Kinematics of stars in Kovalsky-Kapteyn figures. II

Rostov State Pedagogical Institute; All-Union Scientific Research Institute Gradient. Translated from Astrofizika, Vol. 33, No. 3, pp. 379–393, November–December, 1990.     

Abundance and degree of residency of humpback dolphins Sousa plumbea in Mossel Bay,South Africa

Indian Ocean humpback dolphins Sousa plumbea inhabit nearshore waters from South Africa to eastern India. Humpback dolphins are vulnerable to conservation threats due to their naturally small population sizes and use of nearshore habitats, where human activities are highest. We investigated the abundance and residency of this species inhabiting Mossel Bay, South Africa, using photographic mark-recapture. Data were collected during 81 surveys in Mossel Bay between 2011 and 2013. Open population modelling using the POPAN parameterisation produced a ‘super-population’ estimate of 125 individuals (95% CI: 61–260) and within-year estimates of between 33 and 86 individuals (2011: 71 [95% CI: 30–168]; 2012: 33 [15–73], 32 [15–70]; 2013: 46 [20–108]). Although less appropriate, closed capture models were also run for comparison with previous studies in the region and generated similar, but slightly smaller, population estimates within each year. We compared our catalogue with opportunistic data collected from East London, Plettenberg Bay, De Hoop and Gansbaai. The only catalogue matches attained were between Plettenberg Bay (n = 44 identified) and Mossel Bay (n = 67 identified), separated by 140?km. Population exchange was moderate, with nine individuals resighted in multiple years between these two areas. This study supports previous findings of long-range movements for this species and provides a baseline from which to assess future impacts on the population.     

Age and origin of the Kitoi sillimanite schist deposit,eastern Siberia

Doklady Earth Sciences -     

Weissbergite (TlSbS2) and Avicennite (Tl2O3), Rare Thallium Minerals: First Findings in Yakutia

Geology of Ore Deposits - Rare thallium minerals, avicennite and weissbergite, were found for the first time within the karst zones of the Khokhoy field of the Verkhnyaya Amga gold area, South...     

Discharge of Salt Groundwater in the Estuary of the Razdol’naya River (Amur Bay) in February 2020

Water Resources - In February 2020, geochemical tracers along with hydrochemical and hydrological characteristics were used to reveal a discharge site of salt groundwaters in the head of the...     

Relationship between Magmatic,Metamorphic, and Hydrothermal Processes within the Baikal–Muya Terrane (Eastern Siberia): Constraints from High-Precision Geochronological Study of the Kedrovskii Granitoid Massif

Doklady Earth Sciences - High-precision dating of granitoids is of key significance for age identification of the main stages of crust formation in various blocks of the continental crust. Here we...     

General approaches to the assessment of the state and the prediction of changes in the reliability of power line river crossings

The procedure for assessment developed in the paper for the conditions of northwestern, central, and southern European Russia is an efficient means for comparative analysis of power lines in terms of individual and integral impact of hazardous hydrological and slope processes on their vulnerability, for determining of the periodicity of monitoring observations and the composition of such studies.     

The late Tonian Zhaunkar granite complex of the Ulutau sialic massif,Central Kazakhstan

The crystallization age of Zhaunkar granites (829 ± 10 Ma) was determined by U–Pb zircon dating. Taking into account the data obtained earlier on the granite age (791 ± 7 Ma) in the Aktas Complex and the syenite age (673 ± 2 Ma) in the Karsakpai Complex, the Ulutau sialic massif is assumed to be composed of three igneous complexes formed during the Tonian–Cryogenian periods of the Neoproterozoic.     

The Early Cambrian age of intraplate mafic–ultramafic plutons of the Ulutau sialic Massif (Central Kazakhstan)

U–Pb dating of tonalite of the Shaytantas Pluton located within the Ulutau sialic Massif (Central Kazakhstan) has been carried out. Their crystallization age of 521 ± 2 Ma corresponds to the Early Cambrian (boundary of Stages 2 and 3). The obtained geochronological data allow us to identify the Early Cambrian stage of the intraplate magmatic activity in the history of formation of the sialic massifs in the western part of the Central Asian fold belt.