扬子克拉通古大陆边缘Mo同位素特征及对有机埋藏量的指示意义   总被引：5，自引：0，他引：5  

周炼  周红兵  李茉  王峰 《地球科学》2007,32(6):759-766

通过对扬子克拉通古大陆边缘不同时期沉积岩的Mo同位素进行测定,结合Mo微量元素组成,对古大陆边缘Mo的自生作用规律进行了研究,并根据Mo丰度对原始有机碳堆积速率进行了计算.结果表明,其原始有机碳堆积速率在0.17～0.67mmol/m2/day之间.利用已建立的现代大陆边缘δ98Mo与有机碳埋藏速率模型,对该区不同时期沉积岩的有机碳埋藏速率进行恢复.结果表明,扬子克拉通显生宙不同时期沉积岩的有机碳埋藏速率有较大的变化范围(0.43～2.87mmol/m2/day),并与原始有机碳堆积速率具有明显的相关性,因此,δ98Mo有可能成为评价有效烃源岩的潜在指标.  相似文献   

Structure and components for the emergency response and warning system on Turtle Mountain,Alberta, Canada   总被引：1，自引：0，他引：1  

Corey R. Froese  Francisco Moreno 《Natural Hazards》2014,70(3):1689-1712

Since 2003, a series of over eighty sensors has been installed at Turtle Mountain, site of the 1903 Frank Slide. The purpose of these instruments is to both characterize and provide warning for a second large rock avalanche from the eastern face of the mountain, where various unstable masses have been identified. Although studies continue on the mountain to better understand the deformation patterns and interpretations of the slope kinematics, significant effort has been expended to develop a structure for the warning and emergency response that clearly outlines not only responsibilities and communications protocols during an emergency, but also day-to-day operational responses and procedures to ensure that the system remains operational. From a day-to-day operational perspective, a systematic and repeatable set of procedures is required in order to ensure that not only are data trends reviewed and reported on, but scheduled checks of system functionality are undertaken. An internal Roles and Responsibilities Manual has been developed to clearly outline responsibilities for geoengineering, information technology (IT), and management staff to ensure that system checks are completed and that support is in place on a 24/7 basis should components of the system cease to operate properly or should unacceptable deformations require review. In addition to that, a clear and concise troubleshooting manual has been developed. This document provides simple diagnoses of problems within the system and a clear roadmap of how to fix each component. From a warning and emergency response perspective, a series of color-coded alert conditions has been developed should unacceptable deformations be observed. At each alert level, clear responsibilities for actions and communications have been identified for geoengineering staff, provincial emergency management authorities, municipal officials, and first responders. This has been documented in the emergency response protocol. All documents described here are “living” documents that are updated on a regular basis as changes to the system are made. An annual mock warning exercise has been developed and run in order to test responses to a hypothetical emergency and generate updates to the system documentation.  相似文献   

Late prehistoric soil fertility,irrigation management,and agricultural production in northwest coastal Peru     

Lee Nordt  Frances Hayashida  Tom Hallmark  Corey Crawford 《Geoarchaeology》2004,19(1):21-46

The Pampa de Chaparrí (Pampa) in hyperarid northwest coastal Peru is an ideal area to study late prehispanic agricultural technology and production because irrigation canals and furrowed fields have been preserved since abandonment approximately 500 years ago. We collected 55 samples for soil characterization, fertility, and micromorphic analyses and compared these results to a noncultivated control soil previously sampled in an adjacent valley. Natural soil fertility levels for maize, cotton, and bean production were generally high during late prehispanic cultivation in the Pampa. Maintaining adequate nitrogren levels for production, however, would have required external inputs from livestock manure, guano, or leguminous plants. The management of low soil salinity levels was possible because of rapidly permeable soils and irrigation waters low in salt. Based on available water capacity and climate conditions, the Blaney‐Criddle Equation yields evapotranspiration rates indicating that irrigation frequency was necessary in a range of every 10–16 days during the growing season. © 2004 Wiley Periodicals, Inc.  相似文献