The carboniferous brachiopod assemblages zone of yanbian , sichuan .
四川盐边石炭纪腕足动物组合带。
However robert berner of yale university thinks oxygen levels plummeted after the carboniferous before slowly rising to present day levels ( see graph ) .
然而，耶鲁大学的罗伯特伯奈尔认为，在石炭纪后，含氧量曾骤然跌落，然后慢慢上升到现在的水平（如图）。
The lush swamp forestsof the carboniferous were gradually replacedbyconifers , seed ferns , and other drought - resistant plants .
石炭纪的葱翠的沼泽地正在慢慢被针叶林,种子蕨类以及其他抗干旱植物所代替.
The tianshan carboniferous early permian rift related volcanism in northwestern china represents a newly recognized large igneous province .
中国西北部天山石炭纪早二叠世裂谷火山作用代表了一个新近被认可的大火成岩省。
During the late carboniferous , sedimentary rocks-rocks eroded by wind and water and deposited as fine sediments-carpeted much of the region , which might have been partially flooded from time to time . Subsequent lava flows deposited volcanic rocks up to 20 meters ( 65 feet ) thick in some places .
