摘要
本文研究黑龙江北安地区下白垩统 2个岩石单位中的孢粉组合。其中营城组孢粉组合是松辽盆地北部营城组孢粉化石类型最丰富的组合 ,时代属巴列姆期或巴列姆 -阿普第期 ;沙河子组下段孢粉类型相对较少 ,组合时代暂定为早白垩世早期 (可能相当贝里阿斯 -戈特列夫期 )。沙河子组下段为温暖潮湿的亚热带气候。营城组沉积时期在温暖湿润的亚热带气候下 ,南方的干旱气候对北安地区也有一定的影响。
The Lower Cretaceous sequence within the Bei'an-depression situated in the far-north of Songliao Basin, NE China consists ascendingly of the Huoshiling (?), Shahezi, Yingcheng and Denglouku formations. The material studied herein is collected from the Shahezi and Yingcheng formations of the Well Beican 1 in the south of Bei'an City, Heilongjiang Province. Palynological study is significant for stratigraphical divison and correlation for this area. 1. Spore-pollen assemblage from the Lower Member of Shahezi Formation (probably Berriasian-Hauterivian, Table 1) This assemblage is composed of gymnospermous pollen (55.8% in content) and pteridophyte spores (44.2%). No angiospermous pollen has been found. Among the pteridophyte spores, Levigatosporites sp. (7.7%), Biretisporites cf. potoniaei (5.8%), and Lophotriletes sp., Neoreaistrickia sp. and Osmundacidites sp. (3.8% respectively) occur frequently; Lycopodiumsporites austroclavatidites, Cicatricosisporites sp., Cibotiumsporites cf. juncta, Deltoidospora sp., Cyathidites minor, Granulatisporites sp., Acanthotriletes sp., Apiculatisporites sp., and Foraminisporis asymmetricus are common (1.9% respectively). Gymnoserpmous pollen are dominated by Pinuspollenites sp. and Podocarpidites sp. (15.4% in highest respectively), with other frequent species: Abietineaepollenites sp. (11.5%), Piceaepollenites sp. (5.8%), Palaeoconiferus sp. (5.8%) and cedripites sp. (1.9%). 2. Spore-pollen assemblage from the Yingcheng Formation (Barremian-Aptian, Table 1) This assemblage is dominated by pteridophyte spores (73.2%—87.7%), with more or less gymnospermous pollen (10.2%—26.8%), algae (Concentricystes sp. 5.1%) and problematic angiospermous pollen (Polyporites ? sp., <1%). Among the pteridophyte spores, Cicatricosisporites australiensis, C. gracili and C. sp. occur frequently, amounting to 5.1%—11.6% in content and increasing ascendingly; Leiotriletes sp. varies greatly from 0.9% to 58.0; the common species include Cyathidites minor (0.5%? ?7.1%), Franulatisporites sp. (0—15.3%), Laevigatosporites sp. (0.5%—10.2%) etc.: the following species are rare, but significant for dating the Yingcheng Formation: Foveotriletes subtriangularis (1.7%? ?.7%), Aequitriradites echinatus (0—2.7%), Cooksonites sp. (0—2.7%), Concavissimisporites sp. (0—2.7%), Klukisporites sp. (0—1.8%), Maculatisporites sp. (0—l.8%), Hsuisporites sp. (0—0.9%), Fixisporites sp. (0? ?.9%), Schizaeoisporites sp. (0—0.9%), Lygodioisporites confertus (0—0.9%), Pilosisporites trichopapillosus (0—0.9%), Foraminisporis asymmetricus (0—0.9%), Foraminisporis wonthaggensis (0—0.9%), Appendicisporites potomacensis (0? ?.5%), Lygodiumsporites subsimplex (0—0.5%), Impardecispora cavanosa (0—0.5%), Leptolepidites sp. (0—0.5%), Densoisporites sp. (0—0.5%) etc.Main gymnospermous pollen are: Abletineaepollenires sp. (0—0.7%). Cedripites sp. (0—5.4%), Taxodiaceaepollenites hiatus (0.5%? ?.1%), Podocarpidites sp. (0—3.6%) are the next. Pinuspollenites sp. (0.5%—1.8%), Piceaepollenites sp. (0—1.8%), Inaperturopollenites sp. (0? ?.8%), Classopollis sp. (0—1.7%), Caytonipollenites cf.pallidus (0—1.7%), Monosulcites sp. (0—0.9%), Concentrisporites sp. (0—0.9%) etc.
出处
《微体古生物学报》
CSCD
北大核心
2002年第1期83-90,共8页
Acta Micropalaeontologica Sinica
关键词
孢粉组合
早白垩世
古植被
古气候
北安地区
黑龙江
Early Cretaceous, spore-pollen assemblage, paleovegetation, paleoclimate, Beian area, Heilongjiang
