Upper Carboniferous successions in European sedimentary basins contain cyclothems related to glacial cycles of approximately 100 Ky duration. Within the UK Pennine Basin both simple and complex cyclothems are recogniz...Upper Carboniferous successions in European sedimentary basins contain cyclothems related to glacial cycles of approximately 100 Ky duration. Within the UK Pennine Basin both simple and complex cyclothems are recognized. In the latter, mid-cycle deltas were flooded by sea-level rises, possibly related to short period orbital forcing events. They were followed by late cycle forced regression delta channels and then by incised coarse-grained channels active after the glacial maximum. Other European successions commonly contain coarse incised channel fills in the same cyclothems;these were deposited during colder glacial periods. Simple cyclothems formed during warmer periods contain only lobate mid-cycle deltas. The distribution of different cyclothem types is not random. Correlation with the eastern Australian succession using revised published radiometric dates from Eastern Europe suggests that the early Namurian C1 glaciation in Australia correlates with a group of Pennine complex cycles of late Pendleian to early Arnsbergian age. The C2 glaciation began just prior to the late Kinderscoutian and possibly lasted into the early Langsettian;the Pennine succession shows evidence for a number of colder periods with complex cycles, especially in the late Kinderscoutian and mid Marsdenian. The intervening period, particularly from Alportian to mid Kinderscoutian was warmer.展开更多
文摘Upper Carboniferous successions in European sedimentary basins contain cyclothems related to glacial cycles of approximately 100 Ky duration. Within the UK Pennine Basin both simple and complex cyclothems are recognized. In the latter, mid-cycle deltas were flooded by sea-level rises, possibly related to short period orbital forcing events. They were followed by late cycle forced regression delta channels and then by incised coarse-grained channels active after the glacial maximum. Other European successions commonly contain coarse incised channel fills in the same cyclothems;these were deposited during colder glacial periods. Simple cyclothems formed during warmer periods contain only lobate mid-cycle deltas. The distribution of different cyclothem types is not random. Correlation with the eastern Australian succession using revised published radiometric dates from Eastern Europe suggests that the early Namurian C1 glaciation in Australia correlates with a group of Pennine complex cycles of late Pendleian to early Arnsbergian age. The C2 glaciation began just prior to the late Kinderscoutian and possibly lasted into the early Langsettian;the Pennine succession shows evidence for a number of colder periods with complex cycles, especially in the late Kinderscoutian and mid Marsdenian. The intervening period, particularly from Alportian to mid Kinderscoutian was warmer.
