我国东北黑土区的土壤侵蚀状况比较严峻，黑土资源出现了严重的退化现象，黑土厚度变薄，肥力降低，破坏了土壤资源的可持续发展。因此要制定合理可行的治理方式和恢复方法来保护黑土资源，遏制黑土的继续退化，其主要依据就是黑土的容许土壤流失量，和自身的形成过程与形成条件。土壤的母质是土壤形成和生长发育的物质基础，母质沉积物的物质来源分析能够确定土壤沉积物性质，及沉积物搬运路径，为土壤成土环境重建提供依据。土壤的成土年龄是重建土壤形成过程及其环境的一个关键，为其提供时间标尺。本研究以东北黑土区黑龙江省典型小流域为研究区，通过在典型小流域的岗顶、岗中、岗底部位和天然林地挖1.5 m深的剖面，以10 cm为间隔采集土壤与母质样品，分析样品的粒度组成特征和石英颗粒表面微结构特征，确定土壤母质沉积物的物质来源及其沉积环境特征；采用光释光测年方法和有机质的AMS 14C方法，测定东北黑土的沉积埋藏年龄与成土年龄。主要的结论如下：（1）通过分析岗顶、岗中、岗底和天然林地四个研究剖面样品的粒度特征，发现剖面粒度组成随剖面深度是有变化的，充分体现了沉积搬运过程中其介质的搬运动能大小的变化。岗顶剖面20-100 cm深度粒度主要集中在粉粒部分，粗颗粒含量比较低，而在100-150 cm深度则表现了明显的粗颗粒含量占主导，砂粒含量丰富，其粒度累积曲线呈现了典型的河流沉积特征。岗中剖面在剖面上部（20-50 cm）和底部（140-150 cm）粒度组成相对较粗，而在剖面中部（140-150 cm）其粒度组成则为细颗粒为主，粘粒含量最高。岗底剖面在整个剖面所有深度层位粒度组成基本没有变化，粉粒含量最高，体现了岗底沉积的特征。天然林地剖面上部0-50 cm粒度组成相对较细以粘粒为主，50 cm以下砂粒含量较上层明显增大，其中在70-100 cm深度范围内砂粒含量最高。（2）通过观察统计岗顶和天然林地剖面土壤及其母质石英颗粒表面微形态，发现所有样品的石英颗粒形态多为棱块状和椭圆状，颗粒磨圆度不高，多为棱角状、次棱角状和次圆状。大部分表面具有贝壳状解理、磨光面和V形坑等明显的水下环境石英表面微结构特征。依此可以断定研究区沉积物质是水成沉积物。（3）岗顶、岗中、岗底和天然林地四个剖面不同深度层位的大部分OSL埋藏年龄与地层埋藏顺序一致，所有OSL年龄处于晚更新世晚期和整个全新世。由于土壤侵蚀的发生导致了每个剖面表层的最小值OSL年龄值差异较大，尤其位于流域顶部的岗顶剖面，其剖面0.25 m处OSL年龄已达12.08±1.02 ka，岗中和岗底剖面表层0.25 m深度OSL年龄分别为5.75±0.49 ka和2.62±0.25 ka。（4）综合分析黑土层厚度分布及其母质的埋藏年代，认为黑土开始成土发育的起点时间应小于12 ka，其成土发育阶段应该在全新世时期内。（5）天然林地剖面，在0-0.5 m深度沉积埋藏速率为0.384 m/ka，比0.55-1.45 m深度沉积速率0.048 m/ka大很多。晚全新世暖湿气候的作用使得与干冷气候下的晚更新世晚期相比，增加了径流量，增大了搬运动力，使沉积埋藏加速。其他剖面沉积速率也是一样，在全新世阶段要比晚更新世晚期快。（6）岗顶和岗中剖面14C年龄范围分别在4264±7 至19166±248 cal a BP和6043±42 至17883±213 cal a BP时间范围内。从剖面表层到底部，14C年龄随深度增加而增大。所有14C年龄值处于整个全新世和晚更新世阶段。岗顶和岗中剖面的大部分样品OSL年龄值均大于14C年龄值，可能是混入新碳导致14C年龄偏年轻或者由于矿物未晒退完全OSL高估所致。农地的岗顶、岗中、岗底和天然林地四个剖面的整体变化趋势基本一致，14C年龄随深度的增加而增大变老。岗底剖面各深度的14C年龄值都明显小于岗顶和岗中剖面。天然林地剖面其表层（0.2-0.5 m深）的14C年龄值，明显低于农地剖面，剖面下部的14C年龄值则明显低于岗顶和岗中剖面。所有14C年龄值处于整个全新世和晚更新世阶段。

The soil losses have been serious in the black soil region of Northeast China. The continuous soil erosion have caused that fertile black soils are severely degrading. So it is urgent to take practices for soil conservation and to understand the soil loss rate for the Northeastern of China. In the soil erosion studies, it is critical to determine the formation of conditions and environmental characteristics and the soil loss tolerance providing a performance criterion to take measures for erosion-control. Theoretically, the soil loss tolerance is severe may be judged relative to the rate of soil formation. Rate of soil formation is the basis of the soil erosion studies and the lack of quantitative information on rates of soil formation is regrettable. And also the soil formation dominated over the history of deposit sediment deposition which can also be called as soil parent materials. Establishment of a timeframe is the starting point for understanding the deposition history in a region. In this study, the typical black soil area of Northeast in China as the study area. Dug a section with the depth of 1.5 m on the natural woodland that was undisturbed and deemed that there was no human activities affecting and natural erosion and deposition appearing in the study area. And other three sections were dug on the top, the central and the bottom of the small watershed. A total of fifteen samples were collected from the each study section with the intervals of 10 cm for every sample. Analyzed grain size characteristics and the micro-structural features of quartz grain surface of the soil and its parent material to determine the source of the soil parent material sediments and their sedimentary environment characteristics. Based on Optically Stimulated Luminescence (OSL) dating techniques and AMS 14C dating techniques, and established the accurate chronologies for burial age of the black soil parent and formation ages of the black soil. The main results and conclusions are shown as follows: (1) The samples on all depth layers of the section on the bottom of the slope were with the highest silt content, and that was reflected the deposition characteristics. This section located in the bottom of the small watershed. In the erosion and deposition process, the soil particles that were eroded from small watershed down accumulated on the sit of this section, and the most deposition were finer particles. The composition of partical changed with depth of section in the other three sections (the top of slope section, the middle of slope section and the natural woodland section). It was fully demonstrated that the change of moving media handling of the kinetic energy in the sediment deposition process. In the sediment particles, sand content was dominant indicating that the larger river carrying capacity, water energy, and be able to relatively coarse particles move. Likewise, fine particles were in a dominant position, indicating that the river carrying capacity was weakened, and could not drive the coarse particles to move. (2) Observed the quartz grain surface micromorphology of quartz grains of the all soil and its parent material samples. The most morphology of quartz grains were the edge block and oval-shaped, multi-angularsubangular and rounded, and particle roundness was not high. Most of the surface of quartz grains has a conchoidal cleavage, polished surface and V-shaped pits, and other obvious micro-structural features of underwater environment quartz surface. So, it could be concluded that the sediments of this study area was the river sediments. (3) In the four studied sections, the majority of OSL burial ages were in the same order of strata buried, and all OSL ages were scattered in the late Pleistocene and the whole Holocene. Different values of the OSL ages were shown in each section surface due to the occurrence of soil erosion. Especially the top of slope section in the small watershed, OSL age reached 12.08 ka at the depth of 0.25 m. (4) Based on the depths of black soil and the bureial date of black soil parent, it could be estimated that the starting age point of pedogenic development of black soil should be less than 12 ka. So, the pedogenesis developmental stages should be in the Holocene period. (5) In the natural woodland section, from the surface to the depth of 0.5 m, the burial rate was 0.384 m•ka-1. And the slower deposition rate was 0.048 m•ka-1 at the depth of 0.55 to 1.45 m. The significant difference (order of magnitude different) was appeared at these two layers. In the late Pleistocene stage the climate was dry and cold, however with the Ice Age ended and transition into the Late Holocene, the climate was gradually warming. Because of the role of the warmer climate, runoff increased with the increasing power of handling media. These caused that the burial accelerated. The other sections were the same deposition rate characteristics that the deposition rates were faster at the Holocene phase than the late Pleistocene. (6) The 14C ages trend are consistent in the four section, that are 14C ages increases older with increasing depth. The 14C ages of different depth in the bottom of slope section are significantly lower than the top and middle of slope section. In the natural woodland section, from the surface to the depth of 0.5 m the 14C ages values are significantly lower than the other three sections of agriculture land, and the 14C ages values are lower than the top and middle of slope section on the lower part of the sections. All 14C ages were in the Holocene and Late Pleistocene stage stage.