摘要
西沙群岛中新世晚期和上新世晚期的白云岩厚达数十米。可以用咸淡水混合模式解释其成因。中新世晚期的白云岩化是米辛尼亚事件的表现。上新世晚期的白云岩化,亦应与一次全球性的气候事件有关。这种白云岩化对改善生物礁的储油物性有重要意义。
Owing to the sea level falling in late Miocene and late Pliocene, the islands in the Xisha region were exposed and subjected to dolomitization, forming secondary dolomites of tens of meters thick. The dolomites in the two horizons mentioned above are traceable in space, related to hiatus and no selection to rock types. Because of the dolomitization, Sr was moved away, δ18O kept normal and δ13C became heavier. The dorag model was used to interprete the features mentioned.
The dolomitization was resulted from Messinian event when the sea level fell to 80m lower. The Pliocene dolomitization marked another event then.
The dolomitization is helpful to the formation of oil reservoirs.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
1990年第2期45-55,共11页
Marine Geology & Quaternary Geology
