Ore Petrology<\/p>\n
1- Explain briefly (with illustrations) :\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026(20 marks)<\/p>\n
A) The petrological interrelationships of ore minerals in the following ore deposits: (15 marks)
\n1) Fe-Ti oxide deposits.
\n2) Fe- Cu-Ni sulfide deposits.
\n3) Alpine-type chromite deposits.
\nB) The method of Sharpe et al (1985) of arsenopyrite geothermometry. (5 marks)<\/p>\n
2-Choose the correct answer (10 marks)
\na- Growth of sulfide minerals in lavas takes place in the form of (skeletal crystals – round droplets – euhedral to subhedral crystals).<\/p>\n
b- The tubular disconcordant orebodies are characterized by (pinch and swell structure – branching and anastomosing – stockworks).<\/p>\n
c- (Stratiform \u2013 Starabound \u2013 Disseminated) deposits show a considerable development parallel to bedding and a limited development perpendicular to it.<\/p>\n
d- Diamond deposits in kimberlite represent (concordant orebodies- discordant orebodies- residual orebodies).<\/p>\n
e- Replacement of magnetite by martite is carried out through (change in oxidation state – change in anions – selective remove of one cation).<\/p>\n
4- Put (\uf0d6) after the true statement and (X) after the false one in the following: (10 marks)
\na-Rounding-off of wall-rock surfaces on both sides of a mineral deposit within a fracture indicates its formation by open space deposition. ( ).<\/p>\n
b- Starabound orebodies are restricted to a particular part of the stratigraphic column, regardless whether the orebody is concordant or discordant ( ).<\/p>\n
c- “Pinch and swell structure” results from later replacement of fracture walls ( ).<\/p>\n
d- Layered chromite deposits are formed in tectonically unstable environments while podiform ones are formed in tectonically stable conditions ( ).<\/p>\n
e- Metamorphic fluids are produced by break down of hydrous silicate and carbonate minerals at the transition from greenscist to amphipolite facies.<\/p>\n
5- Complete the missing parts in the following statements (5 marks):
\na- \u2026\u2026\u2026\u2026 results from deformation of crustified veins during or after ore formation.
\nb- The exsolution type in which structures of both phases are completely different or without crystallographic continuity across the interface between phases is called\u2026\u2026\u2026\u2026\u2026\u2026..
\nc- Experimental work showed that chalcopyrite disease is not an exsolution, so it is most propably to be\u2026\u2026\u2026\u2026\u2026\u2026\u2026
\nd- \u2026\u2026\u2026. are generally stratiform lenticular or sheetlike orebodies developed at interfaces or horizons of pauses in volcanism or change from volcanism to sedimentation.
\ne- In Ag-Bi-Co-Ni-As vein deposits, \u2026\u2026\u2026\u2026is petrologically found in dendritic patterns that are surrounded by rosettes of colloform arsenides.<\/p>\n","protected":false},"excerpt":{"rendered":"
Ore Petrology 1- Explain briefly (with illustrations) :\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026(20 marks) A) The petrological interrelationships of ore minerals in the following ore deposits: (15 marks) 1) Fe-Ti oxide deposits. 2) Fe- Cu-Ni sulfide deposits. 3) Alpine-type chromite deposits. B) The method of Sharpe et al (1985) of arsenopyrite geothermometry. (5 marks) 2-Choose the correct answer (10 marks) […]<\/p>\n","protected":false},"author":1,"featured_media":2514,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"zakra_page_container_layout":"customizer","zakra_page_sidebar_layout":"customizer","zakra_remove_content_margin":false,"zakra_sidebar":"customizer","zakra_transparent_header":"customizer","zakra_logo":0,"zakra_main_header_style":"default","zakra_menu_item_color":"","zakra_menu_item_hover_color":"","zakra_menu_item_active_color":"","zakra_menu_active_style":"","zakra_page_header":true,"footnotes":""},"categories":[18],"tags":[],"class_list":["post-2513","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-18"],"rttpg_featured_image_url":{"full":["https:\/\/sci.sohag-univ.edu.eg\/main\/wp-content\/uploads\/2013\/01\/10img10fb0fb6b0261.png",450,350,false],"landscape":["https:\/\/sci.sohag-univ.edu.eg\/main\/wp-content\/uploads\/2013\/01\/10img10fb0fb6b0261.png",450,350,false],"portraits":["https:\/\/sci.sohag-univ.edu.eg\/main\/wp-content\/uploads\/2013\/01\/10img10fb0fb6b0261.png",450,350,false],"thumbnail":["https:\/\/sci.sohag-univ.edu.eg\/main\/wp-content\/uploads\/2013\/01\/10img10fb0fb6b0261-150x150.png",150,150,true],"medium":["https:\/\/sci.sohag-univ.edu.eg\/main\/wp-content\/uploads\/2013\/01\/10img10fb0fb6b0261-300x233.png",300,233,true],"large":["https:\/\/sci.sohag-univ.edu.eg\/main\/wp-content\/uploads\/2013\/01\/10img10fb0fb6b0261.png",450,350,false],"1536x1536":["https:\/\/sci.sohag-univ.edu.eg\/main\/wp-content\/uploads\/2013\/01\/10img10fb0fb6b0261.png",450,350,false],"2048x2048":["https:\/\/sci.sohag-univ.edu.eg\/main\/wp-content\/uploads\/2013\/01\/10img10fb0fb6b0261.png",450,350,false]},"rttpg_author":{"display_name":"admin","author_link":"https:\/\/sci.sohag-univ.edu.eg\/main\/author\/admin\/"},"rttpg_comment":0,"rttpg_category":"\u0645\u0633\u062a\u0646\u062f\u0627\u062a \u0644\u0644\u062a\u062d\u0645\u064a\u0644<\/a>","rttpg_excerpt":"Ore Petrology 1- Explain briefly (with illustrations) :\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026(20 marks) A) The petrological interrelationships of ore minerals in the following ore deposits: (15 marks) 1) Fe-Ti oxide deposits. 2) Fe- Cu-Ni sulfide deposits. 3) Alpine-type chromite deposits. B) The method of Sharpe et al (1985) of arsenopyrite geothermometry. (5 marks) 2-Choose the correct answer (10 marks)…","_links":{"self":[{"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/posts\/2513","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/comments?post=2513"}],"version-history":[{"count":4,"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/posts\/2513\/revisions"}],"predecessor-version":[{"id":2517,"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/posts\/2513\/revisions\/2517"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/media\/2514"}],"wp:attachment":[{"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/media?parent=2513"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/categories?post=2513"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sci.sohag-univ.edu.eg\/main\/wp-json\/wp\/v2\/tags?post=2513"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}