APPLICATION AND SIGNIFICANCE OF BASIC SEQUENCES AND MARKER BEDS TO 1:50000 REGIONAL GEOLOGICAL SURVEYING:EXAMPLES FROM THE PALAEOZOIC AND TRIASSIC STRATA IN THE SANDU AND XIUSHUI SHEETS NORTHWESTERN JIANGXI

It is notorious that the marker beds have played an important part in the stratigraphic division and correlation of the regional strata,and prospecting of ore deposits.The basic sequences have constituted an important part of sequence stratigraphy since the 1990s,and are classified in terms of the superimposition of individual beds in the vertical sequences and boundary characteristics of sedimentary strata.They may be widely applied to the lithostratigraphic units composed of several lithologies.Exemplified by the Palaeozoic and Triassic strata in northwestern Jiangxi,the present paper has shed light on the application and integration of these methods cited above and their importance in the 1:50000 regional geological surveying.In addition,caution should be exercised in the integration pf sequence stratigraphy and high-resolution stratigraphy so as to improve our knowledge of regional sequence stratigraphy.