Pub Date : 2021-10-01DOI: 10.21608/egjg.2021.106000.1013
M. Kabesh, N. Shallaly
ZEOLITES and clay minerals are common authigenic minerals in volcano-sedimentary rock association in the Abu Treifiya basin. They are formed by hydrolysis alteration of basic volcanic glass by reaction with percolating water in a partly closed basin of salinealkaline lacustrine environment. The zeolites and associated clay minerals and calcite are studied and described in detail microscopically and by X-ray diffraction, also occasionally scanning electron microprobe and Raman techniques are applied. The zeolite mineral species of phillipsite, thomsonite, tobermorite, chabazite, natrolite and analcime are recorded and described. Palagonitization and alteration of volcanic glass result in three stages of authigenic mineral formation; 1) clay minerals as smectite, chlorite/smectite (mixed layer) and chlorite, 2) zeolite minerals, and 3) finally calcite. These associations are found to form in two paragenetic phases: A) diagenetic phase, represented by clay minerals, followed by phillipsite or thomsonite that may be overgrown by phillipsite, filling interstitial spaces, vesicles and amygdales in mostly all facies types of the volcano-sedimentary succession. These resulted from volcanic glass alteration during increasing pH, alkalinity and salinity of the environment. Analcime granular crystals form in lapilli tuff and hyaloclastite tuff in higher Na rich saline -alkaline environment at extreme palagonitization, and B) hydrothermal phase represented by open space filling of cross cutting fractures and/or manifested by formation of tobermorite spherules along basalt lacustrine carbonate contacts. Large vugs exhibit sequential crystallization of Ca zeolite thomsonite spherules followed by calcsodic zeolite Cachabazite; with decreasing temperature and increase in Na in the fluid Na rich fibrous natrolite crystallize. Hydrothermal veins are filled by large euhedral Nachabazite associated with chalcedony, Feoxyhydroxides and clays.
{"title":"ZEOLITE CRYSTAL GROWTH GENERATIONS DURING DIAGENETIC AND HYDROTHERMAL PROCESSES- CASE STUDY OF LACUSTRINE VOLCANICLASTICS, ABU TREIFIYA AREA, CAIRO-SUEZ ROAD, EGYPT","authors":"M. Kabesh, N. Shallaly","doi":"10.21608/egjg.2021.106000.1013","DOIUrl":"https://doi.org/10.21608/egjg.2021.106000.1013","url":null,"abstract":"ZEOLITES and clay minerals are common authigenic minerals in volcano-sedimentary rock association in the Abu Treifiya basin. They are formed by hydrolysis alteration of basic volcanic glass by reaction with percolating water in a partly closed basin of salinealkaline lacustrine environment. The zeolites and associated clay minerals and calcite are studied and described in detail microscopically and by X-ray diffraction, also occasionally scanning electron microprobe and Raman techniques are applied. The zeolite mineral species of phillipsite, thomsonite, tobermorite, chabazite, natrolite and analcime are recorded and described. Palagonitization and alteration of volcanic glass result in three stages of authigenic mineral formation; 1) clay minerals as smectite, chlorite/smectite (mixed layer) and chlorite, 2) zeolite minerals, and 3) finally calcite. These associations are found to form in two paragenetic phases: A) diagenetic phase, represented by clay minerals, followed by phillipsite or thomsonite that may be overgrown by phillipsite, filling interstitial spaces, vesicles and amygdales in mostly all facies types of the volcano-sedimentary succession. These resulted from volcanic glass alteration during increasing pH, alkalinity and salinity of the environment. Analcime granular crystals form in lapilli tuff and hyaloclastite tuff in higher Na rich saline -alkaline environment at extreme palagonitization, and B) hydrothermal phase represented by open space filling of cross cutting fractures and/or manifested by formation of tobermorite spherules along basalt lacustrine carbonate contacts. Large vugs exhibit sequential crystallization of Ca zeolite thomsonite spherules followed by calcsodic zeolite Cachabazite; with decreasing temperature and increase in Na in the fluid Na rich fibrous natrolite crystallize. Hydrothermal veins are filled by large euhedral Nachabazite associated with chalcedony, Feoxyhydroxides and clays.","PeriodicalId":282322,"journal":{"name":"Egyptian Journal of Geology","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130696358","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}
Pub Date : 2020-01-01DOI: 10.21608/egjg.2020.215755
Abdul Ghaffar
The use of mineralogical characteristics, chemical analysis and mechanical characteristics in addressing the behavior of some alkaline rocks to resist weathering action is discussed in the present research paper. The alkaline rocks outcropping at two selected areas in the southern Eastern Desert, namely Hamrat Salma and Abu Khrug are studied. Field relation, petrography and chemical analysis of the rocks in areas, durability and unconfined compressive strength were done. Durability and unconfined compressive strength tests evaluate the resistance of the studied alkaline rocks to natural weathering. The studied alkaline rocks in both areas are classified mineralogically and chemically as trachyte, and syenite. In Hamrat Salma, the alkaline rocks are represented by trachyte, whereas in Abu Khrug area, they are discriminated to trachydacite and syenite. All the studied alkaline rocks have alkaline affinity and emplaced in anorogenic tectonic regime. The results of compressive strength and durability of Hamrat Salma trachyte and Abu Khrug syenite showed very strong strength. The lowest value was obtained from syenite with xenoliths and trachyte of Abu Khrug showing medium strength. Negative relation between uniaxial compressive strength and durability is recorded. The existence of xenoliths, veins and porphyritic texture create a weak relationship. There is a linear relationship between compressive strength and some major oxides (SiO2, Al2O3 and Na2O) for the rock types. Also, a direct relation between durability and (Fe2O3, K2O) was recorded.
{"title":"RELATION BETWEEN MINERALOGY, GEOCHEMISTRY AND DURABILITY OF SOME ALKALINE ROCKS, SOUTH EASTERN DESERT, EGYPT","authors":"Abdul Ghaffar","doi":"10.21608/egjg.2020.215755","DOIUrl":"https://doi.org/10.21608/egjg.2020.215755","url":null,"abstract":"The use of mineralogical characteristics, chemical analysis and mechanical characteristics in addressing the behavior of some alkaline rocks to resist weathering action is discussed in the present research paper. The alkaline rocks outcropping at two selected areas in the southern Eastern Desert, namely Hamrat Salma and Abu Khrug are studied. Field relation, petrography and chemical analysis of the rocks in areas, durability and unconfined compressive strength were done. Durability and unconfined compressive strength tests evaluate the resistance of the studied alkaline rocks to natural weathering. The studied alkaline rocks in both areas are classified mineralogically and chemically as trachyte, and syenite. In Hamrat Salma, the alkaline rocks are represented by trachyte, whereas in Abu Khrug area, they are discriminated to trachydacite and syenite. All the studied alkaline rocks have alkaline affinity and emplaced in anorogenic tectonic regime. The results of compressive strength and durability of Hamrat Salma trachyte and Abu Khrug syenite showed very strong strength. The lowest value was obtained from syenite with xenoliths and trachyte of Abu Khrug showing medium strength. Negative relation between uniaxial compressive strength and durability is recorded. The existence of xenoliths, veins and porphyritic texture create a weak relationship. There is a linear relationship between compressive strength and some major oxides (SiO2, Al2O3 and Na2O) for the rock types. Also, a direct relation between durability and (Fe2O3, K2O) was recorded.","PeriodicalId":282322,"journal":{"name":"Egyptian Journal of Geology","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125908271","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}
Pub Date : 2020-01-01DOI: 10.21608/egjg.2020.215448
Abu Setta
Groundwater represents the main source of water supply in Wadi El Tarfa area. Wadi El Tarfa is one of the largest basins in the Eastern Desert which located east of the Nile River and has a surface area reaches 4939 Km. The geologic setting plays a vital role in groundwater occurrences, quantity and quality. The evaluation of the groundwater resources at Wadi El Tarfa has been achieved through the detailed studies of geomorphological, geological, hydrogeological and hydrogeochemical characteristics. The groundwater is available from two water bearing formations; Maghagha marly limestone aquifer and Samalut limestone aquifer which occur under free water table conditions. The groundwater of Maghagha aquifer is recorded at depth ranges from 38.95 m to 59.27 m and the salinity varies from 862.54 mg/l to 978.47 mg/l. The depth to the water of Samalut aquifer varies from 10 m to 80 m and the salinity ranges from 227.51 mg/l to 2545.11 mg/l. The transmissivity ranges from 19.82 m/day to 4125.60 m/day. The collected groundwater samples were chemically analyzed and interpreted. The groundwater origin has been determined through the stable isotope analysis for some selected samples. Finally, the best sites for groundwater exploitation from Samalut aquifer at Wadi El Tarfa basin have been determined.
地下水是Wadi El Tarfa地区供水的主要来源。Wadi El Tarfa是东部沙漠中最大的盆地之一，位于尼罗河以东，表面积达到4939公里。地质环境对地下水的赋存、数量和质量起着至关重要的作用。通过详细的地貌、地质、水文地质和水文地球化学特征研究，实现了对瓦迪塔尔法地下水资源的评价。地下水可从两个含水地层获得;Maghagha灰岩含水层和Samalut灰岩含水层在自由地下水位条件下形成。Maghagha含水层的地下水记录深度为38.95 ~ 59.27 m，盐度为862.54 ~ 978.47 mg/l。Samalut含水层的水深为10 ~ 80 m，盐度为227.51 ~ 2545.11 mg/l。透过率范围为19.82 ~ 4125.60 m/d。收集的地下水样本进行了化学分析和解释。通过对部分样品的稳定同位素分析，确定了地下水的来源。最后，确定了Wadi El Tarfa盆地Samalut含水层地下水的最佳开采地点。
{"title":"HYDROGEOLOGICAL CHARACTERISTICS AND GROUNDWATER ORIGIN OF THE MIDDLE EOCENE FRACTURED CARBONATE AQUIFERS AT WADI EL TARFA BASIN, EASTERN DESERT, EGYPT","authors":"Abu Setta","doi":"10.21608/egjg.2020.215448","DOIUrl":"https://doi.org/10.21608/egjg.2020.215448","url":null,"abstract":"Groundwater represents the main source of water supply in Wadi El Tarfa area. Wadi El Tarfa is one of the largest basins in the Eastern Desert which located east of the Nile River and has a surface area reaches 4939 Km. The geologic setting plays a vital role in groundwater occurrences, quantity and quality. The evaluation of the groundwater resources at Wadi El Tarfa has been achieved through the detailed studies of geomorphological, geological, hydrogeological and hydrogeochemical characteristics. The groundwater is available from two water bearing formations; Maghagha marly limestone aquifer and Samalut limestone aquifer which occur under free water table conditions. The groundwater of Maghagha aquifer is recorded at depth ranges from 38.95 m to 59.27 m and the salinity varies from 862.54 mg/l to 978.47 mg/l. The depth to the water of Samalut aquifer varies from 10 m to 80 m and the salinity ranges from 227.51 mg/l to 2545.11 mg/l. The transmissivity ranges from 19.82 m/day to 4125.60 m/day. The collected groundwater samples were chemically analyzed and interpreted. The groundwater origin has been determined through the stable isotope analysis for some selected samples. Finally, the best sites for groundwater exploitation from Samalut aquifer at Wadi El Tarfa basin have been determined.","PeriodicalId":282322,"journal":{"name":"Egyptian Journal of Geology","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115088801","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}
Pub Date : 2020-01-01DOI: 10.21608/egjg.2020.215760
S. H. Seddiek, El Afandy, El Kaliouby
The present work provides the geology, geochemistry, and petrogenesis of the Dokhan volcanics rocks exposed at the areas surrounding Wadi Um Sidra and Wadi Um Asmer in the northern Eastern Desert of Egypt, between Latitudes 27° 14 ́ and 27o 26 ́ N and Longitudes 33o 8 ́ and 33o 22 ́ E. The Dokhan volcanic rocks are exposed in the central (Gabal Dokhan) and the eastern parts of the mapped area. They cut by several sets of faults causing distinctive rugged topography, whereas narrow wadis run through these rocks. Based on the field and petrographical studies, the Dokhan volcanics are represented by a thick sequence of stratified lava flows of andesites, dacites, rhyolites and scarce amounts of basaltic rocks with pyroclastics which are composed of tuffs, agglomerates and ignimbrite. The Dokhan volcanics are intruded by monzogranites, syenogranites and alkali feldspar granites with sharp and irregular contacts, and sometimes are represented by large apophyses and several offshoots in syenogranites and as roof pendant over the monzogranites. Geochemically, these rocks have shown metaluminous to slightly peraluminous, medium to highK calcalkaline affinities and are unmetamorphosed with dominantly porphyritic texture and they enriched in LREE. The REE patterns of the rhyolites are characterized by wing shape with strong negative Eu anomaly, reflecting plagioclase fractionation. The studied Dokhan volcanic rocks have geochemical characteristics similar to the rocks developed in volcanic arc setting in subduction environment rather than transitional or post-collisional setting. Rhyolites have geochemical characteristics of lavas erupted in collisional setting.The systematic variations of major oxides and trace element abundances along continuous trends of decreasing Al2O3, CaO, MgO, Fe2O3, TiO2, P2O5, Ni, Cr and Sr and increasing K2O, Rb, Nb and Zr with increasing SiO2can be interpreted in terms of fractional crystallization. The similarity and parallel nature of the normalized REE patterns with increasing total REE contents and decreasing Eu/Eu∗ with increasing SiO2 imply a major role of crystal fractionation during the evolution of these rocks.
目前的工作提供了在埃及东部沙漠北部Wadi Um Sidra和Wadi Um Asmer周围地区暴露的Dokhan火山岩的地质、地球化学和岩石成因，这些地区位于纬度27°14°和27°26°N之间，经度330°8°和330°22°e之间。Dokhan火山岩暴露在地图区域的中部(Gabal Dokhan)和东部。它们被几组断层切割，形成了独特的崎岖地形，而狭窄的河流穿过这些岩石。根据野外和岩石学研究，多汗火山以安山岩、英安岩、流纹岩的厚层状熔岩流和少量的玄武岩为代表，火山碎屑由凝灰岩、砾岩和火成岩组成。多罕火山岩由二长花岗岩、正长花岗岩和碱长石花岗岩侵入，接触尖而不规则，有时在正长花岗岩中表现为大的针状体和若干分枝，并在二长花岗岩上形成垂顶。地球化学特征表明，这些岩石具有铝质至微过铝质、中高钾碱性亲和，未变质，以斑岩结构为主，低稀土元素富集。流纹岩的稀土元素模式呈翼状，具有较强的负Eu异常，反映斜长石分馏作用。研究的多汗火山岩具有类似于俯冲环境下的火山弧环境下发育的岩石的地球化学特征，而不是过渡性或后碰撞环境下发育的岩石。流纹岩具有碰撞喷发熔岩的地球化学特征。主要氧化物和微量元素丰度的系统变化趋势是Al2O3、CaO、MgO、Fe2O3、TiO2、P2O5、Ni、Cr和Sr随着sio2的增加而减少，K2O、Rb、Nb和Zr随着sio2的增加而增加。稀土元素归一化模式的相似性和平行性表明，稀土元素总含量随SiO2的增加而增加，而Eu/Eu∗随SiO2的增加而减少，这表明晶体分馏在这些岩石的演化过程中起主要作用。
{"title":"PETROLOGICAL AND GEOCHEMICAL INVESTIGATIONS ON DOKHAN VOLCANICS AT WADI UM SIDRA-WADI UM ASMER AREA, NORTH EASTERN DESERT, EGYPT","authors":"S. H. Seddiek, El Afandy, El Kaliouby","doi":"10.21608/egjg.2020.215760","DOIUrl":"https://doi.org/10.21608/egjg.2020.215760","url":null,"abstract":"The present work provides the geology, geochemistry, and petrogenesis of the Dokhan volcanics rocks exposed at the areas surrounding Wadi Um Sidra and Wadi Um Asmer in the northern Eastern Desert of Egypt, between Latitudes 27° 14 ́ and 27o 26 ́ N and Longitudes 33o 8 ́ and 33o 22 ́ E. The Dokhan volcanic rocks are exposed in the central (Gabal Dokhan) and the eastern parts of the mapped area. They cut by several sets of faults causing distinctive rugged topography, whereas narrow wadis run through these rocks. Based on the field and petrographical studies, the Dokhan volcanics are represented by a thick sequence of stratified lava flows of andesites, dacites, rhyolites and scarce amounts of basaltic rocks with pyroclastics which are composed of tuffs, agglomerates and ignimbrite. The Dokhan volcanics are intruded by monzogranites, syenogranites and alkali feldspar granites with sharp and irregular contacts, and sometimes are represented by large apophyses and several offshoots in syenogranites and as roof pendant over the monzogranites. Geochemically, these rocks have shown metaluminous to slightly peraluminous, medium to highK calcalkaline affinities and are unmetamorphosed with dominantly porphyritic texture and they enriched in LREE. The REE patterns of the rhyolites are characterized by wing shape with strong negative Eu anomaly, reflecting plagioclase fractionation. The studied Dokhan volcanic rocks have geochemical characteristics similar to the rocks developed in volcanic arc setting in subduction environment rather than transitional or post-collisional setting. Rhyolites have geochemical characteristics of lavas erupted in collisional setting.The systematic variations of major oxides and trace element abundances along continuous trends of decreasing Al2O3, CaO, MgO, Fe2O3, TiO2, P2O5, Ni, Cr and Sr and increasing K2O, Rb, Nb and Zr with increasing SiO2can be interpreted in terms of fractional crystallization. The similarity and parallel nature of the normalized REE patterns with increasing total REE contents and decreasing Eu/Eu∗ with increasing SiO2 imply a major role of crystal fractionation during the evolution of these rocks.","PeriodicalId":282322,"journal":{"name":"Egyptian Journal of Geology","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122557961","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}
Pub Date : 2020-01-01DOI: 10.21608/egjg.2020.216324
El-Kahawy, El-Shafeiy, Helal, Aboul-Ela
Bottom sediment samples were collected from two sites located at the Red Sea coast of Egypt namely, Ras Gharib and Quseir. The samples were treated for their ostracods content. Identification, taxonomy, distribution, ecology, zoogeographical, and environmental aspects were carried out on the assemblage of the Ostracoda. Twenty-three ostracod species belonging to 20 genera, and 12 families were identified. The percentages of the most common ostracods are Quadracythere (19.35% and 17.83%), Xestolebris (10.42% and 7.4%), Loxocorniculum (17.37% and 14.42%), Ghardaglaia (4.22% and 17.91%), and Moosella (10.17% and 9.45%) for Ras Gharib and Quseir sites, respectively. Most of the observed fauna are Indo-Pacific. From the environmental geochemical point of view, the Quseir area is characterized by sediments that are more enriched in some heavy metals, compared to the average shallow marine sediment contents. Ras Gharib site has, relatively, less heavy metal contents with coarser-grained sediments. Based on the Canonical Correspondences Analysis (CCA), pollution-tolerant species were observed in the contaminated stations such as Ghardaglaia triebeli, Alocopocythere reticulata, Moosella striata, and Hiltermannicythere rubrimaris, which can act as survivors. On the other hand, pollution-sensitive taxa such as Jugosocythereis borchersi, Loxocorniculum ghardaqensis, and Xestolebris ghardaqae, are characterizing the Ras Gharib area. Careful consideration should be maintained before long to conserve the Red Sea ecoand geosystems.
{"title":"TAXONOMY, DISTRIBUTION, AND ENVIRONMENTAL IMPLICATIONS OF BENTHIC MARINE OSTRACODS, ALONG THE RED SEA COAST OF EGYPT","authors":"El-Kahawy, El-Shafeiy, Helal, Aboul-Ela","doi":"10.21608/egjg.2020.216324","DOIUrl":"https://doi.org/10.21608/egjg.2020.216324","url":null,"abstract":"Bottom sediment samples were collected from two sites located at the Red Sea coast of Egypt namely, Ras Gharib and Quseir. The samples were treated for their ostracods content. Identification, taxonomy, distribution, ecology, zoogeographical, and environmental aspects were carried out on the assemblage of the Ostracoda. Twenty-three ostracod species belonging to 20 genera, and 12 families were identified. The percentages of the most common ostracods are Quadracythere (19.35% and 17.83%), Xestolebris (10.42% and 7.4%), Loxocorniculum (17.37% and 14.42%), Ghardaglaia (4.22% and 17.91%), and Moosella (10.17% and 9.45%) for Ras Gharib and Quseir sites, respectively. Most of the observed fauna are Indo-Pacific. From the environmental geochemical point of view, the Quseir area is characterized by sediments that are more enriched in some heavy metals, compared to the average shallow marine sediment contents. Ras Gharib site has, relatively, less heavy metal contents with coarser-grained sediments. Based on the Canonical Correspondences Analysis (CCA), pollution-tolerant species were observed in the contaminated stations such as Ghardaglaia triebeli, Alocopocythere reticulata, Moosella striata, and Hiltermannicythere rubrimaris, which can act as survivors. On the other hand, pollution-sensitive taxa such as Jugosocythereis borchersi, Loxocorniculum ghardaqensis, and Xestolebris ghardaqae, are characterizing the Ras Gharib area. Careful consideration should be maintained before long to conserve the Red Sea ecoand geosystems.","PeriodicalId":282322,"journal":{"name":"Egyptian Journal of Geology","volume":"194 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122932179","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}
Pub Date : 2020-01-01DOI: 10.21608/egjg.2020.216318
T. F. Mostafa
Well–preserved palynomorphs dominated by miospores and subordinate acritarchs and chitinozoans are recovered from some cuttings of Ie 11 2 borehole drilled in the Ghazalat Basin in the west of Qattara depression, Egypt . A total of 36 species of palynomorphs (25species of spores, 8 species of acritarchs and 3 chitinozoan species) are identified. The palynological investigation of the studied stratigraphic interval enabled the recognition of three informal zones ranging in age from Lochkovian to Emsian. Most of the palynomorph taxa encountered are closely comparable with coeval assemblages recorded from North Africa, Saudi Arabia, Western Europe and Canada, indicating the close relationship of the present area to other parts of the western Gondwana and southern Euramerican provinces during that time interval. Frequent representation of marine taxa (acritarchs and chitinozoans) together with associated spores indicate near-shore marine depositional environment for the Lower and Middle Devonian (Zeitoun Formation) deposits in north Western Desert region of Egypt. Keyword: Devonian; palynomorphs biostratigraphy; Ghazalat Basin; West Qattara Depression.
{"title":"PALYNOMORPH BIOSTRATIGRAPHY OF THE SUBSURFACE DEVONIAN ROCKS, GHAZALAT BASIN, WEST QATTARA DEPRESSION, EGYPT","authors":"T. F. Mostafa","doi":"10.21608/egjg.2020.216318","DOIUrl":"https://doi.org/10.21608/egjg.2020.216318","url":null,"abstract":"Well–preserved palynomorphs dominated by miospores and subordinate acritarchs and chitinozoans are recovered from some cuttings of Ie 11 2 borehole drilled in the Ghazalat Basin in the west of Qattara depression, Egypt . A total of 36 species of palynomorphs (25species of spores, 8 species of acritarchs and 3 chitinozoan species) are identified. The palynological investigation of the studied stratigraphic interval enabled the recognition of three informal zones ranging in age from Lochkovian to Emsian. Most of the palynomorph taxa encountered are closely comparable with coeval assemblages recorded from North Africa, Saudi Arabia, Western Europe and Canada, indicating the close relationship of the present area to other parts of the western Gondwana and southern Euramerican provinces during that time interval. Frequent representation of marine taxa (acritarchs and chitinozoans) together with associated spores indicate near-shore marine depositional environment for the Lower and Middle Devonian (Zeitoun Formation) deposits in north Western Desert region of Egypt. Keyword: Devonian; palynomorphs biostratigraphy; Ghazalat Basin; West Qattara Depression.","PeriodicalId":282322,"journal":{"name":"Egyptian Journal of Geology","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114571537","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}
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