Late Quaternary stratigraphy of the lower Androscoggin Valley, southern Maine

Guidebook for field trips in southwestern Maine: New England Intercollegiate Geological Conference, 78th annual meeting, Bates College, Lewiston, Maine, October 17, 18, and 19, 1986: Trip A-

Glacialmarine facies relations in the lower Androscoggin Valley, southwest Maine

A facies model is proposed for late Wisconsinan glaciomarine deposits in the lower Androscoggin Valley that includes for lithofacies assemblages that are defined by morphology and detailed stratigraphic and sedimentologic analysis. The end moraine facies assemblage includes subglacial and resedimented diamicton, and interbedded and locally deformed sand and gravel beds. The sediments from linear ridges which are former grounding line positions of the tidewater glacier margin. The submarine outwash fan facies assemblage commonly drapes or flanks the end moraine assemblage. In proximal regions of the fan, gravel, bedded sand, and diamicton lithofacies predominate and represent rapid deposition at the mouth of the meltwater tunnel by fluvial and mass flow processes. Distal and lateral to the ice margin, fan sediments consist of graded and cross-laminated sands deposited from suspension. The shallow marine facies assemblage consists of well-sorted tidal to subtidal sand lithofacies, poorly sorted gravelly and bouldery lad deposits on moraine crests, and lagoonal muds. Collectively, these lithofacies were deposited as a result of reworking previously deposited sediments during isostatic emergence

600 Years of Late Holocene Climate Variability Inferred from a Varved Proglacial Sediment Record Linnévatnet, Svalbard, Norway

The varved proglacial sediment record preserved in Linnévatnet, Svalbard, Norway contains a valuable climate signal that can be used to reconstruct local Late Holocene climate variability. Two cores analyzed in this study, LH-4 and LH-Long were collected in May, 2012 from a distal location 1.5 km from the main inlet. This distal location allowed for a long record to be collected and the lack of sub-annual layers allowed for accurate measurement of varve thickness, the primary climate proxy. Through analysis of the Linnédalen proglacial system, and comparisons to the instrumental record it is clear that varve thickness is directly related to Linnéelva yearly sediment flux, Linnébreen mass balance, and summer temperature. Varve thickness and other potential climate proxy measurements were accurately placed back through time through the development of a plutonium-verified varve chronology. The varve chronology derived from counting and measuring yearly lamination couplets throughout core LH-4, is one of the highest resolution chronologies established in Linnévatnet. From the interpretation of the Linnévatnet climate proxies and comparisons with other Svalbard paleoclimate reconstructions four periods of warm summer temperatures and four periods of cool summer temperatures in Linnédalen were projected. The warm periods, defined from AD pre- 1379 to late 1390’s, from AD 1760’s-1790’s, from AD 1850’s to AD 1870’s, from AD 1980’s-present, relate to either steady increases in LH-4 varve thickness or intervals where varve thickness remains above average. The cool periods, defined from AD 1400-1450’s, AD 1550’s-1580’s, AD 1790’s-1850’s and AD 1950’s-1980’s, relate to either steady decreases in LH-4 varve thickness or intervals where varve thickness remains below average. Further comparisons between the paleoclimate reconstruction presented in this study and regional-scale Late Holocene climate reconstructions indicate strong correlation between climate conditions in Linnédalen and NAO mode. This relationship confirms the influence of the NAO on the climate of western Spitsbergen

Relative sea level chronology determined from raised marine sediments and coastal isolation basins, northeastern Ellesmere Island, Arctic Canada

A new relative sea level curve for the Robeson Channel area constrasts with previously published curves for the area by inferring that rapid emergence may have commenced at c7400 BP, as much as 1200yr earlier than previously predicted. Subsequently, uplift may have occurred at much lower rates from c6000 BP to present. A comparison of shell dates used for the relative sea level curve and dates on disseminated total organic carbon (TOC) fraction from lacustrine and marine sediments from sediment cores from emerged coastal lakes shows wide discrepancies