Glaciomorphological features of the North and Middle Lithuania Lowlands

Abstract

  Glaciomorphological features of the North and Middle Lithuania Lowlands are described and interpreted. The ridged relief of the morainic plain in the NW part (Akmenė district, North Lithuania) is characterized by mega-scale glacial lineation (MSGL) forms, testifying to the active movement of the glacier; they do not correlate with the sub-Quaternary palaeosurface. The relief structure of the Nevėžis Moraine Plain located farther south includes areas of obscure MSGL that were affected by glaciolacustrine accumulation and abrasion, glaciofluvial accumulation and erosion, as well as intensive land drainage (amelioration) in the 20th century. Typical MSGL forms in the Mūša-Nemunėlis Moraine Plain and relicts of MSGL forms in the Nevėžis Moraine Plain, as well as patterns of orientation and inclination of macroclast long axes due to mixing of the moraine material (till), reflect the dynamics of the sliding glacier. These features show that the moraine plains of Middle and North Lithuania were formed by an actively moving glacier, which left an identifiable till layer when geological and hydrological conditions allowed.