词条 | Pliensbachian Stage |
释义 | Pliensbachian Stage geology third of the four divisions of the Lower Jurassic Series, representing all rocks formed worldwide during the Pliensbachian Age, which occurred between 189.6 million and 183 million years ago during the Early Jurassic Period. The Pliensbachian Stage overlies the Sinemurian Stage and underlies the Toarcian Stage. The stage's name is derived from the village of Pliensbach, Germany, which is near Boll in the Swabian Alps (Swabian Alp). The Pliensbachian Stage is represented by up to 195 metres (640 feet) of deposits, mostly marls (marl), in Germany, Belgium, and Luxembourg. Five ammonite (ammonoid) biozones (biozone), beginning with Uptonia jamesoni and ending with Pleuroceras spinatum, are recognized for the Lower and Upper Pliensbachian of northwestern Europe. The ammonites of this age worldwide exhibit a high level of regional differentiation, making global correlation difficult. |
随便看 |
|
百科全书收录100133条中英文百科知识,基本涵盖了大多数领域的百科知识,是一部内容开放、自由的电子版百科全书。