Matches in SemOpenAlex for { <https://semopenalex.org/work/W1480297807> ?p ?o ?g. }
Showing items 1 to 65 of
65
with 100 items per page.
- W1480297807 abstract "The Ranger No. 1 and No. 3 orebodies contain about 124,000 tonnes U3O8 in highly chloritized metasediments of the lower Proterozoic Cahill Formation within about 500 m of the projected sub-Kombolgie Formation unconformity. In both orebodies, oxidized and reduced uranium minerals occur chiefly in quartzose schists that have highly variable amounts of muscovite, sericite, and chlorite. The effects of several periods of alteration are pervasive in the vicinity of orebodies where biotite and garnet are altered to chlorite, and feldspars to white mica or chlorite. Oxidized uranium minerals, associated with earthy iron oxides, occur from the surface to a depth of about 60 m. Below the oxidized zone, uranium occurs chiefly as uraninite and pitchblende disseminated through thick sections of quartz-chlorite-muscovite schist and has no apparent association with graphite or sulfides. In fact, graphite is rare and sulfides are generally low in abundance (<0.5 percent). Higher ore grades occur in disrupted zones a few centimeters thick and in some quartz-chlorite vein-like zones of uncertain origin. Uranium correlates strongly with chlorite, but not all of the many ages of chlorite have associated uranium. At least five textural varieties of chlorite are present and represent at least 3 ages. Preliminary microprobe analyses suggest that Mg-Fe-Al contents are relatively uniform. Apatite commonly occurs with chlorite. Uranium is not common in carbonate rocks and seems to occur only in disrupted zones that have chlorite alteration. Chloritization and silicification are more widespread and intense in the No. 1 orebody than in the No. 3. In both orebodies, hematite occurs tens to hundreds of meters below the weathered zone, in both altered and largely unaltered rocks, with and without uranium. The structure of the orebodies is outwardly simple, particularly in No. 3; dips are less than 40? on most lithologic contacts. The No. 1 orebody is in a basin-like structure about 400 m wide that probably formed in part by progressive removal of carbonate rocks that are as much as 200 m thick adjacent to the No. 1 orebody and below the No. 3 orebody. Quartz-chlorite breccias have formed in the zone of carbonate thinning; uranium is spotty and low grade in these breccias. Chloritized and uraniferous broken and sheared zones, a few centimeters to a few meters thick, have an unknown attitude but must have small displacement. Blocks of altered Kombolgie sandstone are downfaulted into the No. 3 orebody and locally contain reduced uranium minerals. One or more shear zones 5-30 m thick of crushed and smeared fine to coarse rock fragments occur below the orebodies, and other low-angle shears probably occur in the orebodies. The shear zone dips about 40 o and displacement on it is not known. The footwall rocks generally are less retrograded than those in the hanging wall (orebody) and consist of quartz-biotite-feldspar schists and gneisses flanking the Nanambu Complex. A few scattered fractures in the footwall sequence contain pitchblende of unknown age and origin. Major element chemical analyses confirm the lithologic observations of large changes in composition during multiple stages of alteration. Granitic dikes and pelitic schists have gained Fe and Mg and lost Si, Ca, Na, and K during chloritization. Marbles have gained Si, Al, Fe, and P, and lost Mg, Ca, and K during jasperoid-chlorite alteration. Total net chemical gains and losses in the Ranger No. 1 orebody were huge: equal to about 37 percent of the mass of the ore-bearing rock that will be mined. There were net gains in Si and P and net losses in Al, Fe, Mg, Ca, K, and Na. The geologic age(s) of uranium emplacement are obscure because there are few age criteria. Reduced uranium minerals are younger than 1.8-b.y.-old granite dikes, and some occur locally in 1.65-b.y.-old Kombolgie Formation. Diabase dikes (age not known) are thoroughly chloritized and contain sparse ore minerals. Oxidized ura" @default.
- W1480297807 created "2016-06-24" @default.
- W1480297807 creator A5027838763 @default.
- W1480297807 creator A5036016535 @default.
- W1480297807 date "1982-01-01" @default.
- W1480297807 modified "2023-09-26" @default.
- W1480297807 title "Progress report on geologic studies of the Ranger orebodies, Northern Territory, Australia" @default.
- W1480297807 doi "https://doi.org/10.3133/ofr82936" @default.
- W1480297807 hasPublicationYear "1982" @default.
- W1480297807 type Work @default.
- W1480297807 sameAs 1480297807 @default.
- W1480297807 citedByCount "2" @default.
- W1480297807 crossrefType "journal-article" @default.
- W1480297807 hasAuthorship W1480297807A5027838763 @default.
- W1480297807 hasAuthorship W1480297807A5036016535 @default.
- W1480297807 hasBestOaLocation W14802978071 @default.
- W1480297807 hasConcept C101139013 @default.
- W1480297807 hasConcept C127313418 @default.
- W1480297807 hasConcept C151730666 @default.
- W1480297807 hasConcept C17409809 @default.
- W1480297807 hasConcept C191897082 @default.
- W1480297807 hasConcept C192562407 @default.
- W1480297807 hasConcept C199289684 @default.
- W1480297807 hasConcept C26687426 @default.
- W1480297807 hasConcept C2776581184 @default.
- W1480297807 hasConcept C2777229588 @default.
- W1480297807 hasConcept C2777844515 @default.
- W1480297807 hasConcept C2778583526 @default.
- W1480297807 hasConcept C2779870107 @default.
- W1480297807 hasConcept C35391346 @default.
- W1480297807 hasConcept C555451288 @default.
- W1480297807 hasConcept C82844589 @default.
- W1480297807 hasConceptScore W1480297807C101139013 @default.
- W1480297807 hasConceptScore W1480297807C127313418 @default.
- W1480297807 hasConceptScore W1480297807C151730666 @default.
- W1480297807 hasConceptScore W1480297807C17409809 @default.
- W1480297807 hasConceptScore W1480297807C191897082 @default.
- W1480297807 hasConceptScore W1480297807C192562407 @default.
- W1480297807 hasConceptScore W1480297807C199289684 @default.
- W1480297807 hasConceptScore W1480297807C26687426 @default.
- W1480297807 hasConceptScore W1480297807C2776581184 @default.
- W1480297807 hasConceptScore W1480297807C2777229588 @default.
- W1480297807 hasConceptScore W1480297807C2777844515 @default.
- W1480297807 hasConceptScore W1480297807C2778583526 @default.
- W1480297807 hasConceptScore W1480297807C2779870107 @default.
- W1480297807 hasConceptScore W1480297807C35391346 @default.
- W1480297807 hasConceptScore W1480297807C555451288 @default.
- W1480297807 hasConceptScore W1480297807C82844589 @default.
- W1480297807 hasLocation W14802978071 @default.
- W1480297807 hasOpenAccess W1480297807 @default.
- W1480297807 hasPrimaryLocation W14802978071 @default.
- W1480297807 hasRelatedWork W1480297807 @default.
- W1480297807 hasRelatedWork W1989089164 @default.
- W1480297807 hasRelatedWork W1997553798 @default.
- W1480297807 hasRelatedWork W2027851355 @default.
- W1480297807 hasRelatedWork W2300635040 @default.
- W1480297807 hasRelatedWork W2313223524 @default.
- W1480297807 hasRelatedWork W2374610640 @default.
- W1480297807 hasRelatedWork W2554887432 @default.
- W1480297807 hasRelatedWork W2961005957 @default.
- W1480297807 hasRelatedWork W2182992252 @default.
- W1480297807 isParatext "false" @default.
- W1480297807 isRetracted "false" @default.
- W1480297807 magId "1480297807" @default.
- W1480297807 workType "article" @default.