Abstract

The Cretaceous fossil flora in deposits of the Okhotsk–Chukotka volcanic belt is drastically different in systematic composition from the paleoflora of similar ages in deposits of the Northeast Asian coastal lowlands and inland depressions. In the volcanic burials, paleoflora features are the most evident in the Chaun flora found in the Pegtymel trough in the Central Chukotka region and described in the monograph by L.B. Golovneva “The Chaun Flora of the Okhotsk–Chukotka Volcanic Belt.” Based on these data and our own experience in studying the Okhotsk–Chukotka belt stratigraphy and the vegetation cover dynamics in the Kamchatka recent volcanism area, we have proven that the Chaun flora was formed not on the volcanic highlands, as Golovneva stated, but on the lowlands, on a periodically renewed juvenile surface of the central part of the vast volcanic field separately from the background diaspora sources. This flora is not characterized by a clear lateral and stratigraphic confinement, because the characteristic plant fossils can be found in deposits of different ages throughout the volcanic belt. They are indicative of particular vegetation and burying conditions in the surface volcanism from the Turonian to the Campanian inclusive.

中文翻译：

---

楚科奇Nonmarine白垩纪Chaun古生物群

摘要

鄂霍次克–楚科奇火山带沉积物中的白垩纪化石植物群与东北亚沿海低地和内陆洼地沉积物中相似年龄的古植物群在系统组成上有很大的不同。在火山掩埋中，古植物群的特征在楚科奇中部地区佩格泰梅尔谷中发现的Chaun植物群中最为明显，并由LB Golovneva的专着“鄂霍次克–楚科奇火山带的Chaun植物群”描述。根据这些数据以及我们在研究鄂霍次克-楚科奇火山带地层学和堪察加半岛最近火山活动区植被覆盖动力学方面的经验，我们证明了Chaun植物区系不是像Golovneva所说的那样形成在火山高地上，而是在火山高地上形成的。低地，在大范围火山场中部定期更新的幼年表面上，与散居在外的背景源分开。该植物区系没有明确的侧向和地层限制，因为在整个火山带的不同年龄的沉积物中都可以找到特征性的植物化石。它们表示从土伦时代到坎帕尼亚时代的地表火山活动中特定的植被和掩埋条件。