The Geologic Time Scale and the Italian stratigraphic record

The construction of the Geologic Time Scale (GTS) is a titanic scientific challenge that has been under way for two centuries and will require much dedicated effort in the future. Italy preserves a paramount stratigraphic record of Mesozoic and Cenozoic marine sediments that have been significant in the development of the modern GTS. The Italian stratigraphic record has been histori-cally important in introducing and defining the standard Chronostratigraphic Units (CUs) of the Neogene and Quaternary. Pelagic successions from Northern Apen-nines and Southern Alps have been used in the seventies for integrating the late Cretaceous-Paleogene Geomag-netic Polarity Time Scale (GPTS) with planktonic microfossil biostratieraohv and standard CUs. This was a major contribution to the construction of a new gener-ation of GTS based on integrated magnetobiochronol-ogy. The middle Miocene to early Pleistocene marinerecord from Sicily and southern Italy has been funda-mental for establishing the recently developed Astro-nomical Time Scale (ATS). In prospect, there are many potentials still to be exploited in the Italian marine stratigraphic record for implementing the GTS by defin-ing GSSPs of various CUs, improving magneto-biochronology and extending downwards the ATS.     

Mantle processes during ocean formation：Petrologic records in peridotites from the Alpine－Apennine ophiolites

Mantle peridotites were early exposed at the sea-floor of the Jurassic Tethys derived from the subcontinental mantle of the Europe-Adria system. During continental rifting and oceanic spreading, these lithospheric peri-dotites were percolated via diffuse reactive porous flowby melt fractions produced by near-fractional melting of the upwelling asthenosphere. Ascending melts inter-acted with the lower lithosphere, dissolving pyroxenes and precipitating olivine, and crystallized at shallower levels in the mantle column causing melt impregnation.Subsequent focused porous flow formed replacive dunitechannels, cutting the impregnated oeridotites, which were conduits for upward migration of MORB-type liq-uids. Melt migration produced depletionlrefertilization and significant heating of the percolatedlimpregnated mantle, i.e the thermochemical erosion of the litho-sphere. Impregnated and thermally modified lithos-pheric mantle was cooled by conductive heat loss dur-ing progressive lithosphere thinning and was intrudeaby MORB magmas, which formed Mg-rich and Fe-richgabbroic dykes and bodies. Alpine-Apennine ophiolitic peridotites record the deep-seated migration of melts which changed their compositions and dynamics during the rift evolution. The thermochemical erosion of the lithospheric mantle by the ascending asthenospheric melts, which induces significant compositional and rhe-ological changes in the lower lithosphere, is a major process in the evolution of the continent-ocean transi-tion towards a slow spreading oceanic system.     

塔上无人提引器的应用

塔上无人提引器,在60年代已被广泛使用,但由于经常发生“跑管”事故,故许多地质队没有继续使用。1987年,我队在绳索取心钻进工作中,使用塔上无人爬杆斜脱式提引器,5年中完成钻探工作量12363.63m,基本上消除了因提引器而造成的事故。所用钻机为THJ-500型或XU-1000型;钻塔为14.5m角铁斜塔;钻具为φ75或φ59绳     

九脊游仆虫(Euplotes novemcarinata Wang,1930)的纤毛下器与银线系研究(纤毛动物门,腹毛目)

九脊游仆虫(Euplotes novemcarinata Wang、1930)是土壤及淡水中生活的原生动物。本文对其重要的分类特征诸如银线系及纤毛下器做了形态学研究,确认了其分类地位,并比较了国外迄今的研究工作,在此基础上,将同物异名苔藓游仆虫(E.muscicolaKahl、1932)作了归并。     

一种新的温度记录器

本文提出一个以带有定时器的低功耗微处理机为主体的温度记录器。其定时器用于开动微处理机,可由一个开关定为0.5、1、3或30分钟。仪器通过处理一个电容器向热敏电阻放电的时间来测量温度。仪器在工作中能显示温度值,并把温度值保存在微处理机的RAM之中。总共资料容量为2816次测值,量程为0～35℃,精度±0.1℃,分辨±0.02℃。 温度记录器具有液晶显示器,可直接读出温度值,配有标准计算机接口RS-232,能把保存的资料方便地倒给个人计算机。 这项工作是伍兹霍尔海洋研究所A.Bradley博士指导的。他提出的原理对研制可靠而廉价的温度记录器是一条新的途径。     

LZY1—1型光电浊度仪

本文介绍了LZY_(1-1)型光电浊度仪的设计原理,标定方法及使用结果,该仪器用经典法校准后,能快速测量大批量样品的悬浮物含量。     

高能潮道中的灰泥层——风暴沉积的记录

1992年8月23—24日，安德鲁飓风经过了美国大巴哈马滩北部的两个典型的鲕沉积地区(catcay和Joulfefscay)．在风暴后7个星期，观察到在风暴中沉积于高能潮道(4m深)中的碳酸盐灰泥纹层已经暴露在水下鲕丘的丘槽中，