ALBERT

Description: Centennial-scale records of sea-surface temperature and opal composition spanning the Last Glacial Maximum and Termination 1 (circa 25-6 ka) are presented here from Guaymas Basin in the Gulf of California. Through the application of two organic geochemistry proxies, the UK37' index and the TEX86H index, we present evidence for rapid, stepped changes in temperatures during deglaciation. These occur in both temperature proxies at 13 ka (~3°C increase in 270 years), 10.0 ka (~2°C decrease over ~250 years) and at 8.2 ka (3°C increase in 〈200 years). An additional rapid warming step is also observed in TEX86H at 11.5 ka. In comparing the two temperature proxies and opal content, we consider the potential for upwelling intensity to be recorded and link this millennial-scale variability to shifting Intertropical Convergence Zone position and variations in the strength of the Subtropical High. The onset of the deglacial warming from 17 to 18 ka is comparable to a "southern hemisphere" signal, although the opal record mimics the ice-rafting events of the north Atlantic (Heinrich events). Neither the modern seasonal cycle nor El Niño/Southern Oscillation patterns provide valid analogues for the trends we observe in comparison with other regional records. Fully coupled climate model simulations confirm this result, and in combination we question whether the seasonal or interannual climate variations of the modern climate are valid analogues for the glacial and deglacial tropical Pacific.

Description: Calcareous nannofossils from upper Campanian-lower Maestrichtian Deep Sea Drilling Project Leg 71 Cores 511-23 and 511-24 are described and correlated with assemblages of similar age from piston and drill cores on the Falkland Plateau, South Atlantic Ocean. The Leg 71 cores partially fill a drilling gap of at least 20 meters left within a thick (50 m) carbonate section first drilled by DSDP Leg 36 at Site 327. Cores 511-23 and 511-24 both fall within the upper portion of the Biscutum coronum Zone of Wind and demonstrate an overlap in the range of Monomarginatus quaternarius with the ranges of M. pectinatus, Misceomarginatus pleniporus, and Biscutum coronum across the Campanian/ Maestrichtian boundary. Resolution of the sequence of highest occurrence datums for the latter species must await the recovery of a more complete section. Comparison of the Site 511 assemblages with those from Mas Orcadas Core 07-75-44 to the north confirms earlier speculation that the Falkland Plateau served as an important boundary between major water masses during the Late Cretaceous.

Description: Waterfall Bluff, in Eastern Mpondoland (Eastern Cape Province, South Africa), is a recently excavated archaeological site with deposits spanning Marine Isotope Stage (MIS) 3 to the Middle Holocene. Here, we present preliminary results of a multi-proxy palaeoenvironmental study combining macro-botanical remains, charcoal, phytoliths, pollen and plant waxes derived from the same archaeological record. We aim to understand the interactions between hunter-gatherer plant foraging and climate and environmental change in coastal Mpondoland from MIS 3 to the Early Holocene at Waterfall Bluff. The charcoal and pollen records at Waterfall Bluff show the gathering of a variety of woody taxa characterised by their combustion and medicinal properties (e.g., Millettia grandis and Apodytes dimidiate). The leaves identified in the macrobotanics and in the phytolith record might belong to some of these taxa and it is likely that they were used for medicinal purposes. From a palaeoenvironmental perspective, our results indicate low precipitation and low rainfall seasonality under cool conditions during MIS 3 and the Last Glacial Maximum (LGM). Under these conditions, open woodlands interspersed with dry and hygrophilous grasslands and bushveld vegetation with significant representation of fynbos elements occurred in the local landscapes probably along Podocarpus/Afrocarpus forests. The latter could have been (1) present along river valleys and scarps on the Mpondoland exposed continental shelf towards the south and west of Waterfall Bluff, supported by palaeorivers and cool temperatures favouring low evapotranspiration, or (2) present in the interior with pollen grains possibly transported to the site by intensified westerly winds. These forests contracted as a result of the post-glacial marine transgression or reduced westerlies following the LGM. During the Early Holocene, the palaeoenvironmental signal points to higher summer rainfall and higher seasonality than during MIS 3, the LGM and the LGIT. These changes are coeval with an increase of coastal forests and C4 mesic grasslands with localized wetland vegetation around Waterfall Bluff. These multi-proxy archaeobotanical and biochemical data show that landscapes surrounding Waterfall Bluff changed in relation to marine transgressions/regressions and changes in rainfall intensity and seasonality. The people of Waterfall Bluff foraged the coasts during glacial periods to collect wood.

Description: This dataset is associated with Phelps et al. (2020, DOI: 10.1111/ecog.04990), and is comprised of paleoecological information from African subfossil pollen assemblages over the past 20,000 years. Data includes the following information: Appendix 1: a list of collated sites from the APD, EPD, and other publications Appendix 2: a list of collated entities from the APD, EPD, and other publications Appendix 3: a list of citations for each entity in appendix 2, whether analyzed or not Appendix 4: a harmonized taxa list with original taxa names and numbers Appendix 5: a list of collated samples from the APD, EPD, and other publications Appendix 6: a list of counts from the APD, EPD, ACER, and other publications Appendix 7: a list of dates (14C, etc) from the APD, EPD, ACER, and other publications Appendix 8: a list of CLAM outputs calculated (Blaauw 2010) from the list of radiocarbon dates Appendix 9: a harmonized biomization scheme for "direct" and "indirect" methods For use of these datasets, associated publications (see appendix 3) and databases should be cited: The African Pollen Database (APD: Vincens et al. 2007, http://fpd.sedoo.fr/fpd/bibli.do) The European Pollen Database (EPD: Fyfe et al. 2009, http://www.europeanpollendatabase.net/getdata/) The ACER Pollen and Charcoal Database (Sánchez Goñi et al. 2017) Additional information was added to these appendices in association with the following publications (note: information was extracted from publications and/or contributed by authors): Brenac 1988, Burrough & Willis 2015, Chase et al. 2015b, Cheddadi et al. 2015, 2016, 2017, Cordova et al. 2017, Giresse et al. 1994, Lim et al. 2016, Maley 1991, Maley & Brenac 1998, Metwally et al. 2014, Quick et al. 2016, 2018, Valsecchi et al. 2013, Waller et al. 2007. The harmonized biomization scheme (appendix 9), is based on six primary publications: Jolly et al. 1998, Elenga et al. 2000, Vincens et al. 2006, Vincens et al. 2007, Lebamba et al. 2009, Lézine et al. 2009, with reference to the African Plant Database (version 3.4.0).