According to the determination and analysis for the soluble salts of Sihenan lake sediments, the paleo-hydrological evolvement of the lake in Mid-Holocene can be recovered. Five kinds of ions were selected for the determination, including HCO₃^-，Cl^-，SO₄^2-，Ca²⁺ and Mg²⁺.The results indicate that the lake was a freshwater lake of hi-carbonate type, and the salt concentration increased with the evolvement of the lake. Two salting periods appeared around 5660aBP and 4040aBP respectively. Compared with the results concluded from the study for pollens and mollusk fossils, the conclusion drawn from soluble salts coincides with them, which also accords with the lake evolvement history in the background of regional climate change.

The analysis of the sedimentary facies of the reservoir is important for the exploration and development of one oilfield. And obvious types of facies symbols which are macro and micro are necessary to the division of the sedimentary facies. During the study of the sandstone reservoir of the Neogene in Huatugou oilfield, Qaidam Basin, on the basis of the general columnar section of the Neogene in Huatugou oilfield and the data of 2 systemic wells and 12 exploration wells, the authors have obtained some macro facies symbols helpful to divide the sedimentary facies with the Markov Main Analysis and Time-Trend Analysis, such as the cycles of the lithologic variation and the main types of the rhythm and its assemblage. Conjoint with the color, the laminations, the deformation structures, the types of the carbonate rocks and the special sediments, the authors analyzed the sedimentary facies of the Neogene reservoir in Huatugou oil field. It is concluded that (1) it is a important assistant means of ascertaining the key beds of a exploration well to obtain the cycles of the lithologic variation with Markov Main Analysis; (2) main deposits and main modes of the lithologic transference obtained by Time-Trend Analysis are helpful to ascertain the hydrodynamic condition and the evolvement process of sedimentary environment; (3) the main types of the sedimentary facies of the Neogene in the Huatugou oilfield include braided channel deltaic plain, deltaic frontal margin, fore-delta, littoral lake and shallow lake facies.

A holocene paleosol-loess sediment profile and lacustrine sediment profile were found in Mengjin, Henan province. The authors investigated the stratum in this area and analysed samples from the paleosol-loess sediment profile to study middle Holocene environmental change in Mengjin as well as its impact on human activity. Based on particle-size analysis and magnetic susceptibility, CaCO₃ measurement of the paleosol-loess sediment profile, together with the comparison between the paleosol-loess sediment profile and the lacustrine sediment profile, it was concluded that during 5660-7020aBP and 3755-4610aBP, an ancient lake and paleosol were formed in this area, climate was wet and warm; The climate fluctuated during 4610-5660aBP, the ancient lake shrank to sporadic bogs, and the paleosol ceased to develop; During 3055-3755aBP, the ancient lake shrank and dried up, and loess began to accumulate, the climate turned to cold and dry. Human began to lived on the paleosol during late Henan Longshan period, because the lake level was high in this period; During Erlitou period, however, as the ancient lake withered away, human activities expanded gradually to lower land; when the ancient lake dried up, human became to live on lacustrine sediment.

The high resolution palynological records from Sihenan profile reveal that the non-arboreal pollen is the most important part of the pollen assemblage in Luoyang, Henan province within the last 7.000 aBP. The non-arboreal pollen mainly includes Artemisia, Gramineae and Chinopodiaceae. The arboreal pollen is sparse and mainly consists of Pinus. Five pollen assemblage zones are established through the stratigraphical changes of the pollen. 5.625--6.120 aBP interval is the best period in Holocene with a warm and wet climate. The profile includes two major cold peaks at 4.580--5.275 aBP and 6.120--6.375 aBP. The centennial-scale climate instability is obvious, which exists even in Holocene Optimum.

The discovery of the Holocene lacustrine sediment in the Central North Chin a has provided acceptable records of the paleoenvironment during approximately 5660 aBP to 3500 aBP. The vertical distribution and fluctuation of aquatic, amphibian and terrestrial mollusks remains in Sihenan Profile represent the physical environmental history of this area. The process of birth, expansion, and vanishment of the ancient lake was well recorded through the presence and absence of aquatic species. And from the abundance variation of hygrophilous-warmthand moisture-loving species, It can be known that the Central North China was warmer and moister than the present during the period of 5000 aBP to 4000 aBP.

According to the sedimentation, a preliminary assessment was conducted on the polluted standard of the heavy metals in the deposit of the lake, in use of I_geo. The polluted standard of the metals in the deposit is at a very low level. The variance between the particle diameter of the upper and the lower parts of the sediment is the main cause of the changing regularity of the elements.

Prehistoric cataclysms and their impacts on human paleo-culture have been a focus of the scientists in the world. Some ancient trees relatively undamaged back, roots and branches were unearthed from paleochannel in the Peking University campus. The burying position, the characteristics and the age of the trees indicate that the flowage of ancient Yongding River resulted in the event at about 5000a B P. The trees, together with the Neolithic culture relic unearthed at the same time, show that the disastrous floods definitely occurred at about 5000a B P in Peking area.

According to the variation of stable isotopic composition of carbonate in lacustrine deposite in Weiminghu Lake, Peking University, the section can be subdivided into four oxygen-carbon-isotope stages. They are as follows: a) 50～26cm (1747-1866a A.D.), which gave higher value of oxygen and lower value of carbon isotope. The δ¹⁸O value of samples ranges from -4.70‰ to -6.03‰, the δ¹³C value ranges from -3.63‰ to -6.03‰. b) 26～22cm (1867-1886a A.D.), which is characterized by a rapid change of value of oxygen and of carbon isotope. The δ¹⁸O value have a rapid downfall from -5.23‰ to -7.58‰, and the δ¹³C value have a rapid uplift from -5.70‰ to -2.18‰. c) 20～0cm (1886-1997a A.D.), which gave lower value of oxygen and higher value of carbon isotope. The δ¹⁸O value of samples ranges from -7.02‰ to -8.08‰, the δ¹³C value ranges from -2.03‰ to -2.63‰. Generally, the values of δ¹⁸O in lacustrine sediment has a positive correlation with that of the δ¹⁸O values of rainwater in the Asian monsoon region, and the latter are controlled by monsoon climate. The summer monsoon have a lower value of oxygen isotope, and the winder monsoon have a higher value of oxygen isotope. The values of δ¹³C of carbonate in lacustrine sediment are controlled by that of the algae activity in the lake water and the latter has a positive correlation with temperature and humidity. So the high value of oxygen and lower carbon isotope (δ¹⁸O and δ¹³C) in lacustrine sediment in Weiminghu lake represents a relatively cool and dry weather while the low value of oxygen and higher carbon isotope represents a rather hot and wet weather. The variation of oxygen and carbon isotopic value among the section indicates a cool-dry climate during 1747—1866a A.D., a hot-wet climate during 1886—1997a A.D., and a rapid change of climate from 1866 to 1886a A.D..

Dongfang Square is situated in Wangfujin area of Beijing. Under the ground lever there is an upper sand layer of river at 10.5m and a lower sand layer of river at 12m. Some fossils, stone artifacts or ashes were found in the layers while digging bases for some buildings. The upper layer age is 15 to 19ka B.P. and the lower layer age is 22 to 26ka B.P. with thermoluminescence dating.

The Paleolithic site found in Dongfang Square Wangfujing in Beijing is a late Paleolithic cultural site. It consists of two cultural layers. The TL age of the sample from the upper layer we obtained is (1.5- 1.9)×10⁴a B.P. and the age of the lower layer is (2.2- 2.6)×10⁴a B.P.. This site is located on a plaeo-levee of a river and is a place of ancient human activity during a short period. This discovery has a important significance for studying the relationship between human active history and paleoenvironment evolution on Beijing Plain.

According to the variation of stable isotopic composition of carbonate in lacustrine deposited in Hutouliang, Nihewan Basin, the section can be subdivided into four oxygen-carbon-isotope stages. They are as follows from top downwards: (1) 0.00-1.85m, which gave lower value of oxygen and carbon isotope. The (δ)¹⁸O value of 4 samples ranges from -7.16 to -7.88, (δ)¹⁸O(avg)=-7.53; the (δ)¹³C value ranges from -3.40 to -5.57, (δ)¹³C(avg)=-4.30. (2) 1.85-7.00m, which gave higher value of oxygen and carbon isotope. The (δ)¹⁸O value of 12 samples ranges from 0.46 to -5.52, (δ)¹⁸O(avg)=-2.59; the (δ)¹³C value ranges from 0.23 to -3.66, (δ)¹³C(avg)=-1.17. (3) 7.00-10.10m, which gave lower value of oxygen and carbon isotope. The (δ)¹⁸O value of 4 samples ranges from -6.97 to -9.39, (δ)¹⁸O(avg)=-8.50; the (δ)¹³C value ranges from -2.68 to -6.85, (δ)¹³C(avg)=-4.04. (4)10.10-14.87m, which gave higher value of oxygen and carb on isotope. The (δ)¹⁸O value of 11 samples ranges from 0.57 to 6.36, (δ)¹⁸O(avg)=-2.94; the (δ)¹³C values ranges from 3.43 to -3.52, (δ)¹³C(avg)=-0.73. Generally, the values of (δ)¹⁸O and (δ)¹³C of carbonate in lacustrite sediment have a positive correlation with that of the water saltness, the saltness has a positive correlation with evaporativity, and the evaporativity has a positive correlation with temperature and a negative correlation with humidity. So the high value of oxygen and carbon isotope ((δ)¹⁸O and (δ)¹³C) in Nihewan represents a relatively hot and dry weather while the low value of which represents a rather cool and wet weather. The variation of oxygen and carbon isotopic value among the section indicates the alternation between hot-dry and cool-wet climate during the last interglacial period.