| dc.creator |
Messo, Charles W. |
|
| dc.creator |
Yamashita, K. |
|
| dc.creator |
Kobayashi, Katsura |
|
| dc.creator |
Makishima, Akio |
|
| dc.creator |
Sakaguchi, C. |
|
| dc.creator |
Nakamura, Eizo |
|
| dc.date |
2016-07-14T20:56:34Z |
|
| dc.date |
2016-07-14T20:56:34Z |
|
| dc.date |
2000 |
|
| dc.date.accessioned |
2018-03-27T08:57:28Z |
|
| dc.date.available |
2018-03-27T08:57:28Z |
|
| dc.identifier |
Messo, C.W., Yamashita, K., Kobayashi, K., Makishima, A., Sakaguchi, C. and Nakamura, E., 2000. Geochemistry of volcanic and plutonic rocks from the southern Musoma-Mara greenstone belt: Implication for the evolution of the Tanzania craton. Space Sci. Rev, 92, pp.133-152. |
|
| dc.identifier |
http://hdl.handle.net/20.500.11810/3227 |
|
| dc.identifier.uri |
http://hdl.handle.net/20.500.11810/3227 |
|
| dc.description |
The Neoarchean Tanzania craton contains patches of
greenstone belts set in granitoid masses that occupy a large
percent of the craton. Because of limited geological,
geochronological and geochemical information, very little is
known about this craton and its constituent terrains. We report
new U-Pb chronological, Nd-Hf isotopic and major and trace
element data for volcanic and granitoid rocks from the
southern Musoma-Mara greenstone belts of the Northeast
Tanzania craton. The volcanic rocks are mainly basaltic with
minor felsic volcanic rocks. The intrusive rocks are mostly
granodiorites and granites with few trondhjemitic samples.
Geochemically, the basalts are tholeiitic and MORB-like but
with minor depletions of Nb and Ti relative to N-MORB. The
felsic volcanic and granitoid rocks are calc-alkaline with
normal arc to adakitic signature. The basalts yielded a Sm -
Nd isochron age of 2842 ± 65 Ma (εNd = +2.1, MSWD = 1.6)
and εHf2840 = +1.7 - +3.2. One granitoid yielded U-Pb zircon
age of 2689 ± 12 Ma which is similar to those reported for the
oldest rocks in the North Musoma-Mara greenstone belt [1],
and is interpreted to represent the age of granitoids and felsic
metavolcanic rocks. The felsic volcanic rocks have εNd2689 ~
+1.6 - +2.5 and εHf2689 ~ +0.1 - +1.6 that are within error of
those for granitods and meta-basalts. Collectively, these data
show that the basaltic rocks may not be related to the felsic
volcanic and intrusive rocks by fractionation but were likely
formed from equally depleted sources, possibly in arc-back arc
environment. The spatial association of MORB-like tholeiites
and arc-like volcanic and granitoid rocks is not uncommon in
the Tanzania craton [2], as well as other late-Archean cratons
worldwide [3, 4], and may imply that the tectono-magmatic
processes that produced this association were widespread
during this period. |
|
| dc.language |
en |
|
| dc.title |
Geochemistry of Volcanic and Plutonic Rocks from the Southern Musoma-Mara Greenstone Belt: Implication for the Evolution of the Tanzania Craton |
|
| dc.type |
Journal Article |
|