Background: High-resolutionary lacustrine sediments from Maar Lakes are very important to construct and understand the mechanism of paleoclimatic changes. Purpose: To study the tendency of climatic changes and the global warming in the 20th century

proxy indexes for temperature and precipitation during the Late-Holocene (from AD1282?AD1988) were obtained by high-resolutionary geochemical analysis on the varved sediments of Erlongwan Maar Lake (Northeastern China). Methods: Synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) was performed on the lake sediments from Erlongwan Maar Lake and six elements including As

Br

K

Mn

Rb and Ti were obtained. Factor analysis on these elemental data was used to facilitate the interpretation of the results. Results: The three main factors

F1

F2 and F3

were extracted. These three factors are related to early diagenesis

biogenesis factor and basin erosion

respectively. The F2 and F3 scores may also be used as climate proxy indexes for changes in temperature and precipitation

respectively. Varve chronology over past 700 years from this core gives a precise time scale for evaluating this sediment sequence

climatic and environmental changes. Conclusion: Particularly during the Little Ice Age (LIA)

the climate was not homogenous but characterized by three cold spells. After AD1890

the region had generally a warm and humid climate and concomitant trends of rising temperature and falling precipitation could be observed as a reflection of global warming in the 20th century.Cited