River basin,China

Palaeoflood slackwater deposits (SWDs), are the natural record of overbank flooding and are often found within aeolian loess‐soil profiles along the river valleys of the middle Yellow River basin. These pedo‐stratigraphic sequences are studied using a multi‐disciplinarily approach to reconstruct Holocene hydro‐climatic variations. Our field investigations along the lower Jinghe River valley have identified palaeoflood SWDs at several sites along the riverbanks based on sedimentological criteria. Analytical results, including magnetic susceptibility, particle‐size distribution and concentrations of chemical elements, indicate that these well‐sorted palaeoflood SWD beds were deposited from the suspended sediment load in floodwaters. We identify two episodes of extraordinary palaeoflood events along the Jinghe River valley. These hydro‐climatic events were dated to 4200–4000 and 3200–2800 a BP, by using the optically stimulated luminescence method in combination with archaeological dating of retrieved anthropogenic remains, and with pedo‐stratigraphic correlations with the previously studied Holocene pedo‐stratigraphy in the Jinghe River drainage basin. The flooding events are therefore considered to be a regional expression of known climatic events in the northern hemisphere and demonstrate Holocene climate was far from stable. This study provides important data in understanding the interactions between regional hydro‐climatic systems and global change in semi‐arid and sub‐humid regions. Copyright © 2012 John Wiley & Sons, Ltd.     

中国西部叠合盆地油气藏形成、演化与分布预测

中国西部叠合盆地经历了多期构造变动和多旋回的油气成藏作用,研究叠合盆地油气藏的形成、演化和分布预测具有重要的意义。叠合盆地指不同时期形成的不同类型的沉积盆地或地层在同一地理位置上的叠加和复合,具有地层沉积不连续、地层构造不连续、地层应力应变作用不连续等三大标志性特征,依据构造剖面上地层年代的关联性,将叠合盆地分为五种类型,即连续沉积型叠合盆地、中晚期地层叠合盆地、早晚期地层叠合盆地、早中期地层叠合盆地、长期暴露型叠合盆地。叠合盆地普遍发育复杂油气藏,三种作用（剥蚀作用、断裂作用、褶皱作用）六种机制（渗漏、扩散、溢散、氧化、降解和裂解）形成复杂油气藏,依据成因特征分为五类,原成型油气藏,圈闭调整型油气藏,组分变异型油气藏,相态转换型油气藏,规模改造型油气藏。研究表明,复杂油气藏中天然气的地下产状特征和分布特征与地表产状特征和分布特征有很大差异。中国西部叠合盆地油气分布主要受烃源灶、古隆起、沉积相、断裂带、构造变动和区域盖层等六大因素的控制。其中烃源灶（S）、古隆起（M）、沉积相（D）和盖层（C）等四大要素控制着油气成藏的形成和分布,并建立了多要素匹配（T-CDMS）成藏模式,用以预测有利成藏领域。油气藏形成之后,多期的构造变动对早成的油气藏进行调整、改造和破坏,主要受构造变动强度、构造变动时间、构造变动次数、构造变动时盖层的封油气性能等四大要素控制,并以此建立了多期构造变动破坏油气藏后剩余潜力评价模型,利用这一模型可以预测出有利勘探区带并评价出有利勘探区带中的剩余资源潜力。油气藏经过改造,表现出晚期成藏效应,并受相势耦合作用的控制最后定位,利用晚期成藏效应和相势耦合理论可以预测有利勘探目标,并指出潜在有利勘探目标。     

哈尔滨市冬末逆温、大气稳定度与大气污染概率关系

利用2006～2008年2月逐日地面常规观测资料和高空探测资料以及逐日的污染监测资料,统计分析了哈尔滨市2月风速、逆温和大气稳定度与大气污染的概率关系。分析结果表明：哈尔滨市2月的大气污染主要发生在风速〈3 m/s,污染物浓度随着风速的增大而减小,在一定程度上反映了哈尔滨市2月的污染主要是局地污染物的累积;发生大气污染时一定有逆温出现,但有逆温时不一定就发生大气污染;大气稳定度增加,大气污染概率增大。     

鄂尔多斯盆地中及上三叠统延长组沉积相与油气勘探的突破

鄂尔多斯盆地位于中国的中西部,跨陕、甘、宁、蒙、晋5省区,盆地本部面积25万km2.中及上三叠统延长组在盆地内广为展布,厚逾千米,发育冲积扇、河流、三角洲、湖泊等沉积相,是该地区重要的油气产层.根据盆地腹地100多口井的钻井资料及盆地周边地区的露头资料,以及长庆油田长时期对延长组的油气勘探经验,编制出了鄂尔多斯盆地中及...     

Observation of CO2 degassing in Tianshuihai Lake Basin of the Qinghai-Tibetan Plateau

A large volume of underground gas in the permafrost region of the Qinghai-Tibetan Plateau has been identified. Although many studies were performed to investigate the soil organic carbon dynamics and Earth degassing in volcanic areas, this is the first report of a large amount of non-volcanic CO₂ contained in permafrost. The gas was mostly CO₂ (81.76 vol. %) and nitrogen (14.59 vol. %). The gas composition and the evidence from carbon stable isotope values (?23.9 ‰, PDB) suggested that the gases possibly had a deep origin. The gas emissions may be triggered by permafrost degradation, which means mitigation of the barrier effect of permafrost for the gas. In addition, plate tectonic processes may also lead to gas emissions, as the tectonic activity is strong in the area. Therefore, particular attention should be paid to the underground gases in the study of global change and permafrost degradation.     

漳州盆地水热系统氚同位素研究

本文依据26个天然水样品的氚同位素测试数据,分析了漳州盆地地下热水及其它天然水的氚值特征及其形成条件;利用“活塞模型”方法计算了漳州盆地地下水和地下热水的年龄;为弄清全盆地地下水的补给、迳流和排泄的总体格局和揭示地下热水的成因提供了依据。     

Quaternary geomorphological evolution of the Kunlun Pass area and uplift of the Qinghai-Xizang (Tibet) Plateau

There is a set of Late Cenozoic sediments in the Kunlun Pass area, Tibetan Plateau, China. Paleomagnetic, ESR and TL dating suggest that they date from the Late Pliocene to the Early Pleistocene. Analyses of stratigraphy, sedimentary characteristic, and evolution of the fauna and flora indicate that, from the Pliocene to the early Quaternary (about 5–1.1 Ma BP), there was a relatively warm and humid environment, and a paleolake occurred around the Kunlun Pass. The elevation of the Kunlun Pass area was no more than 1500 m, and only one low topographic divide existed between the Qaidam Basin and the Kunlun Pass Basin. The geomorphic pattern in the Kunlun Pass area was influenced by the Kunlun–Yellow River Tectonic Movement 1.1–0.6 Ma BP. The Wangkun Glaciation (0.7–0.5 Ma) is the maximum Quaternary glaciation in the Pass and in other areas of the Plateau. During the glaciation, the area of the glaciers was 3–5 times larger than that of the present glacier in the Pass area. There was no Xidatan Valley that time. The extreme geomorphic changes in the Kunlun Pass area reflect an abrupt uplift of the Tibet Plateau during the Early and Middle Pleistocene. This uplift of the Plateau has significance on both the Plateau itself and the surrounding area.