Understanding our fragile environment; Lessons from geochemical studies

Circular ◽  
1993 ◽  
Author(s):  
Larry P. Gough ◽  
Sigrid Asher-Bolinder ◽  
Laurie S. Balistrieri ◽  
George N. Breit ◽  
Thomas J. Casadevall ◽  
...  
Keyword(s):  
Fragile Environment ◽  
Geochemical Studies

Volcanoes of the southwestern extension of the active Mariana island arc: New swath-mapping and geochemical studies

Island Arc ◽  
1998 ◽  
Vol 7 (3) ◽  
pp. 596-607
Author(s):  
F RYER ◽  
S UJIMOTO ◽  
S EKINE ◽  
J OHNSON ◽  
K ASAHARA ◽  
...  
Keyword(s):  
Island Arc ◽  
Swath Mapping ◽  
Geochemical Studies ◽  
Mariana Island Arc

Genesis of crustal xenoliths from andesite in the Southeast Mátra Mts (Hungary) based on petrologic and geochemical studies

2006 ◽  
Vol 49 (4) ◽  
pp. 311-330
Author(s):  
Anita Jávor ◽  
Zuárd Ditrói-Puskás ◽  
Gábor Dobosi
Keyword(s):  
Crustal Xenoliths ◽  
Geochemical Studies

Geochemical studies of rare earth elements in the Portuguese pyrite belt, and geologic and geochemical controls on gold distribution

1998 ◽  
Author(s):  
David J. Grimes ◽  
Robert L. Earhart ◽  
Delfim de Carvalho ◽  
Vitor Oliveira ◽  
Jose T. Oliveira ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Geochemical Controls ◽  
Geochemical Studies

scholarly journals Radiogenic Pb Enrichment of Mississippi Valley-Type Metallic Ore Deposits, Southern Ozarks: Constraints Based on Geochemical Studies of Source Rocks and Their Diagenetic History

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 172
Author(s):  
Jonathan Chick ◽  
Sydney E. McKim ◽  
Adriana Potra ◽  
Walter L. Manger ◽  
John R. Samuelsen
Keyword(s):  
Linear Trend ◽  
Ore Deposits ◽  
Source Rocks ◽  
Mississippi Valley ◽  
Isotopic Signatures ◽  
Boone Formation ◽  
Tripolitic Chert ◽  
Geochemical Studies ◽  
Mississippi Valley Type ◽  
Valley Type

Southern Ozark Mississippi Valley-type ores are enriched in radiogenic Pb, with isotopic signatures suggesting that metals were supplied by two end-member components. While the less radiogenic component appears to be derived from various shale and sandstone units, the source of the more radiogenic component has not yet been identified. Analyses of cherts from the Early Ordovician Cotter Dolomite and tripolitic chert from the Early Mississippian Boone Formation contain highly radiogenic Pb, with isotopic ratios comparable to those of ores. However, most samples have lower 208Pb/204Pb and 207Pb/204Pb for a given 206Pb/204Pb compared to ores. These relationships demonstrate that the enriched Pb isotopic values of the ore array cannot be related to the host and regional lithologies sampled, suggesting that the source of high ratios may lay further afield. The slope of the linear trend defined by the Pb isotope ratios of ores corresponds to an age of about 1.19 Ga. Therefore, an alternative for the linear array is the involvement of Precambrian basement in supplying ore Pb. Rare earth element patterns show that diagenetic processes involving the action of groundwater and hydrothermal fluids affected the sampled lithologies to various degrees, with Cotter Dolomite having experienced the highest degree of alteration.

The Late Cretaceous magmatic arc of the south Aegean: Geodynamic implications from petrological and geochemical studies of granitoids from Anafi island (Cyclades – Greece)

2021 ◽  
pp. 1-24
Author(s):  
Petros Koutsovitis ◽  
Konstantinos Soukis ◽  
Panagiotis Voudouris ◽  
Stylianos Lozios ◽  
Theodoros Ntaflos ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
The South ◽  
Magmatic Arc ◽  
Geochemical Studies
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