New evidences for sedimentary attributes and timing of the “Macaoyuan conglomerates” on the northern margin of the Yangtze block in southern China.

Highlights: [•] The tuff from the Macaoyuan Group was formed at 1157±19Ma. [•] The maximum depositional age of the Macaoyuan Group is not older than 1180Ma. [•] “Macaoyuan conglomerates” are made up of the slope carbonate gravity flow deposits. [•] The Macaoyuan Group is one part of the basement strata beneath the rift succession. [•] ∼2.60Ga peak age represents an important period for the Yangtze block's formation. [ABSTRACT FROM AUTHOR]