TROPICAL GEOGRAPHY ›› 1997, Vol. 17 ›› Issue (3): 253-259.

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MINERALOGIC-PETROLGIC CHARACTERISTICS AND ORIGIN OF THE “OLD RED SAND”OF GUANGDONG AND HAINAN

Wang Jianhua, Liang Zhirong   

  1. Department of Geosciences, Zhongshan University, Guangzhou 510275
  • Received:1996-10-01 Online:1997-01-30 Published:1997-01-30

Abstract:

The "Old Red Sand" is a quarternary sediment appearing along the coastal areas from Shandong Province to Hainan Province. Much controversy has been evoked about its origin,age and paleogeographic significance. In fact,the "Old Red Sand" has a homogeneous framework with a fine grain-size. But sometimes,there appears a very low angle cross-stratification or some eluvial gravels from weathered granitic ground. The analyses of grain-size and superficial microfeature of quartz sands show that its characters are similar to dune sand. In these sediments the unstable minerals such as hornblende,feldspar,etc,disappear after laterization,that causes an accumulation of quartz,kaolinite and hematite,with a decrease of SiO2/Al2O3,and SiO2/R2O3. The TL dating indicates the depositional ages of "Old Red Sand" from 51900 a.B.P.. to 16200 a.B.P. The authors consider that the "Old Red Sand" belongs to the coastal eolian deposit of the last glacial age. The sedimentary materials were transported from proximal exposed sandy beach,and became red after laterization during a humid and warm climate period.

Key words: eolian deposit, laterization, Late-Pleistocene, Coast