| Abstract: | Thirteen deposits or districts in the western U.S. have been examined in which titaniummineral
resources have been reported or implied. These deposits are of the following
general types (in probable order of importance): 1) Cretaceous shoreline placer deposits,
2) silica-sand deposits of California, 3) fluvial monazite placers of Idaho, 4) anorthositerelated
deposits, and 5) clay and bauxite deposits of the northwestern U.S.
Relative to previous reports, this one shows some greater and some lesser
resources (table 1). In any case, titanium-mineral resources of the western U.S. (west of
103o longitude) remain modest at world scale except as unconventional (especially
perovskite) and by-product (especially porphyry) resources. Some deposits, however,
have enhanced value to the titanium explorationist for the geologic relations they
illustrate. Among the new conclusions are:
a) Loci of Cretaceous shoreline placers form linear patterns, nested as a function of age,
that can be traced for thousands of kilometers, permitting focused exploration in whole
new mountain ranges.
b) Medial hematite-ilmenite solid-solution, which is highly magnetic, is a major carrier of
TiO2 values in the Cretaceous deposits of Wyoming. This phase was previously thought
to be relatively rare.
c) Regressive shoreline placer deposits in indurated Cretaceous sequences expose
intricate facies relations, such as the construction of shoreface sequences by long-shore
drift over tidal-channel fill, without much loss of paleogeographic information.
d) Due to deep weathering, virtually every Eocene sediment that accumulated in the Ione
basin at the foot of the Sierra Nevada has economic value, permitting recovery of altered
ilmenite and zircon along with silica, clay, coal, and gold. Ilmenite is most abundant in
newly recognized shoreline sands.
e) Upper Tertiary fluvial placers of Idaho formed in and filled fault-bounded basins and
thus are far more voluminous than deposits in the modern valley system. Previously
reported resources are thus far too low.
f) Mafic igneous rocks of Proterozoic age near Bagdad, Arizona are of ophiolitic affinity,
but contain nelsonitic ilmenite enrichments associated with anorthositic layers. |
| Genre: | USGS Numbered Series |
| ProdID: | 23050 |
| Citation Author: | Force, Eric R.; Creely, Scott |
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| Citation Language: | ENGLISH |
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| Citation Phsyical Description: | 34, [9] leaves :ill., maps ;28 cm. |
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| Citation Publisher: | U.S. Dept. of the Interior, U.S. Geological Survey, |
| Citation Series: | Open-File Report |
| Citation Series Code: | OFR |
| Citation Series Number: | 2000-442 |
| Citation Search Results Text: | Titanium mineral resources of the western U.S. : an update; 2000; OFR; 2000-442; Force, Eric R.; Creely, Scott |
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| Citation Year: | 2000 |
| Type: | citation/reference |
| Text: | Titanium mineral resources of the western U.S. : an update; 2000; OFR; 2000-442; Force, Eric R.; Creely, Scott |
| URL (THUMBNAIL): | http://pubs.usgs.gov/of/2000/0442/report-thumb.jpg |
| URL (INDEX PAGE): | http://geopubs.wr.usgs.gov/open-file/of00-442/ |
| URL (DOCUMENT): | http://pubs.usgs.gov/of/2000/0442/report.pdf |
| Date Other: | Sat, 1 Dec 2001 00:00 -0600 |
| Publisher: | U.S. Dept. of the Interior, U.S. Geological Survey, |
