New data on Archaeointensities Obtained from Investigation of Halafian Settlement of Yarim Tepe 2 (Northern Iraq) 

Статья посвящена исследованию быстрых вариаций напряженности геомагнитного поля в течение VI тыс. до н.э. на Ближнем Востоке. Представлены новые результаты археоинтенсивности, полученные из керамических фрагментов, собранных советскими археологами на поздненеолитическом многослойном поселении Ярым Тепе 2 в Северном Ираке. Новые данные археонапряженности были получены с помощью метода Телье-Телье, основанного на возможности магнитных минералов, входящих в состав глиняной массы, из которой был изготовлен археологический артефакт, записывать в процессе остывания ниже температуры Кюри параметры окружающего магнитного поля. Было отобрано 30 групп фрагментов (от 3 до 10 фрагментов в каждой группе) из различных слоев Ярым Тепе 2. Достаточная археоинтенсивность была получена от 23 групп фрагментов. От 3 фрагментов костей из разных слоев Ярым Тепе 2 были получены радиокарбонные даты. Новые результаты продемонстрировали явный тренд уменьшения интенсивности магнитного поля в течение VI тыс. до н.э. при наличии пика напряженности в районе 5500 лет до н.э. This study is devoted to the investigation of the rapid geomagnetic field intensity fluctuations during the 6th millennium BC in the middle East. We present the new archeointensity results, obtained from pottery fragments, collected by Soviet Archeologists from the Late Neolithic multilayered settlement Yarim Tepe II, situated in Northern Iraq. The site comprises 7-m thick sequence of cultural deposits, divided into 9 archeological levels. Archeointensity determinations were obtained using the protocol, derived from the classical Thellier-Thellier method. This protocol was developed for the three-axes vibrating sample magnetometer Triaxe, making it possible to heat samples directly up to high temperatures. Archeointensity measurements were complemented by the rock-magnetic analyses in order to test the properties of the magnetic carriers, as well as to avoid as much as possible the probable alterations of the mineralogy during the heating. In addition, we performed the 3 test in order to detect the potential outliers within the groups of fragments and, by rejecting them, increase the reliability of the obtained data. We collected 30 groups of fragments from superposed stratigraphic levels of approximately 20 cm thick in average, covering the entire archeological sequence of the Yarim Tepe II site. Each group consists of minimum 3 (up to 10) fragments. The sufficient archeointensity determinations were obtained from 23 groups of fragments. We carried out the radiocarbon dating of the three bone-samples, collected from three different archeological levels. The new ages show, that the settlement probably was not occupied before the beginning of the Middle Halaf period. In order to present the new archeointensity results as a function of time we constructed the age model using a bootstrap procedure with several tie-points within the archeological sequence. The new results show the clear trend of the magnetic field intensity decrease during the 6th millennium BC, with the occurrence of the step-like evolution during the 54005600 BC time interval. The intensity values dropped drastically by 12 T. This drop of intensity was accompanied by the narrow (perhaps, less than one century) intensity peak around 5500 BC. The variation rates associated with the peak are 0,150,25 T/year, which is lower, than the variation rates proposed for the periods of the geomagnetic spikes, but appear similar to those observed in Western Europe around 700 BC and during the 1st millennium AD.