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Ni And Fe Isotope Fractionation During Weathering And The Formation Of Ni Laterite Ore Deposits In The Philippines, Congxi Zhu Sep 2019

Ni And Fe Isotope Fractionation During Weathering And The Formation Of Ni Laterite Ore Deposits In The Philippines, Congxi Zhu

Electronic Thesis and Dissertation Repository

Weathering processes on Ni-rich ultramafic rocks in tropical areas produce laterites that become exploitable for Ni mining. To better understand these processes, samples were collected stratigraphically with water samples from several Ni mines in the Philippines and studied for Ni and Fe isotope compositions. This study found that Ni isotope fractionation takes place during the formation of Ni-enriched minerals (goethite), when light Ni isotopes are preferentially incorporated into new minerals formed, leaving heavy Ni isotopes in groundwater. The Δ60NiLimonite-Bedrock is up to -0.19 ± 0.32‰. Even though Fe is partitioned with redox state change during these reactions, …


Stable Cu, Fe, And Ni Isotopic Systematics Of The Sudbury Offset Dikes And Associated Rocks, Peter Christoffersen Dec 2017

Stable Cu, Fe, And Ni Isotopic Systematics Of The Sudbury Offset Dikes And Associated Rocks, Peter Christoffersen

Electronic Thesis and Dissertation Repository

The stable isotope ratio compositions of Fe, Ni, and Cu (δ56Fe, δ60Ni, and δ65Cu) are reported for the first time in rocks from the Sudbury Igneous Complex (SIC). Massive sulfide ores, Quartz Diorite (QD), Inclusion bearing Quartz Diorite (IQD), and rocks from members of the Main Mass of the SIC were analyzed. The objective was to better understand the origin(s) and source(s) of the Offset Dikes and the associated sulfide mineralization. Based on stable isotope ratios and petrographic observations, two distinct types of sulfide mineralization hosted within the Offset Dikes are identified. Massive sulfide …