Sedimentary characteristics and provenance analysis of the Lower
Cretaceous Tenggeer Formation in Daerqi area of Baiyinchagan Sag， Erlian Basin， Inner Mongolia
1 State Key Laboratory of Ore Genesis， Department of Earth Sciences， Nanjing University， Nanjing210093，Jiangsu
2 Exploration Department of Shanghai Branch of CNOOC， Shanghai200030
Sedimentary characteristics and the planar distribution of sedimentary facies of four intervals of the Tenggeer Formation were investigated based on core observation， well logging data and regional information in Daerqi area. The researches show that during the deposition of the Tenggeer Formation， braidedfluvial delta， lacustrine and turbidite facies were deposited in Daerqi area. From the margin to the center of the sag， the sedimentary environments gradually changed from braidedfluvial delta， shoreshallow lacustrine to semideep and deep lacustrine settings. During the deposition of the Tenggeer Formation， transgression occurred in Daerqi area. Vertically， braidedfluvial delta and lacustrine deposits were prograded. Turbidite facies was deposited near Well Da 17 in interval Ⅵ of the Tenggeer Formation. Based on the analyses of thin sections and heavy mineral data， the clastic components were observed and the relative content were calculated. The heavy mineral coefficients of stability and changing patterns of the ZTR index were analyzed. The results indicated that the provenance of Daerqi area was from the Saihuduge uplift and was characterized by a shortdistance transportation and quick accumulation. The compositional maturities were different at different depths of the same well. It is concluded that the sediments were deposited multicyclically and spasmodically. Based on the types of clastics and heavy mineral associations， the parent rocks of Daerqi area are of three types: intermediate and basic magmatic rocks， sedimentary rocks and metamorphic rocks.
. Sedimentary characteristics and provenance analysis of the Lower
Cretaceous Tenggeer Formation in Daerqi area of Baiyinchagan Sag， Erlian Basin， Inner Mongolia[J]. JOPC, 2008, 10(6): 599-612.
