ГЕОДИНАМИКА ЗОН СОЧЛЕНЕНИЯ СПРЕДИНГОВЫХ ХРЕБТОВ РЕЙКЬЯНЕС И КОЛБЕНСЕЙ С РИФТОВЫМИ ЗОНАМИ ИСЛАНДИИ

Зоны сочленения спрединговых хребтов Рейкьянес и Колбенсей с рифтами Исландской крупной магматической провинции имеют ряд существенных отличий в структуре от прилегающих спрединговых сегментов, несмотря на схожую кинематику. Трансформная зона Тьёрнес является сложноустроенной и включает в себя ряд вулканических и амагматических структур. Рейкьянесская рифтовая зона, напротив, отличается относительно простым строением при однородном, в целом, характере тектонической и магматической активности. Причины различий в строении трансформных зон и их современная динамика остаются не до конца объясненными. На основе методики анализа морфометрических показателей сбросовых уступов было установлено, что столь значительные различия трансформных зон обусловлены пространственно-временной стабильностью прилегающих к ним структур, в свою очередь контролируемой периодическим увеличением магматической активности Исландского плюма. Развитие рифтогенных структур в пределах трансформных зон находится в прямой связи с их расположением относительно прилегающих спрединговых сегментов и с их магматическим состоянием. Современное развитие обеих трансформных зон связано с нестабильностью и миграцией рифтовых зон Исландии под действием термических импульсов Исландского плюма и, как следствие, кинематической перестройкой самих трансформных зон. Для трансформной зоны Тьёрнес это выражается в постепенном упрощении ее структуры: отмирании западной ветви и прекращении активности блоковых структур. Для Рейкьянесской рифтовой зоны наблюдается постепенное смещение оси в южном направлении, с чем также связывается наличие интенсивного вулканизма в ее пределах.

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