Journal of African Earth Sciences (and the Middle East)最新文献_第3页

Landsat TM data processing for lithological discrimination in the Caraculo area (Namibe Province, SW Angola) Landsat TM数据处理在Caraculo地区(安哥拉西南部纳米贝省)岩性识别中的应用

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-10-01 DOI: 10.1016/0899-5362(93)90072-X

A. Alberti , V. Alessandro , U. Pieruccini , E. Pranzini

{"title":"Landsat TM data processing for lithological discrimination in the Caraculo area (Namibe Province, SW Angola)","authors":"A. Alberti , V. Alessandro , U. Pieruccini , E. Pranzini","doi":"10.1016/0899-5362(93)90072-X","DOIUrl":"10.1016/0899-5362(93)90072-X","url":null,"abstract":"<div>Landsat TM data were used for lithological discrimination and mapping in the little-known, semiarid 900 km2 area around Caraculo station and the middle course of the Rio Giraul (Namibe Province, SW Angola) following two main procedures. The first of these was based on visual evaluation of three-band composites, band-ratio composites and Principal Component Analysis. The second method relied on the extraction of spectral signatures, and their use to obtain automatic classifications. Satisfactory results were reached with the first procedure, thus allowing - with limited support of ground information — the draft of a lithological map, while the second method was not systematically efficient, even for confirmation of data acquired with the first procedure.Image interpretation suggests that an extensive but hithertoun differentiated metasedimentary complex consisting of a heterogeneous supracrustal sequence should be subdivided into at least two units. Field observations proved that one of these is marked by a notable frequency of marbles and the other is characterized by a widespread occurrence of amphibolitic bodies. Moreover, a belt of undetermined (thermally metamorphosed ?) metamorphic rocks is interposed between them.The distinction of so far unidentified units, though restricted to interpretation of processed Landsat TM data, has significant geological implications also in the regional context and will be helpful in guiding future work with conventional geological methods.</div>","PeriodicalId":100750,"journal":{"name":"Journal of African Earth Sciences (and the Middle East)","volume":"17 3","pages":"Pages 261-274"},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0899-5362(93)90072-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53886022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Combined gravity and aeromagnetic surveys of the Khulais basin of western Saudi Arabia 沙特阿拉伯西部Khulais盆地的重力和航磁联合测量

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-10-01 DOI: 10.1016/0899-5362(93)90080-A

K.E. Ibrahim, M.N. Al-Akhras, A.S. Bazuhair

引用次数: 3

Sequence stratigraphy and micropaleontology of the Triassic series from the southern part of Tunisia 突尼斯南部三叠系层序地层学与微古生物学

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-10-01 DOI: 10.1016/0899-5362(93)90074-Z

B. Peybernes , F. Kamoun , M. Ben Youssef , A. Trigui , M. Ghanmi , M. Zarbout , M. Frechengues

{"title":"Sequence stratigraphy and micropaleontology of the Triassic series from the southern part of Tunisia","authors":"B. Peybernes , F. Kamoun , M. Ben Youssef , A. Trigui , M. Ghanmi , M. Zarbout , M. Frechengues","doi":"10.1016/0899-5362(93)90074-Z","DOIUrl":"10.1016/0899-5362(93)90074-Z","url":null,"abstract":"<div>The Triassic series in the southern part of Tunisia, only known from the oil exploration wells in the Kirchaou area (sandy series from Early Scythian to Ladinian) and in its Djeffara/Dahar-North outcrops (alternating series from Ladinian to Rhaetian) is now subdivided into 10 Depositional Sequences (DS) sensu Vail et al. (1987), T1 to T10 corresponding approximately to most of the 3rd order eustatic cycle from the Haq et al. curve (1987). Within the DS succession, 3 basal discontinuities (or sequence boundaries) appear to be important in Tunisia: the base of T2, correlated to the “H Discordanz” from the “Germanic Triassic” (intrascythian); the base of T6 (intracarnian), well-marked by the Sidi Stout angular discordance from Dahar North; the base of T8 (intranoirian additional DS, previously recognized in Germany) pointed by the cartographic discordance of Low Stand conglomerates. The shallow-water facies from the carbonate Transgressive Systems Tracts of 7 Tunisian DS contain macrofauna, such as Myophoria, and particularly 6 successive benthonic Foraminifera assemblages, F1 to F6 giving chronostratigraphic informations as complement of Palynomorphs and Conodonts. Belonging to the genus Meandrospira, Triadodiscus, Aulotortus, Lamelliconus, Endothyranella, Pilamminella, Agathammina, Gandinella etc.…, most of them, commonly used as zone-indices in Europe, are new in Tunisia.</div>","PeriodicalId":100750,"journal":{"name":"Journal of African Earth Sciences (and the Middle East)","volume":"17 3","pages":"Pages 293-305"},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0899-5362(93)90074-Z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53886073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 23

Modelling of high overpressure in an off-shore Nigerian Basin: slant fault models with non-horizontal beds 尼日利亚近海盆地高超压模拟:带非水平层的倾斜断层模型

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-10-01 DOI: 10.1016/0899-5362(93)90075-2

O. Bour , I. Lerche , D. Grauls

{"title":"Modelling of high overpressure in an off-shore Nigerian Basin: slant fault models with non-horizontal beds","authors":"O. Bour , I. Lerche , D. Grauls","doi":"10.1016/0899-5362(93)90075-2","DOIUrl":"10.1016/0899-5362(93)90075-2","url":null,"abstract":"<div>The main feature of this young (9.5 Ma) off-shore Nigerian basin is rapid sedimentation of shales leading to very high overpressure development. The ratio of total fluid pressure to sedimentary load is estimated to be between about 0.9 to 0.95 at the bottom of well A, while the main tectonic activity appears to be gravitational, characterized by the development of growth faults. To model these conditions, where slant faults could have played an important role in the development of overpressure, a 2-D fluid-flow/ compaction model must reproduce the geometry of the basin according to the development of faults and in relation to their possible effects as pathways for fluid migration.For this reason, the 2-D model is designed to respect, as much as possible, the geometry of the system. A significant improvement over previous uses of the 2-D fluid-flow/compaction code is the ability to account for inclined layers around faults, instead of only horizontal layers. As a consequence, the basin geometry is much better reproduced. This improvement requires a fine grid of points and a fault throw less than the thickness of the smallest layer offset by the fault, so that no layer is “missing” at any position along the fault. The evolution of excess pressure or temperature with time, especially when fault occur, is consistent with results obtained synthetic tests and using flat layers around faults. Finally, the model reproduces correctly the measured fluid data. To obtain such overpressure, the fracturing must be higher than 0.9 to 0.95, as estimated by previous studies, and the faults cannot be always open.</div>","PeriodicalId":100750,"journal":{"name":"Journal of African Earth Sciences (and the Middle East)","volume":"17 3","pages":"Pages 307-321"},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0899-5362(93)90075-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53886150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Premières données géochronologiques sur le volcanisme alcalin du Jbel Saghro, Anti-Atlas, Maroc 摩洛哥反阿特拉斯Jbel Saghro碱性火山活动的首次地质年代学数据

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-10-01 DOI: 10.1016/0899-5362(93)90077-4

M. Berrahma , M. Delaloye , A. Faure-Muret , H.E.N. Rachdi

引用次数: 36

Origin and geochemistry of Egyptian granitoid rocks in Nuweiba area, eastern Sinai 西奈东部努韦巴地区埃及花岗质岩石成因及地球化学

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-10-01 DOI: 10.1016/0899-5362(93)90082-2

A.M. Ahmed , Y.A. El Sheshtawi , M.M. El Tokhi

{"title":"Origin and geochemistry of Egyptian granitoid rocks in Nuweiba area, eastern Sinai","authors":"A.M. Ahmed , Y.A. El Sheshtawi , M.M. El Tokhi","doi":"10.1016/0899-5362(93)90082-2","DOIUrl":"10.1016/0899-5362(93)90082-2","url":null,"abstract":"<div>Geological, petrological and geochemical studies indicate two distinct types of granitoid rocks: an older quartz diorite to granodiorite assemblage and younger granitoids, the latter occurring in two phases. The older granitoids have a calc-alkaline character, with high MgO, (FeO)t, TiO2 and P2O5 and low SiO2, K2O and Rb. Their major and trace elements compositions, together with a low 87Sr/86Sr (0.7029 ± 0.0008) denote I-type affinites. The second and third phase granitoids range from calc-alkaline to alkaline respectively. The second phase granitoids have a peraluminous chemistry and high Sr, Ba, CaO, MgO, Al2O3 and Ti2O, and low SiO2, K2O, Zr, Nb and Rb relative to the third phase granitoids. The corundum normative nature and field observations suggest that it was formed by partial melting of the lower crust (S-type). The third phase granitoids are characterized by high SiO2, Rb, Y, Zr and low MgO, CaO, Sr and Ba values than younger granitoid phase II. They show A-type granitoids which are generated from below or within existing continental crust.</div>","PeriodicalId":100750,"journal":{"name":"Journal of African Earth Sciences (and the Middle East)","volume":"17 3","pages":"Pages 399-413"},"PeriodicalIF":0.0,"publicationDate":"1993-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0899-5362(93)90082-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53886257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Gravity characteristics of the northern part of the Dahomeyides: continental aggregation-collision orogen and gravity smoothing in the Pan-African (600 ± 100 Ma) 达荷美底构造北段重力特征:泛非大陆聚集-碰撞造山带与重力平滑(600±100 Ma)

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-08-01 DOI: 10.1016/0899-5362(93)90036-P

M El-Hadj Tidjani , P Affaton , P Louis , A Lesquer , A Socohou , R Caby

引用次数: 6

Software survey section 软件调查组

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-08-01 DOI: 10.1016/0899-5362(93)90043-P

引用次数: 0

Géologie, pétrologie et géochimie des syénites de Ninakri : comparaison avec d'autres massifs syénitiques anorogéniques de Côte d'Ivoire et d'Afrique de l'Ouest 尼纳克里正长岩的地质、岩石学和地球化学:与科特迪瓦和西非其他造山正长岩地块的比较

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-08-01 DOI: 10.1016/0899-5362(93)90037-Q

B. Morel , M. Alinat

引用次数: 4

A sedimentological study of the preglacial Pleistocene QI palynozone of Sdom-2 borehole, Southern Dead Sea, Israel 以色列死海南部Sdom-2钻孔前冰期更新世QI孢粉带沉积学研究

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-08-01 DOI: 10.1016/0899-5362(93)90041-N

G. Weinberger

引用次数: 1