Multiple hydrothermal and metamorphic events in the Kidd Creek volcanogenic massive sulphide deposit, Timmins, Ontario: evidence from tourmalines and chlorites
J. F. Slack, P.R. Coad
1989, Canadian Journal of Earth Sciences (26) 694-715
Tourmaline and chlorite are the principal ferromagnesian silicate minerals in the Kidd Creek massive sulphide deposit. Tourmaline is most common in sphalerite-rich peripheral margins of the chalcopyrite stringer zone. Within the north orebody, samples typically contain <1% tourmaline, but small areas (hand-specimen scale) may have 10–20%. Chlorite is more widely...
Geochemical signatures of possible deep-seated ore deposits in Tertiary volcanic centers, Arizona and New Mexico, U.S.A.
K. C. Watts Jr., J.R. Hassemer
1989, Journal of Geochemical Exploration (32) 413-414
A reconnaissance geochemical survey of stream drainages within 21,000 km2 of southeastern Arizona and southwestern New Mexico shows broad zones of low-level to moderate contrast anomalies, many associated with mid-Tertiary eruptive centers and Tertiary fault zones. Of these eruptive centers, few are...
Geochemistry of intrusive rocks associated with the Latir volcanic field, New Mexico, and contrasts between evolution of plutonic and volcanic rocks
C.M. Johnson, G.K. Czamanske, P. W. Lipman
1989, Contributions to Mineralogy and Petrology (103) 90-109
Plutonic rocks associated with the Latir volcanic field comprise three groups: 1) ???25 Ma high-level resurgent plutons composed of monzogranite and silicic metaluminous and peralkaline granite, 2) 23-25 Ma syenogranite, and alkali-feldspar granite intrusions emplaced along the southern caldera margin, and 3) 19-23 Ma granodiorite and granite plutons emplaced south...
The nature of the crust in the Yukon-Koyukuk province as inferred from the chemical and isotopic composition of five Late Cretaceous to Early Tertiary volcanic fields in western Alaska
E. Moll-Stalcup, Joseph G. Arth
1989, Journal of Geophysical Research Solid Earth (94) 15989-16020
Late Cretaceous and early Tertiary volcanic and plutonic rocks in western Alaska comprise a vast magmatic province extending from the Alaska Range north to the Arctic Circle, south to Bristol Bay, and west to the Bering Sea Shelf. The chemical and isotopic composition of five of these Late Cretaceous to...
Contribution of metapelitic sediments to the composition, heat production, and seismic velocity of the lower crust of southern New Mexico, U.S.A.
M. R. Reid, S.R. Hart, E.R. Padovani, G.A. Wandless
1989, Earth and Planetary Science Letters (95) 367-381
Granulite xenoliths erupted at Kilbourne Hole maar were recently extracted from the lower crust of southern New Mexico. Garnet- and sillimanite-bearing quartzofeldspathic xenoliths had pelitic protoliths and were probably emplaced in the lower crust by tectonic underplating at a lower Proterozoic...
The Relief Canyon gold deposit, Nevada: A mineralized solution breccia
A. R. Wallace
1989, Economic Geology (84) 279-290
The Relief Canyon gold deposit in the Humboldt Range of western Nevada is a low-grade, high-tonnage orebody of Tertiary or younger age. The host rocks include limestones of the Triassic Cane Spring Formation, which are overlain by shales of the Triassic Grass Valley Formation. The rocks were folded and metamorphosed...
Pillow basalts of the Angayucham terrane: Oceanic plateau and island crust accreted to the Brooks Range
J.S. Pallister, J. R. Budahn, B.L. Murchey
1989, Journal of Geophysical Research Solid Earth (94) 15901-15923
The Angayucham Mountains (north margin of the Yukon-Koyukuk province) are made up of an imbricate stack of four to eight east-west trending, steeply dipping, fault slabs composed of Paleozoic (Devonian to Mississippean), Middle to Late Triassic, and Early Jurassic oceanic upper crustal rocks (pillow basalt, subordinate diabase, basaltic tuff, and...
Petrologic evolution of divergent peralkaline magmas from the Silent Canyon caldera complex, southwestern Nevada volcanic field
D.A. Sawyer, K. A. Sargent
1989, Journal of Geophysical Research Solid Earth (94) 6021-6040
The Silent Canyon volcanic center consists of a buried Miocene peralkaline caldera complex and outlying peralkaline lava domes. Its location has been corroborated by geophysical data and more than 50 drill holes. Two widespread ash flow sheets, the Tub Spring and overlying Grouse Canyon members of the Miocene Belted Range...
Upper Jurassic mafic magmatic rocks of the eastern Klamath Mountains, northern California: remnant of a volcanic arc built on young continental crust
M. Brouxel, H. Lapierre, J.-L. Zimmermann
1989, Geology (17) 273-276
Diabasic and gabbroic dikes intruding the lower Paleozoic Trinity Ophiolite in the Lovers Leap section, Klamath Mountains, California, display strong calc-alkalic petrological and geochemical features (occurrence of primary amphiboles, zoned plagioclase phenocrysts and biotite, low TiO2, high incompatible trace-element contents, and light rare...
Isotopic and trace element variations in the Ruby Batholith, Alaska, and the nature of the deep crust beneath the Ruby and Angayucham Terranes
Joseph G. Arth, Clara C. Zmuda, Nora K. Foley, Robert E. Criss, W. W. Patton Jr., T. P. Miller
1989, Journal of Geophysical Research B: Solid Earth (94) 15941-15955
Thirty-six samples from plutons of the Ruby batholith of central Alaska were collected and analyzed for 22 trace elements, and many were analyzed for the isotopic compositions of Sr, Nd, O, and Pb in order to delimit the processes that produced the diversity of granodioritic to granitic compositions, to deduce...
Review of magnetic and electric field effects near active faults and volcanoes in the U.S.A.
M.J.S. Johnston
1989, Physics of the Earth and Planetary Interiors (57) 47-63
Synchronized measurements of geomagnetic field have been recorded along 800 km of the San Andreas fault and in the Long Valley caldera since 1974, and during eruptions on Mount St. Helens since 1980. For shorter periods of time, continuous measurements of geoelectric field measurements have been made on Mount St....
Igneous history of the Koyukuk terrane, western Alaska: Constraints on the origin, evolution, and ultimate collision of an accreted island arc terrane
S. E. Box, W. W. Patton Jr.
1989, Journal of Geophysical Research Solid Earth (94) 15843-15867
The Koyukuk terrane of western Alaska consists of volcanic, volcaniclastic, and plutonic rocks which range from Late Paleozoic to Early Cretaceous in age. The terrane crops out in a U-shaped belt which is roughly paralleled by outer belts of ultramafic rocks, oceanic plate basalts and cherts, and retrograded blueschist facies...
The role of catastrophic geomorphic events in central Appalachian landscape evolution
R. B. Jacobson, A.J. Miller, J. A. Smith
1989, Geomorphology (2) 257-284
Catastrophic geomorphic events are taken as those that are large, sudden, and rare on human timescales. In the nonglaciated, low-seismicity central Appalachians, these are dominantly floods and landslides. Evaluation of the role of catastrophic events in landscape evolution includes assessment of...
Back-arc with frontal-arc component origin of Triassic Karmutsen basalt, British Columbia, Canada
F. Barker, Brown A. Sutherland, J. R. Budahn, George Plafker
1989, Chemical Geology (75) 81-102
The largely basaltic, ???4.5-6.2-km-thick, Middle to Upper Triassic Karmutsen Formation is a prominent part of the Wrangellian sequence. Twelve analyses of major and minor elements of representative samples of pillowed and massive basalt flows and sills from Queen Charlotte and Vancouver Islands are ferrotholeiites that show a range of 10.2-3.8%...
Remarkable isotopic and trace element trends in potassic through sodic Cretaceous plutons of the Yukon-Koyukuk Basin, Alaska, and the nature of the lithosphere beneath the Koyukuk terrane
Joseph G. Arth, Robert E. Criss, Clara C. Zmuda, Nora K. Foley, W. W. Patton Jr., T. P. Miller
1989, Journal of Geophysical Research B: Solid Earth (94) 15957-15968
During the period from 110 to 80 m.y. ago, a 450-km-long magmatic belt was active along the northern margin of Yukon-Koyukuk basin and on eastern Seward Peninsula. The plutons intruded Upper Jurassic(?) and Lower Cretaceous volcanic arc rocks and Cretaceous sedimentary rocks in Yukon-Koyukuk basin and Proterozoic and lower Paleozoic...
Significance of loessite in the Maroon Formation (Middle Pennsylvanian to Lower Permian), Eagle Basin, northwest Colorado
S. Y. Johnson
1989, Journal of Sedimentary Petrology (59) 782-791
Quaternary loess deposits are widespread on the earth's surface, yet pre-Quaternary loess deposits have rarely been reported. The Maroon Formation (Middle Pennsylvanian to Lower Permian) of the Eagle Basin, northwest Colorado, includes a siltstone-dominated facies interpreted as loessite (lithified loess) along its downwind...
Replacement of native oak and hickory tree species by the introduced American chestnut (Castanea dentata) in southwestern Wisconsin
Frederick L. Paillet, P. A. Rutter
1989, Canadian Journal of Botany (67) 3457-3469
American chestnut was introduced at West Salem, Wisconsin, about 1880 and had begun to replace native tree species in adjacent oak-hickory woodland before 1930. Chestnut is now an important canopy species over about 20 ha of forested ridge extending north and south of the original plantation. A smaller area of less...
River Valley pluton, Ontario: A late-Archean/early-Proterozoic anorthositic intrusion in the Grenville Province
L.D. Ashwal, J. L. Wooden
1989, Geochimica et Cosmochimica Acta (53) 633-641
The River Valley pluton is a ca. 100 km2 body of anorthositic and gabbroic rocks located about 50 km northeast of Sudbury, Ontario. The pluton is situated entirely within the Grenville Province, but its western margin is a series of imbricate thrust faults associated with the Grenville Front Tectonic Zone. It is...
Enrichment of trace elements in garnet amphibolites from a paleo-subduction zone: Catalina Schist, southern California
Sorena S. Sorensen, J. N. Grossman
1989, Geochimica et Cosmochimica Acta (53) 3155-3177
The abundance, P-T stability, solubility, and element-partitioning behavior of minerals such as rutile, garnet, sphene, apatite, zircon, zoisite, and allanite are critical variables in models for mass transfer from the slab to the mantle wedge in deep regions of subduction zones. The influence of these minerals on the composition of subduction-related magmas...
Ferruginous hawk
R.S. Hall, R.L. Glinski, D. H. Ellis, J.M. Ramakka, D.L. Base
Richard L. Glinski, Beth Giron Pendleton, Mary Beth Moss, Maurice N.= LeFranc Jr., Brian A. Millsap, Stephen W. Hoffman, editor(s)
1988, Book chapter, Proceedings of the Southwest Raptor Management Symposium and Workshop
In the Southwest, the ferruginous hawk is a local and isolated breeder and an uncommon but consistent winter visitor. Apparently, the breeding range of this species in the Southwest was historically much greater than today. The ferruginous hawk is being considered for listing by the U.S. Fish and Wildlife Service...
Bias of animal population trend estimates
P.H. Geissler, W.A. Link
E.J. Wegman, D.T. Gantz, J. J. Miller, editor(s)
1988, Book chapter, Computing Science and Statistics: Proceedings of the 20th Symposium on the Interface
A computer simulation study of the population trend estimator used for the Mourning Dove Call-Count Survey, Woodcock Singing Ground Survey, Breeding Bird Survey and other surveys concluded that the estimator had negligible bias in most situations but that observer covariables should not be used with less than five years of...
Lacustrine varve formation through time
R.Y. Anderson, W.E. Dean
1988, Palaeogeography, Palaeoclimatology, Palaeoecology (62) 215-235
Studies using sediment traps in lakes reveal that the seasonal flux of sediment regulates both the composition and timing of deposition of materials that reach the bottoms of lakes. If the bottom waters of a lake are partly or totally anoxic, the seasonally deposited materials are preserved as annual groupings...
Mines, prospects, and mineral sites, wilderness and RARE II areas, White Mountain National Forest, New Hampshire
G. C. Gazdik, Gazdik Harris, R. A. Welsh, V. P. Girol
1988, Miscellaneous Field Studies Map 1594-E
The Wilderness Act (Public Law 88-577, September 3, 1964) and related acts require the U.S. Geological Survey and the U.S. Bureau of Mines to survey certain areas on Federal lands to determine their mineral value, if any, that may be present. Results must be made available to the public and...
Trace element and rare earth element variation in fluorites collected from skarn and epithermal mineral deposits in the Sierra Cuchillo area, south-central New Mexico
R. G. Eppinger
1988, Open-File Report 88-566
Geology and resources of thorium and associated elements in the Wet Mountains area, Fremont and Custer counties, Colorado
T.J. Armbrustmacher
1988, Professional Paper 1049-F
Thorium in potentially economic amounts occurs in three types of deposits in the Wet Mountains area of Colorado: (1) quartz-baritethorite veins and fracture zones, (2) carbonatite dikes, and (3) red syenite dikes. The quartz-barite-thorite veins and fracture zones contain the largest resources of thorium; they cut all Precambrian and Paleozoic...
