Late Holocene environmental conditions in Coronation Gulf, southwestern Canadian Arctic Archipelago: evidence from dinoflagellate cysts, other non‐pollen palynomorphs, and pollen

Abstract

Boxcore 114.1868 W; 211 m water depth) from Coronation Gulf represents the first decadalscale marine palynology and late Holocene sediment record for the southwestern part of the Northwest Passage. The record was studied for organic-walled microfossils (dinoflagellate cysts, non-pollen palynomorphs), pollen, terrestrial spores, and sediment characteristics. 210 Pb, 137 Cs, and three accelerator mass spectrometry 14 C dates constrain the chronology. Three prominent palaeoenvironmental zones were identified. During the interval AD 1470-1680 (Zone I), the climate was warmer and wetter than at present, and environmental conditions were more favourable to biological activity and northward boreal forest migration, with reduced sea-ice and a longer open-water (growing) season. The interval AD 1680-1940 (Zone II) records sea-ice increase, and generally cool, polar conditions during the Little Ice Age. During AD 1940-2000 (Zone III), organic microfossils indicate an extended open-water season and decreased sea-ice, with suggested amelioration surpassing that of Zone I. Although more marine studies are needed to place this record into an appropriate context, the succession from ameliorated (Zone I) to cooler, sea-ice influenced conditions (Zone II) and finally to 20th-century warming (Zone III) corresponds well with several terrestrial climatic records from the neighbouring mainland and Victoria Island, and with lower-resolution marine records to the west.

Late Holocene Palynological Record and Landscape Change From the Piraquê-Açu and Piraquê-Mirim Estuarine System, Espírito Santo, Brazil

“…The foraminiferal linings are the microforaminifera organic part and is always related to the marine conditions (Stancliffe, 1996). This concentration difference between the two cores may be related to different environmental conditions, related for instance to higher salinity at this local or to the high productivity as observed by Pienkowski et al (2011) in southwestern Canadian Artic Archipelago.…”

“…This algae genus can occur in freshwater as environments with a certain salinity (Traverse, 2008). Pienkowski et al (2011) found this colonial alga in the Coronation Gulf and associated its occurrence with increasing fluvial input.…”

New Insights on the systematic classification of certain palynological taxa (tintinnomorphs) from Holocene deposits of the Coastal Plain of Southern Brazil

“…The earliest known occurrences are from the Lower Triassic of Ireland and Israel (Van Waveren, 1994) and the Lower Cretaceous of France (Gorin & Steffen, 1991). Although there are several gaps in the fossil record of this group, tintinnid organic remains are frequent only from Holocene marine deposits (Reid, 1975;Reid & John, 1978;Grill et al, 2002;Roncaglia, 2004;Borromei & Quattrocchio, 2001Meckler et al, 2008;Mudie et al, 2010;Pienkowski et al, 2011Pienkowski et al, , 2013, and may aid in understanding recent environmental changes (Grill et al, 2002;Roncaglia, 2004;Borromei & Quattrocchio, 2001Meckler et al, 2008;Mudie et al, 2010).…”

“…Nevertheless, many loricae and cysts are recovered by palynological processing (Reid & John, 1978;Meckler et al, 2008;Mudie et al, 2010Mudie et al, , 2011Pienkowski et al, 2011Pienkowski et al, , 2013, being classified within the palynomorphs as zoomorphs (Traverse, 1994). In modern marine sediments, a large quantity and variety of tintinnid cysts and loricae is known (Reid, 1975;Reid & John, 1978;Van Waveren, 1994;Van Waveren & Visscher, 1994;Kawamura, 2004;Hardy & Wrenn, 2009;Lipps et al, 2013;Pienkowski et al, 2011Pienkowski et al, , 2013Matsuoka et al, 2017).…”

“…In modern marine sediments, a large quantity and variety of tintinnid cysts and loricae is known (Reid, 1975;Reid & John, 1978;Van Waveren, 1994;Van Waveren & Visscher, 1994;Kawamura, 2004;Hardy & Wrenn, 2009;Lipps et al, 2013;Pienkowski et al, 2011Pienkowski et al, , 2013Matsuoka et al, 2017).…”