首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到7条相似文献,搜索用时 0 毫秒
1.
The hypothesis that basinal brines inherited their major ion chemistries and elevated salinities from evaporated paleoseawaters is tested by comparing the compositions of basinal brines in Silurian (Michigan basin, Illinois basin, Appalachian basin in eastern Ohio) and Jurassic/Cretaceous (Central Mississippi Salt Dome basin, Arkansas shelf, and south‐central Texas) host rocks, when the world oceans were ‘CaCl2 seas’, with those from Permian and Pennsylvanian rocks (Palo Duro basin, Central Basin Platform, and Delaware basin, Texas and New Mexico) when the world oceans were ‘MgSO4 seas’. Basinal brines examined are assumed to have originally formed from evaporation of the same seawaters that produced major evaporites. Sulfate, Mg and K levels in basinal brines are below the concentrations expected from evaporation of seawater of any type, which emphasizes the importance of diagenetic mineral–brine interactions in controlling basinal brine chemistry. There are no major differences in SO4, Mg and K concentrations between basinal brines hosted by rocks originally formed during ages when the world oceans were MgSO4 seas versus CaCl2 seas. Basinal brines in Pennsylvanian–Permian rocks are compositionally distinct (relatively high Na and low Ca) from basinal brines in Silurian, Jurassic and Cretaceous host rocks, which may reflect original differences in seawater chemistry. Basinal brines enriched in Ca and depleted in Na relative to evaporated seawater of any type have traditionally been interpreted to form by albitization of plagioclase feldspar. A new explanation for Ca enrichment and Na depletion of basinal brines is the mixing of evaporated CaCl2‐type seawater with more dilute water. Some basinal brines are similar in major ion composition to evaporated seawater of a particular age, for example basinal brines in the Cretaceous Edwards Group carbonates, Texas, where dolomitization is the only reaction required to convert evaporated Mesozoic CaCl2 seawater into Edwards Group brine.  相似文献   

2.
A common assumption in Near Eastern tell archaeology is that the majority of sediments originate from degraded mud bricks. Little is known about the mechanism of mud brick wall degradation. Here we present a detailed macro- and microscopic ethnoarchaeological study of the degradation of a mud brick house and propose a comprehensive mechanism for tell formation processes in arid environments. The study took place in southern Israel by trenching a ca. 60 year old abandoned mud brick house, followed by extensive sediment sampling. Macroscopic observations showed that mud brick walls degrade by collapse of single bricks and/or collapse of intact wall parts, either inwards or outwards. In addition, infill sediments within the house and outside it, in close proximity to its walls, form alternating sedimentary layers of various colors and textures. The degraded mud brick material lost its distinctive macroscopic structure, which makes it impossible to accurately identify this material by field observations alone. Mineralogical and elemental analyses established the sources of the house infill sediments, namely mud bricks and wind blown sediments. Alternating layers mostly originate from mixing between degraded mud brick material and wind blown sediments. Micromorphological observations revealed microscopic mechanisms of mud brick degradation and include processes of mud slurry gravity flows, sediment coatings and infillings, wind abrasion of walls, small-scale puddling, and bioturbation. This study provides a working scheme for site formation of abandoned mud brick structures in arid environments. It provides a set of criteria by which it is possible to differentiate floors from post-abandonment sedimentary features and thus improves the reliability of activity area research.  相似文献   

3.
This paper discusses the historical use of music to produce more efficient, more committed, industrial workers. First emerging in academia early in the twentieth century, psychological interest in the industrial application of music had grown into a topic of popular interest and government investigation by the 1940s. Catalysed by the need for vast increases in production and the desire to cultivate ‘citizenship’ amongst industrial workers which the Second World War produced, consideration of how music could be employed as an affective soundtrack in factories—to raise employees' work rates, to increase their efficiency, to combat fatigue and boredom, to improve morale, to access and manipulate their emotions and loyalties—became a prominent area of psychological research. This paper examines that psychological research and its largest scale application in the BBC radio show Music While You Work, broadcast daily to millions of British factory workers from 1940 until 1967. The paper focuses particularly on conceptualizations of music's affective power and its utilization to exert ‘emotional control’ over spaces of work and the working self. This paper is centrally concerned with the practice of Music While You Work as a programme broadcasting specifically for factory spaces, and how this confronted the BBC's music policies for a national and domestic audience, impacting on the radical nature of the affective soundtrack to work which was produced.  相似文献   

4.
The author explores the reasons for the failure of a plan for population exchanges that took place between Jews and Arabs in Palestine in the 1930s. Special focus is given to the success of previous exchanges between Greece and Turkey that took place during the 1920s and why this model failed in Palestine. The author concludes that "the Zionist plans which assumed that one could encourage voluntary transfer by creating attractive economic conditions in the target areas, did not take into account the factors of nationalism, ties to place of residence, religion, etc. These factors carried no less weight than the economic factor and they could effectively prevent any voluntary transfer of the Arab population."  相似文献   

5.
6.
The determination of groundstone tool sources bears the potential to examine aspects like raw material selection and preference, mobility, trade and exchange patterns, control over resources and long term use of raw material sources. The discovery of the Neolithic/Chalcolithic basanite bifacial quarry of Giv'at Kipod in the Jezreel Valley, Israel, provides the opportunity of raw material centred provenance studies of bifacials in the southern Levant. The basis for reliable provenance analyses is a clear geochemical characterization of the extraction site and its discrimination from other potential sources. To achieve this, the Miocene magmatic rocks of the Jezreel Valley were sampled and analysed by XRF and La-ICP-MS. The geochemical evaluation, combined with cluster analyses, resulted in a clear discrimination of the Giv'at Kipod lava from other basaltic sources in the area. Based on the geochemical field data, a Giv'at Kipod provenance for six bifacial tools found in three archaeological sites dated to the Neolithic and the Chalcolithic periods was established. The results suggest that the quarry was in use for several millennia. This pilot study demonstrates that for provenance analyses lava outcrops in the southern Levant can be geochemically discriminated from each other on a very small spatial scale, on the basis of a detailed field sampling and the application of multivariate methods.  相似文献   

7.
Numerous local, regional and family historians in the nineteenthand early twentieth century collected oral narrations and conductedinterviews as a form to document information that otherwisemight have never been preserved. Family historians, in particular,not only practiced interviewing relatives for family histories,but also encouraged the practice in how-to-do manuals amongtheir peers. While advocating the practice, family historiansalso reflected about the value of "traditionary evidence" collectedthrough interviews and other means. These reflections by familyhistorians mirrored the discussions about the value of traditionsand memories as historical sources among several professionalhistorians at the time. These reflections were shaped by a modernizedunderstanding of tradition, which combined a reverential approachto the authoritarian element of tradition with a critical approachquestioning the validity of tradition. In this context, oralhistory was both a tool to negotiate the value of traditionand a mirror to the contemporary understanding of tradition.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号