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The mantle plume/rift system model developed by three of the present authors (v. C., d. T., K.) for the northern Hesperian Massif is expanded to that of an aulacogen/ensialic orogen for the entire massif. The first author (v. d. M. M.) contributes a review of the supracrustal history of the massif and its predrift adjacent areas, summarized in a time-stratigraphic table of the Cambro-Ordovician and a palinspastic-palaeogeographic sketch map of the general region in Middle Cambrian times. The infrastructural history is also reviewed, and it is concluded that the early Palaeozoic features of the Massif are consistent with those of an aulacogen oriented at a high angle to the Iapetus ocean. In the Late Palaeozoic its features changed into those of an ensialic orogen without appreciable loss of continuity as shown by the facies- and age record of sedimentary, igneous and metamorphic events.

The distribution of major components in 1847 analyses of granitoids from the Spanish Hesperian massif is summarized.

In 1863, Mr. W. H. Edwards described a male Hesperian from Michigan under the name of Hesperia Pontiac, closely resembling the species figured by Boisduval and LeConte, under the name of Arpa, as well as the larger Florida species Edwards subsequently described under the name of Pilatka. In the same paper in which Pontiac was described and immediately preceding it, he described, also from Michigan, a female under the name of Hesperia conspicua.

Geodynamics is the liaison science between physics and geology. Its purpose is to correlate data obtained by geology, geophysics, and experimental physics. The major units of the southern Hesperian sea, derived from geophysical studies and presented at the geological congress in Monaco, are described in relation to the structures of the Provence littoral zone. The M-discontinuity is less than 12 km deep under the Hesperian sea. Deformation of the mantle in the Hesperian region is an indirect consequence of the Oligocene-Burdigalian compaction. The bulging of the mantle revealed by gravimetric anomalies along the coast represents the prolongation of the principal Pyrenean axis.

A model of mantle-plume diapirism, lower crustal rejuvenation, continental rifting and incipient seafloor spreading is proposed for the Early Paleozoic lithosphere of the northern Hesperian Massif in western Galicia (NW Spain). Geological, geophysical, geochemical and geochronological data are presented that confirm and allow refinement of the model.

Male expands 1.3 inches. Al1 the wings dark brown above. The primaries throughout the middle and basal areas sparingly sprinkled with fulvous scales. This color is deepest around the stigma, which consists of a velvety black bar extending obliquely from near the middle of the submedian vein to the cell, and is often divided into two equal parts by the fourth median veinlet. A large square patch, not sprinkled with fulvous, occurs in the middle area at the termination of the cell ; and a small detached yellow spot lies immidiately below, and outward from the anterior termination of the stigma.

Upper side blackish-brown ; primaries have the costal margin to cell and nearly to apex densely covered with fulvous ; the basal area and the inner margin sprinkled with fulvous scales; and the cell wholly deep fulvous except towards the outer end, where through the middle runs an oar-shaped blackish stripe; midway between cell and apex an elongated yellow-white spot, cut into three by the sub-costal nervules, the one of these spots nearest costa nearly lost in the fulvous ground ; across the disk an oblique band of yellow-white spots, the upper one small and in the upper discoidal interspace, placed a little outside the costal spot, the lower one in the submedian interspace, the spots widening as they proceed towards inner margin, and the 3rd and 4th deeply excavated on the outer side.

It is proposed that the rapid release of water under great pressure from deeply buried aquifers is responsible for the formation of the Martian channels suggestive of catastrophic flooding (outflow channels). Fine channels in the Martian surface suggest the presence of surface water early in the history of the planet, which would have entered the ground water system through the porous near-surface rocks. Subsequent global cooling would have trapped the ground water under a thick permafrost layer and formed a system of confined aquifers. High pore pressures within the aquifers are considered to have triggered the breakout of water from the aquifers at rates of from 10 to the 5th to 10 to the 7th cu m/sec, which would be prevented from reentering the ground water system by the layer of permafrost. Outflow from the aquifer is also considered to have caused the undermining of adjacent areas and the collapse of the surface to form areas of chaos, often associated with channels.

Commentaire des deux recueils d'hymnes compiles par W. Hauser a la fin du 19 siecle aux Etats-Unis

A detailed planetwide stratigraphy for Mars has been developed from global mapping based on Viking images and crater counting of geologic units. The original Noachian, Hesperian, and Amazonian Systems are divided into eight series corresponding to stratigraphic referents. Characteristic crater densities and material referents of each series are (1) Lower Noachian [N(16)] (number of craters > 16 km in diameter per 106 km2) > 200] basement material; (2) Middle Noachian [N(16) = 100–200] cratered terrain material; (3) Upper Noachian [N(16) = 25–100; N(5) = 200–400] intercrater plains material; (4) Lower Hesperian [N(5) = 125–200] ridged plains material; (5) Upper Hesperian [N(5) = 67–125; N(2) = 400–750] complex plains material; (6) Lower Amazonian [N(2) = 150–400] smooth plains material in southern Acidalia Planitia; (7) Middle Amazonian [N(2) = 40–150] lava flows in Amazonis Planitia; and (8) Upper Amazonian [N(2) < 40] flood‐plain material in southern Elysium Planitia. Correlations between various crater size‐frequency distributions of highland materials on the moon and Mars suggest that rocks of the Middle Noachian Series are about 3.92–3.85 b.y. old. Stratigraphic ages compiled for units and features of various origins show that volcanism, tectonism, and meteorite bombardment have generally decreased through Mars' geologic history. In recent time, surficial processes have dominated the formation and modification of rock units. The overall stratigraphy of Mars is complex, however, because of temporal and spatial variations in geologic activity.

From a reexamination of the medium and high-resolution Viking images of Amazonian and Hesperian age volcanic centers on Mars, it is believed that an excellent example of well-preserved explosive activity does indeed exist close to the summit of Hecates Tholus. A mantled region to the west of the summit caldera is seen as an example of a geologically very recent plinian air fall ash deposit. Morphological evidence is presented for describing this as explosively generated material, and numerical models of magma ascent and eruption in the Martian environment are used to estimate the physical characteristics (eruption cloud height, magma discharge rate, magma volatile content, duration of activity, and vent size) for this event. Attention is also given to the implication of this eruptive style for the composition of the erupted magma.