The Neoproterozoic Hüttenberg δ13C anomaly: Genesis and global implications

The Neoproterozoic Hüttenberg Formation in northeastern Namibia records a remarkable δ13Ccarb positive excursion with a sustained plateau of values up to +12‰ (i.e., the Hüttenberg anomaly). High-resolution chemostratigraphic analyses of drill core samples spanning the upper Elandshoek and Hüttenberg formations reveal multiple new observations: (1) overall high but oscillatory δ13Ccarb values; (2) δ18Ocarb values ranging from −8‰ to −2‰; (3) significant enrichment of 13C in organic carbon and a broad co-variation between δ13Ccarb and δ13Corg; (4) a profound negative excursion in δ34Spyrite from +30‰ to −10‰; (5) an overall inverse δ13C–δ34S relationship; and (6) 87Sr/86Sr values down to 0.7074 in limestone samples. The new data suggest that the Hüttenberg anomaly records dynamic fluctuations in marine redox conditions, which may include an oxygenation event during the height of the δ13Ccarb positive excursion and a deoxygenation event at its termination. The δ34Spyrite negative excursion suggests the buildup of the marine sulfate reservoir, likely due to enhanced pyrite oxidation during the oxygenation event. The δ34Spyrite increase at the end of the Hüttenberg anomaly may result from a seawater sulfate concentration drawdown towards pre-anomaly conditions. On one hand, the Hüttenberg anomaly may reflect restricted basin signals that are deviated from the Ediacaran open ocean; on the other hand, the Ediacaran Hüttenberg anomaly, together with the Cryogenian δ13Ccarb positive excursions, suggests a stepwise pattern of the Neoproterozoic Oxygenation Event. Both local and global environmental factors may have contributed to the Hüttenberg anomaly. The Hüttenberg anomaly therefore represents a local enhancement of global oxygenation signals. Our data support the emerging view that the Neoproterozoic Oxygenation Event may have facilitated the evolution of early life at that time

Anisotropic distribution functions for spherical galaxies

A method is presented for finding anisotropic distribution functions for stellar systems with known, spherically symmetric, densities, which depends only on the two classical integrals of the energy and the magnitude of the angular momentum. It requires the density to be expressed as a sum of products of functions of the potential and of the radial coordinate. The solution corresponding to this type of density is in turn a sum of products of functions of the energy and of the magnitude of the angular momentum. The products of the density and its radial and transverse velocity dispersions can be also expressed as a sum of products of functions of the potential and of the radial coordinate. Several examples are given, including some of new anisotropic distribution functions. This device can be extended further to the related problem of finding two-integral distribution functions for axisymmetric galaxies.Comment: 5 figure

Power transformers winding fault diagnosis by the on-load exciting current extended Park's vector approach

This paper presents the application of the on-load exciting current Extended Park's Vector Approach to diagnose incipient turn-to-turn winding faults in operating power transformers. Experimental and simulation test results demonstrate the effectiveness of the proposed technique, which is based on the spectral analysis of the AC component of the on-load exciting current Park's Vector modulus

Respectful Terminology in Archaeological Compliance

Archaeological compliance is defined by state and federal legislation and the constrained, precise language in which it is written. Rules and policies operationalize the law but provide some flexibility in its interpretation and implementation. The pronounced use of "legal"and "scientific"language in archaeological compliance can be considered insensitive or offensive to some tribal members when discussing the disposition and care of the remains and belongings of their ancestors. The language we use constructs our reality and defines how we interpret our interactions of the lived experience. It is therefore necessary to revise the language employed in archaeological compliance to ensure that it reflects the values of the communities that these laws define to determine treatment and ultimate disposition of their ancestral remains and belongings. This article describes and encourages the use of a respectful terminology, developed in conjunction with compliance professionals and tribal representatives, to restructure the language we use and redefine our interactions as more considerate of tribal concerns for repatriation. Copyright © The Author(s), 2022. Published by Cambridge University Press on behalf of Society for American Archaeology.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Earth observation for land-atmosphere interaction science

The European Space Agency (ESA), iLEAPS (Inte-grated Land Ecosystem-Atmosphere Processes Study, i.e. the land-atmosphere core project of the International Geosphere-Biosphere Programme), and the European Geosciences Union (EGU) jointly organized the “Earth Observation for Land-Atmosphere Interaction Science” Conference, which took place from 3rd to 5th November 2010 at the Italian premises of ESA in Frascati (Rome). The event represented an attempt to effectively draw together Earth-observation (EO) and Earth-system scientists investigating land-atmosphere processes in order to better understand the current gaps in science and derive recommendations to advance in the use of EO technology in the context of this important topic. Around 200 people from more than 30 countries worldwide met and discussed for three intensive days. This paper reports keypoints and the main recommendations of the Symposium for each of the key Themes addressed during the Conference