论文部分内容阅读
The Lopingian is one of the fastest rising periods of seawater strontium isotopic ratios(87Sr/86Sr) in earth history, and its mechanisms and increasing rates of the 87Sr/86 Sr evolution were still disputed widely. These disputations among researchers were caused mainly by timeframe selection(sections’ thickness or data of radiometric ages), and different stratigraphic boundaries and un-upmost dated ages. This paper examined published 87Sr/86 Sr data of the Lopingian, and projected them on timescales based on evolutionary and age constrained conodonts fossils. 87Sr/86 Sr evolution vs fossil constraining timescales was re-established in this period. This research suggests:(1) 87Sr/86 Sr excursion projects on fossil zones can truly support 87Sr/86 Sr evolutionary pattern in the period;(2) 87Sr/86 Sr evolution provides a new approach for stratigraphic research of marine carbonate sections in lieu of biostratigraphic data;(3) 87Sr/86 Sr stratigraphy works on marine carbonate sections of different sedimentation rates even between different basins;(4) the 87Sr/86 Sr data and its shift was dependent on samples materials and chemical treatment methods;(5) the increasing rate of marine water 87Sr/86 Sr in the Late Permian is suggested as 5.4×10?5/Ma or slightly lower;(6) sedimentation age and its 87Sr/86 Sr of the Lopingian marine carbonate suggested as: DPro=259?(RS? 0.70695)/5.4×10?5(Ma).
The Lopingian is one of the fastest rising periods of seawater strontium isotopic ratios (87Sr / 86Sr) in earth history, and its mechanisms and increasing rates of the 87Sr / 86 Sr evolution were still disputed widely. These disputations among researchers were caused mainly by timeframe selection (sections’ thickness or data of radiometric ages), and different stratigraphic boundaries and un-upmost dated ages. This paper examined published 87 Sr / 86 Sr data of the Lopingian, and projected them on timescales based on evolutionary and age constrained conodonts fossils. 87Sr / 86 Sr evolution versus fossil constraining timescales was re-established in this period. This research suggests: (1) 87Sr / 86 Sr excursion projects on fossil zones can truly support 87Sr / 86 Sr evolutionary patterns in the period; (2) 87Sr / 86 Sr evolution provides a new approach for stratigraphic research of marine carbonate sections in lieu of biostratigraphic data; (3) 87 Sr / 86 Sr stratigraphy works on marine carbonate sections of dif (4) the 87 Sr / 86 Sr data and its shift was dependent on the samples materials and chemical treatment methods; (5) the increasing rate of marine water 87 Sr / 86 Sr in the Late Permian is suggested as 5.4 × 10 5 / Ma or slightly lower; (6) sedimentation age and its 87 Sr / 86 Sr of the Lopingian marine carbonate suggested as: DPro = 259? (RS? 0.70695) /5.4×10? 5 (Ma).