An April–May 2000 ‘‘Coon Creek Fire’’ burned f 37.5 km of the Sierra Ancha Mountains, 32.3 km miles north of Globe, AZ—including 25 sandstone and 19 diorite boulders surveyed in 1989 and resurveyed after the burn, after the summer 2000 monsoon season, and after the winter 2001 season. When viewed from the perspective of cumulative eroded area, both sandstone and diorite displayed bimodal patter...

[1] Field data from channels in the Henry Mountains of Utah demonstrate that abundant coarse sediment can inhibit fluvial incision into bedrock by armoring channel beds (the cover effect). We compare several small channels that share tributary junctions and have incised into the same sedimentary bedrock unit (Navajo Sandstone) but contain differing amounts of coarse diorite clasts owing to the ...

The Big Jim complex is a concentrically zoned ultramafic to felsic plutonic complex which intruded the pelitic Chiwaukum schist. Most of the major plutonic rock types (from websterite through hornblendite, gabbronorite, hornblende gabbro and diorite, to granodiorite) enclose harzburgite and metaperidotite xenoliths similar to foliated metaperidotite lenses included in the Chiwaukum schist. The ...

features of the area. Sills of hornblende-porphyritic clioritc, are part of the Hedley Intrusive suite believed to bc Latf Triassic or Early Jurassi.: (199 Ma based on U-Pb dates 0 ' zircons from the Banbury stock, 3.5 kilometres west o' Hedley). In this location the sills, which vary.from I to 2f' metres in thickness, make up almost 50 per cent '3f thl: stratigraphic column whtxe they intrude ...

Rocks ranging in composition from trondhjemite to diorite (plagiogranites) have been recovered from ocean ridges and are common constituents of ophiolites. Velocities and densities of diorite and trondhjemite from the MidAtlantic Ridge are shown to differ significantly from similar properties of metadolerite and gabbro. Compressional (V p) and shear (V s.>velocities of plagiogranites are relati...

[1] The Coast Ridge Belt (CRB, Santa Lucia Mts., central California) comprises mid-crustal rocks (750–800 C and 0.8 GPa) of the California magmatic arc. We estimated the bulk composition of the CRB and converted our results to seismic velocities expected at the observed pressures and temperatures. The bulk composition of this arc section changes abruptly at 25 km depth from a granodiorite to a ...

The Christmas copper mine is in the Banner mining district, Gila County, Arizona. It is 8 miles north of Winkelman and 22 miles south of Globe. The mine was opened in 1905; to the end of 1943 it had produced about 55,340,000 pounds of copper. In 1946 it was operated under lease. The ore is high-lime fluxing ore, required by the smelter at Hayden. The ore produced during 1942 averaged 2.16 perce...

The Wooley Creek batholith and Slinkard pluton are adjacent plutons with identical U-Pb zircon ages of 161 +4/-2 Ma. The plutons dip toward each other, which suggests that they are connected in the subsurface. Geologic and thermochemical evidence shows that the Slinkard pluton is the structurally lowest part of the system and the Wooley Creek batholith the structurally highest, with a total str...

The Neoproterozoic rocks of the Bir Madi area, south Eastern Desert, comprise a metagabbrodiorite complex (GDC) and a tonalite-granodiorite suite (TGrS). The GDC has a weak tholeiitic to strong calc-alkaline character and is made up of olivine gabbro, hornblende gabbro, diorite and monzodiorite. The olivine gabbro is characterized by abundance of augite and labradorite with pseudomorphic serpen...