Geologic mapping of Argyre Planitia

This report describes the results from the geologic mapping of the central and southern Argyre basin of Mars. At the Mars Geologic Mapper's Meeting in Flagstaff during July, 1993, Dave Scott (United States Geological Survey, Mars Geologic Mapping Steering Committee Chair) recommended that all four quadrangles be combined into a single 1:1,000,000 scale map for publication. It was agreed that this would be cost-effective and that the decrease in scale would not compromise the original science goals of the mapping. Tim Parker completed mapping on the 1:500,000 scale base maps, for which all the necessary materials had already been produced, and included the work as a chapter in his dissertation, which was completed in the fall of 1994. Geologic mapping of the two southernmost quadrangles (MTM -55036 and MTM -55043; MTM=Mars Transverse Mercator) was completed as planned during the first year of work. These maps and a detailed draft of the map text were given a preliminary review by Dave Scott during summer, 1993. Geologic mapping of the remaining two quadrangles (MTM -50036 and MTM -50043) was completed by summer, 1994. Results were described at the Mars Geologic Mappers Meeting, held in Pocatello, Idaho, during July, 1994. Funds for the third and final year of the project have been transferred to the Jet Propulsion Laboratory, where Tim Parker will revise and finalize all maps and map text for publication by the United States Geological Survey at the 1:1,000,000 map scale

Apron heights around stepped massifs in the Cydonia Mensae region: Do they record the local paleobathymetry of Oceanus Borealis?

The use of photoclinometry and shadow measurements to determine the basin volume without linking the measurements to a global datum is described. Since the boundary, or shoreline, of the basin cannot be tied to the datum and typically has no useful local relative height to measure, what is needed is a number of measurements of the height of the paleoshorelines distributed across the basin. Photoclinometric profiles are being compiled from Viking Orbiter images of the Cydonia Mensae region, which includes images with high sun elevations, necessary to avoid shadows, and images with low sun elevations, to enable the use of shadow measurements as an independent check, at high resolution (40 to 100 m/pixel). Both asymmetric and symmetric photoclinometric profile models are being used, and the results cross checked with one another to minimize errors. An apron-height map, potentially a paleobathymetric map of part of the margin of Oceanus Borealis, can be compiled from this data to determine whether variations in apron height are consistent with a lacustrine interpretation

Catalyst-controlled doubly enantioconvergent coupling of racemic alkyl nucleophiles and electrophiles

Stereochemical control in the construction of carbon-carbon bonds between an alkyl electrophile and an alkyl nucleophile is a persistent challenge in organic synthesis. Classical substitution reactions via S_N1 and S_N2 pathways are limited in their ability to generate carbon-carbon bonds (inadequate scope, due to side reactions such as rearrangements and eliminations) and to control stereochemistry when beginning with readily available racemic starting materials (racemic products). Here, we report a chiral nickel catalyst that couples racemic electrophiles (propargylic halides) with racemic nucleophiles (β-zincated amides) to form carbon-carbon bonds in doubly stereoconvergent processes, affording a single stereoisomer of the product from two stereochemical mixtures of reactants

VIRTUAL PROGRAMMING INSTRUMENT EXTENDED HEWLETT-PACKARD [VPI/EHP]

No abstract available

The American Historical Playing Card Deck

American Bicentennial Historical Playing Card Deck, made by U.S. Games Systems. Includes deck of cards (3948 A), booklet (3948 B), and two-piece box (3948 C) with text, etc. This object is a small red book with seal of the United States of America on the front cover. On the back of the book, there are four images of prominent figures from American history including: Ulysses S. Grant, George Washington and others. created by Stuart R. Kaplan (1932-present), illustrated by Douglas Gorsline (American, 1913\u271985), published by U.S. Games Systems, Inc. (American, 1968-present)https://scholarsjunction.msstate.edu/fvw-artifacts/4660/thumbnail.jp

Sea surface temperature changes in the southern California borderlands during the last glacial-interglacial cycle

A variety of evidence suggests that average sea surface temperatures (SSTs) during the last glacial maximum in the California Borderlands region were significantly colder than during the Holocene. Planktonic foraminiferal δ18O evidence and average SST estimates derived by the modern analog technique indicate that temperatures were 6°-10°C cooler during the last glacial relative to the present. The glacial plankton assemblage is dominated by the planktonic foraminifer Neogloboquadrina pachyderma (sinistral coiling) and the coccolith Coccolithus pelagicus, both of which are currently restricted to subpolar regions of the North Pacific. The glacial-interglacial average SST change determined in this study is considerably larger than the 2°C change estimated by Climate: Long-Range Investigation, Mapping, and Prediction (CLIMAP) [1981]. We propose that a strengthened California Current flow was associated with the advance of subpolar surface waters into the Borderlands region during the last glacial