海洋心血管药物及活性物质的研究现状与展望

按照海洋心血管活性成分的化学分类，本文较系统地列举了该领域中的研究成果和动态，对有代表意义的重点药物作较详细的评述，并探讨了有关海洋心血管药物研究工作的特点及发展前景。     

Kane Fracture Zone

The Kane Fracture Zone probably is better covered by geophysical survey data, acquired both by design and incidentally, than any other fracture zone in the North Atlantic Ocean. We have used this data to map the basement morphology of the fracture zone and the adjacent crust for nearly 5700 km, from near Cape Hatteras to the middle of the Mesozoic magnetic anomalies west of Cap Blanc, northwest Africa. We use the trends of the Kane transform valley and its inactive fracture valley to determine the record of plate-motion changes, and we interpret the basement structural data to examine how the Kane transform evolved in response to changes in plate motion. Prior to about 133 Ma the Kane was a small-offset transform and its fracture valley is structurally expressed only as a shallow ( < 0.5 km) trough. In younger crust, the offset may have increased to as much as 190 km (present offset 150 km) and the fracture valley typically is up to 1.2 km deep. This part of the fracture valley records significant changes in direction of relative plate motion (5°–30°) near 102 Ma, 92 Ma, 59 Ma, 22 Ma, and 17 Ma. Each change corresponds to a major reorganization of plate boundaries in areas around the Atlantic, and the fracture-zone orientation appears to be a sensitive recorder of these events. The Kane transform has exhibited characteristic responses to changes in relative plate motion. Counterclockwise plate-motion changes put the left-lateral transform offset into extension, and the response was for ridge tips at the ridge-transform intersections to propagate across the transform valley and against the truncating lithosphere. Heating of this lithosphere appears to have produced uplift and formation of a well developed transverse ridge that bounds the inactive fracture valley on its older side. The propagating ridge tips also rotated toward the transform fault in response to the local stress field, forming prominent hooked ridges that now extend into or across the inactive fracture valley. Clockwise (compressional) changes in relative plate motion produced none of these features, and the resulting fracture valleys typically have a wide-V shape. The Kane transform experienced severe adaptions to the changes in relative plate motion at about 102 Ma (compressional shift) and 92 Ma (extensional shift), and new transform faults were formed in crust outside the contemporary transform valley. Subsequently, the transform offset has been smaller and the rates of change in plate motion have been more gradual, so transform-fault adjustment has been contained within the transform valley. The fracture-valley structure formed during extensional and compressional changes in relative plate motion can be decidedly asymmetrical in conjugate limbs of the fracture zone. This asymmetry appears to be related to the ‘absolute’ motion of the plate boundary with respect to the asthenosphere.     

新型船载气象卫星接收系统

新型船载气象卫星接收系统为南极考察船的航海气象保障和在南大洋冰区中航行导航专门研制.该系统能够适应高温、高湿和低温超饱和的气候环境,在12级以上大风和船在破冰时剧烈摇摆和振动以及有雷达等强磁场信号干扰的情况下,具有自我保护能力.有极轨高分辨和静止低分辨卫星的双套接收和图像处理系统.该系统的关键创新之处:(1)采用了有源陀螺仪稳定平台.利用惯性测量和三轴伺服机构控制天线和隔离船摇.解决极轨卫星低仰角和过顶轨道高仰角跟踪丢线的矛盾,解决了船在运动状态下,不断改变位置、方向以及摇摆的状态下,准确地跟踪和捕捉到卫星,接收到清晰的卫星云图.(2)图像处理系统用了最新的BORLAND-DELPHI语言编程,采用两行元素的轨道模式计算动态定位套网格系统.利用电子地图网格数据,用迭代法画出地形海岸线.计算出每一像元素的位置;能够在图上显示任意一点的经纬度,标出任意目标物.解决了在海洋中航行找不到参照物时的困惑.能够监测云和温度、林火、海洋及陆地的异常变化.能够输出24位真彩色的高清晰度的卫星云图.该系统整体结构技术先进,体积小,重量轻,适应恶劣气候和海洋环境,图像处理系统功能齐全、分辨率高,操作方便.既适用于各种船只,也适用于陆地.     

Fault patterns at outer trench walls

Profiles across subduction-related trenches commonly show normal faulting of the outer trench wall. Such faulting is generally parallel or sub-parallel to the trench and is ascribed to tension in the upper part of the oceanic plate as it is bent into the subduction zone. A number of authors have noted that outer trench wall faulting may involve re-activation of the oceanic spreading fabric of the subducting plate, even when the trend of this fabric is noticeably oblique to the extensional stress direction. However, one previous review of outer trench wall fault patterns questioned the occurrence of a consistent link between fault orientation and such controlling factors. This latter study predated the widespread availability of swath bathymetry and longrange sidescan sonar data over trenches. Based only on profile data, it was unable to analyse fault patterns with the accuracy now possible. This paper therefore re-examines the relationship between outer trench wall faulting and the structure of the subduction zone and subducting plate using GLORIA and Seabeam swath mapping data from several locations around the Pacific and Indian Oceans. The principal conclusions is that the trend of outer trench wall faults is almost always controlled by either the subducting slab strike or by the inherited oceanic spreading fabric in the subducting plate. The latter control operates when the spreading fabric is oblique to the subducting slab strike by less than 25–30°; in all other cases the faults are parallel to slab strike (and parallel or sub-parallel to the trench). Where the angle between spreading fabric and slab strike is close to 30°, two fault trends may coexist; evidence from the Aleutian Trench indicates a gradual change from spreading fabric to slab strike control of fault trend as the angle between the two increases from 25 to 30°. The only observed exception to the above rule of fault control comes from the western Aleutian Trench, where outer trench wall faults are oblique to the slab strike, almost perpendicular to the spreading fabric, and parallel to the convergence direction. Re-orientation of the extensional stress direction due to right-lateral shear at this highly oblique plate boundary is the best explanation of this apparently anomalous observation.     

Quantitative mapping of active mud volcanism at the western Mediterranean Ridge-backstop contact

Based on a new quantitative analysis of sidescan sonar data combined with coring, we propose a revised model for the origin for Mediterranean Ridge mud volcanism. Image analysis techniques are used to produce a synthetic and objective map of recent mud flows covering a 640 × 700 km² area, which represents more than half of the entire Mediterranean Ridge mud belt. We identify 215 mud flows, extruded during the last 37,000–60,000 years. This time period corresponds to the limit of penetration of the sonar, that we evaluate through geoacoustic modeling of the backscattered signal returned by the mud breccia-hemipelagites contact, and calibrate by coring. We show that during this period, at least 96% of the mud volume has been extruded at the Mediterranean Ridge-Hellenic backstop contact, the remaining being scattered over the prism. We suggest that the source is a Messinian (5–6 Ma) mud reservoir that remained close to the backstop contact, at variance with the classical transport-through-the-wedge model. A revised mud budget indicates that steady-state input is not needed. We propose that the source layer was deposited in deep and narrow pre-Messinian basins, sealed by Messinian evaporites, and finally inverted in post-Messinian times. Onset of motion of the Anatolia-Aegea microplate in the Pliocene resulted in change from slow to fast convergence, triggering shear partitioning at the edges of the backstop and basin inversion. Mud volcanism initiation is probably coeval with the latest events of this kinematic re-organization, i.e. opening of the Corinth Gulf and activation of the Kephalonia fault around 1–2 Ma.     

Palaeozoic suturing of eastern and western Tasmania in the west Tamar region: Implications for the tectonic evolution of southeast Australia

A new tectonic model for Tasmania incorporates subduction at the boundary between eastern and western Tasmania. This model integrates thin‐ and thick‐skinned tectonics, providing a mechanism for emplacement of allochthonous elements on to both eastern and western Tasmania as well as rapid burial, metamorphism and exhumation of high‐pressure metamorphic rocks. The west Tamar region in northern Tasmania lies at the boundary between eastern and western Tasmania. Here, rocks in the Port Sorell Formation were metamorphosed at high pressures (700–1400 MPa) and temperatures (400–500°C), indicating subduction to depths of up to 30 km. The eastern boundary of the Port Sorell Formation with mafic‐ultramafic rocks of the Andersons Creek Ultramafic Complex is hidden beneath allochthonous ?Mesoproterozoic turbidites of the Badger Head Group. At depth, this boundary coincides with the inferred boundary between eastern and western Tasmania, imaged in seismic data as a series of east‐dipping reflections. The Andersons Creek Ultramafic Complex was previously thought of as allochthonous, based mainly on associations with other mafic‐ultramafic complexes in western Tasmania. However, the base of the Andersons Creek Ultramafic Complex is not exposed and, given its position east of the boundary with western Tasmania, it is equally likely that it represents the exposed western edge of autochthonous eastern Tasmanian basement. A thin sliver of faulted and metamorphosed rock, including amphibolites, partially separates the Badger Head Group from the Andersons Creek Ultramafic Complex. Mafic rocks in this package match geochemically mafic rocks in the Port Sorell Formation. This match is consistent with two structural events in the Badger Head Group showing tectonic transport of the group from the west during Cambrian Delamerian orogenesis. Rather than being subducted, emplacement of the Badger Head Group onto the Andersons Creek Ultramafic Complex indicates accretion of the Badger Head Group onto eastern Tasmania. Subsequent folding and thrusting in the west Tamar region also accompanied Devonian Tabberabberan orogenesis. Reversal from northeast to southwest tectonic vergence saw imbricate thrusting of Proterozoic and Palaeozoic strata, possibly coinciding with reactivation of the suture separating eastern and western Tasmania.     

Hydrochemical and sedimentary responses of paired High Arctic watersheds to unusual climate and permafrost disturbance,Cape Bounty,Melville Island,Canada

High Arctic river responses to changing hydroclimatic and landscape processes are poorly understood. In non‐glacierized basins, snowmelt and rainfall generate river discharge, which provides first order control over fluxes. Further factors include the seasonality of precipitation, seasonal active layer development, and permafrost disturbance. These controls were evaluated in terms of sedimentary and biogeochemical fluxes from paired catchments at Cape Bounty, Melville Island, Nunavut during 2006–2009. Results indicate that the source of runoff can be more important than the amount of runoff for sediment, solutes, and organic yields. Although the snowmelt period is typically the most important time for these yields, heavy late summer precipitation events can create disproportionately large yields. Rainfall increases yields because it hydrologically connects areas otherwise isolated. Inorganic solute yields from late summer rainfall are higher because the thick active layer maximizes hydrologic interactions with mineral soils and generates high solute concentrations. Results also indicate that while the catchments are broadly similar, subtle topographic differences result in important inter‐catchment differences in runoff and suspended and dissolved loads. The East watershed, which had less extensive permafrost disturbance, consistently had higher concentrations of dissolved solids. These higher dissolved fluxes cannot therefore be explained by thermokarst features, but rather by deeper active layer development, due to a greater proportion of south‐facing slopes. Although warm temperatures in 2007 led to extensive active layer disturbance in the West watershed, because the disturbances were largely hydrologically disconnected, the total disturbed area was small, and inter‐annual variability in discharge was high, there was no detectable response in dissolved loads to disturbances. Sediment availability increased after 2007, but yields have largely returned to pre‐disturbance levels. Results indicate that seasonality and frequency‐magnitude characteristics of projected increases in precipitation must be considered along with active layer changes to predict the fluvial sedimentary and biogeochemical response to regional climate change. Copyright © 2011 John Wiley & Sons, Ltd.     

Geodynamically indicated targeting strategy for shale‐hosted massive sulfide Pb–Zn–Ag mineralisation in the Western Fold Belt,Mt Isa terrane

There is ongoing debate with respect to the genetic models for shale‐hosted massive sulfide Pb–Zn–Ag deposits contained in the Palaeoproterozoic to Mesoproterozoic intracontinental Isa Superbasin in the Western Fold Belt, Mt Isa terrane. Favourable sites of mineralisation can be predicted based on understanding the tectonic setting of the Isa Superbasin, the structural controls of mineralisation and the chemically favourable environments for ore deposition. Shale‐hosted massive sulfide Pb–Zn–Ag deposits are hosted in successions deposited during the dominant sag‐phase of the Isa Superbasin. These deposits are localised at the intersections of major basin‐scale extensional faults and are hosted in both shallow‐marine and deeper water carbonaceous shales that are characteristically anoxic and located near or at maximum flooding surfaces. All major shale‐hosted massive sulfide Pb–Zn–Ag deposits are located to the west of the Mt Isa Rift (ca 1710–1670 Ma). This spatial association is explained by an asymmetrical lithosphere extension model for the evolution of the Isa Superbasin. Elevated geothermal gradients at the location of maximum subcrustal lithospheric thinning to the west of the Mt Isa Rift may have driven the migration of basinal brines. Increased subsidence at this location produced favourable anoxic sedimentary horizons for metal precipitation during orebody formation.     

A tale of two synclines: Rifting,inversion and transpressional popouts at Lake Julius,northwestern Mt Isa terrane,Queensland

This study reviews the origin of two approximately east‐west‐trending synclines in the Lake Julius area at the eastern edge of the Leichhardt Rift. The genesis of one of these structures can be found in a north‐south shortening event (D₁) that occurred at the beginning of the compressional Isan Orogeny (at ca 1600 Ma). Metasediments in a cross‐rift were rammed against a competent buttress defined by the pre‐existing rift architecture, producing the approximately east‐west‐trending Somaia Syncline and its associated axial‐plane slaty cleavage. In contrast, the Lake Julius Syncline was produced by reorientation of an originally approximately north‐south‐trending (D₂) fold, in a transpressional zone adjacent to a strike‐slip fault, at the end of the Isan orogeny. The effects of late fault movement can be partially reconstructed, based on correlations assuming that regionally developed trains of upright folds formed during the peak of the Isan Orogeny (D₂). These folds have been offset, as well as having been tightened and disrupted at the same time as fault movements took place. The overall pattern of movement in the Lake Julius region can be explained as the result of an ‘indentor’ ramming into the ancient edge of the Leichhardt Rift, which acted as a buttress.     

利用二维活断层探测资料构建焦作地区浅层三维构造模型

运用专业地震解释及构造建模软件，综合利用焦作地区地震数据、钻孔数据、地质信息对活断层二维浅层地震剖面进行层位与断层解释，同时对断层平面组合与空间展布规律进行研究，实现地质资料与地震数据的有机结合，构建近地表Q₃地层底界面、Q地层底界面、N地层底界面分布模型和第四纪断层模型。以第四纪断层模型为基本骨架，以近地表地层分布为主要分层，模拟Q-Q₃地质体、N-Q地质体的构造形态和断层发育情况，系统反映近地表N地层底界面至Q₃地层底界面的空间结构特征。