This is an archive of CompuServe forum messages from 1985 to 1995, as saved in transcripts by John Foust.
Search Results (18 messages)
Art: Hypothetical geothermal temperature gradients can be found in many references – you might try Ernst's "The Dynamic Planet" (Columbia University Press, 1990) for starters. For a more detailed discussion of heat flow, geothermal gradients, and deep earth structure, see "The Inaccessible Earth" by Brown and Mussett (George Allen &…
Dear George: Re: good geology departments.
Dear George: There are lots of good schools out West. Try looking into Oregon State U., U. of Washington, Stanford, UC Davis, U Nevada-Reno, Colorado School of Mines, New Mexico Tech., U of Arizona. Happy hunting, & good luck! Scott M.
Hello, Guy: Strictly speaking in terms of igneous petrology, the classifications of igneous rocks as "alkalic", "calc-alkaline", "peralkalic", etc., are based on the ratios of Na2O, K2O, CaO (alkali and alkaline earth elements, no?) in the total normative (oxide) composition. Silica saturation (SiO2) is a related, but not identical, compositional…
Hello, Doug: No one seriously questions that it is possible to form a carbonate melt anymore – it's verified by experiment and observation (e.g. East African carbonate lavas). I believe that the mechanisms of emplacement for kimberlites & carbonatites (commonly occuring as diatremes, or "pipes") may not be terribly well…
Doug & Wayne: Re: further notes on ultramafic lavas — komatiites are olivine-rich rocks distinguished by low silica content (v. "undersaturated" in the parlance of petrology). Strictly by the definition of low-silica content, carbonatites can be termed ultramafic but as the name suggests, their composition is quite different from other…
Hello, Mr. Titus: Actually, ultramafic lava flows are present in the geologic record. Have you heard of "komatiites"? These were first described from a type locality along the Komati River in the Barberton Mtns. of southern Africa. Similar rocks have since been recognized in most areas of the world where…
Dear Bill: By *volume* percentage, the most common element in the earth's crust is oxygen. (Believe it or not!) "Top Ten" element lists are fairly common – you should be able to find specific data in geochemistry textbooks by Krauskopf or Levinson. Silicon and aluminum are going to be v.…
Jon: Re: "Hard" vs. "soft" coals. I think that it is just the opposite of what you stated – anthracite is (or was) much more common in the Eastern states (i.e., Appalachia), because those coal measures were mostly in older rocks that had suffered some degree of metamorphism. Out West,…
Elizabeth: Re: self-combusting sulfides. Grain-size certainly is a factor, w/ increased surface area available for reaction in finer materials, etc. I recall anecdotes that Kuroko-type massive sulfides in Japan have problems w/ "self-igniting" ores on occasion. On a field trip to Homestake's McLaughlin mine in CA, we observed a "smoking…
Hi, Doug: I note w/ interest the concerns of mineral/fossil collectors, re: maintaining traditional access to public lands (where the public, it seems, in our Brave New Society is to have few if any remaining privileges). Are you up on the "Congressgram" function in the CI$ "Mail" menu? This is…
Doug, Michael, et al. . . . this comes from a couple of geologists out here in cyberspace, and w/ all due respect & courtesy to the Earth Forum, there is precious little geology over there. Don't get me wrong – love the place! (wg) But . . . Unfortunately…
Hello, Lanny, and welcome! There are a few other geo-types floating around out here in cyberspace. I'm a geologist working for the nonce at the Robinson project down here in Ely (the old copper camp). Others bop in from the Net from time to time, too. What's your work involve…
#Seisms in WY?
Message #119832
. . What's happening in Wyoming/Idaho, re: earthquakes this morning?
Geol. Libraries
Message #117070
Hello, Todd. Caught your note to Michael S. I'm a Stanford AES grad out in the wilds of Nevada these days, working for Magma Copper. Just FYI, the Earth Sciences library at Stanford so far as I know won't cost you anything to get into (that's Branner Library, in the…
Reply to Denver
Message #115500
Paul: My only claims to notoriety might be a thesis on the Mesquite deposit in SE California, back when it belonged to GFMC (now no longer with us). I have in times past (GSA meetings etc) given a couple of abstracts on the beast. I don't know Larry Hobbs; has…
#A Geologist Replies
Message #115378
Michael: Greetings and Happy Holidays from out West. I currently work for Magma Copper Company, one of the majors in Arizona. – Scott M. _
#hello
Message #115251
Greetings, one and all. Just another one of a dying breed, a working minerals exploration geo-type dropping by to say hello. I'm a refugee (g) from the Earth Forum, somewhat bemused that there is rather little to do w/ earth science over there. Mayhap we can fix that! A bit…