在联邦调查局卷宗案例中,档案工作者知道美国之友服务委员会诉讼威廉·H·瓦伯斯特(William H Webster)等人的案件,这一案件反映了与所有档案工作者有关的档案鉴定理论的难题。本文作者记叙了这个案例的经过,并对有关档案鉴定...在联邦调查局卷宗案例中,档案工作者知道美国之友服务委员会诉讼威廉·H·瓦伯斯特(William H Webster)等人的案件,这一案件反映了与所有档案工作者有关的档案鉴定理论的难题。本文作者记叙了这个案例的经过,并对有关档案鉴定的文章作出评价,着重阐述了此案是如何说明在考虑公众的信息需要之前优先考虑政府的凭证需要的鉴定理论,及对之加以重新评价的必要。展开更多
Present-day hot spots and Phanerozoic large igneous provinces(LIPs) and kimberlites mainly occur at the edges of the projections of Large Low Shear Wave Velocity Provinces(LLSVPs) on the earth's surface. If a plat...Present-day hot spots and Phanerozoic large igneous provinces(LIPs) and kimberlites mainly occur at the edges of the projections of Large Low Shear Wave Velocity Provinces(LLSVPs) on the earth's surface. If a plate contains accurately dated LIPs or kimberlites, it is possible to obtain the absolute paleoposition of the plate from the LIP/kimberlite and paleomagnetic data. The presence of Middle Ordovician kimberlites in the North China Block provides an opportunity to determine the absolute paleoposition of the block during the Middle Ordovician. In addition to paleobiogeographical information and the results of previous work on global plate reconstruction for the Ordovician Period, we selected published paleomagnetic data for the North China Block during the Middle Ordovician and determined the most reasonable absolute paleoposition of the North China Block during the Middle Ordovician: paleolatitude of approximately 16.6°S to 19.1°S and paleolongitude of approximately 10°W. The block was located between the Siberian Plate and Gondwana, close to the Siberian Plate. During the Cambrian and Ordovician periods, the North China Block may have moved toward the Siberian Plate and away from the Australian Plate.展开更多
文摘在联邦调查局卷宗案例中,档案工作者知道美国之友服务委员会诉讼威廉·H·瓦伯斯特(William H Webster)等人的案件,这一案件反映了与所有档案工作者有关的档案鉴定理论的难题。本文作者记叙了这个案例的经过,并对有关档案鉴定的文章作出评价,着重阐述了此案是如何说明在考虑公众的信息需要之前优先考虑政府的凭证需要的鉴定理论,及对之加以重新评价的必要。
基金the National Basic Research Program of China (Grant No. 2009CB219302)
文摘Present-day hot spots and Phanerozoic large igneous provinces(LIPs) and kimberlites mainly occur at the edges of the projections of Large Low Shear Wave Velocity Provinces(LLSVPs) on the earth's surface. If a plate contains accurately dated LIPs or kimberlites, it is possible to obtain the absolute paleoposition of the plate from the LIP/kimberlite and paleomagnetic data. The presence of Middle Ordovician kimberlites in the North China Block provides an opportunity to determine the absolute paleoposition of the block during the Middle Ordovician. In addition to paleobiogeographical information and the results of previous work on global plate reconstruction for the Ordovician Period, we selected published paleomagnetic data for the North China Block during the Middle Ordovician and determined the most reasonable absolute paleoposition of the North China Block during the Middle Ordovician: paleolatitude of approximately 16.6°S to 19.1°S and paleolongitude of approximately 10°W. The block was located between the Siberian Plate and Gondwana, close to the Siberian Plate. During the Cambrian and Ordovician periods, the North China Block may have moved toward the Siberian Plate and away from the Australian Plate.
