Climate Evolution in the Northern North Atlantic - 15 Ma to Present more

Chapter 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Abstract This chapter evaluates climatic signals from floras of 11 sedimentary rock formations from Iceland spanning the time interval 15–0.8 Ma. From 15 to 12 Ma, the climate was humid warm temperate probably with hot summers (Cfa climate) as evidenced by the presence of taxodiaceous conifers such as Glyptostrobus and Cryptomeria and warmth-loving angiosperms. The first shift towards cooler conditions occurred between ca 12 and 10 Ma; during this period the Taxodiaceae and warmth-loving angiosperms such as Magnolia, Lauraceae, and Liriodendron disappeared from the vegetation of Iceland, whereas at the same time, a massive immigration of herbaceous plants and small-leaved Ericaceae is recorded. This shift appears to reflect the transition from a Cfa to a Cfb climate. The second shift was between ca 5.5 and ca 4.4 Ma; after this interval, small-leaved Salix species are recorded for the first time and co-occurred with exotic elements such as the large-leaved evergreen Rhododendron subsection Pontica. Mild (Cfb climate) conditions lasted at least until ca 3.6 Ma. Between ca 3.6 and 2.4 Ma, the switch to the modern Cfc and ET climates occurred. This is reflected by the modern appearance of the Pleistocene floras. While cooling on a global scale occurred immediately after the Mid-Miocene Climatic Optimum at ca 17–15 Ma due to the rapid growth of the Eastern Antarctic Ice Sheet, mild and warm conditions lasted until at least ca 12 Ma in Iceland, underscoring the effect of warm sea currents on regional climate. The shift from a warm-house to a cold-house climate, as reflected in the floras of Iceland, coincided with the onset of large-scale glaciations in the northern hemisphere. 13.1 Introduction Climate evolution is often viewed on a global scale, resulting in a mean or averaged climate signal (Pearson and Palmer 2000; Zachos et al. 2001). However, since climate is not evenly distributed across the globe, it may be helpful to T. Denk et al., Late Cainozoic Floras of Iceland, Topics in Geobiology 35, DOI 10.1007/978-94-007-0372-8_13, © Springer Science+Business Media B.V. 2011 669 670 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present evaluate regional or local scale signals in order to develop a more differentiated picture about the evolution of the Earth’s climate and to understand how regional variants of climate interact (cf. Ramstein et al. 1997; McManus et al. 2002; Anderson and Woodhouse 2005; Robinson 2009). A good deal of our present knowledge about Neogene climates is based on data from global deep-sea isotopic records (Pearson and Palmer 2000; Zachos et al. 2001). While the climate was warm and subtropical to tropical across large parts of the northern hemisphere until the Early Eocene (ca 52 Ma; Zachos et al. 2001; Moran et al. 2006), it gradually became cooler and seasonality became more accentuated during the later parts of the Cainozoic (Ramstein et al. 1997). Studies using isotope values from marine organisms generally recognize a short and pronounced warm phase at ca 17–15 Ma, the so-called ‘Mid-Miocene Climatic Optimum’ (Buchardt 1978; Zachos et al. 2001) followed by a “most dramatic cooling phase” (Pearson and Palmer 2000, p. 699). Soon after the Mid-Miocene Climatic Optimum, the first ice-rafted debris are reported from the northernmost North Atlantic (14 Ma, DSDP/ODP Leg 151 site 909, Fram Strait; Thiede et al. 1998), but large-scale glaciations in the northern North Atlantic are not reported prior to ca 3 Ma (Driscoll and Haug 1998; St. John and Krissek 2002). The northern North Atlantic has been a key area affecting global climate during the past 15 Ma due to its role in water exchange between the Arctic Ocean and the southern parts of the North Atlantic Ocean. Specifically, warm waters from the Gulf Stream-North Atlantic Current system and from the northern Sargasso Sea move to the north, forming the North Atlantic Drift Current in the Iceland Basin. The North Atlantic Drift Current is unique in that it transports warm waters to latitudes higher than in any other ocean. As the warm waters reach high North Atlantic latitudes, they give up heat and moisture to the atmosphere, cool, sink, and flow back as a cold and salty deep current, the North Atlantic Deep Water (Bischof et al. 2003; Haug et al. 2004). The initiation of the present North Atlantic current system dates back to the Middle Miocene, 16–15 Ma, at the commencing of the closure of the Central American Seaway (uplift of the Panama Sill) that blocked the exchange of tropical Atlantic and Pacific deep waters (Keller and Barron 1983; Duque-Caro 1990; Wright et al. 1991). From this time on, the developing Gulf Stream started transporting warm surface waters into the northeastern North Atlantic region (British Isles, Norway, and Iceland). Increased evaporation at high latitudes may have triggered the initial switch to a cold-house climate in the northern hemisphere, as indicated by the first ice-rafted debris pulses in the Arctic area (14 Ma; Thiede et al. 1998). At the same time, the influx of warm southerly waters ameliorated the climate in parts of the North Atlantic, and may have compensated for cooling radiating from the Arctic Ocean. As of yet, little is known about climate development in the northern North Atlantic from the Middle Miocene onwards using terrestrial fossils, owing to the absence of sediments yielding plant and animal fossils. In this chapter, we evaluate the climatic signal from approximately 45 floras occurring in 11 plant-bearing sedimentary formations spanning the time interval 15–0.8 Ma (see Chap. 1, Table 1.2). 13.2 Evidence from Potential Modern Analogues of Cainozoic Plant Taxa 671 13.2 Evidence from Potential Modern Analogues of Cainozoic Plant Taxa For all fossil taxa encountered in Icelandic Miocene to Pleistocene sediments, potential modern analogues were chosen based primarily on morphological similarity (Appendix 13.1). Depending on the taxonomic resolution (limited by the quality of the fossil record), potential modern analogues can be families, genera, or several to only a single species. For these taxa, we established their present geographic distribution including their altitudinal range using regional floras and generic monographs (e.g. Standley 1920; Meusel et al. 1965; Ohwi 1965; Hegi 1966; Browicz and Zielińsky 1982, Browicz 1983; Flora of North America Editorial Committee 1993, 1997, 2010; Cao 1995; Peters 1997; Flora of China Editorial Committee 1999, 2001, 2008; Zhu and Song 1999; Iwatsuki et al. 2000, 2006; Erfmeier 2004; Luu and Thomas 2004; Sun et al. 2005). We then chose three to four climate stations that reflect the climatic extremes represented within the biogeographic distribution of each taxon and calculated the mean annual temperature (MAT). For the present study, we used only MAT values based on the assumption that Iceland had a fully humid temperate Cf climate (Kottek et al. 2006) without severe winter frosts throughout the Neogene. Data for climate stations were obtained from Walther and Lieth (1960, 1964) and Lieth et al. (1999), and in some cases from monographic studies of particular plant genera (Cao 1995; Erfmeier 2004). Climate stations often provide data for low altitudes. In contrast, the majority of the identified potential modern analogues display a considerable altitudinal range. To account for this, we used the moist adiabatic lapse rate, assuming that temperature changes 5°C per 1,000 altitudinal metres in humid temperate climates (Henderson-Sellers and Robinson 1986). For a number of taxa, we used Thompson et al. (1999a, 1999b, 2000, 2006) and, in few cases, the database of Utescher and Mosbrugger (2009). We created box-plots based on the minimum MAT (MATmin) requirements for each potential modern analogue for each sedimentary rock formation (Fig. 13.1). In addition, in Appendix 13.1, those taxa are indicated that have the four lowest minimum MAT among the taxa recovered for each sedimentary rock formation (see also Table 13.1). The box-plots (Fig. 13.1) show the 25th and 75th percentiles (boxes), that is, the MATmin values below which 25% and 75% of all taxa recorded for a formation can thrive, and the 10th and 90th percentiles (whiskers). The median (horizontal lines in the boxes) divides the sample in two equally large groups, one comprising taxa with MATmin warmer than the median value and one comprising taxa with MATmin cooler than the median. For all the formations investigated, the distribution of MATmin is quite diffuse among the components. A clear turning point is seen first between the 12 and 10 Ma formations (compare Table 13.1) and after ca 3.6 Ma, whereas the change from ca 12 to 4.4 Ma is gradual. Warm outliers (e.g. Taxodiaceae) in the ca 15 and 12 Ma formations are outside the 5% and 95% 672 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Fig. 13.1 Box-plots based on lower limits of mean annual temperatures for potential modern analogues of fossil species recorded from Iceland (represented by open circles). For each formation, the box indicates the 25th and 75th percentiles, whiskers indicate the 10th and 90th percentiles, and horizontal lines in the boxes are medians. Dark to light red lines indicate the four taxa defining the four warmest MATmin values (i.e. the four most cold-sensitive taxa) in each formation. Note that many of these taxa are outliers in the box-plots (see also Table 13.1, Appendix 13.1) percentiles and may have had different ecologies than their monotypic modern representatives (cf. LePage 2007). Table 13.1 shows the range of MATmin defined by the four warmest values in each formation. The older formations (15 and 12 Ma) are characterized by the presence of warmth-loving Taxodiaceae, which introduce a mixed climatic signal. Glyptostrobus today occurs at much higher MAT than the remaining taxa recorded in the ca 15 and 12 Ma formations. However, as mentioned above, the monotypic genus Glyptostrobus was ecologically diversified and much more abundant during the Tertiary than at present (10–13 species in Europe; Mai 1995). The first clear climatic shift in Iceland occurred between the ca 12 and 10 Ma sedimentary rock formations but overall mild conditions persisted until at least 3.6 Ma. A second shift occurred between ca 5.5 and 4.4 Ma. During this time interval, small-leaved Salix appeared for the first time, introducing a double signal (Table 13.1). Salix arctica Pall. and S. lanata L. today thrive at markedly lower MAT than the remaining taxa recorded in the 4.4–3.6 Ma formation. The last shift occurred between ca 3.6 and 2.4 Ma (Fig. 13.1); this time interval marked the change towards large-scale northern hemisphere glaciations. The Pleistocene floras of Iceland (Chap. 11) were deposited during warmer interglacials, which strongly resemble modern conditions in Iceland. Table 13.1 Qualitative and quantitative features of late Cainozoic climates of Iceland Estimated climate type MATmina Warm-loving Qualitative features Small-leaved Ericaceae Herbs Salix Small-leaved Small-leaved Small-leaved Small-leaved Small- and large-leaved Many taxa Many taxa Many taxa Many taxa Many taxa Present Present Present Present Present Köppen type Cfc, ET Cfc, ET Cfc, ET Cfc, ET Cfbcool variant Last occurrence of temperate hardwood taxa Present ? – – – – elements Shift (S) Formation (°C) MATEST, lowlands 0.8 Ma −9.2 - 1.5 0–5 1.1 Ma 1.7 Ma 2.4–2.1b −9.2 - 3.2 −9.2 - 3.2 – 0–5 0–5 0–5 S3 4.4–3.6 Ma 4.1 - 7.4 6–8 S2 Cfbwarm>cool variant Cfb Cfb Cfb Many taxa Many taxa Large-leaved Large-leaved Large-leaved Large-leaved 5.5 Ma 1.4 - 7.4 6–8 7–6 Ma 3.4 - 5.9 6–8 9–8 Ma 10 Ma 5.9 - 7.4 5.4 - 7.4 8–10 8–10 Last occurrence of Quercus Last occurrence of Fagus Fagus, Quercus Last occurrence of Platanus Absent ? Many taxa First appearance First prominent invasion Herbaceous elements almost absent Absent Herbaceous elements almost absent 13.2 Evidence from Potential Modern Analogues of Cainozoic Plant Taxa S1 Cfa Large-leaved 12 Ma 9.3 - 12.5c 12–14 15 Ma Cfa 7 - 9.4c 12–14 Taxodiaceae, Magnoliaceae, Lauraceae Taxodiaceae Large-leaved a b Defined by the four warmest MATmin values (see Appendix 13.1 for a complete list of potential modern analogues) Data from Akhmetiev et al. 1978 c Glyptostrobus pensilis occurs at MAT 14.5–26.6°C 673 674 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present 13.3 Evidence from Major Vegetation Changes The ca 15 and particularly the ca 12 Ma floras contain a characteristic blend of taxa representing lowland riparian and well-drained forests and temperate upland forests. A number of warmth-loving elements are mainly confined to the floras recorded in the ca 15 and 12 Ma formations (Glyptostrobus, Cercidiphyllum, Magnolia, Liriodendron, and Platanus). Based on the palynological record, these floras were almost devoid of herbaceous species (see Chaps. 4, 5). Modern analogues of this ancient Icelandic vegetation can be found, for example, in riparian and foothill forests in the eastern United States, and in some montane forests along the southern and eastern coasts of the Black Sea. While the riparian vegetation encountered in the Botn flora (ca 15 Ma) contains a mixture of taxa that are at present confined to either North America (Sequoia) or East Asia (Glyptostrobus), these taxa frequently co-occurred in Tertiary plant assemblages in the northern hemisphere (e.g. Schweitzer 1974; Mai 1995; Kvaček and Rember 2000). Presently, Glyptostrobus thrives in almost tropical conditions in southern China (Flora of China Editorial Committee 1999). In contrast, lowland riparian forests in the eastern United States, although they do not contain Glyptostrobus, thrive under a Cfa climate and are closely connected to better drained lowland forests containing taxa such as Magnolia, Sassafras, Liriodendron, and Fagus (Maycock, 1994). The riparian forests of Botn (ca 15 Ma) and the better drained woods around the lake of Surtarbrandsgil (ca 12 Ma) may be fairly well comparable to the eastern North American lowland forests (Cfa climate; Appendix 13.2). The temperate uphill forests of Selárdalur (ca 15 Ma; Chap. 4) resemble various modern forests. Examples may be mixed hardwood forests of the Appalachians in eastern North America, of the coastal range south and east of the Black Sea, and of Japan (northern part of Honshu and Hokkaido; Fukarek et al. 1995). These forests are often dominated by Fagus species with a prominent admixture of large-leaved Rhododendron. Between ca 12 and 10 Ma, several of the warmth-loving elements including the Taxodiaceae entirely disappear from the vegetation of Iceland. A novelty is the occurrence of a diverse herbaceous element in the floras of the ca 10 Ma sedimentary rock formation (Chap. 6). At the same time, a number of small-leaved Ericaceae typical of modern cool temperate areas are recorded for the first time. Overall, the changes seen in the vegetation suggest a slightly cooler climate than in the older formations (cf. Fig. 13.1). The period between ca 10 and 9–8 Ma appears to have been without major vegetational changes. Forests resembling those recorded in the two formations are typical of temperate areas (Cfb climate; Appendix 13.2) covering a rather wide range of MAT (Fig. 13.2, 2–4). A number of the taxa recorded for the ca 10 and 9–8 Ma formations are at present restricted to relict areas resulting from disruptions of formerly larger and continuous areas during the Tertiary (e.g. Calycanthaceae, Mai 1995; Rhododendron sect. Pontica, Milne 2004; Pterocarya fraxinifolia (Lam.) Spach, e.g. Mai 1995). Although their present range is geographically restricted, they tolerate a wide range of climates (Cfa, Cfb warm to cool variants, Fig. 13.2; cf. Denk 2006). The 13.3 Evidence from Major Vegetation Changes 675 Fig. 13.2 Representative climate stations for Cfa and Cfb climates (Climate diagrams from Lieth et al. 1999). 1. Akita, Cfa climate. 2. Santander, Cfb climate. 3. Prince Rupert, Cfb climate. 4. Gothenburg, Cfb climate (climate types according to Köppen, cf. Kottek et al. 2006) 676 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present gradual cooling during the Late Miocene is probably reflected by the decline of Fagus between 8 and 5.5 Ma. While a dominant element in the 9–8 Ma formation, only a single leaf and nut likely belonging to the genus, are recorded in the 7–6 Ma formation, and the genus is absent from the ca 5.5 Ma and younger formations. The subtle shift recorded in the vegetation may correspond to a change from warm to cool variants of a Cfb climate (see climate diagrams for Prince Rupert and Gothenburg in Fig. 13.2, 3 and 4). The last phase of prevailing mild conditions is recorded in the Tjörnes floras (4.4–3.6 Ma; Chap. 10; Fig. 13.1). Humid mild conditions are reflected by the presence of evergreen (understorey) taxa, such as Rhododendron aff. ponticum, Ilex, and, surprisingly, Trigonobalanopsis, representing an extinct type of Fagaceae. Mixed broadleaved deciduous and conifer forests were made up of Acer, Pterocarya, Alnus cecropiifolia (Ettingsh). Berger with an admixture of Abies and other conifers. Between ca 3.6 (beginning of the Late Pliocene) and 2.4 Ma (Early Pleistocene), the switch from mild and warm conditions to the present cool to cold climate occurred. This is mainly marked by the absence of large-leaved Salix in the 2.4–0.8 Ma floras and the dominance of small-leaved Salix spp., Betula pubescens Ehrh. and B. nana L. leaf types, Arctic-Alpine Ericaceae, and Sorbus aucuparia (Chaix.) DC. All these elements are also found in the modern vegetation of Iceland. One exception among the woody taxa recorded in the 2.4–0.8 Ma floras is Alnus viridis, which is absent from the present flora of Iceland but is common in Greenland. 13.4 Estimated Climate Types for the Sedimentary Formations 15–0.8 Ma Climatic conditions during the time of deposition of the 15–0.8 Ma sedimentary rock formations in Iceland can be estimated from temperature requirements of potential modern analogues (Appendix 13.1) and from modern vegetation types comparable to the ancient ones (see above). Overall, a Cfa climate can be inferred for lowland areas at the time when the ca 15 and 12 Ma formations were deposited, that is, a humid subtropical mild climate with no dry season and a relatively hot summer (Table 13.2; Appendix 13.2). The presence of various Taxodiaceae and Fagus suggests a lowland-upland vegetation corresponding to modern forests in the (south)eastern United States, the southern and eastern coasts of the Black Sea, and (south)eastern China and Japan (except Hokkaido). A Cf, i.e. fully humid, climate type is highly likely given the position of Iceland in the centre of the northern North Atlantic; a Cfa climate, indicating relatively hot summers, is inferred from the presence of Glyptostrobus, Laurophyllum, Platanus, and Liriodendron, among others. It should be noted that a Cfa climate does not necessarily differ from a Cfb climate in terms of MAT, but mainly in the temperature of the four warmest months (see Fig. 13.2, 1 and 2; Akita versus Santander). Climates comparable to the one estimated for the 15 and 12 Ma formations are found, 13.5 Climate Evolution in the Northern North Atlantic 677 Table 13.2 Climatic parameters of Köppen climate types relevant for late Cainozoic floras of Iceland (From Kottek et al. 2006; see also Appendix 13.2) Köppen climate types C …… Warm temperate; T coldest month ³ −3.0°C and <18°C D …… Snow climate; T coldest month < −3.0°C f ... Fully humid without dry season w ... Winter dry s ... Summer dry (PSmin < PWmin; PWmax > 3PSmin; PSmin < 40 mm) a Hot summer; T warmest month ³22°C Cfa b Warm summer; T warmest month <22°C and ³4 months >10°C Cfb c Cool summer; T warmest month <22°C and <4 months >10°C and coldest Cfc month > −38°C E …… Polar; T warmest month <10°C T … Tundra; T warmest month >0°C ET PSmin/max = minimum/maximum summer precipitation PWmin/max = minimum/maximum winter precipitation for example, in Akita (Fig. 13.2), northern Honshu, and Wajima (see Fig. 4.3), central eastern Honshu. Cfb climates were most likely present in upland areas during time of sedimentation of the ca 15 and 12 sedimentary rock formations and from ca 10 to 3.6 Ma. Summer temperatures in a Cfb climate basically are cooler than in a Cfa climate (Table 13.2). Cfb climates are typical of the temperate parts of Europe, including most of the British Isles. This climate type includes a wide range of mean annual temperatures as can be seen in Fig. 13.2 (compare Gothenburg with Santander). In southwestern Europe, Asia Minor (along the southern and eastern coast of the Black Sea), and Japan, Cfa climates gradually change into Cfb climates. In North America, Cfb climates are much less common than Cfa climates and are restricted to northwestern North America and higher elevations in the Appalachian Mountains (Kottek et al. 2006). From ca 3 Ma onwards, a Cfc climate, similar to the Cfb type but with cool summers, prevailed during the warm phases. Also, ET climate types (Tundra climate with no true summer) occurred from that time on (Table 13.2; Appendix 13.2). Today, the southern and southwestern coasts of Iceland, including the area of Svínafell (0.8 Ma sedimentary rock formation; Chap. 11) and some interior fjords and valleys in the east and north have a Cfc climate, whereas the remaining island has an ET climate (Sjörs 2004; Kottek et al. 2006). 13.5 Climate Evolution in the Northern North Atlantic The Earth’s climate has gradually cooled during the Tertiary (the last 65 Ma). This trend has been punctuated by three steps marked by higher rates of cooling; during the Late Eocene-Early Oligocene (ca 34 Ma), during the Middle Miocene (ca 14 Ma), and at the Pliocene-Pleistocene boundary (ca 2.6 Ma; Zachos et al. 2001; 678 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Gibbard and Cohen 2009). The first two steps were mainly triggered by two phases of rapid expansion of the Antarctic continental ice sheets, whereas the third one was a consequence of the onset of major ice sheets in the northern hemisphere. 13.5.1 Mid-Miocene Climatic Optimum Global climate change for this period is mostly reconstructed from the deep-sea stable isotope record (Zachos et al. 2001; Zhao et al. 2001; Holbourn et al. 2005; among many others). A phase of global warming, the Mid-Miocene Climatic Optimum, peaked between ca 17 and 15 Ma and was followed by cooling and re-establishment of a major ice sheet on Antarctica (Zachos et al. 2001). The termination of the Miocene warm phase is marked by the Middle Miocene climatic transition between ca 14.2 and 13.8 Ma. Stepwise cooling of Antarctic Circumpolar surface waters (Shevenell et al. 2004) was followed by a rapid expansion of the Antarctic ice sheet between 13.9 and 13.8 Ma (Holbourn et al. 2005). A number of studies using palaeontological data from terrestrial sediments of both hemispheres detected a similar signal of marked warming followed by rapid cooling in the mid-Miocene. White et al. (1997) found abundant thermophilous broadleaved deciduous and conifer taxa in 15 Ma sediments from northwestern Canada and Alaska (Fagaceae, Taxodiaceae, Juglandaceae), which are entirely absent in younger sediments that are dominated by Betulaceae and Pinaceae, and from 7 Ma onwards, by herbaceous taxa. Floras clearly indicating warm conditions (Cfa climate) are also recorded by Matthews and Ovenden (1990) from 18 Ma sediments of Banks Island, N.W.T. For Central Europe, Kvaček et al. (2006) inferred a clear cooling trend from the Karpatian-early Badenian (corresponding to the MidMiocene Climatic Optimum) to the late Badenian-earliest Sarmatian (ca 12.6 Ma), which is fairly consistent with the oxygen isotope curve. From East Antarctica, Lewis et al. (2009) report the extinction of tundra plants and animals between ca 14 and 13.8 Ma, caused by rapidly expanding glaciers during this time interval. They suggest that the transition to cold-based, alpine glacial regimes at 13.85 Ma was never subsequently reversed. In stark contrast, deteriorating conditions between 15 and 12 Ma as recorded in continental floras and by marine isotope data can not be seen in the climatic signal of well-dated late Cainozoic floras of Iceland. Why is this? The Middle Miocene was a period of tectonic changes that had dramatic consequences on global ocean circulation, which, in turn, were important factors for Cainozoic climatic development. Tectonically, the uplift of the Panama Sill blocked the exchange of deep water between the Atlantic and Pacific Oceans (Keller and Barron 1983) and the collision of the African and Eurasian plates caused the termination of the connection between the Atlantic and the Indian Oceans. Thus, a deepwater source in the northern Indian Ocean (Tethyan Indian Saline Water) was terminated at about 15 Ma (Woodruff and Savin 1989; Flower and Kennett 1995). The Indian-Paratethys-Caribbean Seaway was replaced by north–south currents in 13.5 Climate Evolution in the Northern North Atlantic 679 the northern and southern Atlantic. As a consequence, diminished heat transport to the high southern latitudes and an increase in the (cold) Southern Component Water fostered major Eastern Antarctic Ice Sheet growth, leading to global cooling (Flower and Kennett 1995). At the same time, the re-organisation of the global ocean currents led to an intensifying Gulf Stream transporting warm surface water into the northeastern North Atlantic region (Keller and Barron 1983). Increased evaporation at high latitudes triggered the switch to a cold-house climate in the northern hemisphere, as indicated by the first ice-rafted debris pulses in the High Arctic (14 Ma; Thiede and Myhre 1995; Thiede et al. 1998). Mild and warm conditions in Iceland outlasted the Mid-Miocene Climatic Optimum by at least 2 million years (Fig. 13.1, Table 13.1). This could have been caused by the influx of warm southerly waters (the Gulf Stream), which ameliorated the climate in the central parts of the northern North Atlantic (Iceland), and may have compensated for cooling radiating from the Arctic Ocean. Interestingly, a similar scenario has been reported for the last interglacial warm period. McManus et al. (2002) found that regional warm conditions in the northern North Atlantic were considerably prolonged relative to the duration of the marine isotope stage MIS 5e (reflecting a minimum in global ice volume) and continued well into the glacial growth of MIS 5d. They concluded that enhanced thermohaline circulation provided the heat transport that helped prolong the interglacial warmth, while at the same time provided an ideal moisture source for ice-sheet growth. This demonstrates the direct influence of the thermohaline circulation and the warm Gulf Stream on the regional climate. Comparable conditions may have been present in southern New Zealand. Field et al. (2009) found no significant change in the palynological content of an inshore marine sequence spanning the time interval from ca 16 to ca 11.6 Ma, although a clear positive d18O baseline shift was detected between 13.9 and 13.8 Ma. These authors speculated that the mid-latitude maritime setting muted the effects of Middle Miocene global climate change. 13.5.2 Late Miocene Gradual Cooling The sudden appearance of many herbaceous plants recorded in the ca 10 Ma floras, and the presence of small-leaved Ericaceae, are indicative of climate cooling in the early Late Miocene (Chap. 6). Herbaceous taxa such as Asteraceae, Caryophyllaceae, Chenopodiaceae, and some Ranunculaceae (Thalictrum) and Rosaceae (Potentilla) became important elements of the European vegetation in the course of the Miocene (Mai 1995), indicating the availability of more open landscapes, which, in turn, may have been the result of cooler and/or more continental conditions (Ramstein et al. 1997). Mild conditions prevailed until at least 9–8 Ma (abundant Fagus; Chap. 7). Several ice-rafted debris pulses in the Fram Strait recorded at the DSDP/ODP Leg 151 site 909 between 10.8 and 8.6 Ma, around 7.2, 6.8, and 6.3 Ma indicate a further stepwise increase of northern hemisphere cooling (Thiede et al. 1998). 680 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Larsen et al. (1994) suggested that cooling in southeastern Greenland started after 10 Ma and glaciers large enough to reach sea level were present at around 7 Ma, contemporaneous with southern hemisphere glacial expansion. Gradual cooling is also recorded in the oxygen isotope curve (Abreu and Haddad 1998) for the Late Miocene. 13.5.3 Pliocene Warming and Onset of Northern Hemisphere Glaciations The final closure of the Central American Seaway between 5 and 3.6 Ma partitioned the Atlantic and Pacific oceans and dramatically changed global ocean circulation. Increased evaporation in the tropical Atlantic increased the salinity of the Atlantic. At the same time, the Gulf Stream intensified and transported more salty and warm water masses to high latitudes where they cooled and sank, fuelling the Global Ocean Conveyor (Haug et al. 2004). The warm and steady climate that the Earth experienced between 4.5 and 2.7 Ma, and that was to a large degree a consequence of this re-arrangement of ocean currents, has been termed the Mid-Pliocene Climatic Optimum (Dowsett et al. 1996, 2009; Raymo et al. 1996; Kim and Crowley 2000; Robinson 2009). Raymo et al. (1996) suggested that this warm period was associated with increased North Atlantic Deep Water production and that a stronger thermohaline circulation in the Atlantic Ocean may have enhanced sea ice retreat and decreasing high latitude albedo. In Iceland, terrestrial sediments yielding the warm Pliocene floras of Tjörnes (4.4–3.6 Ma) are intercalated within the marine Tjörnes beds. The floras of Tjörnes contain a number of warmth-loving exotic taxa (see Sect. 13.3). Based on the oxygen isotope composition of marine molluscs spanning a sequence from 4.3 to 2.6 Ma, Buchardt and Símonarson (2003) reconstructed warm-water conditions (summer temperatures between 10 and 15°C) interrupted by a few cold spells of which the most prominent coincided with the first major glaciation in southeastern Greenland at ca 3.5 Ma ( St. John and Krissek 2002). Warmth-loving plant taxa are also present in 4–3 Ma sediments from the Canadian Arctic Archipelago (Meighen Island, Ellesmere Island; Matthews and Ovenden 1990) and Alaska (Matthews et al. 2003). Together with an unusual warm insect fauna (Elias and Matthews 2002) and an exceptionally rich mammal fauna (Ellesmere Island; Tedford and Harrington 2003), these data provide strong evidence for markedly warmer conditions than today in Arctic regions of the northern hemisphere just before the onset of widespread northern hemisphere glacial expansion at ca 2.7 Ma. At 2.55–2.45 Ma, the first extensive glaciation occurred in Iceland (Eiríksson 2008) coinciding with the first occurrence of high-Arctic shallow marine molluscs such as Portlandia arctica (Gray) (Símonarson and Leifsdóttir 2002). The youngest floras described in this book were deposited in Pleistocene interglacial sediments (2.4–2.1, Hvalfjördur, Akhmetiev et al. 1978; 1.7–0.8 Ma floras, Chap. 11). Appendix 13.1 Appendix 13.1 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters Potential modern analogue Polypodium Polypodiaceae Cryptomeria japonica Glyptostrobus pensilis Juniperus Sequoia sempervirens Cathaya argyrophylla Picea Pinus Tsuga diversifolia –8.9 Cosmopolitan 6.2 9.3 9.4 Cosmopolitan 15.3 18.6 21.7 17.2 7a 14.5 20.5 26.6 Cosmopolitan Cosmopolitan MAT low °C MAT high °C Selárdalur-Botn Formation TAxA Polypodiaceae Polypodium sp. 1 Polypodiaceae gen. et spec. indet. 1 Cupressaceae s.1 Cryptomeria sp. Glyptostrobus europaeus Juniperus sp. Sequoia abietina Pinaceae Cathaya sp. ?Picea sp Pinus sp. 1 Diploxylon Tsuga sp. 1 Aquifoliaceae Ilex sp. 1 Ilex aquifolium Ilex opaca Ilex decidua 7.2 7.4 11.1 18.2 22.4 22.1 7.2 22.4 Betulaceae Alnus sp. 1 Alnus japonica Alnus rhombifolia Alnus subcordata 0.2 0 7.2 24.4 16.3 18.6 } } 0 24.5 (continued) 681 682 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue MAT low °C MAT high °C Selárdalur-Botn Formation TAxA Betula sp. 1 Betula ermannii Betula delavayi Betula chinensis var. fargesii Betula utilis Carpinus cordata 16.7 14.9 Lonicera xylosteum 0.1 Carpinus sp. Caprifoliaceae Lonicera sp. Viburnum sp. Cercidiphyllaceae Cercidiphyllum sp. Cercidiphyllum japonicum Cercidiphyllum magnificum Rhododendron maximum Rhododendron ponticum Fagus crenata Fagus grandifolia Pterocarya macrocarpa Liliaceae Magnolia Platanus occidentalis 3 4.4 –1.9 Cosmopolitan 6.2 5.4 27 21.1 4.6 4.1 7.6 4.6 17 11.6 17.5 18.3 13 22.1 19.8 –7 4.1 2.9 –0.4 3 14.6 15.3 11.4 22.5 } } } –7 22.5 4.6 17 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Ericaceae cf. Rhododendron sp. Rhododendron sp. 1 Fagaceae Fagus friedrichii 3 22.1 Juglandaceae Pterocarya sp. Liliaceae Liliaceae gen. et spec. indet. 1 Magnoliaceae cf. Magnolia sp. Platanaceae Platanus leucophylla Selárdalur-Botn Formation TAxA Rosaceae Rosaceae Rosaceae Sanguisorba officinalis 15.8 17.8 23.2 Salix caprea Salix scouleriana –9 –5.6 Appendix 13.1 Cosmopolitan Cosmopolitan Cosmopolitan 1.4 Potential modern analogue MAT low °C MAT high °C Rosaceae Rosaceae gen et. spec. indet. 1 Rosaceae gen et. spec. indet. 2 Rosaceae gen et. spec. indet. 3 Sanguisorba sp. Salicaceae Salix sp. 1 } –9 23.2 Sapindaceae Acer sp. 1 Acer sp. 2 Aesculus sp. Acer rubrum Acer saccharum Aesculus flava Aesculus pavia Tilia americana Tilia platyphyllos Tetracentron sinense Ulmus –1.2 2.2 1.1 3.4 16.1 14 19 24.3 19.8 21.4 –1.1 –1.1 8.6 0.2 23.8 15.8 22.1 24.4 0.2 24.4 Tiliaceae Tilia selardalense } } 1.1 16.1 Trochodendraceae Tetracentron atlanticum Ulmaceae Ulmus sp. MTI Vitaceae Parthenocissus sp. Parthenocissus quinquefolia Parthenocissus laetevirens 2.1 9.3 } – – 2.1 21.4 Incertae sedis – Magnoliophyta Pollen type 1 – a Grey shading indicates the four warmest MATmin values encountered; dark grey shading indicates this taxon is a climatic outlier (see text for explanation) 683 684 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Hepaticae Lycopodium Equisetum Osmunda regalis Polypodiaceae Polypodiaceae – Ephedra distachya Cryptomeria japonica Glyptostrobus pensilis Sequoia sempervirens Abies Cathaya argyrophylla Picea Tsuga diversifolia Sciadopitys verticillata 7 14.5 9.4 –6.7 9.3 –8.9 6.2 7.4 9.4 – 18.9 20.5 26.6 15.3 27.4 18.6 21.7 17.2 16.6 Cosmopolitan Cosmopolitan 3.2 23.9 Cosmopolitan Cosmopolitan Cosmopolitan MAT low °C MAT high °C Brjánslækur-Seljá Formation TAxA Bryophyta Hepaticae gen. et spec. indet. Lycopodiaceae Lycopodium sp. Equisetaceae Equisetum sp. Osmundaceae Osmunda parschlugiana Polypodiaceae Polypodiaceae gen. et spec. indet. 1 Polypodiaceae gen. et spec. indet. 2 Incertae sedis - unassigned spores Trilete spore fam. gen. et spec. indet. 1 Ephedraceae Ephedra sp. Cupressaceae incl. Taxodiaceae Cryptomeria anglica Glyptostrobus sp. Sequoia sp. Pinaceae Abies steenstrupiana 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Cathaya sp. Picea sect. Picea Tsuga sp. Sciadopityaceae Sciadopitys sp. Aquifoliaceae Brjánslækur-Seljá Formation TAxA Ilex aquifolium Ilex opaca Ilex decidua 7.2 22.4 7.2 7.4 11.1 18.2 22.4 21.1 Potential modern analogue MAT low °C MAT high °C Ilex sp. 1 Appendix 13.1 Betulaceae Alnus cecropiifolia 17.4 22.4 16.3 –3.3 0.2 –7 Alnus gaudinii } } 22.4 24.4 22.5 2.5 28.2 } Betula islandica 24.4 18.6 14.6 15.3 22.5 15.5 28.2 16.7 17.9 19 18.4 Carpinus sp. MT1 Carpinus sp. MT2 Corylus sp. } 13.4 19.4 18.3 20 } Alnus glutinosa Alnus nitida Alnus rhombifolia Alnus japonica Alnus subcordata Betula ermannii Betula delavayi Betula utilis Carpinus betulus Carpinus caroliniana Carpinus cordata Corylus americana Corylus avellana Corylus chinensis –2.7 –3.3 5.6 0 0.2 7.2 –7 4.1 –0.4 4.3 2.5 3 –0.4 1.3 –2.7 19 Calycanthaceae aff. Calycanthaceae Calycanthus chinensis Calycanthus floridus Calycanthus occidentalis Chimonanthus spp. Lonicera xylosteum Viburnum opulus Cyperaceae Rhododendron ponticum Rhododendron maximum 0.1 1 11.5 8.7 5.3 7 } 14.9 14 Cosmopolitan 4.1 4.6 18.3 17.5 5.3 20 685 Caprifoliaceae Lonicera sp. 1 Viburnum sp. Cyperaceae Cyperaceae gen. et spec. indet. A Ericaceae Rhododendron sp. 1 Rhododendron sp. 2 (continued) 686 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue 4.4 MAT low °C MAT high °C 22.4 Brjánslækur-Seljá Formation TAxA Juglandaceae Carya sp. cf. Juglans Pterocarya sp. Carya cathayensis Carya glabra Juglans mandshurica Pterocarya fraxinifolia Pterocarya macrocarpa –1.9 Laurus nobilis Sassafras albidum Sassafras tzumu Lemna Cosmopolitan 6.7 8.4 18.1 19.1 12.5 19.2 8.5 4.4 0.4 8.1 –1.9 18.4 22.4 20 18.1 19.1 } } 19.1 Lauraceae Laurophyllum sp. (Laurus) Sassafras ferrettianum } 22| 18 27 6.7 20.6 Lemnaceae Lemna sp. Magnoliaceae Liriodendron procaccinii Liriodendron tulipifera Liriodendron chinensis Magnolia Comptonia peregrina Fraxinus Platanus occidentalis Phragmites 3.4 3.1 5.4 4.4 11 6.2 Magnolia sp. } 15.6 21.1 21.1 Cosmopolitan 4.4 22 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Myricaceae Comptonia hesperia Oleaceae cf. Fraxinus sp. Platanaceae Platanus sp. Poaceae Phragmites sp. Appendix 13.1 Rosaceae Rosaceae Rosaceae Sanguisorba officinalis 15.8 19 Populus tremula 1.6 Rosaceae Rosaceae gen et. spec. indet. A Rosaceae gen et. spec. indet. B Rosaceae gen et. spec. indet. C Sanguisorba sp. Salicaceae Populus sp. A (ex group P. tremula L.) Cosmopolitan Cosmopolitan Cosmopolitan 1.4 Salix gruberi } –21.8 –9 25.3 23.2 Populus tremuloides Salix caprea Salix scouleriana –21.8 –9 –5.6 25.3 17.8 23.2 } Acer saccharum Acer rubrum Smilax Tetracentron sinense Extinct genus Ulmus –1.2 Cosmopolitan Valeriana 2.2 3.4 –1.1 –1.1 15.8 23.8 18.8 19 24.3 687 Sapindaceae Acer askelssonii Acer crenatifolium subsp. islandicum Smilacaceae Smilax sp. Trochodendraceae Tetracentron atlanticum Ulmaceae aff. Cedrelospermum sp. Ulmus cf. pyramidalis Valerianaceae Valerianaceae gen. et spec. indet. Incertae sedis – Magnoliophyta Dicotylophyllum sp. A Pollen type 1 Pollen type 2 Pollen type 3 Pollen type 4 Pollen type 5 Pollen type 6 Pollen type 7 – – – – – – – – – – – – – – – – – – – – – – – – (continued) Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Sphagnum Lycopodium Huperzia Osmunda regalis Pteridophyta Equisetum Polypodium Polypodiaceae Polypodiaceae Polypodiaceae Polypodiaceae Ginkgo biloba Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Natural distribution unknown –14.5 –8.9 –9.2 –3.9 6.2 7.4 16.1 21.7 25.5 24.8 17.2 16.6 Cosmopolitan – 3.2 23.9 Cosmopolitan Cosmopolitan Cosmopolitan MAT low °C MAT high °C 688 Tröllatunga-Gautshamar Formation TAxA Bryophyta Sphagnum sp. Lycopodiaceae Lycopodium sp. aff. Huperzia sp. Osmundaceae Osmunda parschlugiana Polypodiopsida Pteridophyta gen. et spec. indet. 1 Equisetaceae Equisetum sp. Polypodiaceae Polypodium sp. 1 Polypodiaceae gen. et spec. indet. 1 Polypodiaceae gen. et spec. indet. 3 Polypodiaceae gen. et spec. indet. 4 Polypodiaceae gen. et spec. indet. 5 Ginkgoaceae Ginkgo sp. 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Pinaceae Larix sp. Picea sect. Picea Pinus sp. 2 Diploxylon Pseudotsuga sp. Tsuga sp. 1 Larix Picea Pinus Pseudotsuga Tsuga diversifolia Sciadopitys verticillata Sciadopityaceae Sciadopitys sp. Tröllatunga-Gautshamar Formation TAxA Apiaceae Apiaceae Artemisia Artemisia Asteraceae Asteraceae Asteraceae Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Potential modern analogue MAT low °C MAT high °C Appendix 13.1 Apiaceae Apiaceae gen. et spec. indet. 1 Apiaceae gen. et spec. indet. 2 Asteraceae Artemisia sp. 1 Artemisia sp. 2 Asteraceae gen. et spec. indet. 1 Asteraceae gen. et spec. indet. 2 Asteraceae gen. et spec. indet. 3 Betulaceae Alnus cecropiifolia 17.4 22.4 16.3 14.6 15.3 22.5 15.5 28.2 –3.3 22.4 Betula islandica Carpinus sp. } } 16.7 17.9 19 18.4 –7 22.5 Alnus glutinosa Alnus nitida Alnus rhombifolia Betula ermannii Betula delavayi Betula utilis Carpinus betulus Carpinus caroliniana Carpinus cordata Corylus americana Corylus avellana Corylus chinensis –0.4 1.3 –2.7 –3.3 5.6 0 –7 4.1 –0.4 4.3 2.5 3 2.5 28.2 Corylus sp. Calycanthaceae aff. Calycanthaceae Calycanthus chinensis Calycanthus floridus Calycanthus occidentalis Chimonanthus spp. } 13.4 19.4 18.3 20 11.5 8.7 5.3 7 –2.7 19 } 5.3 20 689 (continued) 690 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Lonicera xylosteum 0.1 14.9 MAT low °C MAT high °C Tröllatunga-Gautshamar Formation TAxA Caryophyllaceae Caryophyllaceae Caryophyllaceae Chenopodium Chenopodiaceae Cyperaceae Arctostaphylos Rhododendron ponticum Vaccinium Ericaceae Fagus sylvatica Fagus longipetiolata Extinct genus 5.9 6 –11.9 4.1 –12.4 Cosmopolitan Cosmopolitan 21.4 18.3 20.8 Cosmopolitan Cosmopolitan Caprifoliaceae Lonicera sp. 1 Lonicera sp. 2 Caryophyllaceae Caryophyllaceae gen et. epec. indet. 1 Caryophyllaceae gen et. epec. indet. 2 Caryophyllaceae gen et. epec. indet. 3 Chenopodiaceae aff. Chenopodium sp. Chenopodiaceae gen. et spec. indet. 1 Cyperaceae Cyperaceae gen. et spec. indet. A Ericaceae Arctostaphylos sp. Rhododendron aff. ponticum Vaccinium sp. Ericaceae gen. et spec. indet. 1 Fagaceae Fagus sp. Cosmopolitan Cosmopolitan Cosmopolitan 15.7 16.7 } 3.5 8.1 –1.9 Cosmopolitan 20.5 18.1 19.8 5.9 16.7 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Trigonobalanopsis sp. Juglandaceae Cyclocarya sp. Pterocarya sp. Cyclocarya paliurus Pterocarya fraxinifolia Pterocarya macrocarpa Lemnaceae } –1.9 19.8 Lemnaceae (syn. Lemnaoideae in Araceae) Lemnaceae gen. et spec. indet. Appendix 13.1 Liliaceae Liliaceae Decodon verticillatus Nuphar Plantago lanceolata Platanus occidentalis Poaceae Polygonum Rumex Anemone Ranunculus Thalictrum Ranunculaceae Ranunculaceae Rosaceae Sanguisorba officinalis Salix caprea Salix scouleriana Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan 1.4 –9 –5.6 Cosmopolitan Northern hemisphere Cosmopolitan 5.4 21.1 Temperate northern hemisphere Cosmopolitan 2.1 19.8 Liliaceae Liliaceae gen. et spec. indet. 1 Liliaceae gen. et spec. indet. 2 Lythraceae Decodon sp. Nympheaceae cf. Nuphar sp. Plantaginaceae aff. Plantago lanceolata Platanaceae Platanus sp. Cosmopolitan Cosmopolitan Poaceae Poaceae gen. et spec. indet. 1 Polygonaceae Polygonum sect. Aconogonon sp. Rumex sp. Ranunculaceae Anemone ps. Ranunculus sp. 1 Thalictrum sp. 1 Ranunculaceae gen. et spec. indet. 1 Ranunculaceae gen. et spec. indet. 2 Rosaceae Rosaceae gen. et spec. indet. type A Sanguisorba sp. Salicaceae Salix gruberi 15.8 17.8 23.2 } –9 23.2 (continued) 691 692 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Acer saccharum Acer rubrum Smilax Tilia americana Tilia platyphyllos Tetracentron sinense Ulmus Parthenocissus quinquefolia Parthenocissus heterophylla – – – – – – – – – – – – – – – – – – – – 2.1 9.3 –1.2 2.2 19 24.3 19.8 21.4 – – – – – – – – – – 1.1 3.4 16.1 14 3.4 18.8 –1.1 –1.1 15.8 23.8 MAT low °C MAT high °C Tröllatunga-Gautshamar Formation TAxA Sapindaceae Acer askelssonii Acer crenatifolium subsp. islandicum Smilacaceae Smilax sp. Tiliaceae Tilia sp. } 1.1 16.1 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Trochodendraceae Tetracentron atlanticum Umaceae Ulmus sp. Vitaceae Parthenocissus sp. Incertae sedis-Magnoliophyta Dicotylophyllum sp. B Dicotylophyllum sp. C Pollen type 8 Pollen type 9 Pollen type 10 Pollen type 11 Pollen type 12 Pollen type 13 Pollen type 14 Pollen type 15 Pollen type 16 } 2.1 21.4 Pollen type 17 Pollen type 18 Pollen type 19 Pollen type 20 Potential modern analogue Lycopodiella Lycopodium Huperzia Osmunda regalis Polypodiaceae Polypodiaceae – – Larix Picea Pinus Pseudotsuga Tsuga diversifolia Tsuga Sciadopitys verticillata Apiaceae –14.5 –8.9 –9.2 –3.9 6.2 1.8 7.4 Cosmopolitan (continued) 16.1 21.7 25.5 24.8 17.2 21.9 16.6 Cosmopolitan Cosmopolitan 3.2 23.9 Cosmopolitar Cosmopolitar Cosmopolitar MAT low °C MAT high °C – – – – – – – – – – – – Appendix 13.1 Skarðsströnd-Mókollsdalur Formation TAxA Lycopodiaceae Lycopodiella sp. Lycopodium sp. aff. Huperzia sp. Osmundaceae Osmunda sp. Polypodiaceae Polypodiaceae gen. et spec. indet. 1 Polypodiaceae gen. et spec. indet. 6 Incertae sedis – unassigned spores Monolete spore, fam., gen. et spec. indet. 1 Monolete spore, fam., gen. et spec. indet. 2 Pinaceae Larix sp. Picea sect. Picea Pinus sp. 2 Diploxylon Pseudotsuga sp. Tsuga sp. 1 Tsuga sp. 2 Sciadopityaceae Sciadopitys sp. Apiaceae Apiaceae gen. et spec. indet. 1 693 694 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue MAT low °C MAT high °C Skarðsströnd-Mókollsdalur Formation TAxA Aquifoliaceae Ilex sp. 2 Ilex aquifolium Ilex opaca Ilex decidua 7.2 Asteraceae Cosmopolitan 7.2 7.4 11.1 18.2 22.4 22.1 Asteraceae Asteraceae gen. et spec. indet. 1 Betulaceae Alnus cecropiifolia 17.1 22.4 16.3 17.1 13.5 12.5 15.5 28.2 16.5 } –3.3 –5.5 22.4 22.4 Betula cristata 17.1 cf. Carpinus Alnus glutinosa Alnus nitida Alnus rhombifolia Betual lenta Betula maximowicziana Betula papyrifera Carpinus betulus Carpinus caroliniana Carpinus cordata –3.3 5.6 0 1.9 3.1 –5.5 4.3 2.5 3 Calycanthaceae aff. Calycanthaceae Calycanthus chinensis Calycanthus floridus Calycanthus occidentalis Chimonanthus spp. Cornus florida Cornus alba Rhododendron maximum } } } 11.5 8.7 5.3 7 5.5 –8.7 4.6 13.4 19.4 18.3 16.7 22 19.7 17.5 2.5 28.2 Cornaceae Cornus sp. } 5.3 20 } –8.7 22 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Ericaceae Rhododendron sp. 2 Skarðsströnd-Mókollsdalur Formation TAxA Fagus sylvatica Fagus longipetiolata Quercus robur 5.9 16.7 5.9 6 3.3 15.7 16.7 15 Potential modern analogue MAT low °C MAT high °C Appendix 13.1 Fagaceae Fagus gussonii } 2.5 19.8 Quercus infrageneric group Quercus sp. 1 Juglandaceae Cyclocarya sp. Pterocarya sp. Cyclocarya paliurus Pterocarya fraxinifolia Pterocarya macrocarpa Myrica gale Myrica pensylvanica Poaceae Thalictrum Ranunculaceae Salix caprea Salix scouleriana –9 –5.6 Cosmopolitar Cosmopolitan 17.8 23.2 Cosmopolitan 0.6 1.4 14.2 16.1 3.5 8.1 2.5 20.5 18.1 19.8 Myricaceae Myrica sp. } } 0.6 16.1 Poaceae Poaceae gen. et spec. indet. 1 Ranunculaceae Thalictrum sp. 2 Ranunculaceae gen. et spec. indet. 2 Salicaceae Salix gruberi } 23.8 15.8 15 –9 23.2 Sapindaceae Acer crenatifolium subsp. islandicum Acer askelssonii Acer rubrum Acersaccharum Acer platanoides Tetracentron sinense Ulmus – – –1.1 –1.1 2 2.2 –1.2 – – } 19 24.3 – –1.1 17.5 695 Trochodendraceae Tetracentron atlanticum Ulmaceae Ulmus section Ulmus sp. Incertae sedis – Magnoliophyta Dicotylophyllum sp. D Dicotylophyllum sp. E Angiosperm fam. et gen. indet. A – (continued) 696 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Equisetum Polypodiaceae Polypodiaceae – Abies Larix Picea Pinus Pseudotsuga Tsuga –6.7 –14.5 –8.9 –9.2 –3.9 1.8 27.4 16.1 21.7 25.5 24.8 21.9 Cosmopolitan Cosmopolitan Cosmopolitan MAT low ºC MAT high ºC Hreðavatn-Stafholt Formation TAxA Equisetaceae Equisetum sp. Polypodiaceae Polypodiaceae gen.et spec. indet. 1 Polypodiaceae gen.et spec. indet. 6 Incertae sedis – unassigned spores Trilete spore, fam., gen. et spec. indet. 1 Pinaceae Abies steenstrupiana Larix sp. Picea sect. Picea Pinus sp. Pseudotsuga sp. Tsuga sp. Betulaceae Alnus cecropiifolia 17.4 22.4 16.3 13.5 12.5 Betula cristata } –3.3 5.6 0 3.1 –5.5 –3.3 22.4 Alnus glutinosa Alnus nitida Alnus rhombifolia Betula maximowicziana Betula papyrifera } 11.5 8.7 5.3 7 Cosmopolitan 13.4 19.4 18.3 20 –5.5 13.5 Calycanthaceae aff. Calycanthaceae 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Calycanthus chinensis Calycanthus floridus Calycanthus occidentalis Chimonanthus spp. Caryophyllaceae Caryophyllaceae Caryophyllaceae gen. et spec. indet. 3 } 5.3 20 Hreðavatn-Stafholt Formation TAxA Ceratophyllum Cyperaceae Rhododendron ponticum Fagus sylvatica Fagus longipetiolata Cyclocarya paliurus Phragmites Persicaria amphibia Sorbus aria Rosaceae 3 Cosmopolitan Northern hemisphere 14.7 Cosmopolitan 3.5 20.5 5.9 6 15.7 16.7 4.1 18.3 Cosmopolitan Cosmopolitan Appendix 13.1 Potential modern analogue MAT low ºC MAT high ºC Ceratophyllaceae Ceratophyllum sp. Cyperaceae Cyperaceae gen. et spec. indet. B Ericaceae Rhododendron aff. ponticum Fagaceae Fagus gussonii Juglandaceae cf. Cyclocarya sp. } 5.9 16.7 Poaceae Phragmites sp. Polygonaceae Persicaria sp. aff. P. amphibia Rosaceae aff. Sorbus sp. (‘S. aria type’) Rosaceae gen. et. spec. indet. A Salicaceae Populus sp. B Salix gruberi Populus Salix caprea Salix scouleriana Salix Acer saccharum Acer platanoides Euphrasia, Melampyrum Tetracetron sinense – – –6.7 –9 –5.6 –9.0 –1.1 2 Salix sp. A Sapindaceae Acer askelssonii 26 17.8 23.2 23.2 15.8 15 Cosmopolitan } } 2.2 – – 19 – – –9.0 23.2 –1.1 15.8 697 Scrophulariaceae aff. Euphrasia vel Melampyrum sp. Trochodendraceae Tetracentron atlanticum Incertae sedis – Magnoliophyta Angiosperm fam. gen. et spec. indet. B (continued) 698 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Sphagnum Equisetum Lycopodium Polypodiaceae Polypodiaceae Polypodiaceae – Abies Cathaya argyrophylla Picea Pinus Pseudotsuga/Larix Sciadopitys verticillata Apiaceae Artemisia Asteraceae –8.9 –9.2 –14.5 7.4 Cosmopolitan Cosmopolitan Cosmopolitan 9.3 –6.7 27.4 18.6 21.7 25.5 21.7 16.6 Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan MAT low °C MAT high °C Fnjóskadalur Formation TAxA Bryophyta Sphagnum sp. Equisetaceae Equisetum sp. Lycopodiaceae Lycopodium Polypodiaceae Polypodiaceae gen. et spec. indet. 1 Polypodiaceae gen. et spec. indet. 7 Polypodiaceae gen. et spec. indet. 8 Incertae sedis – unassigned spores Trilete spore, fam., gen. et spec. indet. 2 Pinaceae Abies steenstrupiana Cathaya sp. Picea sect. Picea Pinus sp. 2 Pseudotsuga/Larix sp. Sciadopityaceae Sciadopitys sp. 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Apiaceae Apiaceae gen. et. spec indet. 1 Asteraceae Artemisia sp. 1 Artemisia sp. 2 Asteraceae gen. et spec. indet. 1 Appendix 13.1 Fnjóskadalur Formation TAxA Potential modern analogue MAT low °C MAT high °C Asteraceae gen. et spec. indet. 2 Asteraceae gen. et spec. indet. 4 Betulaceae Alnus cecropiifolia 17.4 22.4 16.3 –3.3 13.5 12.5 16.9 –5.5 22.4 Betula cristata Betula sp. A (section Betulaster) Calycanthaceae aff. Calycanthaceae Calycanthus chinensis Calycanths floridus Calycanthus occidentalis Chimonanthus spp. Caryophyllaceae Ericaceae Ericaceae Quercus rubra Myriophyllum Liliaceae Cosmopolitan Cosmopolitan Cosmopolitan –1.1 Cosmopolitan Cosmopolitan 19.4 11.5 8.7 5.3 7 13.4 19.4 18.3 20 Alnus glutinosa Alnus nitida Alnus rhombifolia Betula maximowicziana Betula papyrifera Betula luminifera –3.3 5.6 0 3.1 –5.5 1.4 } } 13.5 Caryophyllaceae Caryophyllaceae gen. et spec. indet. 4 Ericaceae Ericaceae gen. et spec. indet. 2 Ericaceae gen. et spec. indet. 3 Fagaceae Quercus infrageneric group Quercus sp. 2 Haloragidaceae Myriophyllum sp. Liliaceae Liliaceae gen. et spec. indet. 3 } 5.3 20 (continued) 699 700 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Menyanthes trifoliata Northern temperate and circumpolar Temperate northern hemisphere Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Circumpolar Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan MAT low °C MAT high °C Fnjóskadalur Formation TAxA Menyanthaceae Menyanthes sp. Nymphaceae Nuphar sp. Nuphar Plantago lanceolata Phragmites Poaceae Poales Polygonum viviparum Ranunculus Ranunculus Thalictrum Ranunculaceae Ranunculaceae Plantaginaceae aff. Plantago lanceolata Poaceae Phragmites sp. Poaceae gen. et spec. indet. 2 Poales Poales fam., gen. et spec. indet. 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Polygonaceae Polygonum viviparum Ranunculaceae Ranunculus sp. 1 Ranunculus sp. 2 Thalictrum sp. 1 Ranunculaceae gen. et spec. indet. 2 Ranunculaceae gen. et spec. indet. 3 Rosaceae Sanguisorba sp. Sanguisorba officinalis Rosaceae Rosaceae Salix caprea Salix scouleriana Salix Sparganium Tetracentron sinense Valeriana – – – – – – – – – (continued) Cosmopolitan 2.2 19 Cosmopolitan –9 –5.6 –9 17.8 23.2 23.2 Cosmopolitan Cosmopolitan 1.4 15.8 Appendix 13.1 Rosaceae gen. et spec. indet. 10 Rosaceae gen. et spec. indet. 11 Salicaceae Salix gruberi Salix sp. A Sparganiaceae Sparganium sp. Trochodendraceae Tetracentron atlanticum Valerianaceae aff. Valeriana sp. Incertae sedis – Magnoliophyta Pollen type 21 Pollen type 22 Pollen type 23 701 702 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Sphagnum Equisetum Lycopodiella Lycopodium Huperzia Lycopodiaceae Selaginella Osmunda regalia Polypodium Polypodiaceae Polypodiaceae Polypodiaceae – – – – – Abies Picea – – – – – –6.7 –8.9 3.2 Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan – – – – – 27.4 21.7 Cosmopolitan 23.9 Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan MAT low ºC MAT high ºC Tjörnes beds TAxA 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Bryophyta Sphagnum sp. Equisetaceae Equisetum sp. Lycopodiaceae Lycopodiella sp. Lycopodium sp. aff. Huperzia sp. Lycopodiaceae gen. et. spec. indet. 1 Selaginellaceae Selaginella sp. Osmundaceae Osmunda sp. Polypodiaceae Polypodium sp. 1 Polypodiaceae gen. et. spec. indet. 1 Polypodiaceae gen. et spec. indet. 2 Polypodiaceae gen. et spec. indet. 6 Incertae sedis – unassigned spores Trilete spore, fam., gen. et spec. indet. 3 Trilete spore, fam., gen. et spec. indet. 4 Trilete spore, fam., gen. et. spec. indet. 5 Monolete spore, fam., gen. spec. indet. 3 Monolete spore, fam., gen. et spec. indet. 4 Pinaceae Abies sp. 2 Picea sp. Tjörnes beds TAxA Pinus Larix Tsuga Sciadopitys verticillata Apiaceae Apiaceae Apiaceae Cosmopolitan Cosmopolitan Cosmopolitan 7.4 16.6 –9.2 –14.5 1.8 25.5 16.1 21.9 Potential modern analogue MAT low ºC MAT high ºC Appendix 13.1 Pinus sp. 2 Larix sp. Tsuga sp. 1 Sciadopityaceae Sciadopitys sp. Apiaceae Apiaceae gen. et spec. indet. 1 Apiaceae gen. et spec. indet. 2 Apiaceae gen. et spec. indet. 3 Aquifoliaceae Ilex sp. 1 Ilex aquifolium Ilex opaca Ilex decidua Arum Northern hemispheric 7.2 7.4 11.1 18.2 22.4 22.1 } 7.2 22.4 Araceae aff. Arum sp. Asteraceae Cirsium sp. Asteraceae gen. et spec. indet. 1 Asteraceae gen. et spec. indet. 5 Asteraceae gen. et spec. indet. 6 Asteraceae gen. et spec. indet. 7 Asteraceae gen. et spec. indet. 8 Betulaceae Alnus cecropiifolia Asteraceae Asteraceae Asteraceae Asteraceae Asteraceae Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Alnus glutinosa Alnus nitida Alnus rhombifolia Alnus viridis Betula Alnus aff. viridis Betula sp. –3.3 17.4 22.4 5.6 –3.3 16.3 0 Temperate and subarctic northern hemisphere } 22.4 (continued) 703 704 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue MAT low ºC MAT high ºC Tjörnes beds TAxA Calycanthaceae aff. Calycanthaceae Calycanthus chinensis Calycanthus floridus Calycanthus occidentalis Chimonanthus spp. 5.3 Campanula Caryophyllaceae Caryophyllaceae Caryophyllaceae Chenopodium Carex Kobresia Cosmopolitan Cosmopolitan Northern hemisphere high mountain areas 4.1 18.3 Cosmopolitan Cosmopolitan Cosmopolitan Northern hemispheric 11.5 8.7 5.3 7 13.4 19.4 18.3 20 Campanulaceae Campanula sp. Caryophyllaceae Caryophyllaceae gen. et spec. indet. 1 Caryophyllaceae gen. et spec. indet. 4 Caryophyllaceae gen. et spec. indet. 5 Chenopodiaceae aff. Chenopodium sp. Cyperaceae Carex sp. Kobresia sp. } 20 Ericaceae Rhododendron aff. ponticum Rhododendron ponticum Rhododendron maximum Vaccinium uliginosum 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Rhododendron sp. 2 Vaccinium cf. uliginosum Ericaceae gen. et spec. indet. 4 Ericaceae gen. et spec. indet. 5 Ericaceae gen. et spec. indet. 6 Ericaceae gen. et spec. indet. 7 Ericaceae Ericaceae Ericaceae Ericaceae 4.6 17.5 Temperate and subarctic northern hemisphere Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Appendix 13.1 Euphorbiaceae Euphorbia sp. Fagaceae Trigonobalanopsis sp. Euphorbia cyparissias Extinct genus 18.1 19.8 1 11.1 Juglandaceae Pterocarya sp. Pterocarya fraxinifolia Pterocarya macroptera 8.1 –1.9 –1.9 } 19.8 Myriophyllum Liliaceae Menyanthes trifoliata Northern temperate and circumpolar 0.6 Cosmopolitan 14.2 Cosmopolitan Haloragidaceae Myriophyllum sp. Liliaceae Liliaceae gen. et spec. indet. 3 Menyanthaceae Menyanthes sp. Cosmopolitan Myrica gale Epilobium Plantago coronopus Myricaceae Myrica sp. Onagraceae Epilobium sp. Plantaginaceae Plantago coronopus Poaceae Phargmites Poaceae Poaceae Phragmites sp. Poaceae gen. et spec. indet. 1 Poaceae gen. et spec. indet. 3 Sahara to Scandinavia and the Faeroe Islands, edaphically controlled Cosmopolitan Cosmopolitan Cosmopolitan (continued) 705 706 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Rumex Persicaria amphibia Polygonum viviparum Potamogeton Ranunculus Ranunculus Thalictrum Ranunculaceae Ranunculaceae Ranunculaceae Filipendula Fragaria Northern temperate Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan MAT low ºC MAT high ºC Tjörnes beds TAxA Polygonaceae Rumex sp. Northern hemisphere Northern hemisphere Circumpolar Persicaria sp. aff. P. amphibia Polygonum viviparum Potamogetonaceae Potamogeton sp. Ranunculaceae Ranunculus sp. 1 Ranunculus sp. 2 Thalictrum sp. 2 Ranunculaceae gen. et spec. indet. 2 Ranunculaceae gen. et spec. indet. 4 Ranunculaceae gen. et spec. indet. 5 Rosaceae Filipendula sp. Fragaria sp. 1 Fragaria sp. 2 Sanguisorba sp. Sorbus aff. aucuparia 15.8 14.7 15.7 9.8 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Rosaceae gen. et spec. indet. 11 Rosaceae gen. et spec. indet. 12 Sanguisorba officinalis Sorbus aucuparia Sorbus americana Sorbus decora Rosaceae Rosaceae 1.4 –2.1 –15.1 –6.2 Cosmopolitan Cosmopolitan } –6.2 15.7 Salicaceae Salix gruberi –9 –18.2 8.5 23.2 Salix caprea Salix scouleriana Salix arctica Salix lanata Salix caprea Acer saccharum Acer rubrum Sparganium Tetracentron sinense Valeriana Viscum album – – – – – – – – – – – – – – – – – – 5.2 Cosmopolitan 17.4 – – – – – – – – – (continued) 2.2 19 Cosmopolitan –1.1 –1.1 15.8 23.8 –9 –5.6 –18.2 –7.3 –9 17.8 23.2 5.5 8.5 17.8 Appendix 13.1 Salix sp. B (‘S. arctica’ type) } } Salix sp. 4 Sapindaceae Acer sp. 1 Acer sp. 2 Sparganiaceae Sparganium sp. Trochodendraceae Tetracentron atlanticum Valerianaceae aff. Valeriana sp. Viscaceae Viscum aff. album Incertae sedis – Magnoliophyta Monocotyledonae fam.et gen. indet. 1 Angiosperm fam. gen. et spec. indet. C Pollen type 24 Pollen type 25 Pollen type 26 Pollen type 27 Pollen type 28 Pollen type 29 Pollen type 30 707 708 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Sphagnum Lycopodium Huperzia Osmunda regalis Polypodiaceae Pinus Artemisia Asteraceae -9.2 Cosmopolitan Cosmopolitan 25.5 Cosmopolitan 3.2 23.9 Cosmopolitan Cosmopolitan Cosmopolitan MAT low °C MAT high °C Viðidalur Formation TAxA Bryophyta Sphagnum sp. Lycopodiaceae Lycopodium sp. aff. Huperzia sp. Osmundaceae Osmunda sp. Polypodiaceae Polypodiaceae gen. et spec. indet. 1 Incertae sedis - unassigned spores Trilete spore, fam., gen. et spec. indet. 6 Trilete spore, fam., gen. et spec. indet. 7 Pinaceae Pinus sp. 2 Diploxylon Asteraceae Artemisia sp. 1 Asteraceae gen. et spec. indet. 1 Betulaceae Alnus aff. viridis Betula nana x pubescens Alnus viridis Betula nana Betula pubescens Caryophyllaceae Caryophyllaceae Caryophyllaceae Kobresia -12.4 -12.4 -2.3 Cosmopolitan Cosmopolitan Cosmopolitan 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present 12.4 14.3 12.3 14.3 14.2 Caryophyllaceae Caryophyllaceae gen. et spec. indet. 4 Caryophyllaceae gen. et spec. indet. 6 Caryophyllaceae gen. et spec. indet. 7 Cyperaceae Kobresia sp. } Northern hemisphere high mountains Ericaceae Ericaceae gen. et spec. indet. 8 Vaccinium cf. uliginosum Ericaceae Vaccinium uliginosum Cosmopolitan Temperate, subarctic n. hemisphere Cosmopolitan -1.5 Cosmopolitan Northern hemisphere Northern hemisphere Cosmopolitan Cosmopolitan -2.3 Cosmopolitan Cosmopolitan 12.3 Appendix 13.1 Menyanthes Myrica gale Polygonum Polygonum viviparum Rumex Ranunculus Thalictrum Trollius europaeus Ranunculaceae Ranunculaceae Dryas octopetala Fragaria Sanguisorba officinalis Rosaceae Salix arctica Salix lanata Saxifraga - Menyanthaceae Menyanthes sp. Myricaceae Myrica sp. Polygonaceae Plygonum sect. Aconogonon sp. Polygonum viviparum Rumex sp. Ranunculaceae Ranunculus sp. 3 Thalictrum sp. 2 Trollius sp. 12.2 Ranunculaceae gen. et spec. indet. 2 Ranunculaceae gen. et spec. indet. 6 Rosaceae Dryas octopetala Fragaria sp. 1 Sanguisorba sp. Arctic-Alpine, northern hemisphere Cosmopolitan 1.4 15.8 Cosmopolitan -18.2 -7.3 Arctic-Alpine 709 5.5 8.5 Rosaceae gen. et spec. indet. 13 Salicaceae Salix sp. B (‘S. arctica’ type) Saxifragaceae Saxifraga sp. Incertae sedis - Magnoliophyta Pollen type 28 } -18.2 8.5 (continued) 710 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Lycopodium Huperzia Lycopodiaceae Osmunda regalis Polypodiaceae – Pinus Artemisia Asteraceae Asteraceae Asteraceae Asteraceae Asteraceae Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopotian –9.2 25.5 Cosmopolitan 3.2 23.9 Cosmopolitan Cosmopolitan Cosmopolitan MAT low °C MAT high °C Búlandshöfði Formation TAxA Lycopodiaceae Lycopodium sp. aff. Huperzia sp. Lycopodiaceae gen. et spec. indet. 2 Osmundaceae Osmunda sp. Polypodiaceae Polypodiaceae gen. et spec. indet. 1 Incertae sedis – unassigned spores Trilete spore, fam., gen. et spec. indet. 6 Pinaceae Pinus sp. 2 Diploxylon 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Asteraceae Artemisia sp. 1 Asteraceae gen. et spec. indet. 1 Asteraceae gen. et spec. indet. 4 Asteraceae gen. et spec. indet. 8 Asteraceae gen. et spec. indet. 9 Asteraceae gen. et spec. indet. 10 Betulaceae Alnus sp. 3 Betula sp. 1 Alnus viridis Betula nana Betula pubescens Caryophyllaceae Caryophyllaceae Caryophyllaceae Caryophyllaceae –12.4 –12.4 –2.3 12.3 14.3 14.2 Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan } –12.4 14.3 Caryophyllaceae Caryophyllaceae gen. et spec. indet. 6 Caryophyllaceae gen. et spec. indet. 8 Caryophyllaceae gen. et spec. indet. 9 Caryophyllaceae gen. et spec. indet. 10 Búlandshöfði Formation TAxA Empetrum nigrum Vaccinium uliginosum Appendix 13.1 –12.4 8.2 Potential modern analogue MAT low °C MAT high °C Empetraceae Empetrum nigrum Ericaceae Vaccinium cf. uliginosum Ericaceae gen. et spec. indet. 6 Euphorbiaceae Mercurialis perennis Mercurialis perennis Onagraceae Plantago coronopus Sahara to Scandinavia, Faeroe Islands Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Circumpolar 2.7 17.6 Ericaceae Temperate, subarctic n. hemisphere Cosmopolitan Onagraceae Onagraceae gen. et spec. indet. Plantaginaceae Plantago coronopus Poaceae Poaceae Poales Polygonum aviculare Polygonum viviparum Ranunculaceae Potentilla Poaceae Poaceae gen. et spec. indet. 1 Poaceae gen. et spec. indet. 4 Poales Poales gen. et spec. indet. Polygonaceae Polygonum aviculare Polygonum viviparum Rumex sp. Ranunculaceae Ranunculaceae gen. et spec. indet. 2 Rosaceae Potentilla sp. A Cosmopolitan Northern hemisphere Salicaceae Salix sp. B (‘S. arctica’ type) 711 Salix arctica Salix lanata –18.2 –7.3 5.5 8.5 } –18.2 8.5 (continued) 712 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Salix herbacea Valeriana officinalis – – – Potential modern analogue Sphagnum Equisetum Lycopodium Polypodiaceae Polypodiaceae Thelipteris limbosperma – Pinus Apiaceae Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan 0.7 – –9.2 Cosmopolitan 7.2 – 25.5 Cosmopolitan MAT low MAT high – – – – – – 1.3 14.7 –12.2 7.2 MAT low °C MAT high °C Búlandshöfði Formation TAxA Salix herbacea Valerianaceae Valeriana sp. Incertae sedis – Magnoliophyta Monocotyledonae fam. et gen. indet. 2 Pollen type 28 Pollen type 31 Svínafellsfjall Formation TAxA Bryophytes Sphagnum sp. Equisetaceae Equisetum sp. Lycopodiaceae Lycopodium sp. Polypodiaceae Polypodiaceae gen. et spec. indet. 1 Polypodiaceae gen. et spec. indet. A Thelipteridaceae Thelipteris limbosperma 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Incertae sedis – unassigned spores Trilete spore, fam., gen. et spec. indet. 8 Pinaceae Pinus sp. 2 Diploxylon Apiaceae Apiaceae gen. et spec. indet. 2 Asteraceae Svínafellsfjall Formation TAxA Appendix 13.1 Artemisia Artemisia Asteraceae Asteraceae Asteraceae Asteraceae Asteraceae Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Potential modern analogue MAT low MAT high Artemisia sp. 1 Artemisia sp. 2 Asteraceae gen. et spec. indet. 3 Asteraceae gen. et spec. indet. 4 Asteraceae gen. et spec. indet. 8 Asteraceae gen. et spec. indet. 11 Asteraceae gen. et spec. indet. 12 Betulaceae Alnus cf. viridis Betula sp. 1 Alnus viridis Betula nana Betula pubescens –12.4 –12.4 –2.3 12.3 14.3 14.2 } –12.4 14.3 Chenopodiaceae Cyperaceae Vaccinium uliginosum Cosmopolitan Chenopodiaceae Chenopodiaceae gen. et spec. indet. 2 Cyperaceae Cyperaceae gen. et spec. indet. C Ericaceae Vaccinium cf. uliginosum Cosmopolitan Ericaceae Ericaceae Menyanthes Poaceae Poaceae Poaceae Poaceae Poales Temperate, subarctic northern hemisphere Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan Cosmopolitan 713 Cosmopolitan (continued) Ericaceae gen. et spec. indet. 6 Ericaceae gen. et spec. indet. 9 Menyanthaceae Menyanthes sp. Poaceae Poaceae gen. et spec. indet. 4 Poaceae gen. et spec. indet. 5 Poaceae gen. et spec. indet. 6 Poaceae gen. et spec. indet. 7 Poales Poales fam. gen. et spec. indet. 714 Taxa lists for 10 formations from the Cainozoic of Iceland indicating potential modern analogues and their climatic (MAT) parameters (continued) Potential modern analogue Polygonum viviparum Rumex Circumpolar Northern hemisphere Cosmopolitan Cosmopolitan Cosmopolitan 1.5 14.2 MAT low MAT high Svínafellsfjall Formation TAxA Polygonaceae Polygonum viviparum Rumex sp. Thalictrum Ranunculaceae Ranunculus Alchemilla vulgaris Dryas octopetala Ranunculaceae Thalictrum sp. 1 Thalictrum sp. 2 Ranunculaceae gen. et spec. indet. 7 Ranunculus sp. A Rosaceae Alchemilla sp. Dryas octopetala Sorbus aff. aucuparia Sorbus aucuparia Sorbus americana Sorbus decora Galium Arctic-Alpine, northern hemisphere –2.1 –5.1 –6.2 Cosmopolitan 14.7 15.7 9.8 Rubiaceae Galium sp. Salicaceae Salix sp. B (‘S. arctica’ type) Salix arctica Salix lanata Salix herbacea Scrophulariaceae – } –18.2 –7.3 –12.2 Cosmopolitan Cosmopolitan – 5.5 8.5 7.2 7.2 –6.2 15.7 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present Salix herbacea Scrophulariaceae Scrophulariaceae gen. et spec. indet. Incertae sedis – Magnoliophyta Pollen type 32 } – –18.2 8.5 Appendix 13.2 715 Appendix 13.2 Maps of Köppen-Geiger climate types for North America, western Eurasia, and Central and East Asia (from Kottek et al. 2006) 716 13 Climate Evolution in the Northern North Atlantic – 15 Ma to Present References 717 References Abreu, V. S., & Haddad, E. A. (1998). Glacioeustatic fluctuations: The mechanism linking stable isotope events and sequence stratigraphy from the Early Oligocene to Middle Miocene. In C.-P. Graciansky, J. Hardenbol, T. Jacquin, & P. R. Vail (Eds.), Mesozoic and Cenozoic sequence stratigraphy of European Basins (pp. 245–260). Tulsa, Oklahoma: SEPM, Special Publications, 60. Akhmetiev, M. A., Bratzeva, G. M., Giterman, R. E., Golubeva, L. V., & Moiseyeva, A. I. (1978). Late Cenozoic stratigraphy and flora of Iceland. Transactions of the Academy of Sciences USSR, 316, 1–188. Anderson, D. M., & Woodhouse, C. A. (2005). Let all the voices be heard. Nature, 433, 587–588. 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