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Hay, Richard L. Liu, Junzhe 2015-09-28T15:12:34Z 2015-09-28T15:12:34Z 10000-01-01 1997 1997 K/Ar dating of different size fractions of I/S samples reveals three episodes of illitization in the alteration profiles: 432-424 Ma, 410-383 Ma, and ${\sim}{-}314$ Ma. Rb-Sr and oxygen isotopic data suggest I/S of the 432-424 episode may have formed from the same fluids that formed the coarse-grained authigenic K-feldspar at 448-424 Ma. The most likely fluids for I/S of the younger episodes are basinal brines either driven by gravity or expelled by continental collisions during the Acadian and Alleghanian orogenies. However, sources and pathways of such fluids are yet to be determined. Made available in DSpace on 2015-09-28T15:12:34Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9737180.pdf: 9875556 bytes, checksum: 8057bdff44b6c5958141bd71e7d62f8d (MD5) Previous issue date: 1997 Embargo set by: Seth Robbins for item 87826 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 227 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1997. http://hdl.handle.net/2142/86545 (MiAaPQ)AAI9737180 eng Geology K-Metasomatism in Uppermost Precambrian Rocks in West-Central Wisconsin and Southeastern Missouri text Geology Geology University of Illinois at Urbana-Champaign Dissertation Ph.D.