Iron-manganese nodules from nares abyssal plain: geochemistry and mineralogy

Three nodules from a core taken north of Puerto Rico are composed chiefly of an x-ray amorphous, hydrated, iron-manganese oxide, with secondary goethite, and minor detrital silicates incorporated during growth of the nodules. No primary manganese mineral is apparent. The nodules are enriched in iron and depleted in manganese relative to Atlantic Ocean averages. The formation of these nodules appears to have been contemporary with sedimentation and related to volcanic activity.     

Giant amphipod from the abyssal pacific ocean

A baited camera has recorded a lysianassid amphipod that is twice as large as the largest amphipod previously recorded. The locality for this mobile omnivore is the sterile bottom of the eastern North Pacific Ocean, at a depth of 5304 meters.     

Estimates of diapycnal mixing in the abyssal ocean

Profiles of diapycnal eddy diffusivity to a maximum depth of 4000 meters were derived from ocean velocity and temperature microstructure data obtained in conjunction with separate experiments in the Northeast Pacific and Northeast Atlantic oceans. These profiles indicate that in the ocean interior where the internal wave field is at background intensity, the diapycnal eddy diffusivity is small (on the order of 0.1 x 10(-4) meters squared per second) and independent of depth, in apparent contradiction with large-scale budget studies. Enhanced dissipation is observed in regions of elevated internal wave energy, particularly near steeply sloping boundaries (where the eddy diffusivity estimates exceed 1 x 10(-4) meters squared per second). These results suggest that basin-averaged mixing rates may be dominated by processes occurring near the ocean boundaries.     

Fossil evidence on origin of the mammalian brain

Many hypotheses have been postulated regarding the early evolution of the mammalian brain. Here, x-ray tomography of the Early Jurassic mammaliaforms Morganucodon and Hadrocodium sheds light on this history. We found that relative brain size expanded to mammalian levels, with enlarged olfactory bulbs, neocortex, olfactory (pyriform) cortex, and cerebellum, in two evolutionary pulses. The initial pulse was probably driven by increased resolution in olfaction and improvements in tactile sensitivity (from body hair) and neuromuscular coordination. A second pulse of olfactory enhancement then enlarged the brain to mammalian levels. The origin of crown Mammalia saw a third pulse of olfactory enhancement, with ossified ethmoid turbinals supporting an expansive olfactory epithelium in the nasal cavity, allowing full expression of a huge odorant receptor genome.     

Dredged trachyte and basalt from kodiak seamount and the adjacent aleutian trench, alaska

Blocky fragments of aegirine-augite trachyte (with accompanying icerafted gravels.) were recovered from the upper slopes of Kodiak Seamount in several dredge hauls. An alkali basalt pillow segment was also dredged from a moatlike depression, at a depth of 5000 meters, near the west base of the seamount. These retrievals confirm the volcanic origin of Kodiak Seamount and further support the view of Engel, Engel, and Havens that the higher elevations of seamounts are composed of alkali basalts or related variants.     

Reproductive patterns in the deep-sea benthos

The reproductive condition of a variety of benthic invertebrates from the bathyal San Diego Trough was monitored periodically. In this physically seasonless, deep-sea environment most species reproduce throughout the year, and only a few display highly synchronous, annual reproductive cycles. These few are not typical deep-sea species; they are known from shallow water and belong to groups which are relatively unimportant in abyssal depths. Of the 11 species examined, 3 bivalves, 2 ophiuroids, 2 isopods, 1 amphipod, and 1 polychaete breed year-round, and 1 brachiopod and 1 scaphopod spawn seasonally.     

Fossil peccary from the pliocene of South Africa

Pecarichoerus africanus, new species, from Langebaanweg, Cape Province, is the first fossil peccary to be described from Africa and represents the youngest record of the peccary family in the Old World.     

Fossil fuel combustion and the major sedimentary cycle

The combustion of the fossil fuels coal, oil, and lignite potentially can mobilize many elements into the atmosphere at rates, in general, less than but comparable to their rates of flow through natural waters during the weathering cycle. Since the principal sites of fossil fuel combustion are in the mid-latitudes of the Northern Hemisphere, changes in the composition of natural waters and air, as a consequence of this activity, will be most evident at these latitudes.     

A pleistocene sand sea on the alaskan arctic coastal plain

A ridge and thermokarst-basin landscape that is strikingly portrayed in Landsat winter imagery consists of large Pleistocene dunes that have been modified by younger eolian activity and thermokarst processes. This is the most extensive area of large stabilized dunes yet reported in the North American Arctic; the landscape is of particular interest because it has been proposed as a first-order analog for martian fretted terrain. Recognition of the large dunes permits a new interpretation for linear and curvilinear trends visible in Landsat summer imagery.     

平原区土壤水资源量计算模型的研究

土壤水资源是独立于地表水资源和地下水资源并具有独特存储空间和性质的水资源,本研究结合河北省土壤水资源评价工作,明确了土壤水资源的概念,提出了计算模型。阐述了评价层概念和河北平原区评价层的确定,针对土壤水资源的概念和动态特性,运用水量平衡原理,在地表产流上基于超渗产流模型计算,在评价层以下损失量(不形成土壤水资源的量)上基于蓄满排泄模型计算,以日为计算时段长度,综合考虑截流、蒸发等损失,周年土壤水资源量为逐日降雨量和与逐日损失量和之差。该模型已用于河北省土壤水资源的评价工作。     

基于古生物化石资源的辽西地区旅游开发研究

通过对辽西地区古生物化石资源现状的说明,分析了辽西地区开发古生物化石资源的优势,提出了辽西地区应如何利用古生物化石资源来进行旅游深度开发的措施和建议。     

Fossil penguin from the late cenozoic of South Africa

Spheniscus predemersus, new species, from the late Pliocene of Langebaanweg, Cape Province, is the first fossil penguin to be described from Africa. It is closely related and possibly ancestral to the living species, Spheniscus demnersus, of southern and southwestern Africa.     

Fossil counterparts of giant penguins from the north pacific

New fossils of giant, flightless penguinlike birds have been found in late Oligocene and early Miocene rocks in Japan and in the state of Washington. These birds belong to the order Pelecaniformes, in the extinct family Plotopteridae, previously known by a single fragment of bone from California. Hindlimb and pelvic morphology is most similar to that of Recent anhingas, but the wing is paddlelike and remarkably convergent toward penguins and flightless auks. Both the Plotopteridae and the giant penguins became extinct by the middle Miocene, possibly because of competition from seals and porpoises.