A C-14 Date for the Muscotah Marsh

Abstract

Located 1 /2 miles south of Muscotah in the NE 1/4 sec. 16, T. 6 S., R. 17E., Atchison County, Kansas, is a raised artesian marsh at the edge of the Delaware River flood plain. The maximum height of the raised portion is 7 feet above the surrounding flat terrain, the width is 15 to 54 yards, and the length is 274 yards. The mound consists primarily of plant material which is only partially decomposed. Below the raised area is a stratum of 15 feet consisting of decomposed and fragmentary plant materials. Next is a 5 foot layer consisting of clay, sand, and about 8% organic material. This is followed by a 6 foot layer of fragmentary plant materials mixed with clay and sand. The bottom 3 feet is a mixture of clay, sand, and plant material. The whole deposit consists of 36 feet of material through which artesian water flows to the surface. Horr and McGregor (1948) described the surface features of the marsh and gave a list of 65 vascular plants growing on the raised area. In 1950 I obtained a core of the entire 36 feet of the marsh and at the lower levels found needles, twigs, wood, and pollen of Abies, Picea, Larix, and Tsuga. Nearer the surface, remains of grass and sedge culms, achenes of sedges and Polygonun were found. Horr (1955) described the pollen of the deposit but did not include a discussion of identifiable wood, twigs, needles, and fruits associated with the pollen when he published his profile. In the core I obtained there were Abies needles, twigs, and wood associated with Abies pollen in the lower 16 feet of the deposit. A large sample of Abies needles obtained from the 36 foot or bottom layer was submitted to the Harrison M. Randall Laboratory of Physics at the University of Michigan by W. H. Horr. Their number 352 gave the C-14 date as 15,500 years ? 1,500. Though Abies pollen is found in all but the upper 10 feet of the deposit, macro remains are not found above the 20 foot level. This level coincides with the period during which evidence indicates that the boreal forest was immediately succeeded by prairie without an intermediate pine or deciduous forest stage. The grass-sedge pollen at and above this level is associated with macro evidence of those groups.