Herbivory in Antarctic fossil forests and comparisons with modern analogues in Chile

During the Tertiary (-50 million years ago) forests were present in Antarctica, but fossil evidence of insect life in the forests is rare. Extensive fossil floras from Antarctica contain evidence of insect herbivory on the leaves; these provide indirect evidence of past insect life. Such preservation of the behaviour of insects (insect trace fossil) can be used to examine the diversity of insects that lived in the forests of Antarctica in the past. Palaeogene (65 Ma - 35 Ma) fossil floras from two localities on the Antarctic Peninsula (King George Island and Seymour Island) were examined for the presence of insect trace fossils. Fossil leaves were preserved as impressions and compressions within siltstones and sandstones and represent leaves that were preserved within a quiet lake environment (King George Island) or shallow marine setting (Seymour Island). The floras were dominated by leaf morphotypes that resemble modem Nothofagaceae (Southern beeches), but leaves similar to other Southern Hemisphere families were also present, including the Cunoniaceae, Proteaceae and Lauraceae. Over 2,000 fossil leaves were examined for traces of past insect activity. Over 150 fossil leaves (6.9%) contained evidence of feeding traces on the leaves (54 trace types from King George Island and 19 from Seymour Island). The trace fossils were grouped into four functional feeding types: general leaf chewing, skeleton feeding, leaf mines and leaf galls. General leaf chewing was the most common trace type at both localities and leaf mines the least common. The nearest living analogues of the Antarctic Palaeogene forests are the Valdivian and Magellanic forests of Chile and so insect activity in these forests was studied in order to understand past insect activity in Antarctica. The diversity of insect traces in the Chilean forests was investigated at six sites within National Parks, covering a latitudinal range between 37°S and 55°S. Insects associated with two deciduous species, Nothofagus pumilio and Nothofagus antarctica, were of particular focus. The factors that affected the level of insect damage and the proportion of leaf mines and galls included height within the tree, orientation of leaf within the tree, altitude, season, leaf age, latitude, plant species and insect species. Insects which created similar general leaf chewing traces in the modem forests in Chile similar to those on the fossil leaves were larvae of Lepidoptera (Geometridae), Hymenoptera (Symphyta) and the larvae and adults of Coleoptera (Chrysomelidae, Curculionidae, Cerambycidae). Leaf mines were created by species of Coleoptera and Hymenoptera. Species of Diptera (Cecidomyiidae) and Hymenoptera (Cynipidae) created leaf galls. Other invertebrates (Acari (Eriophyidae) and Nematoda (Tylenchid)) also created leaf galls in Chile, similar to fossil leaf galls from Antarctica. Herbivory types on the fossil flora from King George Island were most similar to modem types in Puyehue (a northern study site, Chile) and those from Seymour Island were most similar to Torres in the south, indicating a possible climatic control on their distribution. Based on this relationship, estimates of palaeoclimate of Antarctica suggest that the climate of King George Island to the west of the Peninsula was warmer and wetter (3.5°C -lO.4°C mean annual temperature, 3.5°C - 24.3°C maximum and minimum mean monthly temperature and 1500 mm annual precipitation) than the cooler and more stable environment at Seymour Island to the east (3.5°C -lO.4°C mean annual temperature, -0.4°C -16°C maximum and minimum mean monthly temperature, and 570 mm annual precipitation). The studies of fossil and modem insect traces in Antarctica and Chile have provided a unique opportunity to reconstruct past insect life of Antarctica during the Palaeogene. This is the first documented evidence of insect life during the Palaeogene on Antarctica and highlights the value of modem analogue comparisons to obtain a greater insight into past insect ecology

Neogene stratigraphic architecture and tectonic evolution of Wanganui, King Country, and eastern Taranaki Basins, New Zealand

Analysis of the stratigraphic architecture of the fills of Wanganui, King Country, and eastern Taranaki Basins reveals the occurrence of five 2nd order Late Paleocene and Neogene sequences of tectonic origin. The oldest is the late Eocene-Oligocene Te Kuiti Sequence, followed by the early-early Miocene (Otaian) Mahoenui Sequence, followed by the late-early Miocene (Altonian) Mokau Sequence, all three in King Country Basin. The fourth is the middle Miocene to early Pliocene Whangamomona Sequence, and the fifth is the middle Pliocene-Pleistocene Rangitikei Sequence, both represented in the three basins. Higher order sequences (4th, 5th, 6th) with a eustatic origin occur particularly within the Whangamomona and Rangitikei Sequences, particularly those of 6th order with 41 000 yr periodicity

Influence of low-density polyethylene addition on coking pressure

Different amounts of low-density polyethylene (LDPE) were added to a bituminous coal used to produce metallurgical coke. The effect of the plastic waste on the carbonization process and more exactly, on the coking pressure were investigated. A movable wall oven at semi-pilot scale was used for measuring coking pressure generated. It was found that coking pressure increases for low LDPE addition levels (1-3 wt.%); however higher amounts of LDPE reduce coking pressure. To explain this behavior different blends of the coal and the residue were pyrolysed at three different temperatures (450, 500 and 600 C) in a Gray-King apparatus. The results show that LDPE causes a modification in the pyrolysis process and also influences the swelling process of the plastic stage. The increase of the coking pressure at low LDPE addition rates is associated with a less permeable coal plastic layer, which prevents the removal of the decomposition products and causes their retention in the semicoke matrix, evolving them in the post-plastic stage. Coking pressure decrease at high LDPE addition rates can be due to the charge shrinkage and the better permeability to the migration of oil components, which suggest a lower interaction between the coal and the LDPE. A delay in the degradation of LDPE is confirmed by the data provided by DRIFT and SEM

Shapiro Effect as a Possible Cause of the Low-Frequency Pulsar Timing Noise in Globular Clusters

A prolonged timing of millisecond pulsars has revealed low-frequency uncorrelated noise, presumably of astrophysical origin, in the pulse arrival time (PAT) residuals for some of them. In most cases, pulsars in globular clusters show a low-frequency modulation of their rotational phase and spin rate. The relativistic time delay of the pulsar signal in the curved space time of randomly distributed and moving globular cluster stars (the Shapiro effect) is suggested as a possible cause of this modulation. Given the smallness of the aberration corrections that arise from the nonstationarity of the gravitational field of the randomly distributed ensemble of stars under consideration, a formula is derived for the Shapiro effect for a pulsar in a globular cluster. The derived formula is used to calculate the autocorrelation function of the low-frequency pulsar noise, the slope of its power spectrum, and the behavior of the $\sigma_z$ statistic that characterizes the spectral properties of this noise in the form of a time function. The Shapiro effect under discussion is shown to manifest itself for large impact parameters as a low-frequency noise of the pulsar spin rate with a spectral index of n=-1.8 that depends weakly on the specific model distribution of stars in the globular cluster. For small impact parameters, the spectral index of the noise is n=-1.5.Comment: 23 pages, 6 figure

Age and structure parameters of a remote M31 globular cluster B514 based on HST, 2MASS, GALEX and BATC observations

B514 is a remote M31 globular cluster which locating at a projected distance of R_p~55 kpc. Deep observations with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST) are used to provide the accurate integrated light and star counts of B514. By coupling analysis of the distribution of the integrated light with star counts, we are able to reliably follow the profile of the cluster out to ~40". Based on the combined profile, we study in detail its surface brightness distribution in F606W and F814W filters, and determine its structural parameters by fitting a single-mass isotropic King model. The results showed that, the surface brightness distribution departs from the best-fit King model for r>10". B514 is quite flatted in the inner region, and has a larger half-light radius than majority of normal globular clusters of the same luminosity. It is interesting that, in the M_V versus log R_h plane, B514 lies nearly on the threshold for ordinary globular clusters as defined by Mackey & van den Bergh. In addition, B514 was observed as part of the Beijing-Arizona-Taiwan-Connecticut (BATC) Multicolor Sky Survey, using 13 intermediate-band filters covering a wavelength range of 3000--8500 \AA. Based on aperture photometry, we obtain its SEDs as defined by the 13 BATC filters. We determine the cluster's age and mass by comparing its SEDs (from 2267 to 20000{\AA}, comprising photometric data in the near-ultraviolet of GALEX, 5 SDSS bands, 13 BATC intermediate-band, and 2MASS near-infrared JHKs} filters) with theoretical stellar population synthesis models, resulting in age of $11.5\pm3.5$ Gyr. This age confirms the previous suggestion that B514 is an old GC in M31. B514 has a mass of $0.96-1.08 \times 10^6 \rm M_sun$, and is a medium-mass globular cluster in M31.Comment: Accepted for Publication in AJ, 18 pages, 6 figures and 9 table

Plate motions recorded in tectonostratigraphic terranes of the Franciscan Complex and evolution of the Mendocino triple junction, northwestern California

The Mendocino triple junction area of northern California is underlain by the Coastal belt of the Franciscan complex, flanked on the east by the Central and Eastern belts of the Franciscan Complex. The coastal belt is further divided into three tectonostratigraphic terranes. Upper Cretaceous through middle Miocene rocks included in these terranes were accreted to the North American plate margin partly during normal convergence with the Farallon plate between 49 and 25 Ma at poleward rates of 2 to 5cm /yr, and partly during translation with the Pacific plate between 14 and 2 Ma at poleward rates of 3 to 6cm/yr. The evolution of the triple junction is discussed. -from Author

Structural parameters for globular clusters in M31 and generalizations for the fundamental plane

The structures of globular clusters (GCs) reflect their dynamical states and past histories. High-resolution imaging allows the exploration of morphologies of clusters in other galaxies. Surface brightness profiles from new Hubble Space Telescope observations of 34 globular clusters in M31 are presented, together with fits of several different structural models to each cluster. M31 clusters appear to be adequately fit by standard King models, and do not obviously require alternate descriptions with relatively stronger halos, such as are needed to fit many GCs in other nearby galaxies. The derived structural parameters are combined with corrected versions of those measured in an earlier survey to construct a comprehensive catalog of structural and dynamical parameters for M31 GCs with a sample size similar to that for the Milky Way. Clusters in M31, the Milky Way, Magellanic Clouds, Fornax dwarf spheroidal and NGC 5128 define a very tight fundamental plane with identical slopes. The combined evidence for these widely different galaxies strongly reinforces the view that old globular clusters have near-universal structural properties regardless of host environment.Comment: AJ in press; 59 pages including 16 figure