... of this survey, the two alternative hypotheses to explain the seismic data must be reconsidered. These are (1) the existence of a crustal low velocity zone, and (2) a major deformation of the basement and overlying rocks due to the trench being an ancient zone of weakness, which coincides with the western limit...

...J. R. Allan; R. K. Matthews Abstract Carbon isotopic values reported in the literature for low-magnesium calcite Pleistocene limestones are generally more negative than −4‰ PDB, while values reported for most ancient limestones are more positive than −2‰ PDB. This relationship has recently led...

... in the accretion of the flanks of carbonate platforms. Micritic carbonate build-ups similar to lithoherms have been recognized in the geologic record. The mounds of the Waulsortian bank margin offer one possible ancient analog. Geological Society of America 1977 ...

...Frederic L. Schwab Abstract The rate at which sedimentary fill accumulates in both modern and ancient depositional basins is related to plate tectonic setting, among other factors. The tectonic setting of any basin can be specified in terms of type of substratum (oceanic, continental...

... maintained for one billion years or more. This ancient age implies that the source region is divorced from the source regions for ocean-floor basalts. Geological Society of America 1976 *Present address: U.S. Geological Survey, Menlo Park, California 94025 ...

...MAGNUS S. GARSON; MIROSLAV KRS Abstract Wilson's concept that transform faults were initiated along ancient fractures is supported by evidence from southeastern Egypt. Geophysical and geological investigations have outlined blocks bounded by transverse fractures oriented perpendicular to the Red...

... of naturally silicified algae, demonstrate that certain morphologies are artifacts of the silicification process, and suggest possible explanations of observed organic chemical trends in recent and ancient sediments. Geological Society of America 1976 Precambrian paleontology experimental...

...Frederic L. Schwab Abstract Compositional data for modern deep-sea sand and ancient graywacke were used by Crook to postulate that Atlantic, Andean, and western Pacific continental margin types could be distinguished on the basis of unique composition—a progressive decrease in framework quartz...

... ( Deffeyes et al, 1965 ), capillary pumping ( Shinn et al, 1965 ), and solution-cannibalization ( Goodell and Garman, 1969 ) are all inadequate to account for most ancient dolomites. Reflux is an easily grasped hypothesis but is subject to the objection of being hydrologically unlikely and requires...

... probably higher than 40. Our model of lacustrine carbonate formation and transformation offers an explanation for the genesis of Ilich’s Braneshci dolomite deposit. It represents an ancient B-1 stage (type Neusiedler See) with high-magnesian calcite as a primary carbonate mineral deposited at a Mg/Ca...

...M. J. Kocurko Abstract San Andres is a small coralline island 136 km east of the Caribbean coast of Nicaragua. Surface mapping and paleontologic data indicate reefs have been growing actively in the area at least since early Miocene time. Because of the offlap relations of the ancient reef...

... the reefs. Although the effects of these influences usually can be documented in studies of recent reefs, their determination in fossil settings is commonly obscure. This may preclude the use of recent reefs as explicit analogues of ancient ones. The applicability and limitations of such comparisons...

... topography controlled the limits of many modern and ancient shallow-water carbonate platforms. In 1971 Dodd and Siemers showed that the thickness and distribution pattern of Holocene sediments in the Lower Florida Keys was controlled strongly by underlying karst topography. These few, but by no means...