Computer Science
Scientific paper
Dec 1981
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1981e%26psl..56..199c&link_type=abstract
Earth and Planetary Science Letters, Volume 56, p. 199-209.
Computer Science
2
Scientific paper
In an earlier study of Mesozoic and Cenozoic mineralization in Central America and the Caribbean region, we found that lead isotopic compositions of deposits in northern Central America, which is underlain by a pre-Mesozoic craton, ranged to higher 206Pb/204Pb and 207Pb/204Pb compositions than did deposits from elsewhere in the region, where the basement is Mesozoic oceanic material. Using 16 analyses for 12 new deposits, as well as new analyses for 11 of the samples studied previously, we have found that lead isotopic compositions correlate closely with crustal type but show little or no correlation with depth to the M-discontinuity. The deposits are divisible into three main groups including (in order of increasing 207Pb/204Pb and 208Pb/204Pb ratio): (1) deposits in southern Central America and all deposits in the Greater Antilles except Cuba; (2) all deposits in northern Central America; and (3) the Cuban deposits. Southern Central American and Caribbean lead is higher in 207Pb/204Pb and 208Pb/204Pb than most mid-ocean ridge basalts but could have been derived directly or indirectly from undepleted mantle. Northern Central America can be divided into the Maya block, which belongs to the Americas plate, and the Chortis block, which belongs to the Caribbean plate. Maya block deposits fall along a linear array whereas those of the Chortis block (except the Monte Cristo deposit) form a cluster. These results suggest that the Maya block is underlain by crust or mantle with a large range of U/Pb and Th/U ratios, whereas the Chortis block basement is more homogeneous. Two-stage model calculations indicate an age of about 2280+/-310 m.y. for the Maya block basement, although no such rocks are known in the region. Comparison of the Chortis block data to our recently published lead isotopic analyses of Mexican deposits shows considerable similarities suggesting that the Chortis block could have been derived from Mexico.
Cumming George L.
Kesler Stephen E.
Krstic Dragan
No associations
LandOfFree
Source of lead in Central American and Caribbean mineralization, II. Lead isotope provinces does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Source of lead in Central American and Caribbean mineralization, II. Lead isotope provinces, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Source of lead in Central American and Caribbean mineralization, II. Lead isotope provinces will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1262639