Till stratigraphy and ice movement directions in the Kittila area, Finnish Lapland

Abstract

Sedimentological, structural and chemical characteristics of till and weathering crust are studied in the Kittila area of western Finnish Lapland. Four separate till beds and a weathering crust are discovered at three study sites ‐ Pulju, Jerisjarvi and Mantovuoma. An upper grey till bed and a brown till bed are found at each site, the former being interpreted as a melt‐out till, the latter as a lodgement till. A yellowish brown till bed occurs only in the Pulju area and is interpreted as a local saprolite till of a lodgement facies, while a lower grey till bed, seen only in the Jerisjärvi area, is a melt‐out type till. The weathering crust (saprolite) is a product of chemical weathering of long duration and must be preglacial in age. In the earlier stages of glaciation the ice divide was located near the Scandinavian mountain range, ice movement took place from the northwest, and a lower grey till bed was deposited in the study area. In the later stages of deglaciation the ice divide was located south of the area, so the ice flowed from the south, depositing a brown till bed and locally also a yellowish brown till bed. In the latest stages the ice flowed from the southwest, depositing an upper grey till bed.