Journal of African Earth Sciences (and the Middle East)最新文献_第7页

Rare earth elements in rift-hosted ferromanganese nodules, Malawi, Central Africa 中非马拉维裂谷型锰铁结核中的稀土元素

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-05-01 DOI: 10.1016/0899-5362(93)90108-3

T.M. Williams

引用次数: 2

Editorial: Software survey section 编辑:软件调查部分

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-05-01 DOI: 10.1016/0899-5362(93)90111-3

引用次数: 0

Un exemple de volcanisme du Protérozoïque inférieur en Côte d'Ivoire: zone de subduction ou zone de cisaillement? 科特迪瓦下元古代火山活动的一个例子:俯冲带还是剪切带?

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-05-01 DOI: 10.1016/0899-5362(93)90102-V

Koffi Ble Pothin

引用次数: 7

Planktonic foraminifera and chronostratigraphy of the Oligo-Miocene in some wells in the isthmus of Suez and the North-Eastern reach of the Nile Delta, Egypt 埃及苏伊士地峡和尼罗河三角洲东北段部分井的浮游有孔虫和渐新世至中新世的年代地层

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-05-01 DOI: 10.1016/0899-5362(93)90107-2

O.H. Cherif , H. El-Sheikh , S. Mohamed

{"title":"Planktonic foraminifera and chronostratigraphy of the Oligo-Miocene in some wells in the isthmus of Suez and the North-Eastern reach of the Nile Delta, Egypt","authors":"O.H. Cherif , H. El-Sheikh , S. Mohamed","doi":"10.1016/0899-5362(93)90107-2","DOIUrl":"10.1016/0899-5362(93)90107-2","url":null,"abstract":"<div><p>The lithofacies and planktic foraminiferal content of the Oligo-Miocene interval penetrated by four wells (El-Temsah-2, Boughaz-1, Mallaha-1X and San El-Hagar-1) drilled in the Isthmus of Suez and in the eastern reach of the Nile Delta enable to clarify the chronostratigraphy and sedimentological and tectonic history of the studied sequence.</p><p>The Oligocene is represented by the Qantara Formation which is conformably overlain by the Aquitanian-Burdigalian (early Miocene) Rudeis Formation. The early Miocene is separated from the middle Miocene (Langhian-early Serravallian Kareem Formation) by a hiatus, probably reflecting the mid-Clysmic tectonic event that affected the Gulf of Suez region.</p><p>A stratigraphic gap between the early and late Serravallian Kareem and Serravallian to Tortonian Sidi Salim Formations may have been caused by the uplift of the isthmus of Suez which induced the beginning of evaporite sedimentation in restricted basins in the southern part of the Gulf of Suez. The Messinian is either represented by a regressive sequence of coarse siliciclastics known as the Qawasim Formation or by evaporites.</p></div>","PeriodicalId":100750,"journal":{"name":"Journal of African Earth Sciences (and the Middle East)","volume":"16 4","pages":"Pages 499-511"},"PeriodicalIF":0.0,"publicationDate":"1993-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0899-5362(93)90107-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53886405","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: 11

The geology of Libya 利比亚的地质情况

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-05-01 DOI: 10.1016/0899-5362(93)90110-C

J.R. Vail

引用次数: 1

First heat flow density determinations from Southeastern Zaïre (Central Africa) 来自东南部Zaïre(中非)的首次热流密度测定

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-05-01 DOI: 10.1016/0899-5362(93)90100-5

M.N. Sebagenzi , G. Vasseur , P. Louis

引用次数: 16

The mineralogy and geochemistry of some cassiterite from the Younger Granite province of the Jos Plateau, Nigeria 尼日利亚乔斯高原新花岗岩省一些锡石的矿物学和地球化学特征

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-05-01 DOI: 10.1016/0899-5362(93)90104-X

M.I. Ogunbajo

引用次数: 0

Implications of whole-rock PbPb and zircon evaporation dates for the early metamorphic history of the Kasaï craton, Southern Zaïre 全岩Pb()和锆石蒸发日期对南部Kasaï克拉通早期变质史的意义Zaïre

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-05-01 DOI: 10.1016/0899-5362(93)90098-B

F. Walraven , B.T. Rumvegeri

{"title":"Implications of whole-rock PbPb and zircon evaporation dates for the early metamorphic history of the Kasaï craton, Southern Zaïre","authors":"F. Walraven , B.T. Rumvegeri","doi":"10.1016/0899-5362(93)90098-B","DOIUrl":"10.1016/0899-5362(93)90098-B","url":null,"abstract":"<div><p>A whole-rock PbPb date of 3021 + 47–49 Ma, found for granodioritic granitoid occurring within biotite gneiss in the Sandoa-Kapanga region of the Kasaï Craton, southern Zaïre, in reflected in single zircon evaporation data (centered around 3014 ± 2.3 Ma) obtained from the biotite gneiss itself. Other zircon evaporation dates found in the biotite gneiss range from <em>ca.</em> 3.0 Ga to 3.09 Ga and are interpreted as minimum ages of discordant zircon phases overprinted during one or more metamorphic events. Anomalously high Pb initial ratios characterise the granitoid and consequently its <em>ca.</em> 3.02 Ga age, taken together with the corresponding zircon date, is considered to reflect a metamorphic event during which anatectic melting took place to produce the granodioritic magma. During the same event, overgrowths formed on older zircon cores. The <em>ca.</em> 3.02 Ga date is the oldest yet recognised in the southern Kasaï Craton and a correlation is suggested with the D<sub>2</sub> metamorphic event of this region. Additionally a prehistory back to at least 3.09 Ga is indicated by the other zircon dates in the biotite gneiss.</p></div>","PeriodicalId":100750,"journal":{"name":"Journal of African Earth Sciences (and the Middle East)","volume":"16 4","pages":"Pages 395-404"},"PeriodicalIF":0.0,"publicationDate":"1993-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0899-5362(93)90098-B","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53886289","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: 25

An overview of carbonate-hosted mineral deposits in the Otavi Mountain Land, Namibia: implications for ore genesis 纳米比亚奥塔维山地碳酸盐岩矿床概述:对矿石成因的影响

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-04-01 DOI: 10.1016/0899-5362(93)90048-U

F. Pirajno , B.D. Joubert

引用次数: 34

Dating the cessation of Kibaran magmatism in Natal, South Africa 确定南非纳塔尔基巴兰岩浆活动停止的年代

Journal of African Earth Sciences (and the Middle East) Pub Date : 1993-04-01 DOI: 10.1016/0899-5362(93)90046-S

R.J. Thomas , B.M. Eglington , S.A. Bowring

{"title":"Dating the cessation of Kibaran magmatism in Natal, South Africa","authors":"R.J. Thomas , B.M. Eglington , S.A. Bowring","doi":"10.1016/0899-5362(93)90046-S","DOIUrl":"10.1016/0899-5362(93)90046-S","url":null,"abstract":"<div><p>Published U-Pb and Pb-Pb zircon dates from pre- to late-tectonic granitoids of the Kibaran (Grenvillian) Natal Metamorphic Province fall within the range ≈1200 to ≈1040 Ma. A major problem regarding the duration and timing of magmatism in the Natal belt has been the age of the youngest intrusive events. This is important within a Gondwana context, especially with respect to the nature and distribution of the Pan-African event in this area. It is known that the youngest magmatic rocks in Natal are certain undeformed, cross-cutting microgranite dykes (Mbizana Microgranite) from the Margate Terrane. These dykes have previously given a Rb-Sr whole-rock date of ≈950 Ma, showing them to be broadly late Kibaran in age. This paper presents new U-Pb data from four zircon fractions from the Mbizana Microgranite, which give a date of emplacement of 1026 ± 3 Ma. Consequently, this date is considered to define the latest magmatic event in the Natal Metamorphic Province and points to the timing of the cessation of Kibaran magmatism in this area. The data supports recent suggestions that there was no Pan-African magmatic activity in Natal. The ≈950 Ma Rb-Sr dates previously obtained for these rocks are re-interpreted as representing the time at which the dykes cooled through the Rb-Sr biotite and K-feldspar blocking temperatures.</p></div>","PeriodicalId":100750,"journal":{"name":"Journal of African Earth Sciences (and the Middle East)","volume":"16 3","pages":"Pages 247-252"},"PeriodicalIF":0.0,"publicationDate":"1993-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0899-5362(93)90046-S","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53885866","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: 34