Registration of terrestrial laser scanner data using imagery     

Khalil  Al-Manasir  Clive S.  Fraser 《The Photogrammetric Record》2006,21(115):255-268

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Petrology and geochronology of basalt breccia from the 1996 earthquake swarm of Loihi seamount, Hawaii: magmatic history of its 1996 eruption     

Michael O. Garcia  Ken H. Rubin  Marc D. Norman  J. Michael Rhodes  David W. Graham  David W. Muenow  Khalil Spencer 《Bulletin of Volcanology》1998,59(8):577-592

 Samples of basalt were collected during the Rapid Response cruise to Loihi seamount from a breccia that was probably created by the July to August 1996 Loihi earthquake swarm, the largest swarm ever recorded from a Hawaiian volcano. ²¹⁰Po–²¹⁰Pb dating of two fresh lava blocks from this breccia indicates that they were erupted during the first half of 1996, making this the first documented historical eruption of Loihi. Sonobuoys deployed during the August 1996 cruise recorded popping noises north of the breccia site, indicating that the eruption may have been continuing during the swarm. All of the breccia lava fragments are tholeiitic, like the vast majority of Loihi's most recent lavas. Reverse zoning at the rim of clinopyroxene phenocrysts, and the presence of two chemically distinct olivine phenocryst populations, indicate that the magma for the lavas was mixed just prior to eruption. The trace element geochemistry of these lavas indicates there has been a reversal in Loihi's temporal geochemical trend. Although the new Loihi lavas are similar isotopically and geochemically to recent Kilauea lavas and the mantle conduits for these two volcanoes appear to converge at depth, distinct trace element ratios for their recent lavas preclude common parental magmas for these two active volcanoes. The mineralogy of Loihi's recent tholeiitic lavas signify that they crystallized at moderate depths (∼8–9 km) within the volcano, which is approximately 1 km below the hypocenters for earthquakes from the 1996 swarm. Taken together, the petrological and seismic evidence indicates that Loihi's current magma chamber is considerably deeper than the shallow magma chamber (∼3–4 km) in the adjoining active shield volcanoes. Received: 21 August 1997 / Accepted: 15 February 1998  相似文献   

Comments on ‘the influence of geostrophic shear on the cross-isobar angle of the surface wind’     

Arya  S. P. S. 《Boundary-Layer Meteorology》1975,8(2):239-242

Boundary-Layer Meteorology -  相似文献   

Eustatic and tectonic controls on Quaternary Ras Leona marine terraces (Strait of Gibraltar, northern Morocco)     

Khalil El Kadiri  Antonio Pedrera  Ramón Julià 《Quaternary Research》2010,74(2):277-113

Well-preserved Quaternary staircased marine terraces appear on Ras Leona limestone relief. This is a peculiar sector of the Betic-Rif Cordillera, lying in the four-way junction between the Atlantic and the Mediterranean, and Europe and Africa. The age and altitude correlation of the Ras Leona terraces with travertine-covered lateral equivalent terraces fashioned in the neighbouring Beni Younech area, and comparison with those along the Moroccan Atlantic coasts, would suggest that the Ras Leona terraces were mainly formed by eustatic factors. The importance of the eustasy is supported by further comparisons with Spanish and Moroccan Mediterranean terraces and with different marine terraces developed on passive-margin coasts around the world. A tectonic event occurred mainly during the period between the formation of the Maarifian and the Ouljian terraces (i.e., between 370 and 150 ka). The moderate Quaternary tectonic uplift deduced from the marine terraces and its comparison with uplifted marine terraces developed in active subduction setting disagrees with the model of an active eastwards subduction below the Gibraltar tectonic arc.  相似文献   

Estimation of aquifer hydraulic parameters from surface geophysical measurements: a case study of the Upper Cretaceous aquifer, central Sinai, Egypt     

Usama Massoud  Fernando Santos  Mohamed A. Khalil  Ayman Taha  Abbas M. Abbas 《Hydrogeology Journal》2010,18(3):699-710

The integration of geophysical data with direct hydrogeological measurements can provide a minimally invasive approach to characterize the subsurface at a variety of resolutions and over many spatial scales. The field of hydrogeophysics has attracted much attention during the last two decades. In this domain, the geophysical data inverted to geophysical models are interpreted in terms of the hydrogeology to serve as a basis for the definition of hydraulic models in the areas of interest. The hydraulic conductivity (K) value measured in a reference borehole has been combined with the electrical conductivity obtained from nearby geo-electromagnetic sounding data in the Cenomanian (Upper Cretaceous) aquifer, central Sinai, Egypt. The resulting relation was interpreted with Dar Zarrouk parameters to infer the transmissivity variations at other vertical electrical sounding locations, where K values are unknown. Coincident transient electromagnetic data have been adopted to increase accuracy while interpreting the aquifer geoelectrical properties. The results indicate that the transmissivity values in the aquifer of interest vary from 2,446 to 9,694 m²/day, and K varies from 12.9 to 57.0 m/day throughout the studied area.  相似文献   

Investigating the igneous petrogenesis of Martian volcanic rocks using augite quantitative textural analysis of the Yamato nakhlites     

Sammy Griffin  Arya Udry  Luke Daly  Lucy Victoria Forman  Martin R. Lee  Benjamin E. Cohen 《Meteoritics & planetary science》2023,58(1):63-84

To better understand volcanism on planetary bodies other than the Earth, the quantification of physical processes is needed. Here, the petrogenesis of the achondrite Martian Yamato (Y) nakhlites (Y 000593, Y 000749, and Y 000802) is reinvestigated via quantitative analysis of augite (high-Ca clinopyroxene) phenocrysts: crystal size distribution (CSD), spatial distribution patterns (SDP), and electron backscatter diffraction (EBSD). Results from CSD and EBSD quantitative data sets show augite to have continuous uninterrupted growth resulting in calculated minimum magma chamber residence times of either 88–117 ± 6 yr or 9–12 yr. All samples exhibit low-intensity S-LS type crystallographic preferred orientation. Directional strain is observed across all samples with intracrystalline misorientation patterns indicative of (100)[001]:(001)[100] (Y 000593 and Y 000802) and {110}<001>or {110}¹/₂<110> (Y 000749) slip systems. SDP results indicate phenocryst-bearing crystal-clustered rock signatures. Combined findings from this work show that the Yamato nakhlites formed on Mars as individual low-viscosity lava flows or sills. This study shows that through combining these different quantitative techniques over multiple samples, one can more effectively compare and interpret resulting data to gain a more robust, geologically contextualized petrogenetic understanding of the rock suite being studied. The techniques used in this study should be equally applicable to igneous achondrites from other parent bodies.  相似文献   

Potential use of faujasite–phillipsite and phillipsite–chabazite tuff in purification of treated effluent from domestic wastewater treatment plants     

Reyad A. Al Dwairi  Khalil M. Ibrahim  Hani N. Khoury 《Environmental Earth Sciences》2014,71(12):5071-5078

Characterization of zeolitic tuff from Jabal Hannoun (HN) and Mukawir (MR) was carried out to examine the ability of using low-cost natural materials in domestic wastewater treatment. The grain size between 0.3 and 1 mm (0.3–1 mm) of the HN and MR has the highest total zeolite grade (faujasite–phillipsite and phillipsite–chabazite) and suitable cation exchange capacity. They were used as fixed-bed ion exchangers and adsorbents. The zeolitic tuff efficiently removed the organic and nitrogen compounds, Pb and Zn from the effluent. One bed volume (1 BV) of the zeolitic tuff is capable to remove up to 95 % of total organic carbon form 500 BV of the effluent. The removal percent of total nitrogen by HN and MR is close to 95 and 90 %, respectively. The zeolitic tuff has an excellent efficiency to remove Pb and Zn from the effluent. 1 BV of HN completely cleans Zn and Pb from 680 and 730 BV of the effluent, respectively, whereas 1 BV of MR is able to clean completely Zn and Pb from 500 and 685 BV of the effluent, respectively. The greater performance of the HN compared with the MR may be explained by its higher zeolites grade and presence of faujasite.  相似文献   

Nitrate contamination in irrigation groundwater,Isfahan, Iran   总被引：1，自引：1，他引：0  

Ali Esmaeili  Farid Moore  Behnam Keshavarzi 《Environmental Earth Sciences》2014,72(7):2511-2522

Groundwater is one of the major sources of water in Isfahan. Efficient management of these resources requires a good understanding of its status. This paper focuses on the hydrochemistry and also it wants to assess the nitrate concentration in irrigation groundwater of Isfahan suburb. All the groundwater samples are grouped into three categories, including Na-Cl + Ca-Cl (63 %), Na-SO₄ + Ca-SO₄ (23 %) and Ca-HCO₃ (14 %). According to the EC and SAR, the most dominant classes are C3S1, C4S2 and C4S3. 55 % of samples indicate very high salinity and medium to very high alkalinity that is not suitable for irrigation. 84 % of the groundwater samples show nitrate contents higher than HAV (13 mg l^?), while more than 25 % exceeded the maximum contamination level (44.27 mg l^?) according to EPA regulations. The horizontal and vertical distribution patterns of nitrate in groundwater samples show a surficial origin for nitrate contamination. The high nitrate content can be attributed to the agricultural activities along with domestic sewage and industrial wastewaters in populated area. Based on results, using high nitrate groundwater for irrigation can minimize the requirement for inorganic fertilizers and reduce the cost of cultivation and nitrate contamination.  相似文献   

Radiolarian biochronology of Mesozoic deep-water successions in NW Syria and Cyprus: implications for south-Tethyan evolution     

Khalil K. Al-Riyami  Taniel Danelian  Alastair H. F. Robertson 《地学学报》2002,14(4):271-280

ABSTRACT New radiolarian biostratigraphical data have shed light on the Mesozoic tectonic evolution of South-Tethys in the Baer–Bassit region of NW Syria. Radiolarian assemblages of Late Triassic, Middle Jurassic and Early Cretaceous age were extracted from radiolarites in five measured sections. The results are compared with published radiolarian ages from the Mamonia Complex, western Cyprus. These two areas are interpreted as preserved fragments of the conjugate margins of a small South Tethyan oceanic basin formed by Triassic rifting. In the southerly (i.e. Arabian) margin, proximal successions were dominated by shallow-water-derived carbonate, whereas distal successions reveal seamount-type alkaline/peralkaline volcanism, dated as both Late Triassic and Middle Jurassic–Early Cretaceous. Along the inferred northern margin (i.e. western Cyprus) proximal successions are dominantly terrigenous, whereas distal settings include Late Triassic oceanic crust and seamount-type lavas.  相似文献   

巴基斯坦山达克矿区ASTER遥感数据蚀变信息提取及找矿预测     

刘磊  蒲小楠  洪俊  张辉善  YASIR Shaheen Khalil 《地质论评》2022,68(5):2022092008-2022092008

巴基斯坦查盖火山岩浆岩带属于特提斯成矿域的重要组成部分之一,是巴基斯坦境内最重要的斑岩型铜矿带,但目前其相关的遥感研究还较少,制约了对该成矿带的找矿潜力分析。本文以山达克矿床及其周边为研究区,对先进星载热辐射与反射辐射计(Advanced Spaceborne Thermal Emission and Reflection Radiometer, ASTER)数据进行RBD (Relative absorption band depth)比值假彩色合成、主成分分析、光谱角制图等处理,获得蚀变遥感异常信息分布特征,通过对蚀变特征和主要控矿要素进行遥感研究,建立了山达克矿床遥感找矿模型并开展成矿预测,为该成矿带矿产勘查提供借鉴。根据建立的遥感找矿模型,圈定了找矿预测靶区10处。对矿区东矿体和矿区北部的2个靶区进行野外验证,证实了提取结果与实际地质事实吻合较好,对矿区岩石样品进行光谱实测,表明样品实测光谱曲线与标准矿物光谱曲线的吸收特征位置高度相似,证实了研究区绢云母化、青磐岩化等蚀变较强且分布较广。结果表明本次研究提取的矿化蚀变结果可信度较高,可为后续找矿勘查工作提供参考。  相似文献