Canonical forms for symplectic and Hamiltonian matrices

This paper gives a constructive method for finding canonical forms for symplectic and Hamiltonian matrices. No restrictions are made on the eigen values or their multiplicity. Real canonical forms are treated in detail.     

The Hadley Rille enstatite chondrite and its agglutinate-like rim: Impact melting during accretion to the Moon

Abstract— Hadley Rille is a millimeter-size EH chondrite containing euhedral and acicular enstatite grains, kamacite globules and preferentially aligned silicate aggregates separated by elongated kamacite-rich patches. The Hadley Rille chondrite was significantly impact melted when it accreted to the lunar regolith at relative velocities of ～>3 km s^?1; ～65–75% of the chondrules present initially were melted. During the impact, portions of the local regolith were melted and an agglutinate-like rim formed around the chondritic projectile; the rim consists of flow-banded vesicular glass, blebs of troilite and low-Ni metallic Fe, rock fragments, glass(?) shards, and mineral grains. The mineral grains include enstatite (which is otherwise absent from the Moon and must have been derived from the projectile) and poorly characterized, micrometer-size phases enriched in light rare-earth-elements (LREE), which probably formed during the impact. Several of the rock fragments contain <33 mg/g Cl, which was probably derived through impact-induced volatilization of Cl from chondrule mesostases in the EH projectile.     

Interaction between aggrading geomorphic surfaces and the formation of a late pleistocene paleosol in the palouse loess of eastern Washington state

Variable rates of loess deposition contributed to dramatic regional variation in a soil-stratigraphic unit, the Washtucna Soil, in the Palouse loess deposits in the Channeled Scabland of eastern Washington state. Throughout most of the Channeled Scabland, the morphology of the Washtucna Soil is that of a single buried soil, but it bifurcates into two well-developed and pedologically distinct buried soils in areas immediately downwind of the major source of loessial sediment. Regional loess stratigraphy confirms that the two well-developed soils formed during the same interval of time during which only one soil formed in areas that are distal to loess source areas. The variable and perhaps rapid rates of soil formation suggested by the stratigraphy resulted from an interaction between variable rates of loess deposition and the formation of superimposed calcic soils. Petrocalcic horizons with weak Stage IV morphology formed as the zone of carbonate accumulation moved up into former A and cambic horizons that had been profusely burrowed by cicadas. The development of cicada burrows in one phase of soil development that were subsequently engulfed by pedogenic carbonate under a rising land surface seems to have greatly accelerated the development of the petrocalcic horizons. Accelerated rates of formation of the petrocalcic horizons occurred when extrinsic (pulses of loess deposition) and intrinsic (engulfment of burrowed horizons) thresholds were exceeded. Stratigraphic evidence suggests that the soil formation that accompanied the rise in the land surface due to additional loess deposition may have occurred during the late Wisconsin glaciation when giant glacial outburst floods in the channeled Scabland triggered a new cycle of loess deposition.     

An orthographic photomap of the south pole of Mars from Marina 7

Television pictures of the south polar regions of Mars obtained by the Mariner 6 and 7 spacecraft in 1969 are rectified to a standard mapping projection using computer image processing techniques. Mosaicking of these pictures produces the first photomap of the entire south polar cap.     

The nature and origin of Boulder 1, Station 2, Apollo 17

The Boulder 1 breccias are similar in composition to other Taurus-Littrow massif samples and therefore probably derived from the same source, undoubtedly the Serenitatis basin. However, they are substantially different in texture from other Apollo 17 massif rocks, indeed are very nearly unique among the rocks returned by all Apollo missions. The boulder is set apart by its content of dark, rounded inclusions or bombs, up to several tens of centimeters in dimension, consisting largely of very fine, angular, mineral debris, welded together by a lesser amount of extremely fine-grained material that appears to be devitrified glass. To account for these uncommon structures, a phase of the basinforming impact event is sought that would produce relatively small amounts of debris and deposit them on or near the basin rim. It is suggested that the components of the boulder might represent very early, high angle ejecta from the Serenitatis event, and that the dark breccia inclusions are accretional structures formed from a cloud of hot mineral debris, melt droplets, and vapor that was ejected at high angles from the impact point soon after penetration of the Serenitatis meteoroid. This small amount of early high-angle ejecta would have remained in ballistic trajectories while the main phase of crater excavation deposited much larger amounts of deeper-derived debris and melt-rock on the rim of the basin, after which the early ejecta was deposited as a cooler (～450°C) stratum on top. The matrix of this breccia gained its modest degree of coherency by thermal sintering as the capping stratum cooled. The boulder is a fragment of this layer, broken out and rolled to the foot of the South Massif ? 55 m.y. ago.