| Abstract: | Sixty-eight species of fossil spores and pollens referred to 39 genera extracted from the crude oil samples collected from the Turpan Basin of Xinjiang are recorded in this paper. Based on the investigations of fossil spores and pollens in petroleum, the questions on petroleum migration and source rocks are discussed. It is expounded and proved theoretically and practically that the phenomenon that the crude oil samples usually contain the fossil spores and pollen grains with different geological ages from reservoir rocks should result from petroleum migration, but not from resedimentation. The fossil spores and pollens in crude oil of the Middle Jurassic reservoir of the Qiktim Oil-Field of the Turpan Basin comprise mainly Leiotriletes pflugi, Deltoidospora gradata, D. magna, Cyathidites australir, C. minor, Biretisporites cf. potoniaei, Dictyophyllidites harrisii. Cibotiumspora paradoxa, C. jurienensis, Gleicheniidites rousei, G. conflexus, Undulatisporites concavus, U. pflugii, Granulatisporites arenaster, G. minor, Todisporites minor, Osmundacidites wellmanii, dpiculatisporis variabilis, Leptolepidites major, Aratrisporites scabratus Cycadopites nitidus, C. typicus, C. subgranulosus, Chasmatosporites elegans, Classopollis classoides, C. itunen- sis, C. annulatus, C. qiyangensis, Callialarporites dampieri, C. radius, lnaperturopollenites det- tmannii, Protoconiferus funarius, Paleoconiferus asaccatus, CaytonipoUenites pallidus, Vitreis- porites jurassicus, V. jansonii, Pseudowalchia ovalis, P. landesii, P. biangulina, Podocarpidites unicus, P. major, P. multicinus, P. multesimus, P. rousei, P. wapellaensis, Platysaccus lopsinensis, Ovalipollis enigmatica, O. minor, O. canadensis, Pteruchipollenites thomasii, Alisporites grandis, A. bilateralis, Pityosporites similis, P. divulgatus, Piceites expos us, P. podocarpoides, P. latens, Protopicea exilioides, Pseudopicea variabitifornus, Piceaepollenites complanatiformus, Abietineaepollenites dunrobinensis, A. microalatus, A. minimus, Cedripites minor, Eucommiidites troedssonii, etc. Some of the species are also found from the crude oil sampls taken from the Middle Jurassic reservoir of the Shengjinkou Oil-Field of the Turpan Basin. The above mentioned species of spores and pollens are widely distributed in the Lower to Middle Jurassic sediments of North America, Europe, Australia and China. They have also been found from the Lower to Middle Jurassic sediments of the Turpan Basin. Judging from the spores and pollen in petroleum, it may be concluded that the Lower Jurassic Badaowan-Sangonhe Formation and the Middle Jurassic Xishanyao-Toudenhe Formation should contain the favorable petroleum source rocks in the basin. As to petroleum migration mechanism, it is considered that petroleum must have migrated for comparatively short distances to accumulate into petroleum pools in this region. |
