Publications

No abstract available.

Sixty-four major element analyses of rocks representative of the Coast Range ophiolite in California were compared with analyses of other onland ophiolite sequences and those of rocks from oceanic ridges. The rocks can be classed in five groups harzburgite-dunite, clinopyroxenite-wehrlite, gabbro, basalt-spilite, and keratophyre-quartz keratophyre which on various diagrams occupy nonoverlapping fi

Thirty-three morphologic characteristics are reviewed for fresh lunar impact craters wide than1 km. Bar graphs express the way each characteristic varies with crater size. The features are grouped as crater structure, ejecta, and downhill flow features. Major structural transition occur at diameters of about 15 and 200 km. Details of the ejecta blanket, which include several kinds of lineations, d

No abstract available.

No abstract available.

Multiring impact basins, formed after solidification of the lunar crust, account for most or all premare regional deposits and structures expressed in the lunar landscape and for major topographic and gravity variations. A fresh basin has two or more concentric mountain rings, a lineated ejecta blanket, and secondary impact craters. Crackled material on the floor may be impact melt. The ejecta bla

No abstract available.

In northern California, chaotic Franciscan melange occurs beneath the overlying ophiolite and Great Valley Sequence. Identical melanges occur to the west, separating well-bedded, coherent Franciscan units that differ markedly in age. Detailed studies in several places indicate that these melanges mark the boundaries of imbricate thrust sheets, and they appear to occur at several discrete structura

No abstract available.

Apollo 17 landed in a deep graben valley embaying the mountainous highlands southeast of the Serenitatis basin. Impact-generated breccias underlie the massifs adjacent to the valley, and basalt has flooded and leveled the valley floor. The dark mantle inferred from orbital photographs was not recognized as a discrete unit; the unusually thick regolith of the valley floor contains a unique high con

No abstract available.

Geologic evidence suggests that the Dun Mountain ultramafic belt in New Zealand is the basal part of a Lower Permian ophiolite suite. By analogy with other ophiolite suites, and as a result of marine geophysical studies of the present ocean basins, the ophiolite is believed to represent oceanic crust and upper mantle upon which the Upper Permian Maitai Group was deposited. After this, much of the