乍得Bongor盆地基底岩性特征及形成时代.pdf

Open Journal of Nature Science 自然科学, 2016, 4(1), 63-80 Published Online February 2016 in Hans. /journal/ojns /10.12677/ojns.2016.41009 Basement Lithology Characteristics and Forming Age of Bongor Basin Chad Mingyu Zhang1, Bairong Song2, Zhibin Tian1, Naidan Zhang3, Yuhua Shi2, Qi Wang1 1CNPC Greatwall Drilling Company, Panjin Liaoning 2PetroChina Liaohe Oilfield Company, Panjin Liaoning 3Yangtze University, Wuhan Hubei Received: Feb. 1st, 2016; accepted: Feb. 20th, 2016; published: Feb. 23rd, 2016 Copyright ? 2016 by authors and Hans Publishers Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). /licenses/by/4.0/ Abstract The basement of the Bongor basin Chad is formed by a set of crystalline basement rocks before the Early Cambrian, which is rich in oil and gas. Therefore, it is more important to study the type of basement rocks and the formation age of the basin. This paper is mainly based on the core obser- vation and description, by identification of rock slice, single grain zircon U-Pb isotope determina- tion, Chad Bongor basin’s basement lithology of identification and delineation, and the formation and evolution of era were analyzed. The results show that the lithology is composed of metamor- phic rocks and magmatic rocks, which are composed of 14 kinds of 2 sub categories; Single Zircon dating was concentrated in the age of 550 - 600 Ma, the age of metamorphic rocks was mainly con- centrated in 616 ± 6 - 526.5 ± 2.7 Ma, the oldest old rock age was 1006 ± 12 - 946 ± 5 Ma, meta- morphic age was 553 ± 19 - 464 ± 5 Ma, the age of magmatic roc