Methodology of regional geological survey of near-surface sedimentary sequences in muddy coastal zones

Geological survey of near -surface sedimentary sequences of the1:50000Huaidian Township Sheet in Tianjin Municipality provides a new method for the regional survey of deep cover areas.In the new method,shallow drill wells replace geological sites and recent and modern sediment are classified to interpret the change of the sedimentary environment ,and then in combination with the chronostratigraphic study near-surface sedimentary sequences are established.The form of the geological map of near-surface sedimentary sequences is used to show the near-surface strata and evolution of the recent and modern geo-logical environment and the influence of human activities in a survey area,thus furnishing visual geological information with a rich connotation for economic development and decision-making.