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Metamorphosed silicic volcanic and hypabyssal rocks of middle Cretaceous (110 to 100 Ma) age occur in two roof pendants in the Kings Canyon area of the central Sierra Nevada. The metavolcanic remnants are similar in age to or are only slightly older than the voluminous enclosing batholithic rocks. Thus, high...

A marine sampling program, utilizing the PISCES-5 submersible operated by the Hawaii Undersea Research Laboratory (NOAA), has confirmed the presence of a major submerged coral reef offshore from Ka Lae (South Point), Hawaii. The top of the reef is now 150–160 m below sea level. Radiocarbon and Useries dating indicates...

Side-looking sonar (GLORIA) mapping has revealed a series of four arcuate bands of high sonic backscatter on the crest of the Haleakala Ridge, a major rift-zone ridge extending 135 km east of the island of Maui. Dredge recovery indicates that the shallowest of these bands is a drowned coral reef,...

The basal slip systems of biotite and their mechanical expressions have been investigated by shortening single crystals oriented to maximize and minimize shear stresses on (001). Samples loaded at 45° to (001) exhibit gentle external rotations associated with dislocation glide. High‐angle kink bands in these samples, unlike those developed in...

Correspondence analysis of dicot leaf physiognomy of modern vegetational samples from a wide range of environments indicates that >70% of physiognomic variation corresponds to water or temperature factors, or both. Despite wide variation in single physiognomic characters, overall trends can be used to distinguish between samples from different climates. Some...

Colorado River extensional corridor. In the Mohave Mountains and Aubrey Hills of Arizona and the eastern Whipple Mountains of California near Parker Dam, these deposits comprise four unconformity-bounded sequences composed of locally derived epiclastic and volcanic rocks and the Peach Springs Tuff. The three older sequences represent syntectonic units that...

Food habits of grizzly bears were studied for 11 years in the Yellowstone area of Wyoming, Montana, and Idaho by analyzing scats. Ungulate remains constituted a major portion of early-season scats, graminoids of May and June scats, and whitebark pine seeds of late-season scats. Berries composed a minor...

When lake trout Salvelinus namaycush were subjected to a single attack by a sea lamprey Petromyzon marinus in laboratory tests in 1986, percentage mortality was significantly higher in small fish (64%; 469-557 mm; N = 67) than in medium (44%; 559-643 mm; N = 45) or large fish (43%; 660-799...

Shortly after the introduction of the extraterrestrial-impact hypothesis of the terminal Cretaceous event (TCE), plant microfossils, which had been used to locate the Cretaceous/Tertiary (K/T) boundary in nonmarine rocks, became critical to its precise identification; they continue to serve in this capacity. The K/T boundary in nonmarine rocks from New Mexico to Alberta is identified by the coincidence of a palynological extinction horizon...

Morphological, seismic-reflection, and sedimentological evidence indicates that glacial ice tongues cut large sea valleys into the Gulf of Alaska continental shelf during the Pleistocene. During the Holocene, glacially-derived sediments from the Copper River and other meltwater streams have been prograding seaward across the shelf, covering the glacial and glacimarine upper...

Structural relief resulting from middle Tertiary extensional deformation in the Chemehuevi Mountains exposes a unique cross section through a temporally and compositionally zoned (both vertically and horizontally), laccolith-shaped intrusion of Late Cretaceous age. The calc-alkalic, metaluminous to peraluminous Chemehuevi Mountains Plutonic Suite exhibits crude normal, vertical, and temporal zonation. The...

Landsat-5 Thematic Mapper (TM) and SPOT data collected two years apart from an identical area of Dronning (Queen) Maud Land, Antarctica, have been analyzed to detect variations in surface features that may signal climatic change, and to establish a technique that readily identifies such changes. We found that selective principal...

The Slinkard pluton (SP) and Wooley Creek batholith (WCB) are the lower and upper parts, respectively, of a tilted Middle Jurassic magma system. The SP and lower WCB intruded structurally lower ophiolitic mélange of the Marble Mountain terrane; the upper WCB intruded successively structurally higher metavolcanic and metasedimentary rocks of...

No abstract available....

Variations in initial 143Nd/144 Nd in Late Cretaceous plutonic rocks along the South Fork of the Clearwater River (SFCR) supplement results of Sr and O studies, which demonstrate large-scale mixing in magmas forming the western margin of the Idaho batholith. These marginal or border phases of the batholith span the terrane boundary...

Chemical and isotopic characteristics of plutons in the western United States reflect compositions and protoliths of subjacent source materials. A discontinuously exposed shear zone that extends along the length of the Sierra Nevada in California marks a boundary between two areas manifested geologically by wall-rock and roof-pendant lithologies of different...

No abstract available....

Jurassic plutons in the east-central Mojave Desert region are markedly different from older and younger Mesozoic plutons in the region. They form a chemically and texturally heterogeneous group that ranges in composition from diorite to syenogranite; some phases are alkalic. Igneous rocks in the southern Bristol Mountains, southern Providence Mountains,...

We evaluated the ability of three condition indices-condition factor (K), relative condition (Kn), and relative weight (Wr)-to estimate annual growth rates of largemouth bass Micropterus salmoides and white crappies Pomoxis annularis collected during standardized autumn electrofishing and trap-net surveys of Texas reservoirs. Multiple-regression models for estimation of length increments from...

No abstract available....

The Earth Science Information Centers (ESIC) distribute digital cartographic/geographic data files produced by the U.S. Geological Survey (USGS) as part of the National Mapping Program. Digital cartographic data flles are grouped into four basic types. The first of these, called a Digital Line . Graph (DLG), is line map information...