Skip to main content

Table 2 Pollen data of the 20 representative samples from the Tianzhu borehole.

From: Environmental magnetic record of the fluvial sediments from the Tianzhu borehole in Beijing for the last 800 ka

Number Depth (m) Lithology k (SI) Pollen of Trees Chenopodiaceae (%) A/C ratioa Hydrophytes & Cyperaceae (%) Concentration (grains/g) Climate indicatorb
     Mesophilous species Cold-resistant species      
P1 1.86 Silt 8.6 × 10−4 Quercus, Corylus, Ulmus, Carpinus Pinus, Betula, Salix 6.67 2.75 1.67 480 Warm, humid
P2 4.88 Silt 3.9 × 10−4 Ulmus Pinus, Picea, Salix 38 0.02 2.00 972 Cold, dry
P3 14.39 Clay 2.9 × 10−4 Ulmus Pinus, Betula 5.0 1 0.00 3600 Cold
P4 27.09 Sand 9.7 × 10−4 Corylus, Ulmus Salix 13.33 0.3 2.67 666 Warm
P5 42.93 Clay 1.9 × 10−4 Corylus, Ulmus Betula 11.75 1.45 16.33 48000 Warm, humid
P6 58.59 Sand 2.31 × 10−3 Quercus, Corylus, Ulmus, Tilia Pinus, Betula, Salix 6.0 2.78 4.33 360 Warm, humid
P7 63.49 Sandy silt 4.3 × 10−4 Ulmus, Carpinus Pinus, Betula 33.0 0.17 0.67 800 dry
P8 72.2 Sandy silt 7.5 × 10−4 Ulmus, Tilia Pinus, Salix 2.67 2.25 0.00 600 Warm, humid
P9 77.91 Silty clay 1.2 × 10−4 Quercus, Ulmus, Carpinus Pinus, Picea, Abies, Betula 7.33 1.77 1.00 82 Cold, dry
P10 93.61 Sandy silt 1.15 × 10−2 Pinus, Picea, Betula, Salix 25.0 0.05 0.67 1333 Cold, dry
P11 96.36 Silty clay 3.0 × 10−4 Ulmus Pinus, Picea, Betula 30.0 0.01 2.00 7200 Cold, dry
P12 108.66 Silt 1.32 × 10−3 Corylus Salix 12.33 0.54 13.33 36000 Warm, humid
P13 117.14 Silty clay 3.0 × 10−4 Ulmus Pinus, Betula, Salix 6.33 0.84 2.33 36000 Cold
P14 124.52 Sand 1.02 × 10−2 Corylus, Ulmus, Juglans Pinus, Betula, Salix 3.0 1.89 0.00 61 Warm
P15 134.27 Clay silt 2.0 × 10−4 Corylus, Ulmus Salix 38.0 0.07 0.00 18000 dry
P16 143.42 Sand 2.55 × 10−3 Ulmus, Acer Pinus, Betula, Salix 6.33 1.42 0.67 180 Warm
P17 152.3 Silty clay 1.2 × 10−4 Pinus 1.0 4.67 0.33 307 Cool, humid
P18 160.89 Sandy silt 2.19 × 10−3 Carpinus Pinus, Picea, Betula 5.0 1.6 0.33 124 Cold
P19 167.46 Silty clay 1.5 × 10−4 Pinus 10.0 1 0.00 400 Cold
P20 176.18 Silt 8.0 × 10−4 Pinus, Salix 27.5 0.11 4.50 48000 Cold, dry
  1. a A/C ratio refers to the pollen ratio of Artemisia to Chenopodiaceae.
  2. b On the basis of the percentages of Chenopodiaceae, A/C ratio, the species of Trees, the percentages of Hydrophyte and Cyperaceae, and pollen concentration, we can know that cold or dry climate indicator pollen are found in strata with low values of magnetic susceptibility, while warm or humid climate indicator pollen are mostly found in beds with high magnetic susceptibility values.