...N. Mortimer; K. Hoernle; F. Hauff; J.M. Palin; W.J. Dunlap; R. Werner; K. Faure Abstract We present analytical results from four dredge locations across the eastern Zealandia continental margin and adjacent ocean crust. The 115 Ma dacites dredged from the West Wishbone Ridge (WWR) are isotopically...

...Rupert Sutherland; Chris Hollis Abstract Radiolaria and paleomagnetic data from Deep Sea Drilling Project Sites 595 and 596 indicate that Early Cretaceous seafloor was formed at moderate to high latitudes in the Pacific. This inference requires a Cretaceous spreading ridge south of the Pacific...

...Figure 7. Geologic map of the Wishbone Hill area. Note left-lateral faults, synclinal axis, the Moose Creek thrust, and dikes. Key to map units: Qag—alluvial and glacial deposits; Qls—landslide debris; Ti—intrusive rocks (dikes); Tt—Tsadaka Formation; Tw—Wishbone Formation; Tc—Chickaloon Formation...

... glacial features that have survived to the present day. In this paper we describe and interpret the geological evidence of erosion and deposition exposed by the retreat of a cold-based glacier in the Allan Hills, Antarctica. The Allan Hills (76°42′S, 159°40′E) form a wishbone-shaped nunatak located...

... of the Chickaloon shows lithofacies characteristic of marginal marine settings ( Trop et al., 2003 ) and thus the basin was likely at low elevation throughout its depositional history. As the basin filled, coarser alluvial deposits prograded across the paleovalley depositing the Wishbone Formation, which...

...Figure 5. Geologic map of the Wishbone Hill fold, Matanuska Valley (Fig. 2) . Resistant ridge of calcite and siderite veins and cement occurs in the Eska fault, a left-lateral cross-fault that offsets Paleocene and Eocene strata in the Wishbone Hill fold. Qac—Quaternary glacial and fluvial...

... field strength elements (e.g., Zr, Hf, Ti, Y) similar to mid-ocean-ridge basalt and with variable enrichment in fluid-mobile elements (e.g., Cs, Ba, and Pb). Intermediate and felsic rocks show enrichment in the rare earth elements and fluid-mobile elements plus Rb and K, but retain low La/Yb ratios...

... Apatite FT D.S. 80 ± 14 Chatham Islands, Point Somes P82316 −43.8450 −176.8546 0 Greyschist TZ3 155 Ma K–Ar wr 3 Zircon He B.K. 108 ± 8 Wishbone Ridge dredge, 2900 m P67415 −40.7607 −169.8438 0 Sandstone 115 ± 1 Ma U–Pb det zc 4 Apatite He B.K. 110 ± 10 Takahe Seamount...

...Arthur Grantz; Jack A. Wolfe Fig. 2. Generalized geologic map of lower Matanuska Valley, showing type area of Arkose Ridge Formation, fossil plant localities, and location of some possibly correlative beds. 1 Manuscript received, June 9, 1961. Publication authorized...

... and are interpreted as Miocene or younger ( Barnes, 1966 ; Reed and Nelson, 1980 ). Cenozoic strata in the Matanuska remnant forearc basin are Paleocene to Oligocene in age and represent deposition in nonmarine and marginal marine environments. The Paleocene to Eocene Wishbone, Chickaloon, and Arkose Ridge...

... Plateau; CR—Chatham Rise; HP—Hikurangi Plateau; W—Wishbone Ridge; Chall—Challenger Plateau; SLHR—South Lord Howe Rise; STR—South Tasman Rise; ET—East Tasman Rise; SNR—South Norfolk Ridge; IB—Iselin Bank; MCC—metamorphic core complex. ...

... provenance record of a forearc basin modified by slab-window magmatism: detrital-zircon geochronology and sandstone compositions of the Paleogene Arkose Ridge Formation, south-central Alaska . Basin Res. 26 : 436 – 460 . Lathram , E. ; Pomeroy , J. ; Berg , H. ; and Loney , R. 1965...

.... 8a. The Tsadaka Formation as used by Barnes and Payne (1956) contains a pollen flora similar to some part of the Tertiary sequence in the Kenai lowland (Paul Wesendunk, palynologist, Standard Oil Co. of California, oral communication, 1961). 8b. No fossils are known from the Wishbone Formation...

... and folding ( Kirschner and Lyon, 1973 ; Boss et al., 1976 ). Intersection of an oceanic spreading center (possibly the Kula-Resurrection ridge; Haeussler et al., 2003 ) with the continental margin of southern Alaska formed a slab window beneath the North American plate margin in Paleocene-Eocene time (e.g...

... with subduction of an actively spreading ridge, and similar ridge subduction may have been involved in the older event. The Otago Schist belt of southern New Zealand (Fig. 1 ) hosts numerous orogenic gold deposits and occurrences distributed throughout 40,000 km 2 of mainly greenschist facies host rocks...

... spreading-ridge subduction. We apply 40 Ar/ 39 Ar, apatite fission-track (AFT), and apatite (U-Th)/He (AHe) geochronology and thermochronology to plutonic and volcanic rocks in the southern Talkeetna Mountains of Alaska to document regional magmatism, rock cooling, and inferred exhumation patterns...