摘要
该文给出一种简便的定量地层学方法——原始数据排序方法。该方法所研究的原始数据由P个地层剖面中取得的N个样品上观测M个生物属种的出现与否形成,数据矩阵的列代表生物属种,行代表样品。排序最终使某种生物的出现序列达到最紧凑,并且与矩阵对角线最靠近。此时,可以使相似的样品处在相邻近的行位置,相似的生物属种处在相邻近的列位置。
This paper outlines one simple technique, seriation of a data matrix consisting of the presence-absence of M species taken from N samples in P stratigraphic sections. The basic procedure is to arrange the data in the form of a range chart with taxa in the columns and samples in the rows. This is accomplished by grouping the presences along the matrix diagonal so that the number of embedded absences on and near the dingonal is minimized. This also provides the shortest possible range zones of taxa. Seriation, simultaneously, calculates a range chart of taxa and places samples with the most similar faunal composition in adjacent rows of the seriation matrix. A simple test criterion measures the degree of concentration of presences along the diagonal. Two types of seriation solution are available. In the unconstrained solution samples can be grouped in any order, which generaly results in assemblages of samples and taxa that are similar to those derived from multivariate analysis of presence-absence daa. However, groupings of taxa and samples usually are not in stratigraphic order. Stratigraphic control is introduced for sonstrained seriation, in it samples are retained in order of superposition for each ctratigraphic section in the seriated matrix. The stratigraphic constraint is useful in correlation.
关键词
定量地层学
原始数据
排序法
地层
quantitative stratigraphy
seriation of original data matrix
