Quaternary Environments at Cape Deceit (Seward Peninsula, Alaska): Evolution of a Tunclra Ecosystem

J. V. MATTHEWS, JR. Terrain Science; Division, Geological Survey of Canada, 601 Booth, Ottawa, Ontario, Canada K1A OE8

ABSTRACT latest early Pleistocene time, tree line at terrestrial environments in western Alaska Deering was composed of larch instead of — a result of the fact that sediments of that Unconsolidated sediments at Cape Deceit spruce. age in the area are predominantly nearshore near Deering, Alaska, range in age from Except for the mammalian component, marine in origin (Hopkins, 1967b). In con- latest early Pleistocene to Holocene. Plant most ecosystem evolution at Cape Deceit trast, the late Pleistocene environmental and insect fossils from these sediments, as during the last 400,000 yr or more has ap- history of western Alaska is better known well as certain sedimentary features, pro- parently involved little in situ evolution of (Colinvaux, 1967; Hopkins, 1972), al- vide evidence for documenting evolution of taxa. The maximum degree of phyletic though more work will be necessary to ob- the terrestrial ecosystem at Deering. evolution to be documented here is reduc- tain paleoenvironmental data comparable A tundra ecosystem functioned at Deer- tion of the flight wings of the tundra beetle to that now available in areas such as the ing for most of the time represented by the species, Tachinus apterus. Most of the north-central United States and western Cape Deceit sedimentary sequence. The re- phylogenetic splitting that has given rise to Europe. Much of this information will no gional tundra environment of northern pairs or groups of closely related arctic doubt come from continuing palynological Seward Peninsula during early Pleistocene species (especially among the beetles) prob- research in Alaska, but the most valuable time was similar to that of the present; ably occurred well before the early Pleis- studies are likely to employ a combination however, the local environment at Cape tocene during initial formation of the low- of several analytic techniques. Such a mul- Deceit was quite different, being only scant- land tundra realm. tifaceted study is the subject of this paper. ily vegetated. Starting in the middle Pleis- Fossils of pollen, plant macrofragments, tocene, the tundra of northern Seward INTRODUCTION and insects from Quaternary sediments at Peninsula evidently became more grassy, a Recent papers by Hopkins (1967a, 1972) Cape Deceit (Fig. 1; Guthrie and Matthews, trend culminating with steppe-tundra by have admirably summarized present 1971) are analyzed, and attention is also latest Wisconsin time. knowledge of Quaternary geology, paleon- given to the possible paleoclimatic implica- Former periods of warmer climate at tology, and biogeography of the Beringian tions of certain sedimentary structures oc- Deering are indicated by evidence for region, including eastern Siberia, western curring at the Cape Deceit exposure. westward movement of tree line. The last Alaska, and the intervening Bering and Oldest sediments at the Cape Deceit ex- time forest or forest-tundra existed at Deer- Chukchi epicontinental seas. Several gaps posure are of latest early Pleistocene age ing was no later than the penultimate in- in our knowledge of the history of this area (Cromerian). Fossils from them provide terglacial. Spruce tree line probably stood are also revealed by Hopkins' papers. The evidence of several climatic fluctuations closer to but not at Deering during the San- most obvious of these is the paucity of in- during which conifers expanded west to gamon interglacial. At least once, during formation on early and middle Pleistocene grow near Deering and Cape Deceit. Dur-

Geological Society of America Bulletin, v. 85, p. 1353-1384, 17 figs., September 1974

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ing one of these episodes, .a larch tree line existed in the Deering region. The oldest sedimentary unit at Cape Deceit also con- Sj tains the first North American record of the Eurasian rodent genus, Pliomys (Guthrie CAPE DECEIT and Matthews, 1971) and :he most primitive representatives of small mammal lineages whose members dominate contemporary tundra faunas. The various lines of 73-67V , fossil locality evidence discussed below suggest that the 74-S7» ,A station 8 tundra environment in which these primi- * \ tive mammals lived was at least quantita- CHUKCHI tively and probably qualitatively different SEA from that of the present. But this fact is Caps most apparent in the upper (late Pleis- Thompson tocene) part of the Cape Deceit sequence because plant and insect fossils there sug- *t gest a former arctic grassland or steppe- W^ DEERING

tundra. In other words, the character of the -> tundra environment at Cape Deceit has changed markedly during the Pleistocene but appears to have been most different from the present during latest Wisconsin time. The fossils discussed in this paper represent directly or indirectly the state of several trophic levels at different instants of geologic time, and the sedimentary struc- GULF OF ALASKA tures refer to former conditions of the abi- otic environment. Thus, the documented Figure 1. Location of Cape Deceit, Deering, and the fossil locality. Numbers refer to collection sites of surface sequence of environmental change actually pollen samples (Fig. 10, Table 1). Surface sample 97-69 located at "Pingo" (Fig. 2). represents the stages in the evolution of an ecosystem—in this case, the terrestrial with 0.635-mm screens at the fossil locality. as keys and illustrations in Beijerinck tundra ecosystem at Cape Deceit, Alaska. The residue was then sieved again with (1947), Berggren (1969), Bertsch (1941), 0.317-mm screens in the laboratory to re- Brouwer and Stahlin (1955), Martin and METHODS move remaining silt and clay. Next, seeds Barkley (1961), and Katz and others were skimmed from the floating fraction of (1965), aided identification of plant mac- Pollen Samples the residue, and if extremely abundant, a rofossils. I identified most of the insect fos- Pollen samples discussed here have been randomly selected sub sample was used for sils using comparative material in my own prepared using a modified version of a analysis. Finally, the insect fraction of the and museum collections. K.G.A. Hamilton schedule developed by Mehringer (1967) original sieve residue was concentrated identified Homoptera fossils, W.R.M. for alluvial pollen samples. My using a flotation technique developed by Mason examined some of the Hymenoptera modifications (greater numoer of swirls, Coope (1961). A dissecting microscope was fossils, J. M. Campbell checked Tachinus prolonged HF treatment, and elimination then used to isolate identifiable insect frag- arid Micralymma determinations, C. H. of HN03 treatment) help to concentrate ments, which were either stored in alcohol Lindroth examined specimens of Harpalus sufficient pollen for analysis, a common or immediately glued to macrofossil slides. cf, alaskensis Lth., and R. E. Leech problem with samples representing tundra, Samples of felted (oedded) peat, which identified spider fossils. to preserve the partly degraded pollen usu- occur at some levels in the exposure, were The entire fossil collection is presently ally occurring in colluvial sediments. processed differently because they often housed at the Geological Survey of Canada contain exceptionally well-preserved, partly (Ottawa). Macrofossils articulated insect fossi s. Such peat samples The initial step in Mehringer's procedure were collected in blocks and carefully pried GEOGRAPHIC AND of processing pollen is to wash approxi- apart in the laboratory. Articulated fossils BI OTIC SETTING mately 50 ml of sediment through were removed individually and glued to Quaternary exposures discussed here 0.254-mm screen to remove large organic macrofossil slides. Partly articulated insect occur adjacent to Cape Deceit, a prominent and mineral fragments. Residue left on the fossils also occurred occasionally in car- landmark in the low-lying northern coastal screen often contains plant and insect mac- bonate-cemented siltpeds. region of Seward Peninsula (Figs. 1, 2). rofossils, which provide, in some cases, al- De:ering, a small Eskimo village at the ternate evidence for interpretation of pollen Identification Aids mouth of the Inmachuk River, is within 4 data. Pollen and spores were identified using km of the Cape and Quaternary exposures Large sediment samples (200+ kg) from keys, illustrations in current palynological (Fig. 1). Deering is in a region of continuous selected levels in the Cape Deceit exposure literature (Faegri and Iversen, 1964; permafrost. Mean annual temperatures were processed in order to obtain assem- Erdtman, 1965, 1966, 1969; Erdtman and range from —4° to — 8°C, and mean annual blages (samples) of plant and insect mac- others, 1961, 1963; Beug, 1961), and refer- precipitation is between 130 and 150 mm rofossils. Silt and peaty silt were first sieved ence slides. Herbarium specimens, as well (Hulten, 1968).

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i i i gion, grasses are relatively rare, except at 166° W 162° W I5Q= w very dry sites. Artemisia was observed growing only on the unstable, deeply thawed coastal bluffs. Detailed descriptions of the vegetation on other areas of western Alaska are outlined in Hopkins and Sigafoos (1950), Hanson (1953), and Johnson and others (1966). The last report, dealing with the Cape Thompson area, describes several "vegetation types" that also occur in the Deering region. Papers concerned with more northern parts of Alaska (Hultén, 1968; Wiggins and Thomas, 1962; Britton, 1966) show that some important plants of the Deering region — Betula, Alnus — do not occur farther north (Young, 1971). A more severe regional climate is probably the cause. Spruce tree line is located approximately 75 km east of Deering (Fig. 2), although isolated outliers of spruce occur within 40 km of the town. Figure 2 shows that spruce tree line in the Kotzebue Sound area possesses a marked eastern re-entrant that is not dupli- cated on the south side of the Seward Peninsula (Fig. 2). This may be an effect of relatively cold surface waters in Kotzebue Sound (Fleming and Heggarty, 1966).

Figure 2. Seward Peninsula region showing localities mentioned in text, extent of late Pleistocene glaciers, present The insect fauna of western Alaska is position of tree line, and location of former shoreline. poorly documented. Even faunal lists from such intensively studied sites as Cape Thompson (Fig. 1; Watson and others, Local bedrock in the Deering region con- approach to Deering by the terminal 1966) contain obvious omissions. sists mainly of Paleozoic metalimestorie moraine complex now forming Baldwin Nevertheless, the scanty knowledge now (exposed at Cape Deceit) and schistose Peninsula. Thus the potential for thick loess available indicates that shrub tundra sites pelitic rocks of Paleozoic age, locally cov- accumulation at Deering during Wisconsin such as Deering are inhabited by an insect ered by Cenozoic basalts to the south and time was likely much less than during the Il- fauna with strong Hudsonian affinities west of Deering (Hopkins, 1963; Hopkins linoian. (W.R.M. Mason, 1971, oral commun.), and others, 1971). Surficial sediments in the Deering and Cape Deceit are presently implying that the tundra fauna is not radi- area are mostly primary and reworked loess within a region of shrub tundra (Zone 4 of cally different from that in forested areas capped with a thick sedge or moss turf. Young, 1971; "hypoarctic tundra" of Yurt- immediately to the east. Greatest forest ver- Coarse alluvium occurs in the valleys of the sev, 1972). A detailed discussion of the sus tundra faunal distinctions probably larger rivers such as the Inmachuk (Fig. 2). flora and vegetation of the Deering—Cape exist among the Coleoptera (beetles). Marine sands and gravels as well as es- Deceit area is not within the scope of this STRATIGRAPHY AND CHRONOLOGY tuarine detrital peats are in areas that were paper; however, a few general comments inundated or formed shorelines during the are required. Silty soils of the uplands near Stratigraphy last, Sangamon (=Pelukian), interglacial. Deering support a cotton-grass Stratigraphy of the Cape Deceit expo- Northern coastal portions of the Seward (Eriophorum), tussock-dominated tundra sures has been discussed in detail by Peninsula have never been glaciated. Dur- in which certain heaths (Ericales) and pros- Guthrie and Matthews (1971) and is pre- ing Illinoian time glaciers existed in the trate shrub birches (Betula nana) are also sented diagrammatically in Figures 3, 4, headwater region of the Kiwalik River, common. Dryas fellfield frequently occurs and 5. Three major stratigraphic units — southeast of Deering (Fig. 2). Illinoian in dry areas with poorly developed soils. Cape Deceit Formation, Inmachuk Forma- glaciers from the western Brooks Range Sedges and mosses dominate moist areas of tion, and Deering Formation — are recog- approached as close to Deering as Baldwin the lowlands; but where soil is especially nized. These have been subdivided into a Peninsula (Fig. 2), and outwash streams peaty, Rubus chamaemorus (Salmonberry), number of minor stratigraphic units, such emanating from that area and flowing Empetrum nigrum (Crowberry), and dwarf as peat 1, unit 1, etc. Mutual contacts of the across the then-dry floor of inner Kotzebue birches are abundant ("Cloudberry dwarf three formations are angularly unconform- Sound (Fig. 2) no doubt carried silt that was shrub marsh" of Hanson, 1953). Alders, able and otherwise characterized by distinc- deposited as loess on the uplands that pres- shrub willows, and dwarf birches taller tions of color and (or) sediment texture ently form the north shore of Seward Penin- than the prostrate forms existing at most (Guthrie and Matthews, 1971). Organic silt sula. Different conditions prevailed during sites grow on sunny slopes and flood plains is the dominant sediment in all three forma- Wisconsin time when glacier termini were of the larger rivers. Shrub willows also tions; however, some units contain lenses of more distant from the Deering region, and occur near inactive peat rings and at the sand or gravel, as well as laterally continu- outwash streams originating in the western margins of now stable solifluction lobes on ous peat horizons (Figs. 3, 4). Brooks Range were prevented from a close the uplands. Throughout the Deering re- Correlation of some of the peat horizons

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here differs from that given in Guthrie and iments have been stated elsewhere (Guthrie mean that the Cape Deceit Formation is of Matthews (1971). In that report, peat 6 at and Matthews, 1971), but paleoenviron- pre-Cromerian age. As long as the term station 1 was described as consisting of two mental data presented in this paper and Cromerian is applied to a single pre-Mindel peat horizons separated by a thin band of other information not available before interglacial, this conclusion remains valid silts (sample 47—69, Fig. 7). I now feel that 1971 make necessary further discussion of and is further substantiated by recent evi- the designation peat 6 should be restricted the Cape Deceit chronology. Important dat- dence from Siberia. But in the discussion to the lower peat (source of the sample ing criteria are (1) radiometric dates (Deer- below, Cromerian is used in a more exten- dated at 9,150 yr, Fig. 5). The thick upper ing Formation only), (2) stage of evolution sive sense (Zagwijn and others, 1971), re- peat at station 1 is probably equivalent in of certain mammalian taxa, (3) fossil evi- sulting in the entire Cape Deceit Formation age to the late Holocene blocky, moss peat dence of a more western position for tree being of Cromerian age. occurring at the top of otner parts of the line, and (4) sedimentary features indicative Evidence from eastern Siberia for the age Cape Deceit exposure as well as at other of thawing and erosion. A compilation of of the Cape Deceit Formation is based on sites in the Kotzebue Sound region. stratigraphy, dating, and probable correla- fossil mammals of the Olyor Suite on the Figure 6E shows peat 5 and associated tions is presented in Figure 5. Chukochya River (Kolymian Lowland; sediments at one part of the exposure at sta- CapeDeceitFormation. Mammalian fos- Sher, 1971). Small mammals from Olyor tion 8 (Fig. 4). Toward Cape Deceit peat 5 sils from the Cape Deceit local fauna, here- sediments include a species of Microtus merges with overlying organic silts and after referred to as the CD local fauna, equally as primitive as M. deceitensis and a peaty silts (samples 99-68 and 100-68) to provide the best evidence for dating the species of Dicrostonyx that is slightly more form a single organic horizon. Accordingly, Cape Deceit Formation. Comparable advanced dentally than Predicrostonyx the designation peat 5 at station 8 applies to mammalian assemblages exist only in the hopkinsi (A. V. Sher and V. S. Zazhigin, the actual peat horizon as well as im- Palaearctic, hence the use of European ter- 1970, written commun.). The Equus mediately overlying organic silts. Thus, minology in Figure 5. Local Alaskan corre- Terminal phalanx illustrated in Guthrie and samples 99-68, 100-68, and probably lation is difficult because the early and mid- Matthews (1971) is thought by Sher (writ- even macrofossil assemblage (sample) S—5 dle Pleistocene of the state, as presently ten commun., 1970) to represent the Olyor (Fig. 7) should be considered to be within known, is represented primarily by near- species £. (Plesippus) verae Sher. He also the peat 5 stratigraphic unit. Pollen evi- shore marine sediments (Hopkins, 1967b), suggested that the Equus premolar illus- dence presented below shows that organic which are not the type to contain verte- trated in Guthrie and Matthews (1971) is sediments of basal unit 2 at station 1 should brates such as those from Cape Deceit. more advanced than those in the Villafran- not be referred to peat 5 as is done in In the previous report on Cape Deceit chian species E. (Plesippus) stenonis. To Guthrie and Matthews (15'71). (Guthrie and Matthews, 1971), the stage of Sher and Zazhigin, these facts show that the evolution of three newly described small CD local fauna predates the Olyor assem- Chronology mammal taxa from the CD local fauna blage. And because it is the eastern Asian Arguments on the probable age of the (Microtus deceitensis, Pliomys deeringentis, equivalent of the Mindel to Mindel-Riss Cape Deceit Formation arid overlying sed- Predicrostonyx hopkinsi) was taken to Tiraspol fauna of eastern Europe (Gromov,

j". "' Peat - silty peat

• Bedded silts

— - closer spacing for finely bedded silts

:ploty , clayey silts

Sand

Gravel

"Frost crock" structures

m w Wood fragments

Scale (Vertical and Horizontal) Cape Deceit -

4 6 8 meters

' Deering Fm. "Frost Crocks^(Fig.6A) (Fig.6F) Deering Fm. / • , _ - .-j^-f— , y —r- i.inii l — ^ ' T < -f— ^ f

Folded, truncated peat (Fig.6 Dl^r3r —' _ : \ . ' T - ' ' V Jnmachuk Fm.

-2 •> -irr- •>'•"•,-/ Ice Wedge Pseudomorph (Fig.6B)""Trx^.Unit 2 . Cape Deceit Fm. Í-' . .""v^.'TTnr:.-sr"*--"I'V^f'^z ¿"""fop® Deceit Rn.J&zsf-f p fi- .J'umM . V " Unit i ea 37m to Station I -

Figure 3. Stratigraphy of the Cape Deceit Quaternary exposure showing actual lateral and vertical relation of named stratigraphic units and sedimentary features. Vertical and horizontal scales are equal.

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1970; Vangengeim and Sher, 1970), the CD sediments paleomagnetically (as in Zagwijn lowing discussion to be of probable II- local fauna predates the European Mindel and others, 1971) is planned. Also, fossils linoian age (Fig. 5). (=Elster) glaciation. Furthermore the CD of Pliotnys and a very primitive species of Deering Formation. C14 dates show that local fauna occurs below an unconformity Microtus have recently been discovered in unit 2 of the Deering Formation is of Wis- thought to be caused by interglacial thaw- Saskatchewan (A. M. Stalker, 1972, oral consin and Holocene age. Peat 5 is older ing and erosion (Guthrie and Matthews, commun.). When these are studied and than 39,900 yr (Fig. 5). Since it represents 1971); hence, it is probably older than the compared with Cape Deceit fossils, they warmer climate than present (see later dis- interglacial immediately preceding the should allow correlation of the Cape Deceit cussion) and occurs below Late Wisconsin Mindel (Elster). local fauna with one of the established sediments, it is probably either of Wiscon- I have referred to this interglacial as the North American land-mammal ages. An at- sin interstadial or Sangamon interglacial Cromerian (Guthrie and Matthews, 19/1), tempt should also be made to date Cape age. but the Cromerian interval is now known Deceit bones using a technique recently out- Presence of fossils of Dicrostonyx henseli to include a complex of several glacial and lined by Bada (1972). A prerequisite of the Hinton at the base of unit 1 (henseli zone) interglacial fluctuations (Zagwijn and method is that the bones have had a stable was previously cited (Guthrie and Mat- others, 1971; West and Wilson, 19(16). temperature history. Though this cannot be thews, 1971) as evidence that unit 1 is of II- Thus, if that term is to be used at all with assured for the Cape Deceit fossils, they linoian age. This would imply in turn that reference to Cape Deceit, it should be ap- have undoubtedly undergone less underlying peat 4 is of Kotzebuan intergla- plied to both the Cape Deceit Formation fluctuation of temperature than fossils from cial age (=Kotzebuan marine transgression) (which itself represents several climatic any known terrestrial assemblage of com- and that peat 5 is of Sangamon age. fluctuations) and the Cape Deceit- parable age. The argument is based on two facts: (1) Inmachuk hiatus. Thus Cromerian is used Inmachuk Formation. A single Pliomys D. henseli had dentition morphologically here in the same way as in the Netherlands. molar was found in the lower sands of the more primitive than that of the extant There, it represents the series of glacial- Inmachuk Formation. Because Pliomys Holarctic species, D. torquatus, and is interglacial fluctuations occurring 400,000 does not occur in early or late Pleistocene probably ancestral to torquatus. (2) Fossil to 900,000 yr ago, before the Elster glacia- faunas of eastern Siberia, yet must have records suggest that the two species were tion but after the early Pleistocene Mena- passed through that area to get to North neither geographically sympatric or con- pian glaciation (Zagwijn and others, 1971; America (it is of Palaearctic derivation), this temporaries (Agadzhanyan, 1971). D. hud- Van der Hammen and others, 1971). Ac- single fossil tends to indicate that the In- sonius (Pallas), a primitive species similar in cordingly the Cape Deceit Formation is machuk Formation is also of pre-Olyor dentition to D. henseli, thrives today on the judged to have been deposited between (pre-Mindel) age. But if the single fossil was tundra east of Hudson Bay, but its con- 400,000 and 900,000 yr ago. rebedded from the Cape Deceit Formation, tinued existence there is undoubtedly re- More precise correlation of the Cape De- then all that can be said of the age of the lated to its isolation from the more progres- ceit Formation should be possible in the Inmachuk Formation is that it predates sive D. torquatus. Therefore, unless Cape near future because an attempt to date the Deering Formation unit 1, shown in the fol- Deceit henseli fossils refer to a similar relict

r- Peat 6

^i'j Unit 2 --"» Deering Frn^ —— -r ^ \ -r- T T *r- v Unif 1 ']->r . T "Frost crock" Zone - overturneAd .fro sr I ^ " ~~ Inmachuk Fm. ^—T-Z- %•_ overturned frost crocks t -Peat 3 ' - -ü^c.-üd Inmachuk Fm, 4 -f^"' Peat 2 " . - PeaPentt 3 1I 1'''I ' * ~ / - , . Peat 2- Peat 2 - Cape Deceit Fm. - ^ ""-r Z 1 Unit 2 Vegetated . — ' )',t / - _ " - '"large concentration of wood (including overturned stumps) — much wood «•»• *** •-Peat I (fibrous) -S- -= ' : • ' . . ' mossi ve, sandy silts -r^r ~ — Peat I "(felted)""^, c- ' Unit I Cope Deceit Fm. r^'-^''.-^- Si: Unit I

horizontal distance not to scale 17 m to Station 4- (slightly shortened) in this area -Deering Cope C 7 meter interval

See Fig. 3 for key to sedimentory symbols

see Fig. 6E Scole {Verticol and Horizontal) for details. 10

Peat 5

Vegetated / reiafttfnshfstrotigrophipc ' -rr*" '—_ - - —" _ not clear /AJU«./ ' see Fig.6C _ ——r Obscured for details _ ' 8eoch gravels — Peat 4 Obscured by vegetation / (Pelukian)

250 m to Station Figure 4. Stratigraphy of the Cape Deceit Quaternary exposure showing actual lateral and vertical relation of named stratigraphie units and sedimentary features. Vertical and horizontal scales are equal

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Stratigraphie Radiometric Dates and Age Estimates Units Stratigraphy" Description

Blocky, Moss peat 9 50=150yrs. BP" Peat 6 Fibrous peat, intermittent Plotey, clayey, organic silts i;:420=ie0yrs.BPc Slight unconformity Wisconsin (Salmon Lake)' or late Wisconsin Organic, olive Mack sits - deformed by solifluction Peat 5 Silty peat-laterally continuous or intermittent nodules; deformed by solifluction? >39900yrs. BP" iiterglacial Sangamon ( Pelukian) Inorganic, grayish yellow to grayish olive, bedded silts (loess) - with"frost crocks" or mid-Wisconsin ana wedge shaped gully fill structures Illinoian (Nome River) Local unconformity or early Wisconsin

Bedded, oxidized silts(loess) - sandy at base; D. henseli Zcne Peat 4 interglacial (Kotzebuan ?) Woody, fibrous to felted peat - present only at Stations 8 and 9

HIATUS Peat 3 Deformed, silty peat - some places felted and thick Slightly bedded gray silts (loess) Mindel? Oxidized sands (present only one place - see Fig. 3) Fossil of Pliomys sp.

inlerglacial (Einahnuhtan ?) Peat 2 Deformed silty peat and organic silts

Grayish olive to dark olive gray bedded organic silts - w th irterbedded sand lenses and stringers - with ice wedge pseudomorph ard other periglacial structures Predati: s East Siberian equivalent Cape Deceit (Olyor :iuite) of Tiraspol Faunal Crom e ri o n Local Fauna' Complex (Mindel to Mindel-Riss)

Local woody zones - in one area a large concentration of wood, overturned stumps inlerglacial or (Anvilian ?) Peat I Fibrous to felted peat - intermittent in some areas; not wood/ except at two localities int erstadial Angular gravels; sand lenses; organic, bedded silts - with inturbedded peaty zones, and solifluction structures. Banded, pebbly, sandy facies at Station I (Fig.3); silty, organic facies between Stations 5 ana 6 (Fig.4).

Fine grained, finely bedded, pale yellow, metalimestone weathering residuum (Kittik)-exposed only near Station l(Fig.3); base of exposure elsewhere consists of organic, bedded silts with lenses of sand, gravel, and peat. Trench dug below beach near Station 3 (see location of sample 79-68 in Fig.3) re- intnrglacial . . , present beach veals 50cm of black, silty detrital (?) peat above tan, sandy, pebbly silts (bosed on pollen sample 79-68) (Anvilian?)

For stratigraphic symbols and thickness of units see 1-4781; small, autochthonous wood fragments from Vangengïim and Sher, 1970; Sher and Zazhigin, written Figs. 3 and 4 middle of S-6 sample interval (station 8, Fig.4) communication, 1970

"i- 4780; basal 5cm of Peat 6 at Station I dI-4099; Peat 5 at Station 8 fLocal Aluskan equivalent in parenthesis r sensu Zagwijn eta/., 1971 gSee text for explanation of use of European stage names

Figure S. Generalized stratigraphy of Cape Deceit Quaternary exposure including descriptive notes, radiometric dates, and probable correlations.

population contemporaneous with but iso- suggesting that unit 1 of the Deering For- frost crack zone observed at other expo- lated from D. torquatus (no geographical mation is of Illinoian age: sures. A similar colluvial sequence is form- barrier exists in western Alaska that might 1. Primary loess thickness in the Deering ing today where silts derived from the account for this), the presence of henseli Formation exceeds 3m (usually in unit 1 upper levels of the coastal bluffs blanket remains in the lower Deering Formation alone), whereas D. M. Hopkins (1972, erosion-resistant peat 4 at the base. Because implies that those sediments predate the written commun.) reports observing a loess station 9 lies very close to the former posi- first appearance of D. torquatus in Alaska. cover only 1 m thick on gravel making up a tion of a Pelukian shoreline, the sediments Present evidence (Guthrie, 1968b) shows spit of Sangamon age on the west side of exposed there may have a similar origin. that D. torquatus was definitely present Kugruk Lagoon, 10 km east of Deering. If And if so, the Pelukian gravels at station 9 during the Wisconsin. Hence the lower part this observation is a valid index of thickness and peat 4 can hardly be of the same age of the Deering Formation may be pre- of Wisconsin age loess in the Deering area, because Pelukian coastal erosion at station Wisconsin in age. then the Deering Formation must represent 9 has removed a unit—frost crack Recently, an My morphologically inter- more than just Wisconsin and Holocene sediments—that occurs stratigraphically mediate between those in D. henseli and D. time. Almost all of the primary loess in the above peat 4 at station 8. Thus peat 4 pre- torquatus was found in Wisconsin-age sed- Deering Formation occurs in unit 1. This is dates the Pelukian gravels and most likely iments at Cape Espenberg (Fig. 2; D. M. to be expected if it is of Illinoian age be- represents the preceding Kotzebuan inter- Hopkins and C. A. Repenning, 1971, writ- cause outwash streams (source of the loess) glacial. Peat 5, dated at greater than 39,900 ten commun.). However, this fact does not would have passed quite near Cape Deceit yr, is therefore judged to be the Pelukian necessarily invalidate the assumption con- at that time (see section on Geographic and equivalent (Fig. 5). cerning chronologic implications of D. hen- Biotic Setting and Fig. 2). Tiough I believe them to be persuasive, seli because intermediates are to be ex- 2. Differences in the stratigraphy above the above arguments lead at best to a tenta- pected in the evolutionary progression to peat 4 at stations 8 and 9 indicate that tive chronology for the Deering Formation. D. torquatus and are sure to occur if, as Pelukian gravels and peat 4 are not syn- An alternate chronology for the Deering some workers believe, D. henseli and D. chronous. Unlike station 8, the sequence of Formation is also given in Figure 5. Dating torquatus are merely temporal variants of a sediments above peat 4 at station 9 consists of the Cape Deceit Formation is based on single species. There are additional facts of organic, peaty silts lacking the distinctive independent data, and so the conclusion

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Figure 6. Selected sedimentary features of paleoen- vironmenta) significance and location of certain pollen sample suites. Scale: divisions on ice axe handle = 10 cm. Length of bar in B = 60 cm. Lens cap diameter in F = 3 cm. A. Wedge-shaped dessication crack (?) typical of those within the frost crack zone of unit 1 (Deeding Formation). Note change in character of wedge within sediments of henseli zone and banded nature of host sediments (dark tones—10YR 6/8—are ferruginous zones; medium to light tones—2.5Y 5/2 to 5Y 5/2—are glcyed horizons). B. Ice-wedge pseudomorph. Cape Deceit Formation (unit 2) between stations 2 and 3 (Fig. 3). Note angular unconformity at contact of Cape Deceit and Inmachuk Formations. C. Location of pollen samples immediately above peat 4 at station 8 (Fig. 4). 69-67, organic peaty silts associated with peat 4; 56-69, small lens of peat within silty sands. Weakly developed congeliturbation structures visible in silty sands. 57-69, thin peaty horizon containing some small wood fragments; 58-69, small-scale cut-and-fill structure — organic silts; 55-69, inorganic ferruginous banded silts at base of part of unit 1 containing frost cracks. Samples 56—69 to 54—69 from henseli zone. All samples from Deering Formation. D. Contact of Inmachuk and Deer- ing Formations, between stations 2 and 3, showing truncated fold of peat 3. E. Location of pollen samples trom the upper part of unit 1 and lower part of unit 2 (Deer- ing Formation) at station 8. 102-68, peat 5; 100-68, 99—68 from peaty silts that merge laterally with peat 5. Note lenticular nature of peat 5 nodules and thin bands of sand and pebbles within the nodules, weathering horizon in upper part of unit 1 (samples 101-68 and 103—68), and weakly developed frost cracks in unit 1. F. Wedge-shaped gully filling from a locality near station 2 (Fig. 3). Note nearly horizontal bedding of sediments within wedge. Cape Deceit Formation occurs above In- machuk Formation as a result of folding, presumably due to solifluction.

concerning its age would not be changed should future research show that the age of the Deering Formation is as indicated in that alternate chronology.

PALEOENVIRONMENTAL DATA

Sedimentary Features Certain sediments and sedimentary struc- ice-wedge pseudomorphs are of different 1966); however, it is not possible to tell tures exposed at Cape Deceit have paleoen- origin and of less certain paleoenvironmen- from the form of the pseudomorph alone if vironmental significance. The following tal significance. the ice wedge developed during or after discussion concerns such features as well as deposition of unit 2 sediments. But other others of lesser or unknown significance. Ice-Wedge Pseudomorph evidence, such as sharply bounded silt clasts Wedge-Shaped Structures. Several types An ice-wedge pseudomorph occurs in which original bedding is rotated with of wedge-shaped sedimentary structures within the upper part of unit 2 of the Cape respect to bedding of host sediments, occur in the Cape Deceit exposure. One of Deceit Formation between stations 2 and 3 confirms presence of permafrost during unit these, an ice-wedge pseudomorph, has une- (Figs. 3, 6B). This single feature indicates 2 time. quivocal paleoenvironmental implications, that permafrost existed in the Deering re- After its formation, the ice wedge melted but other types that might be mistaken for gion when the ice wedge formed (Pewe, and was replaced by a sediment

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Samples collected primarily for insect fossils designated by 'numbers with letter prefix; pollen samples - numbers only

Larix\ etc.- identified wood samples

Stratigraphie and sedimentary symbols as in Fig. 3

"""""^»^fctSr— ¡-arix 3 Unit I Peat I Unit I

72-67 from upper part of thick, blocky, moss peat (Peat 6?) exposed high on the wall on upper portion of gully

•y« 103-69 Unit I

horizontal distance not to scale St. 6 (slightly shortened) in this area Peat 6 For position of: 105-68, 103-68, 102-68, 101-68, 100-68, 99-68,;98-68 see Fig. 6E

Peat 5

For position of: 69-67, 56-69, 57-69, 52-69, 58-69,54-69, 55-69 see Fig.6C - Peat 5 Deering Fm. 19-67 from estuarine detrital peat above Pelukian gravels exposed / 220 m toward Peering

Peat 4

70-67

Figure 7. Location of pollen and arthropod fossil samples discussed in this paper. Compare with Figures 3 and 4.

Unit 2 Fig.7 - St. 3

FELTED PEAT PEAT

PEAT

SANDY SILT

SANDY SILT UJ ORGAN. SILT UNIT I Q.

FELTED PEAT- within S-ll interval

SILTY, DETRITAL

Stratigraphie symbols of JC, (except for "indet. Pollen" category) 1 "INDET. POLLEN" as in Fig.3 4 = Named taxon present, but 1% or less Figure 8. Pollen diagrams. Solid horizontal lines separate groups of samples derived from a single stratigraphic unit. Dashed lines are used where a sample series crosses a stratigraphic boundary. The terms "Indet. Pollen" (indeterminate pollen) and "Undet. Pollen" (undetermined pollen) are used to indicate, respectively, pollen too degraded for identification and pollen well enough preserved for identification, but not identified. Vertical scales are used only where they apply to vertical series of closely spaced samples. See Figure 7 for vertical position of other samples.

MATTHEWS, FIGURES 8 AND 10 Geological Society of America Bulletin, v. 85, no. 9

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INORGAN. SILT

68-69 T + R 213 67-69 -207

66-69 -200

65-69 206 64-69- 210 Unit I 63-69- 204 Fig..7 - St. 62-69- -203

61-69 204

60-69 208

59-6S9! - 212 I [""' I I' 5 55-69- + + + + -189 INORGAN. SILT

o 54-69- OF SAMPLE S-L 42-68- ORGAN. SILT-«-!

58-69-1 + WOODY, DETRITAL M,11'* ' + PEAT (basal) 52-69-1 ORGAN. SILT & FLSHSE/I ZOHB 57-69-1 + f FELTED PEAT Fig.7 - St. 8, Fig. 6

-210 PEAT

+ + -206 Peat 4 -170 silts exposed below Peat 4 at Station 8, but not assigned to either Inmachuk Fm. or Peering Fm.

+ H |""l 1|""l |""l |""l 1 « » • 1 • I i "i I 1 I i"" i1 r UM.1 , |.l,,| '10 20 10 20 40 ' 10 20 10 20 10 20 10 20 40 ' 10 10 ' to' 10 I""' I""' 10 I 10 20 10 10 ' 10 Stratigraphie symbols \ % of E (except for "indet. pollen" category) of cE.+E. INDET POLLEN M as in Fig. 3 + = Named taxon present, but 1% or less Figure 9. Pollen diagrams. Solid horizontal lines separate groups of samples derived from a single stratigraphic unit. Dashed lines are used where a sample series crosses a stratigraphic boundary. The terms "Indet. Pollen" (indeterminate pollen) and "Undet. Pollen" (undetermined pollen) are used to indicate, respectively, pollen too degraded for identification and pollen well enough preserved for identification, but not identified. Vertical scales are used only where they apply to vertical series of closely spaced samples. See Figure 7 for vertical position of other samples.

t— % of E, (except for "indet. pollen" category) I j stratigraphie- symbols I as in Fig. 3 + = Named taxon present, but 1% or less

Figure 10. Pollen diagrams. Solid horizontal lines separate groups of samples derived from a single stratigraphic unit. Dashed lines are used where a sample series crosses a stratigraphic boundary. The terms "Indet. Pollen" (indeterminate pollen) and "Undet. Pollen" (undetermined pollen) are used to indicate, respectively, pollen too degraded for identification and pollen well enough preserved for identification, but not identified. Vertical scales are used only where they apply to vertical series of closely spaced samples. See Figure 7 for vertical position of other samples.

MATTHEWS, FIGURES 9 AND 10 Geological Society of America Bulletin, v. 85, no. 9

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pseudomorph. The local phenomenon of (Washburn, 196S). Humic materials in the of the Inmachuk Formation, for example, thaw lake formation can :ause such melt- surface depressions associated with the Fig. 4, near station 5) possess folds implying, but if this were the case for the unit 2 Greenland features may be analogous to the ing opposite sense of motion, an unlikely pseudomorph, its sediments and those cap- gleyed zone within some of the Cape Deceit situation if they are due to solifluction ping it should have a lacustrine character. wedges (Siuta and Motowicka-Terelak, alone. Such paired folds resemble folds as- They do not; hence, formation of the 1969). A pulse of sedimentation has appar- sociated with peat rings or similar non- pseudomorph, the erosion that followed ently terminated tie formation of the sorted polygonal features (Hopkins and Cape Deceit sedimentation, and slumping Greenland cracks (Washburn, 1969), and Sigafoos, 1950). However, those features of unit 2 sediments (note the steeply dip- similar conditions could account for the ab- formed by lateral thrusting and frost churn- ping peat 2 near station 5) probably all oc- rupt upper limit of the Cape Deceit fea- ing, a dynamic milieu that would have ob- curred during an interval of regional cli- tures. Rapid loess deposition at Cape Deceit literated the overturned frost cracks and matic warming. Because ice wedges are would have precluded repeated cracking at other primary features observed in associa- presently forming in the Deering area, cli- the same locus—the chief factor responsi- tion with the Inmachuk paired folds. mate then would have been warmer than at ble for the well-defined character of the All that can be concluded is that some of present, possibly like that of contemporary frost crack zone. Significantly a few small ihe folds within the Cape Deceit exposure interior Alaska. cracks do exist above the upper limit of the obviously result from solifluction, although frost crack zone, but they are not obvious others were created by some as yet unde- Frost Cracks because they do not coincide with the origi- termined form of congeliturbation. A cold An important marker horizon in the nal syngenetic cracks. climate and moist substrate, but not neces- Deering Formation is a zone of small sarily permafrost, is indicated. wedge-shaped features, provisionally Loess Gullies Kittik. Kittik is an Eskimo term applied termed frost cracks in a previous report Larger wedge-shaped structures, also to the pale yellow, silt- to sand-size calcare- (Guthrie and Matthews, 1971). For pur- superficially simi ar to ice-wedge ous weathering residuum occurring at the poses of continuity, I use that term here pseudomorphs, occur in the frost crack base of the exposure near station 1 (Fig. 3) even though reassessment of the features zone of unit 1 (Fig. 6F). Host sediments are (Guthrie and Matthews, 1971). Close ex- suggests that they may be desiccation not slumped at the contact with the wedge, amination of kittik sediments reveals that cracks instead. and sediments filling the wedge are horizon- they result from mechanical weathering of Where best developed, the frost crack tally bedded, thus ruling out the possibility the metalimestone bedrock, and thus prob- zone consists of narrow wedges, 30 to 40 that these structures are ice-wedge ably originated during a period of perigla- cm apart, originating rather abruptly at a pseudomorphs. Instead they resemble ci al climate. The lateral extent of the kittik particular level within unit 1 (Deering For- loess-filled gullies observed at exposures in unit is unknown, but it may dip below the mation) and penetrating to a depth of 40 to Poland (Dylik, 1966). present beach level well before station 2 80 cm (Fig. 6A). Ferruginous bands border- Solifluction Features. Solifluction, a (Fig. 3). If so, it is one of the oldest Quater- ing the wedges are sharply downturned at special type of congeliturbation involving nary units of Cape Deceit, predating even some levels and have a sharp contact with downslope movement of soil and vegeta- the lowest exposed levels of Cape Deceit the gleyed wedge filling. Cracks taper to a tion, has played a significant part in deposi- Formation unit 1 (Table 6). narrow ferruginous-bordered seam in the tion of the basal unit of the Cape Deceit ex- Pollen lower part of unit 1 where inorganic loess posure (Guthrie anc. Matthews, 1971). Pollen Diagrams. Compilations of pol- gives way abruptly to the more organic silts Folded sediments, especially peats, at the len data are presented as pollen diagrams of the henseli zone (Figs. 4, 5, and Guthrie other parts of the exposure may be evidence (Figs. 8, 9, 10). Stratigraphic position of the and Matthews, 1971). Thicknesses of the of other periods of solifluction activity. For samples referred to in the diagrams is given wedge fillings vary, but many are narrower example, folds of peat 2 near station 2 (Fig. OIL the diagrams and in Figure 7, which is a at the top of the frost crack zone, suggesting 3) are similar to the buried organic zones simplified version of Figures 3 and 4. syngenetic development (Dylik, 1966; J. seen in cross sections of contemporary Several departures have been made from Dylik, 1969, written commun.). In plan solifluction lobes (Hanson, 1950; Benedict, standard methods of presenting pollen view, the frost cracks form poorly defined 1970). Some folds of peat 2 are conforma- data. Some stratigraphic units were sam- circular to polygonal nets. The small size of ble with deformational structures in the pled more than once at different parts of the these nets and close spacing cf the cracks in upper part of the overlying Inmachuk For- exposure to test the lateral continuity of the section show that they are not ice-wedge mation; therefore, most, if not all, of the pollen spectra and provide additional in- pseudomorphs (Lachenbruch, 1962, 1966; congeliturbation of the peat and associated formation on the former regional pollen Washburn, 1969). Thus, if permafrost ex- sediments occurred after deposition of the rain. Bar diagrams are used instead of the isted at Cape Deceit during deposition of Cape Deceit Formation (possibly even after traditional interpolated histograms where unit 1, the frost cracks would have formed deposition of the Inmachuk Formation). (1) samples were not part of a vertical se- in the active zone. Some puzzling structures are found in the quence, (2) the vertical sample interval was The frost cracks bear a superficial re- upper part of the Inmachuk Formation. too great to justify interpolation, or (3) dif- semblance to small-scale wedge-shaped fea- Truncated folds of peaty sediments (peat 3 ferences between adjacent spectra are obvi- tures illustrated by other authors (Paepe —Fig. 6D) occur at the contact of the In- ously related to the type of sediment sam- and Pissart, 1969; Paepe and Vanhoorne, machuk and Deering Formations. These are pled. Local pollen zones have not been des- 1967) or those observed beneath Dryas analogous to non-truncated structures ob- ignated because grouping the pollen sam- fellfield and Eriophorum tussock com- served near the boundary between unit 1 ples by stratigraphic units serves just as munities in Alaska. But they are most like and unit 2 at the station 8 exposure (Fig. 4). adequately for organizing the data. Pollen the small-scale desiccation cracks observed In neither case is solifluction likely to be the sequences within stratigraphic units are in areas of scanty vegetation and rapid silt sole cause because both sets of features neither long enough nor are the variations deposition in northeastern Greenland (especially some of those in the upper part consistent enough to warrant zonation.

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Ecologic and Taxonomic Notes. soil conditions were widespread during the chamaemorus pollen in surface sample Pleistocene, they could be responsible for 97-69 (Fig. 10) from a site where that 1. Diporate Gramineae pollen: Grass pol- the high Artemisia percentages of many fos- species is dominant (Table 1). Apomixis is len is ordinarily monoporate; however, sil samples. common in northern populations of R. certain polyploid grasses and cereal hybrids Surface Samples. Figures 1, 2, and 10 chamaemorus (Salisbury, 1942). (for example, Triticale = Triticum X and Table 1 include information on five Interpretive Criteria. The most funda- Secale) have diporate, multiporate, or in- surface pollen samples from the Deering re- mental level of paleoenvironmental resolu- apertuate pollen (Erdtman, 1969; Erdtman gion. Together with other samples from the tion one could hope to obtain from the and others, 1963). Pollen sample 56-69 Imuruk region (Colinvaux, 1964; Col- Cape Deceit pollen samples is ability to dis- (Deering Formation) includes an abun- baugh, 1968), they provide some insight for tinguish samples representing forest from dance of diporate grass pollen, indicating interpretation of the Cape Deceit fossil pol- those representing tundra. For this, Picea that polyploid or hybrid grasses occurred at len spectra. percentages are critical because at present the site during its deposition. First, Deering and Imuruk surface sam- (as well as during most of the Pleistocene), 2. Thalictrum: Two species of Thal- ples show that the regional pollen rain in spruces mark the regional and altitudinal ictrum occur in interior and western shrub tundra areas of Seward Peninsula is tree line. Unfortunately, the vagility of Alaska, but only T. alpinum is found on the characterized by relatively high percentages spruce pollen makes it difficult to derive a tundra (Hultén, 1968). Even though pollen of Betula, Alnus, and sedge (sometimes foolproof rule that shows what percentage of the two species cannot be distinguished, grass), and low percentages of Picea and of spruce pollen is indicative of spruce macrofossils of T. alpinum (Fig. 12E) imply Artemisia. forest. In most cases, however, Alaskan that Thalictrum pollen from Cape Deceit Second, the Deering surface samples in samples with at least 15 percent spruce and Formation samples represent alpinum. particular show most clearly the degree to comparable amounts (or more) of Betula 3. Moss spores: The fact that Sphagnum which components of local plant com- and Alnus indicate presence of spruce trees alone is listed in the pollen diagrams does munities may dominate pollen spectra (that in the local environment (Rampton, 1971; not mean that other mosses are absent. is, local overrepresentation). Note, for ex- Matthews, 1970). Very low percentages of Many small moss spores undoubtedly go ample, the high percentage of Ericales pol- Picea, when not due to overrepresentation unnoticed or are not preserved. len in sample 105—69 from an area where of another pollen type, usually indicate 4. Artemisia: Percentages oí Artemisia in the ericads Empetrum nigrum and tundra conditions. most tundra spectra from Cape Deceit are Vaccinium uliginosum are abundant (Table A secondary level of resolution to be higher than in surface samples representing 1). Many of the fossil samples discussed hoped for is recognition of different types contemporary tundra in Alaska and the below are from sediments similar to those of former tundra environments. In previous northern Northwest Territories (Colin- sampled for the surface spectra and there- Alaskan studies (Colinvaux, 1967; Col- vaux, 1964; Matthews, 1970; Rampton, fore might also be expected to show similar baugh, 1968), pollen evidence alone has 1971; Ritchie, 1972); however, amounts of degrees of local overrepresentation. been used to distinguish between shrub Artemisia comparable to those in some Third, certain of the surface spectra illus- tundra that is dominated by dwarf birches samples from the upper part of the Deering trate a source of error — differential pollen with some alders; shrub tundra that in- Formation do occur in surface samples production at the intraspecific level — that cludes dwarf birches, but no alders; and from the northern Great Plains of the is not often mentioned in discussions of herbaceous tundra that lacks dwarf birches United States (McAndrews and Wright, error in pollen analysis. The spruce percen- and alders. Such distinctions are most valid 1969). In Alaska the character of sites tage is relatively high in surface sample when based on lacustrine rather than collu- where Artemisia now occurs (Hanson, 97—69, despite the fact that all of the spruce vial pollen samples because the former are 1951) suggests that it is favored by at least pollen is allochthonous (Table 1). No doubt more apt to represent regional pollen rain two interrelated factors: deep seasonal its abundance is related to the fact that —hence, regional vegetation. However, in thawing and good drainage. Such condi- spruces in present-day western Alaska are most colluvial pollen samples, high percen- tions are not often found in contemporary expanding their range (Hopkins, 1972). tages of an anemophilous pollen type, such tundra areas, no doubt explaining the pres- Under such conditions sexual reproduction, as Betula or Alnus, can be assumed to indi- ent rarity of Artemisia there. involving abundant pollen production, is cate the former presence of the plant in the Continentality of climate has been shown dominant. But would this also be the situa- region, if not at the sample site itself. Low (Yurtsev, 1972) to be the chief limiting fac- tion if spruce tree line, located as at present, percentages, barring statistical bias, most tor in the northern distribution of steppe was receding as a result of cooling climate? often indicate that the plant was regionally plant communities in Eurasia. The climate Recent studies on the effect of cold on con- rare. Ample reason for the qualifying words of unglaciated Alaska was undoubtedly ifer reproduction (Eiche, 1966; Eriksson, "most often" in this last statement is evi- more continental than at present during 1968; Dogra, 1967; Andersson, 1947) in- dent in surface sample 105—69 (Table 1): times when the Bering Land Bridge was ex- dicate a negative answer for this question. although the sample site was within 30 m of posed, and the relatively warm, dry sum- Cold stress causes meiotic disturbances of the nearest Alnus crispa bush, the alder pol- mers that probably characterized such a the pollen mother cell and an increased in- len percentage is lower than in Imuruk Lake climate would have promoted wider dis- cidence of apomixis and self pollination, surface samples from sites more than 10 km tribution in Alaska of xerophytes such as which tend to either reduce pollen produc- from the nearest alders (Colinvaux, 1964). Artemisia. Other more local conditions tion or dispersal. It is possible to envision a (loess deposition or colluvial and alluvial situation in which the few surviving Plant Macrofossils deposition) might also have created a suita- apomictic spruce in a region produce so lit- Identified plant macrofossils are listed in ble habitat for Artemisia by inhibiting de- tle pollen that they go unrepresented in pol- Figure 12. Large numbers of fossils came velopment of extensive moss and len spectra, and a similar condition, in- from the bulk samples (S—6, S—1, and so Eriophorum turf, thus favoring deep sea- volving a different plant, is seemingly illus- forth; Fig. 7, Table 4) collected for fossil in- sonal thawing and good drainage. If such trated by the low percentage of Rubus sects. Some of the samples used for pollen

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+ + + ? + 1 ? + -H- + + * + + + + + + + Unit 2 5? 4? 4 9 3 59 6 53 3 6 2 e P 10 6 2 6 4 4 67 1 44 i 4 # 14 131 1 10 2 60-69 + s-l 1? 10 ' 6 42 120 2 + + • 38-69 + + + 57-69 + P-4 P P p P P + 114-68 + ? + + + + ? + Peat 4 70-67 •H- + 125-68 + + 94-68 Peat 3 s-l 2 4 3 ' 7 ?75 ? 89-69 *+ + 88-69 + + + + 87-69 + + 86-69 + 112-68 + 85-69 + + + + 56-67 + + + + + 55-67 + + + Cf + # + 54-67 + + 52-67 -H-+ + + + + + + 51-67 + + + + + 26-67 + + + + + + + 27-67 + '•ft + + + ? 28-67 * + 30-67 + ? + + + + + 31- 67 + + + + + + + 32-67 + + + 33-67 •ft ? + + + + + + 34-67 ? S 13-67 P P? 1 P 3 5? P 4 2 14 2 3 1 cf 361 P 2 S-2 74 4 2 I ? 103-69 + ? + + 18 102-69 95 4 125 85 4 41 159 1 1 16 13 12 • 3 1? P 2 3 4 3 ? + + + 101-69 •H- + + 16-68 + 119-68 + + + + 11-68 * + 15-68 + + + S-l I I P 1? 1 36 2 S P P P P 2 233 10 2 + = Taxon present

Fossils of named taxon abundant 6, i, ie, 233 ,etc. = Number of fossils in randomly selected sample Cf = "Near to" named taxon p = Present, but not in randomly selected samples Figure 1 i. Plant macrofossils from Quaternary sediments of Cape Deceit. See Figure 7 for stratigraphie provenience of samples. ? = identification questioned. Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/85/9/1353/3428867/i0016-7606-85-9-1353.pdf by guest on 26 September 2021 QUATERNARY ENVIRONMENTS, CAPE DECEIT, ALASKA 1363

analysis also contained identifiable and en- crements in one fragment of an overturned Formation, Fig. 11), but only a few of these vironmentally significant macrofossils. All stump (15+ cm in diameter) had radial di- possess remains of the taxonomically diag- fossils listed in Figure 11 are grouped ac- mensions as low as 80 microns, showing nostic lemmas and palaes. Nevertheless, the cording to the sample number designations that the trees were growing in a marginal similarity of the naked caryopses to those given in Figure 7. tree-line environment. few still bearing lemmas and palaes sug- Ecologic and Taxonomic Notes. 2. Picea: Fossils of both white spruce (P. gests that all represent the same genus— 1. Larix: Abundant seeds, cones, and glauca) and black spruce (P. mariana) occur Poa. A specific determination of the better leaves of Larix (Fig. 12) occur in associa- in peat 4 samples (Fig. 12). A single Picea(}) preserved fossils was not possible; however, tion with or immediately above peat 1 of leaf occurs in the S-l assemblage (Deering size of the lemmas and other features show the Cape Deceit Formation. Larix wood Formation, unit 1), and a well-preserved that they do not represent Poa alpigena or also occurs in peat 1, as well as at the Cape white spruce leaf was found in association P. lanata, two common species of wet or Deceit-Inmachuk contact. The best pre- with sediments of the S-l 3-67 assemblage near aquatic sites (Hulten, 1968; Young, served Larix cones and seeds are very simi- (Cape Deceit Formation); yet both assem- 1971; Wiggins and Thomas, 1962). In- lar to those of Larix laricina (=L. blages are dominated by fossils of tundra stead, the Poa fossils are probably from one alaskensis Wight.); however, the possibility plants and animals. The spruce leaf from or more of the many species occurring now that they represent the extinct Eurasian S—1 may have been rebedded from underly- on mesic to xeric sites. species L. minuta (Vassk.) cannot be ruled ing peat 4 or incorporated in the assem- Most species of Poa are palatable and out.1 They probably do not represent Larix blage during sampling; excellent preserva- nutritious, having high forage value for dahurica Turcz., a species commonly oc- tion of the S—13-67 specimen strongly sug- grazing ungulates (Hitchcock, 1950). With curring at tree line over large areas of gests that it is a recent contaminant. this in mind, note Guthrie's (1968a) con- northeastern Asia (Komarov, 1934). The 3. Potamogeton spp.: Fruits of Po- clusion concerning the predominance of Larix wood samples from sediments as- tamogeton are abundant in a few sam- grazing ungulates in the Alaskan late Pleis- sociated with peat 1 show evidence of re- ples. I have limited confidence in some of tocene mammalian fauna. markably slow tree growth. Annual ring in- the specific determinations because of the 6. Carex maritima: Although this great amount of intraspecific variation in 1 species often occurs in association with Several Soviet workers (A. P. Vasskovskiy, D. I. some species. Several of the species are Dorofeev, I. Y. Kropachinsky, and N. V. Dylis) have ex- sandy or gravelly sea coastal sites (Porsild, amined the Larix cone illustrated in Fig. 12C. Most known to hybridize, which makes specific 1966; Hulten, 1968), inland localities are agreed that the fossil cones were not from L. dahurica identifications for fossil Potamogeton fruits also known. Porsild (1966) lists C. Turcz. Vasskovskiy referred it to L. minuta (Vassk.) more difficult. Pondweeds grow partly or maritima ssp. yukonensis as occurring at Dorofeev. Kropachinskiy suggested a possible relation with L. olgensis or to the Altai-Tuva race of L. sibirtca completely submerged and rooted to the "calcareous silty places in and around a Ldb. N. V. Dylis, a specialist on the genus Larix, while bottom. P. perfoliatus usually occurs in spruce bog" in the Yukon Territory. hesitant to provide a specific determination on the basis deeper water than other species listed in 7. Potentilla: Potentilla achenes are ex- of cone structures, did indicate a possible relation of the Figure 11. P. filiformis, P. pectinatus, and fossil with the species L. olgensis and L. dahurica or to tremely abundant in some samples (Fig. one of the hybrids of L. olgensis with L. maritima, L. P. vaginatus are often found in brackish or 11). Although not assigned to species, they dahurica, or L. koreana (Nakaya). However, his final hard water or in areas with calcareous bed do not represent P. palustris (=Comarium observation was that the fossils probably come from the rock (Berglund and Digerfeldt, 1970; Wig- palustris), a bog plant. Most remaining species L. alaskensis Wight. (= L. laricina), as I have suggested. gins and Thomas, 1962). Alaskan Potentilla species occur on sandy, L. minuta is an extinct species. Its fossils occur in rich 4. Hierochloe: Sample S-6 (Deering gravelly soil where vegetation is scattered coniferous assemblages of Miocene and Pliocene age in Formation) contains two florets (with and grassy (Hulten, 1968). Fossil achenes Eurasia (Yu. P. Baranova and S. F. Biske, 1973, oral caryopses) of Hierochloe. They are from assemblage S-6 (Deering Formation) commun. to D. M. Hopkins) and A. V. Sher (1973, differ consistently from those in samples commun. to D. M. Hopkins) believes that it is rep- definitely not H. alpina and are instead resented in the flora of the early Pleistocene Krestovs- closest to the other Alaskan species, H. S-l 3-67 and S-ll (Cape Deceit Forma- kaya Suite, which occupies a position below Olyor sed- pauciflora, which now grows on tundra tion). iments at some exposures on the Chukochya River, near margins of fresh-water pools (Hulten, 8. Hippuris: Fruits representing this eastern U.S.S.R. (Sher, 1971). Not all the Soviet workers consulted believe that L. minuta is specifically dis- 1968). aquatic plant are abundant in assemblage tinct from L. alaskensis ( = L. laricina) (D. M. Hop- 5. Poa: Caryopses of grasses are rela- S—6 (Fig. 11). No specific determination is kins, 1973, written commun.). tively abundant in assemblage S-6 (Deering provided; however, recent work on heterophylly in Hippuris (McCully and TABLE 1. SURFACE POLLEN SAMPLES* Dale, 1961) suggests that the genus may be

Sample Sample type Local plant community Comments represented in North America by only a

74-67 Bottom mud at margin Sedge dominated pond margin. Pond in an Sedge pollen probably over-represented single species, H. vulgaris. of a small pond area with "Cloud berry, dwarf shrub, marsh" type cormiunity (Hanson, 1953) Tundra Zonation and Plant Macrofos- sils. Well-known regional differences in 73-67 Dry, turf plug Dominant plants: Ledwn, Arotostaphylos Ericales and grass pollen probably over- alpina. represented. Artemisia growing within taxonomic diversity of the contemporary Plants present: Betula nana, Salix 100 m of sample site arctica, Carex Spp., Vaoainium vitis- Holarctic tundra flora permit definition of idea, Empetrum nigrum, Petasites Sp. , grasses modern tundra zones. It might be possible to apply such a zonation scheme to an 75-67 Bottom mud of a Carex Sedges predominate. Sides of gully are Shrub birches are abundant at head of marsh in a coastal grassy gully. Artemisia1 Solidago, and other analysis of the tundra plant macrofossil as- gully compositae are abundant on vegetated parts of near-by coastal bluffs semblages from Cape Deceit.

105-69 Soil plug Alder-willow-heath sere of a floodplain Ericales pollen probably over-repre- In contrast with objectively defined succession (Bliss and Cantlon, 1957). sented Alnus pollen under represented Dominant plants: Empetrum nigrum, Vac- physiognomic boundaries such as northern cinium ulginoBum, Betula nana, willcue, and Alnus crispa tree line, boundaries for tundra zones are both more subjective and based almost en- 97-69 Soil plug Cloudberry-dwarf shrub-marsh community Spruce pollen allochthonous. Rubus (Hanson, 1953). Empetrun nigrum and chamaemoma pollen under-represented tirely on floristic rather than vegetational Rubus ohamaemoruB — co-dominants distinctions. Different floristic criteria may be used for definition of such zones. See Figure 1 for location of sample sites.

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Palynologists working in Alaska have estab- large volume silt samples. Quantitative Table 3 also includes information on the lished tundra zones on the basis of the dis- documentation is provided for some of the distribution and habitat requirements of tribution of alders and dwarf birches (Col- assemblages by tabulating (as in Matthews, certain taxa. Sources for this information invaux, 1967). This is the pragmatic ap- 1968) the minimum number of individual are published notes (chiefly by C. H. Lin- proach because birch and alder pollen are insects represented by the fossils. The total droth, 1966, 1968), locality information on produced in abundance, distributed by number of insects represented by each as- museum specimens that I have examined, wind, and easily identified in pollen sam- semblage and the amount of sediment proc- and my own and others' collecting notes. ples. essed is given in Table 4. It shows that cau- See Table 3 for ecological information on A more refined zonation scheme has been tion must be used in interpretation of in- taxa listed in Figure 13. Stratigraphie posi- proposed by Young (1971). It takes into ac- terassemblage diffe-ences of quantitative tion of all samples listed in Table 3 and Fig- count many more taxa than are used in the abundance or taxonomic diversity (Table ure 13 is given in Figure 7. palynological system as well as floristic dif- 3), because variable sample size is no doubt ferences in regions beyond the limit of both partly responsible fcr such distinctions. For alders and birches. Young uses four zones example, note in Tables 3 and 4 the differ- Ecologie and Taxonomic Notes to characterize regional differences of ence in taxonomic diversity and sample size 1. Homoptera: Fossils of leafhoppers tundra floristic diversity. Zone 1 includes (revealed by the number of individual in- (Cicadellidae) are relatively abundant in areas with the most depauperate flora (high sects) of S—12 (Inmachuk Formation) and some of the assemblages. Most species feed arctic). Zone 4, including all lowland S—6 (Deering Formation). on grasses. Athysanella is chiefly associated tundra areas of Alaska, except the northernmost coast and St. Lawrence Island, represents low arctic (hypoarctic) tundra adjacent to the boreal forest. Boundaries of the four tundra zones are correlated with a parameter representing summer warmth. Young's zonation system has predictive value; that is, the climate and flora of a region can be predicted when only a few of the resident plant species are known. It would be fortunate if fossil plant assemblages, which also represent a very small portion of the former flora, could be used in a like fashion to assess the paleofloristics and paleoclimate of a' region. To even attempt this, however, would require specifically identified fossils, thus limiting application of Young's data to situations where plant macrofossils are available. Table 2 lists plant species included in Srtim Figure 11 and the tundra zone in which they presently find their northern limit. c Note the dominance of low Arctic (Zone 4) species. But because many of those listed are aquatic species, which sometimes are distributed independently of summer warmth (Young, 1971), I hesitate to draw firm paleoclimatic conclusions. It does seem clear, though, that those units at Cape De- ceit that contain identified plant macrofossils were deposited in an environment as floristically diverse and warm as the low to middle arctic tundra of Zones 3 and 4. This does not imply vegetational similarity, and in fact, pollen data show that the importance in former tundra communities of plants such as grasses and Artemisia was greatly different from the present.

Invertebrate Fossils Table 3 and Figure 13 list fossil Arthrop- SCALE BARS (except as indicated) = 1.0 mm oda and Mollusca collected at Cape Deceit. Figure 12. Photos of selected plant macrofossils. A. Female cone, Picea glauca (Moench), peat 4 (Deering Fossils of Coleoptera (beetles) dominate. Formation, Fig. 4, station 9). B. Winged seed, Picea glauca, peat 4 (Deering Formation, Fig. 4, station 9). Derived Figure 13 includes fossils from the residues from a cone of the same sire as cone in A. C. Female com:, Larix laricma (Du Roi), peat 1 (Cape Deceit Formation, of pollen samples. Table 3, on the other Fig. 3, station 6). D. Winged seed, Larix laricma, peat 1 (Cape Deceit Formation, Fig. 3, station 6). E. Achene, Thalictrum alpinum L., residue of pollen sample 52-67 (Cape Deceit Formation, unit 2). F. Achene, Ranunculus hand, lists assemblages of fossils picked trichophyllus Chaix., sample S-6 (Deering Formation, unit 2). G. Seed, Androsace septentrionalis L., sample S-6 from the sieved residue of peat samples and (Deering Formation, unit 2).

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with the "short grasses" (Ball and Beam- tawa). P. nearcticus is presently known belong) and the fact that I have seen only ers, 1940). The genus is not known from only from the islands of the Anderson River one male specimen of biocryus (new record; Alaska today, and except for a few records Delta (northern Northwest Territories). A Alpine interior Alaska; det., G. E. Ball). from relict grassland areas in the Northwest glacial refugium has been postulated for The fossil of P. (Cryobius) nivalis from Territories and northern British Columbia, that area because, in addition to P. nearc- peat 1 is a well-preserved partly articulated it is found only in extensive grassland re- ticus, the species Pterosticbus stantonensis specimen (lacking genitalia). Another partly gions such as the western Canadian prairies Ball and morphologically distinct popula- articulated fossil, P. cf. nivalis (Table 3), (Beirne, 1956; K.G.A. Hamilton, 1970, tions of other species occur only there (Ball, possesses male genitalia slightly different written commun.). Hardya youngi has been 1966). But since P. nearcticus occurred in from those in typical nivalis; however, the collected at Barrow, Alaska (Fig. 1). The western Alaska during the Late Wisconsin, difference may be only a preservation ar- leafhopper genera Sorhoanus, Verdanus, its present restriction to the Anderson River tifact. P. (Cryobius) auriga and P. and Psammotettis, individuals of which are Delta can hardly be an indication of (Cryobius) kotzebuei also occur in the Cape common in contemporary tundra areas of refugial endemism. Deceit Formation, but the distinctive male Alaska, including the Deering area (Hamil- In the Anderson River area, P. nearcticus genitalia of the former species are present ton, 1970, written commun.), are not rep- is found on "sandy soil with open grassy only in sediments of the overlying In- resented in any of the fossil assemblages. vegetation" (Lindroth, 1966). Perhaps the machuk Formation (Table 3, S-12). Like Athysanella, the fulgorid genus prevalence of grassland conditions in late Two male median genital lobes of P. Apkelonema is characteristic of prairie Pleistocene Alaska (Guthrie, 1968a; (Cryobius) similis from the S—13—67 as- areas, but a few specimens have been taken Matthews, 1974c) explains the former semblage (Cape Deceit Fm.) are in northern relict grasslands—not in more cosmopolitan distribution of this confirmation that similis had evolved by Alaska, however (Hamilton, 1970, written species. Other species of the subgenus late early Pleistocene time. Both these fos- commun.). Neither is the psyllid Trioza Derus, to which P. nearcticus belongs, sils match anomalous similis genitalia that quadripunctata Crawford a member of the occur in Siberia. In view of the Late Wiscon- Ball (1966) and I have noted in a few con- contemporary Alaskan fauna. It occurs on sin record of P. nearcticus at Deering, it is temporary specimens. Ball has suggested species of Urtica (Tuthill, 1943), but none not surprising that the species apparently the possibility that the contemporary of the three species of Urtica that now grow also occurred in eastern Siberia during the anomalous specimens are similis X in Alaska has been recorded from lowland Pleistocene (Matthews, 1974a). tareumiut hybrids. This is improbable in tundra areas (Hulten, 1968). 3. Subgenus Cryobius: Fossils of ground the light of S—13—67 fossils, because it is 2. Fterostichus nearcticus Lth. (Fig. beetles of the subgenus Cryobius (genus unlikely that hybridization of two sympatric 14C): The single pronotum referred to this Pterosticbus) are usually abundant in Alas- species would take place over such a long species was compared with the holotype in kan fossil insect assemblages, especially period (400,000+ yr) without occurrence the Canadian National Collection (Ot- those representing treeless environments of either genetic swamping (through intro- (Matthews, 1968, and unpub. data). Some gression) of one parental stock by the other species within the subgenus can be or divergent selection leading to complete TABLE 2. NORTHERNMOST TUNDRA ZONE* IN WHICH SELECTED identified reliably only by reference to the interspecific genetic incompatibility (but CAPE DECEIT FOSSIL PLANT SPECIES ARE FOUND male genitalia, which makes identification note the discussion of H. aquaticus in Fossil Aquatic of fossils especially difficult. But most of the Angus, 1973). The aberrant similis males in assemblage commonly encountered species—P. contemporary populations might mean that Potamogeton alpinus S-2, S-l1 § (Cryobius) nivalis, P. (Cryobius) brevicor- similis is dimorphic in certain genital P. gramneus S 13-67 § S-6 nis, P. (Cryobius) ventricosus, P. (Cryo- characters, as is apparently the case for P. praelengua A" S-5 another carabid, Harpalus amputatus (G. P. foliosus6 4* bius) similis, P. (Cryobius) parasimilis, P. 4 S-6 E. Ball, 1971, oral commun.). Or alterna- P. filiforntis + (Cryobius) kotzebuei, and P. (Cryobius) P. vaginatus 4 S-6, S-l 1 tively, they may indicate that similis, as cur- + tareumiut—can usually be distinguished on Zanichellia palustris 4 S-l 2 rently defined, includes two species. 2 S-6 the basis of pronotal characters alone. Hierochloe pauci flora f Triohophorm caespitosum 4 S-6 The latest phase of Cryobius speciation Hand collecting and pitfall trapping of Eleocharis uniglumis- + almost certainly antedates the Wisconsin insects were carried out at Deering with the palustris^^ 4 S-6 ## 4-3f' (Ball, 1969; Matthews, 1968), making hope of gaining more detailed information Betula glandulosa-nana S-6, S-ll Alnus sp." 4 pollen diag. Cryobius fossils of middle and early Pleis- on habitat requirements of Cryobius 5< 4 pollen diag. Polygonum sect, persicaria ' tocene age potentially valuable for species. The following species occur there: 3 S-6, 58-69 Ranunculus triahophyllus S-6, S 13-67, documentation of evolution in the group. P. brevicornis, P. tereumiut, P. parasimilis, R. saeleratus S-ll Both the Cape Deceit and Inmachuk For- P. similis, P. kotzebuei, P. pinguedineus, P. Thalictrum aVpinum 52-67, 27-67 mations contain such fossils. ventricosus, and P. mandibularoides. P. Lepidivm densiflorum S-6 Five species of Cryobius (tareumiut, nivalis, though not collected by me, proba- kndvosacB aeptentrionalis S-6, 55-67, 31-67, 33-67, similis, pingedineus, ventricosus, and bly occurs in the Deering region, and P. Arabie lyrata S 13-67 mandibularoides) are represented in Cape byrantoides, heretofore known only from 81 -69 Deceit Formation assemblages by fossils in- the Alaska-Yukon border (Ball, 1966), is Myriophyllwi spicatwi S-6 Enpetrum nigrum S-5, S-l, cluding the diagnostic male genitalia (Table now also known from Kotzebue (Fig. 2). Menyanthes trifoliata 54-67, S-2 3). P. brevicornis specimens were common S-6S ,13-67 s-i,s-i;, S-ll, Identifications of P. (Cryobius) only at disturbed sites near the village of tiliaceoradix and P. (Cryobius) biocryus Deering. P. soperi was rare at Deering and, * After Young, 1971. t Northern limit determined using Hulten (1968). (Table 3) are also based on presence of male like P. brevicornis, was not collected at un- § Specific determination questioned in Figure 12. * Hardly or not a tundra plant at present in Alaska genitalia, but they are nevertheless con- disturbed tundra sites. I have collected (Hulten, 1968). ** Emergent aquatic. sidered tentative because of the uncertain soperi in alpine interior Alaska where vege- tt Depending on which species is represented. tation cover is thin and sparse; this possibly §§ Represented by pollen only. status of some species within the planus tilt Either or both named species represented. group (to which tiliaceoradix and biocryus is its preferred habitat. All remaining

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Ecol ,* S-n D-1 Peat 1 510-67 SI 3-67 S-14 S-12 Pest 4 S-l S-7 Peat 5 S-5 S-6

INSECTA

Hetero ptera Corixidae Callioorixa sp. a 2? .. 1 + Lygaeidae, Genu:? sp. Saldldae Chiloxantkus stellabus Abl-2 1 (Curtis) Calaoanthia sp. 1? Teloleuoa sp. 7? w* Salda littovalis (L.) Bel-2 :: Homoptera Cicadellidae Athysanella spp. 0 .. 22 Deltoaephalus cf balli D? 3 Van Duzee Hardy a youngi Beime D? 58? 149 Deltoaephalus sp. 4 21 Genus? sp. Caliscelidae Aphelonema sp. 1 Psyllidae Trioza quadripunatata 2 Crawford Trioza sp. 1 Coleoptera Carabidae Carabus trim oa ^i co I i-i. b Ac3 2 1 4 Eschz. Pelophila borealie Payk. Bb2 Notiaphi lus seriistriatus 'B'd2 i ? Say N. borealis Harris Bd2 2? .. Notiophilus sp.. 1 Diadheila polita Fald. "B"c3 1 2 Elaphrus lapponicus 'B'b2 g+a Gyll. Elaphrus sp. Dysahirius frigidus 'B'c2 Mann. D. nigricomia Motsch. Bc2 Dyschirv&s sp. Patrobus sp. BenbidLon (Plataphodee) sp. B. (Peryphdhee) sp. B. umiatenee Lth. Bembidion sp. PterosHahus mxwctiauB Adl 1 Lth. P.(Cryobius) saperi Ad2 .. g25 Ball P. (Cryobiue) kotzebuei A 1? 1 Ball 5 P.(Cryobius) tareumiut Ac3 g+a + 1 .. 7 .. Ball

P.(Cryobius) hudeonious 'B'c2 • • +a Lec. P. (Cryobius) simi lis |jc2 + + 8 g++ Mann •• C O P. (Cryobius) parasimi lis Ac3 Ball •• g+a +a g31 .. P. !Cryobiue} si-mi lis sp. grp. •• 7 .. P. (Cryobius) tilia- Ed + aeoradix Ball •• 94 P.(Cryobius) bioaryus fl •• gi P. CCryobius) B 3 c gl 6 + pinguedineus Eschz. 1 +a g22 gl 8 P.(Cryobius) auriga n + Ball •• 95 1 9+ .. P. (Cryobius) ventrioosus Bc2 + +? g4 Esch2. 4 .. ++a g41 1 P. (Cryobius1 bivviaornis Bc2 + Kby. 94 +a 1 .. 5 3 P. (Cryobius) A 9 mandibularoices Ball • • P. (Cryobius) nivalis Ac3 +a 4 Sahib. g2 .. g83 g29

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TAXON Samples (see Fig. 7)

Eco1.*S-H D-l Peat 1 S10-67 S13-67 S-14 S-12 Peat 4 S-l S-7 Peat 5 S-5 S-6

P.CCryobiua) cf g+a nivalis Sahib. P. C Cry obi us) breviaomie 5 .. sp. grp. P.(Cryobius) sp. + 18 16 35 P. vemiouloeue Hen. Ac +a P. agonue Horn Ac3 +a "7 !! P. ooetatuB Hen. Ab3 +a I P. aublaevia Sahib. Ad2 4 P. hoematopuB Dej. Bc2 3 g+a II Agonum exaratum Mann. Bb3 Agonum Sp. Amxra alpina Payk. Ad2 37 gl07 +a? gl54 A. bckoH Cslki A +? 3 A. kyperborea Dej. Bel +? A. (Curtonotus) sp. A. bvaani Lth. Be 1? A. (Celia) sp. 2 Barpalm amputatus Say BCd 5 B. nigritarsis Sahib. Bdi! 1 H. cf alaakeneie Lth. 9 Triehooellua mannerheimi Adi! 16 Sahib. Dytiscidae Bydroporue sp. a + +? Agabus sp. a +? Ilybiua sp. a + + Neosautopterua cf Ba +a horni Lec. Colymbetee sp. a Hydrophilidae Belophorus splendidus Aa Sahib. Belophorus sp. a? Cerayon Sp. Staphylinidae Megarthr*us sinuat-inaoZZia B Boisd. Avpedium brachypterum Bc3 (Grav.) Olophrum sp. Boreaphilua henningianus Sahib. Subhaida sp. 42 l Micralymma brevi Kngue Ac 66 35 89 33 Schladt. Stenus spp. b 6 2 2 1 Lathrobium sp. 3 1 8 Quedius spp. '2 1 Tadkinus apterus A g310 g++ gl 2 g63 gl 47 Makl.** gl 6 T. nearcticus Campbell B • • gi Tadkinus sp. Taahyporus sp. 'i .! 2 Bolitobius sp. 1? Gyrnnusa brevicollis Bb3 Payk. Aleocharlnae, Genus? sp. 3 .. 65 Leptodiridae Colon sp. 2 Scydmaenldae, Genus? sp. Scarabaeidae Aphodius cf distinatus .. 69 (Mull.) Byrrhidae Simplooaria basali-a 1? Sahib. S. elcngata Sahib. Morychus aeneolus (Lec.) A 236? Byrrhus Sp. Curimopsis setulosa 6? (Mann.) Elateridae Denin-aollis varians Bd (Germ.) Coccinellldae Scymnus sp. 1 Ceratomegilla sp. 1 Genus? sp. 1 4

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TAXON Samples (see F1g. 7)

Ecol.* S-ll D-l Peat 1 S10-67 S13-67 S-14 S-12 Peat 4 S-l S-7 Peat 5 S-5 S-6

Lathridildae Enicmus sp. Genus sp. Chrysomelidae Donaoia sp. a Chrysolina subsuloata A gii g2 (Mann.) C. subaulaata sp. grp. 6 10 C. caoigera (Sahib.) A +cf 1? C. caurina Brown A 5 C. flaoomarginata vidua D ? (Rogers) C. hudsonioa Brown B 6? 1? C. cf rufilabris (Faid.) gl sp. B C. cf rufilabris (Faid.) gii sp. C C. baailaris (Sa/) B? 2? 9 Chrysolina sp. A 22 Chrysolina spp. 7 Chrysomela sp. Phaedon cf cyaneacens stai Phaedcn sp. Hydrothassa cf vlttata a Oliver Alticinae, Genus? sp. Cassida flaveola Thumb. B Curculionldae Hypera seriatus (Mann.) A 5 Hypera sp. +? 3 1 Lepidophorus lineatioollis Kby. Bd2 5 .. 4 38 597 Vitavitus thulius 91 Kissinger Lepyrus gemellus Kby. B 1 L. canadensis Csy. B 1? L. stefanescni (Leng) B 1 L. cf labradorensis Blair "z 1 L. cf palustris Scop. Lepyrus sp. 'i Cleonus p lumbeuB (Lee.) B ? i 7 Dorytomus sp. ; Sotari8 aethiops ab. B? 1? N. cf flavipi losua gt+a '5 Chitt. Apian sp. 5 1 A.(Eutrichapicm) B 20? oyanitiatum Fai" A. (Eutrichapion) sp. Hhynahaenua sp. +? 4 35 Ceutorhynehus sp. 70 2 C. cf suipubescene 8 Lec. Lepidoptera, larval fragments Diptera Tipulidae Tipula (Vestiplex) 1? 4? bergrothiana Alex. Tipula (Vestiplex) Sp. 15 1 4 Bibionldae, Genus? sp. 1 Xylophagidae Xylopkagus abdominalis •B' +? 2? Loew Mi 1 i chi i dae Meoneura sp. Calliphoridae, Genus? sp. Hymenoptera Symphyta Tenthredinidae Nematus Sp. 1 13 4 Apocrita 56" 76* 97 Braconidae +? Meteorus sp. 2 M. leviventris Wesm. 5 Maaroaentrue innuitorum 13 1 Ualley Orgilus sp.

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Ecol.* S-l1 D-l Peat 1 S10-67 ST3-67 S-14 S-12 Peat 4 S-l S-7 Peat 5 S-5 S-6

Diospilus sp. 1? Agathis sp. 2 Agathidinae, Genus? sp. +? + Iohneutes sp. + Chelcnue spp. C. (MioToahelcm.ua) sp. Alysiinae, Genus? sp. Ttogas sp. Ichneumonidae Bathythrix sp. 1 Aalastus sp. 1 Endasys sp. 2 Phygadeuon sp. Atractodes sp. ì Oresbius spp. 5 Buathra labovator fabricii 1 (Schijidt.) Phaeogenes sp. 4 Ioheumon sp. 4 CoeIi ohneumonops sp. 1 Glypta ap. 1 Ctenopelmatinae, Pionini 1? Pvoolitus sp. 6 Plectiscinae, Genus? sp. Stenomacrua sp. 'ì Hyposoter sp. +? + 1? Cremastinae, Genus? sp. 2 Ancmalon sp. D 4 Anomalinae, Genus? sp. Mesoohorus sp. Pteromalidae Pteromalini, Genus? sp. Eurytomi dae Eurytoma cf gigante a Walsh Gasteruptiidae Gasteruption sp. Proctotrupidae Co'drue sp. Di aprii dae Atelop8Ìlus or Synacra sp. Formi cidae Leptothorax canadeneie •B'd ++ Prov. + Camponotus herouleanus (L.) Api dae Pyrobombus sp. (worker)

ARACHNIDA Acari Oribatidae Ameronothrue sp. Araneae Uycosi dae Tvodhosa sp. Tarentula pioti lis (Emerton) Lynyphi i dae Erigone sp 10 Eperigcme sp. 1? CRUSTACEA Notostraca Lepidwms sp. Cladocera Daphnia (Daphnia) sp. D. (Ctenodaphnia) sp.

BRYOZOA Crietatella sp.

* Ecol. ~ habitat requirements:

Regional: A = Obligate tundra Local: a = aquatic Vegetation: 1 = scantily vegetated, e.g., bare floodplain areas

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TABLE 3 (continued)

B = Tundra and forest b = hygrophilous 2 = moderately vegetated

1B'= Scarcely beyond treeline c = damp to mesic sites 3 = complete vegetation cover, e.g., continuous "B"= Clpen sites when d = xeric sites turf found below treeline

C = Obligate forest

D = Grassland

t Number refers to minimum number of individual insects

§ Symbols: cf = Species near but probably not the named species (possibly undescribed)

? = Fossils lack diagnostic characters needed for positive determination, or suitable series of reference specimens not available.

+ = Taxon present; ++ = Taxon abundant

a = Some fossils partially articulated

g = Some fossils include diagnostic genitalia

# Hymenoptera, Apocrita: Fossils are still under study. Number refers to to:al individuals of Apocrita (mostly Ichneumonoidea) in each sample.

See footnote under discussion of Tachinua apterus in "INVERTEBRATE FOSSILS"

species of Cryobius that occur at Deering, found to be similar to Subhaida, a salts in the substrate or pH, for it is proba- except similis, seem to be perfectly sympat- monotypic genus (S. rainieri Hatch) from bly in these categories that present shoreline ric with few evident differences in habitat the Pacific Northwest (Hatch, 1957). sites differ most from inland tundra. requirements. P. tareumiut and P. 7. Micralymma brevilingue Schidt.: All 8. Tachinus apterus Makl.: Fragments parasimilis were abundant in most pitfall of the fossils referred to this minute of this staphylinid beetle are extremely traps located in areas of thick continuous staphylinid species probably represent the abundant in several of the fossil insect as- turf cover. They were absent, and similis subspecies dicksoni Makl., which occurs in semblages (S—6, S-10—67, and so forth, was more abundant in traps located where arctic coastal areas of northwestern North Table 3). Their specific identity is estab- vegetation cover was sporadic. America and Siberia (Steel, 1958). Al- lished by inclusion in the assemblages of 4. Harpalus amputatus Say: This species though not yet recorded from the Deering partly articulated specimens possessing, in is common in grassland areas of western region, Micralymma brevilingue dicksoni some cases, the diagnostic terminal abdom- North America (Lindroth, 1968). Contem- probably occurs there because it has been inal segments (Campbell, 1973). porary specimens have been collected at collected at sites on the coasts of the Bering Figure 15 presents data on elytral dimen- only two Alaskan sites, and neither of these and Chukchi Seas. sions of T. apterus fossils from several of is in a tundra region. The species did occur M. brevilingue is apparently not re- the samples (assemblages) listed in Table in interior Alaska (Table 5) during the late stricted to the intertidal zone like the re- 3.2 Also shown in Figure 15 are wings of Pleistocene, when that region was largely lated species Micralymma marinum two contemporary T. apterus specimens treeless (Matthews, 1968, 1970). (Stroem); nevertheless, it seems to be 2 primarily a coastal species (W. J. Brown, The genus Tachinus has recently been revised 5. Neoscutopterus cf. horrti Lec.: Peat 1 (Campbell, 1973), but it has become clear since publica- and peat 2 contain partly articulated fossils 1970, oral commun.). Thus it is interesting tion of that paper and during the revision of this manu- that are very near, if not conspecific with, the that the species occurred at Cape Deceit script that the Tachinus apterus species group is morr dytiscid beetle Neoscutopterus horni Lec. approximately 12,000 yr ago, when that complex than originally thought (J. M. Campbell, 1973, area was far removed from the sea (see oral commun.). It includes several new species (now This species now occurs as far west as Nome, being described by J. M. Campbell and W. G. Ullrich). Alaska, and is found in the cold water of position of the -38-m shoreline in Fig. 2; Moreover, Ullrich and Campbell (in prep.) now con- Carex-Sphagnum bogs, usually where the Hopkins, 1974). This anomaly is not due sider T. apterus of Campbell (1973) to include two water is shaded by willows or spruces (D. simply to survival of Micralymma species, T. apterus Makl. and T. brevipennis J. Sahib. populations at the site of an interglacial Because the two species cannot be distinguished on the Larson, 1971, written commun.). basis of elytral characters, the argument based on Figure 6. Subhaida sp. (Fig. 14F): Abundant, shoreline (Pelukian) when sea level dropped 15 is seemingly impaired. But T. apterus and T. well-preserved fossils of a small omaline during the Wisconsin because Micralymma brevipennis are presently allopatric and differ only in staphylinid, belonging to the tribe Cory- brevilingue fossils also occur in interior the microsculpture of the head and pronota (J. M. Alaska (Matthews, 1968; Table 5) — an in- Campbell, 1973, oral commun.), and so in my phiini, occur in assemblage S—1 from the opinion they may be only subspecies of a single species. Deering Formation. The generic identity of land area during all of late Cenozoic time. Even if they are valid species, Figure 15 retains its the specimens is not definitely established, Apparently a critical habitat requirement of significance because the illustrated fossil flight wing but they have been compared with ex- M. brevilingue was formerly fulfilled over comes from an assemblage that appears to contain only amples of several Coryphiini genera large areas of Alaska but today occurs only T. apterus type pronota and heads, whereas the illustrated contemporary flight wings represent the degree of (Boreaphilus, Ephelinus, Occiphelinus, near marine shorelines. It may have some- brachyptery in both T. apterus and T. brevipennis (in Coryphium, Pseudohaida, Subhaida) and thing to do with concentration of soluble fact, according to Campbell and Ullrich, the Point Bar-

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and a left wing that was found folded be- proportions because older fossil elytra are dorsal-lateral sclerotized plates (W. J. neath a T. apterus elytron in the S-10-67 relatively longer with respect to width than Brown, 1962; Kontkanen, 1959). (Cape Deceit Formation) assemblage. Even elytra of late Pleistocene (assemblage S—6) The fossil assemblage from S—6 also in- though the fossil wing is incomplete, several and living specimens. cludes a number of Chrysolina pronota features suggest that its apical margin was T. apterus is a tundra animal, but other- (Chrysolina sp. A, Table 3) that differ from approximately as I have shown: (1) The wise little is known of its ecologic require- pronota in all Nearctic and Holarctic length of the stigma (st.) and the distance ments. Like some other Tachinus species, it species by their relative breadth, protruding between the anterior margin of the stigma may be associated with decaying vegetal or hind angles, and slightly sinuate sides. They and the wing base is less than in specimens animal matter. likely represent one of the species in the of fully winged species similar in size to T. 9. Morychus aeneolus (Lec.); Fig. 14G: complex contemporary Chrysolina fauna of apterus. (2) Neither in the illustrated, un- Fossils that probably represent this species the Palaearctic. folded wing or in other still-folded fossil of byrrhid beetles are abundant in the as- 11. Lepidophorus lineaticollis Kirby: wings from the Cape Deceit Formation is semblage of sample S—6 (Fig. 7, Table 3). Individuals of this phytophagous weevil there evidence of appreciable wing mem- The environmental significance of this fact species occur at xeric sites within forest and brane posterior to the position of the is obscure because very little is known of tundra regions. In the tundra, I have col- stigma. (3) Unlike the situation in contem- the ecological requirements of M. aeneolus lected them only where vegetation cover is porary full-winged Tachinus species, the or other North American species. W. J. sparse (for example, Dryas fellfield), but apex of the fossil wing (when folded) did Brown reported (1971, oral commun.) col- this is no doubt due to the fact that in not rest beneath the opposite elytron. (4) lecting M. aeneolus in a grass lawn in today's sedge-moss dominated tundra, only Very weak development of veins posterior northern Canada. I have one specimen of such sites are sufficiently dry. Abundance of of the stigma in the fossil contrasts with the M. aeneolus (?) from scantily vegetated silts L. lineaticollis in fossil assemblages does condition in wings of specimens of full- on the flood plain of an Alaskan river, and not necessarily indicate former fellfield winged species. the Palaearctic species M. dovrensis Munst. conditions because a drier, more grassy Evidently, the fossil wing was nonfunc- is reported from the same type of habitat tundra than exists at present might also tional, inasmuch as it is shorter and less de- (Andersen, 1968). Abundance of Morychus satisfy its habitat requirements. veloped apically than wings in specimens of fossils in assemblage S-6 (Table 3) may in- 12. Vitavitus thulius Kissinger: This present-day full-winged Tachinus species. dicate existence of scantily vegetated local species of weevils is currently very rare, However, it is considerably larger than conditions at Cape Deceit 12,400 yr ago. being known only from a single specimen wings in contemporary specimens of T. ap- 10. Chrysolina spp.; Fig. 16: Figure 16 taken at Bernard Harbour, Northwest Ter- terus. They are similar in size to the two includes illustrations of several fossil ritories (Kissinger, 1973), but judging from 2 wings illustrated in Figure 15. I have seen genitalia (median lobes) that almost cer- the number of V. thulius fossils in the as- no long-winged specimens of T. apterus (48 tainly belong to Chrysolina but match none semblage from S-10-67 (Table 3), this may specimens examined from Siberia, Alaska, of those of known North American species not always have been the case. V. thulius Yukon Territory), which implies that the (W. J. Brown, 1962). Median lobes illus- also occurs in Pliocene sediments from species is constantly brachypterous (short trated in Figures 16B and 16C are similar to Alaska as well as in Pleistocene sediments 3 winged). If T. apterus is not now, and was those seen in members of the Chrysolina from the Yukon Territory and Alberta (J. not in the past, wing dimorphic, then the rufilabris Fald. species complex (Kontka- V. Matthews, Jr., unpub. data). difference in size between the fossil and nen, 1959; Fig. 16D) The specimen illus- 13. Diptera: The genus Xylophagus contemporary wings represents the amount trated in Figure 16A possesses a sinuation (Xylophagidae) is represented at Cape De- of wing reduction that has occurred during of the upper margins, suggesting that it, like ceit by the distinctive caudal plates of the the last 400,000 to 900,000 yr. According the Nearctic species C. cavigera Sahib, and larvae. Some of these are identical to caudal to Figure 15, evolution of smaller wings the Palaearctic species, C. sylvatica Gebl. plates from last instar larvae of X. ab- was accompanied by changes in elytral and C. subcostata Gebl., once possessed dominalis Loew, the only species of the genus with a far northern distribution (Leonard, 1930). row specimen would be T. brevipennis and the St. Paul species or that it has undergone an evolutionary reversal The puparium of Meoneura (Milichidae) Is. specimen, T. apterus). The data on elytral size in Fig- with respect to flight wing development. The first con- in assemblage S—12 may not be a fossil. It is ure 15 would be altered under the revised concept of T. tingency is not indicated by present evidence and the exceptionally well preserved, and a con- apterus but probably not appreciably because the oldest second is highly unlikely. It is odd that the fossils possess temporary Alaskan species, M. lamellata assemblages (S—13—67 and S-10-67) appear to be weakly developed pruinose spots while contemporary T. monospecific (T. apterus). S—6 (Fig. 15) contains fossils apterus specimens have none. However, this might be Collin, is known to inhabit swallow nests of both T. apterus and T. brevipennis. expected if the pruinose spots are somehow used in wing (Cole, 1969). Entrance passages of nests Ullrich raises a more serious challenge to Figure 15 folding because the wings in the fossils, unlike those of were abundant in the thawed Inmachuk (1973, written commun.) when he suggests that -he contemporary specimens of T. apterus, were long Tachinus fossils from the oldest assemblages may rep- enough to require folding in order to fit beneath the resent a third species T. arcticus (Mötsch.). T. apterus elytra. TABLE 4. MINIMUM NUMBER OF ARTHROPOD INDIVIDUALS and T. arcticus are very similar, even in the form of the I do not pretend that this is the final argument on the IN EACH QUANTITATIVELY ANALYZED ASSEMBLAGE usually diagnostic terminal abdominal segments, ¿.nd Tachinus fossils. They come from a group that is being after examining T. arcticus, I certainly agree that fossils shown by Campbell and Ullrich to be more complex Minimum nurrber Amount of sediment Assent)! age of the two species could be mistaken. However, I still be- than previously thought. More fossils with preserved of individuals* processed (Kg) lieve that all of the fossils from S-10-67 and S-13-67 flight wings have recently been obtained at Pleistocene S 10-67 (Cape Deceit Fm.) 806 340 represent T. apterus. The best evidence for this conclu- exposures in Alaska, and these fossils will be discussed S-12 (Inmachuk Fm.) 246 520 sion is that T. arcticus is full winged and possesses in a future paper. well-defined pruinose spots (Campbell, 1973, p. 11) on S-l (Deering Fm., Unit 1) 509 283 3 the terga. Individuals of the Tachinus population rep- I am aware that such a conclusion is at best tentative S-5 (Deering Fm., Unit 2) 398 227 resented by the fossils were apparendy short winged (as unless more specimens are examined or the beetles are indicated in Fig. 15), and pruinose spots were very shown to have a reduced mesonotum (Chiolino, 1970, S-6 (Deering Fm., Unit 2) 1655 220 weakly developed. To refer these fossils to T. arcticus is and oral commun., 1972), which is not the case for T. * See Matthews (196B) for method of computation. to suggest either that T. arcticus is a wing dimorphic apterus.

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Figure 13. Miscellaneous animal macrofossils from pollen sample residues and macrofossil samples other than those listed in Table 3. ? = identification questioned.

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sediments (see remnant of a tunnel in Fig. 6D). 14. Formicidae (Hymenoptera): A more boreal ant than Camponotus herculeanus (L.) could hardly be found (Gregg, 1963). Its fossils in peat 4 are good evidence for the presence of trees, chiefly conifers and also imply good drainage because C. herculeanus requires dry nesting sites (San- ders, 1964). B Leptothorax canadensis Prov. (Fig. 14E) also occurs in peat 4 and the organic silts associated with peat 5 (Fig. 6E; Fig. 13, sample 99-68). Fossils of L. canadensis are not a definite indicator of forested conditions because the species has been collected in alpine tundra barely beyond the limit of trees (Gregg, 1963) and on tundra at Umiat, north of the Brooks Range in Alaska (L. acervorum canadensis Prov., in Weber, 1948). I did not succeed in collecting L. canadensis at Deering and rather doubt that it occurs there now. If this assumption is correct, then sample 99-68 and others containing L. canadensis fossils were probably deposited when tree line was closer to Deer- ing than at present. 15. Hymenoptera other than Formi- cidae: Most fossils, consisting chiefly of heads and propodea, could be identified only to the tribal or generic level (W.R.M. Mason, 1972, written commun.). Species of the Eurytoma gigantea group (Chalcidae; S-13-67, Table 3) are not presently known from sites north of Alberta or British Columbia in Canada (W.R.M. Mason, 1972, written commun.). Similarly, the present distribution of the ichneumon id genus Anomalon (S-6, Table 3) is chiefly tropical and warm temperate, with only a few species occurring in dry areas of interior British Columbia and south Alberta. Seward Peninsula was definitely not warmer when Eurytoma gigantea and Anomalon existed there, but the tundra at that time may well have been drier and in other respects different from present-day tundra. This fact might explain why these Cape Deceit assemblages that contain s.n abundance of ichneumonid fossils do not include the subfamilies Tryphoninae and Mesoleiinae, which are commonly represented in the fauna of contemporary hypoarctic tundra regions (W.R.M. Mason, 1972, written comm.). H A few fossils from the S-l Deering For- SCALE BARS' 0.5mm mation assemblage were exceptionally well Figure 14. Scanning electron microscope photos of selected arthropod fossils. A. Pronotum, Amara alpina Payk., preserved as a result of having been sample S—13—67 {Cape Deceit Formation, unit 2). B. Pronotum, Amara bokori Csiki, sample S-13-67 (Cape Deceit Formation, unit 2). C. Pronotum, Pterostichus nearcticus Lth., sample S—6 (Deering Formation, unit 2). D. Left side cemented together in silt peds. In one case view of partly articulated specimen, Ceutorhyncbus sp., sample S-10-67 (Cape Deceit Formation, unit 2). Fossil —undoubtedly a host-parasite association indicates excellent state of preservation of some of oldest insect fossils from the Quaternary exposure. E. Head, —fossils representing several specimens of Leptothorax canadensis Prov., peat 4 (Deering Formation, Fig. 4, station 8). F. Articulated left and right elytra, Subhaida sp., sample S—1 (Deering Formation, henseli zone). G. Left elytron, Morychus aeneolus (Lec.)?, sample S-6 the parasitic wasp Macrocentris innuitorum (Deering Formation, unit 2). H. Oribatid mite, dorsal view, Ameronothrus sp., peat 4, Deering Formation, Fig. 4, were found in the same ped with fragments station 8). I. Left elytron, Cassida flaveola Thumb., peat 1 (Cape Deceit Formation, Fig. 3, near station 2). J. Left of the probable larval lepidopteran host. male palpus, Tarentula pictilis (Emerton), sample S-5 (Deering Formation, unit 1).

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16. Tarentula pictilis (Emerton); Fig. diagrams by its combinations of high per- growing larches would have characterized 14J: The male palpus provides the most centages of Picea, Alnus, and Botrychium the landscape. According to the low per- diagnostic characters for specific and low percentages, of sedge and grass pol- centage of spruce pollen and absence of identification of many spiders, but only len. An abundance of spruce pollen cer- spruce macrofossils, tree line was composed rarely is such a small and complex organ tainly means that spruces were growing only of larches — unlike present tree line in preserved as a fossil (Leecli and Matthews, near or at Cape Deceit, though it is difficult Alaska. 1971). One such case is the palpus of to conceive of an analogous contemporary Tree line is a climatically controlled Tarentula pictilis (ident. by R. Leech, Ot- woodland or forest-tundra community boundary (Hopkins, 1959). The fact that tawa) from fossil assemblage S—5. T. pictilis being represented by such a small percent- trees existed at Deering during peat 1 time has not been recorded from Alaska but is age of birch pollen. Also peculiar is the high and do not exist now would seem to indi- known to occur in other subarctic areas of proportion of Botrychium spores. At pres- cate that climate was warmer then. But the North America (R. Leech, 1971, oral com- ent two common Alaskan species, B. analogy is faulty because the trees were mun.). Individuals of T. pictilis are pro- lunaria (L.) and B. boreale (E. Fries), occur larches. Larix does not now occur at tree nounced heliophiles and cs.n often be found in meadow communities of Alaska (Hultén, line in Alaska; moreover, the fossils may at relatively dry sites. 1968), but the percentage of grass pollen in represent an extinct species with unknown 17. Lepidurus sp.: A few isolated man- 79-68 is far too low for it to represent such temperature requirements. Fortunately, the dibles of the tadpole shrimp Lepidurus conditions. Unfortunately no macrofossil peat also contains Nuphar fossils, the occur in some assemblages. Most of them data are available to help resolve these un- climatic implications of which are less probably represent the contemporary certainties. equivocal. At present, Nuphar (pond lily) is northern species L. arcticus Pal. Notostraca Remaining unit 1 pollen spectra are more restricted to the forested regions of Alaska (tadpole shrimp) inhabit small ponds, usu- or less influenced by statistical overrep- (Hulten, 1968); thus, its presence at Cape ally those that are too seasonal or ephem- resentation of locally derived sedge pollen. Deceit during the peat 1 time is good evi- eral to support fish. Nevertheless, all samples imply tundra, a dence that climate was actually warmer Interpretive Criteria. Use of fossil data conclusion verified by the abundance of ob- than now. for paleoenvironmental reconstruction is ligate and facultative tundra insects in assemblages D-l and S-ll (Table 3, Fig. 7). dependent on one major assumption — that TABLE 5. REVISION OF EVA CREEK FOSSIL ARTHROPOD LIST ecological requirements of a species do not No aquatic insects occur in assemblage (LATE PLEISTOCENE, INTERIOR ALASKA)* change through time (Coope, 1967). Under D-l; thus, despite the occurrence in that such an assumption, a marked difference in assemblage of a few fragmented gastropod As originally listed: Change to or add: the former distribution of an insect species, fossils, I suspect that the sediments, if Cymindis unicolor Kirby or a closely compared with its present range, will be in- aquatic at all, were deposited in very small related undescribed species terpreted as evidence of environmental ephemeral ponds. Genus sp Harpalus amputates Say Hydrobuis fuscipes Leach change, rather than change of the species' Most exposures of unit 1 contain evi- {Hydrophilidae). Sample 3-1A habitat requirements. See Coope (1970) for dence of solifluction. Accordingly, the sub- Omaliinae a more detailed discussion of this rationale strate at the site must have been moderately Olophrum latum Makl. and numerous examples of the type of in- damp. Areas too cold for trees generally Micralyrma sp. Micralyrma brevilingue Schifidt. formation to be gleaned from study of fossil possess permafrost; thus, permafrost was Tachyporinae Tachinu8 sp. A ... Taohinus apterus Makl. insects. probably present at Cape Deceit during the Taohinus Sp. A ... Tachyporus sp. Insect assemblages from samples listed in tundra phases of unit 1 deposition. Searabaeidae Table 3 are biased. They represent almost Peat 1. Sample 101-69 contains nearly Aphodius sp. B .... Aphodius cf peotorialis or duplex^ only the terricolous portion of the former 10 percent Larix pollen, a figure compara- Byrrhidae Curimopsis sp. Curimapsis setulosa Mann.? fauna, and of that, chiefly the fraction con- ble to those in surface samples from con- Caenocarc sp move to Anobiidae taining heavily sclerotized insects such as temporary larch stands in Alberta (J. V. Morydhus sp.A, sp.B Represent one species only Coleoptera. This explains the rarity of fos- Matthews, Jr., unpub. data). That larch Elateridae sils of Diptera and Collembola, both of trees were growing at Cape Deceit is further Genus sp. A Denticollis varians (Germ,)^ which are dominant in most contemporary indicated by the abundance in peat 1 sam- Negastrius extricatus (Fall)? Curculionidae tundra faunas (Hurd, 1958; Watson and ples (Fig. 11) of larch seeds and cone frag- Genus spp most fossils are Lepidaphorus lineatioollis Kirby. Also present: others, 1966). ments. Larix tree stumps also occur in the Sitana sp. — sample 3-1A; Hypera cf woody zone overlying peat 1. Because of castor (Lec.) sample 3-3C the absence of spruce or other conifer fos- Family and Genus Unknown sils from the woody zone, I assume that all Genus sp. A Pi8sodes sp. (Circuíionidae) SEQUENCE OF ENVIRONMENTAL Genus sp. B Apion sp. (Curculionidae) CHANGE AT CAPE DECEIT of the stumps are from larches. The con- Rhynchaenus sp. (Curculionidae) centration of wood :.s probably due to slight Dory tonus cf alaskanus Csy. erosion and reworking of the wood after (Curculionidae) The data presented above provide a Genus sp. F Lathridiidae sound basis for discussion of the environ- death of the trees. Genus sp. I Laccobius 1 sp. (Hydrophilidae) mental history of the Cape Deceit region Although the abundance of larch fossils Lathridiidae Ceutorhynckua sp. (Curculionidae) during middle and late Quaternary time. In in peat 1 seems to suggest a larch forest at Colon sp. (Diptera), samples 3-3B, the following paragraphs, the sequence of Cape Deceit, some of the fossil insects, for 3-3C xylcphagus sp. (Diptera), samples environmental changes is presented in example, Carabus truncaticollis and 3-3B, 3-3C terms of the stratigraphy at the exposure. Pterosticbus nivalis (Table 3), imply Tipula {Vestivlex) sp. (Diptera) Table 6 is a summary of this discussion. tundra. Consequently, during peat 1 time, sample 3-3C Cicadellidae (Homoptera) sample 3-3C Cape Deceit was probably within a forest- Cape Deceit Formation tundra ecotone near the western limit of * See Matthews, 1968, for original list and sample designations. Unit 1. Pollen sample 79-68 from the trees on the northern Seward Peninsula. In- t Ident. by H. F. Howden, Carleton University. base of unit 1 differs from all others in the stead of a forest, isolated groves of slow- § Ident. by E. C. Becker, CÍ1C, Ottawa.

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A remarkable feature of macrofossil as- Unit 2. Pollen spectra from this unit dis- as in samples higher in the sequence, that semblage 102-69 (Fig. 11) is its content of play a high degree of lateral and vertical such conditions were of regional extent. But a diverse group of Potamogeton fruits. consistency. They differ from those in other note that Artemisia percentages in the pol- Present are at least seven distinct types of units by the following combination of len samples from unit 2 are slightly higher fruits representing at least as many species. characteristics: (1) low percentages of Picea than in contemporary tundra surface A similar diversity of Potamogeton charac- and Alnus, (2) lower percentages of Betula samples. terizes the carpological assemblage from than in most Seward Peninsula surface Most of the small mammal fossils from Tiraspolian Olyor sediments in eastern samples, (3) high percentages of sedge — the Cape Deceit local fauna (Guthrie and Siberia (Katz and others, 1970), but I doubt exceeding grass percentages in most cases, Matthews, 1971) come from sediments of that one could find any contemporary (4) less than 15 percent Artemisia in all unit 2. Unlike late Pleistocene small mam- Siberian or Alaskan pond with a compara- samples but more than in surface samples mal assemblages from interior Alaska ble diversity of pondweed species. Thus, from Alaska, and (5) more than 5 percent (Guthrie, 1968b) or the small mammal as- peat 1 most likely represents several aquatic Potentilla-Fragaria in most samples. In ad- semblages from upper units at Cape Deceit, biotopes or seres in a fen-bog successional dition to pollen, other types of evidence (in- between 10 and 20 percent of fossils in the sequence. sects, seeds, sedimentary features) confirm Cape Deceit local fauna represent a mam- Discovery of Chamaecyparis (Alaskan that tundra existed during deposition of mal (Pliomys) that presumably filled the cedar) wood in the unit now designated as unit 2. The fact that alder percentages are seed-eating niche occupied now by the red peat 1 (Hopkins, 1967a and written com- lower than in samples from unit 1 may sig- back vole, Clethrionomys rutilus (Guthrie mun., 1968) was the chief reason for my nify that regional climate was colder; how- and Matthews, 1971). Perhaps this means initial interest in the site, because ever, judging from the number of plant that seed- and fruit-producing plants were Chamaecyparis is a tree of southern Alaska species in the macrofossil assemblage that more abundant on the tundra during early and its occurrence in peat 1 would imply have their present northern limit in Young's Pleistocene than late Pleistocene. Abun- relatively great age for that unit. However, I tundra Zone 4, climate was likely not much dance of Pliomys fossils from the Cape De- have been unable to confirm the colder than contemporary areas of northern ceit Formation may in some way be related Chamaecyparis record by collection of ad- Alaska. to the dominance of Potentilla in macrofos- ditional fossils, and the specimen that was An abundance of fossils of the ground sil assemblages S-13-67 and S-ll identified has been discarded (D. M. Hop- beetle Amara alpina and the plant (Fig- 11). kins, written commun., 1970). Cham- Potentilla (achenes and pollen) point to a Peat 2. Pollen samples from this unit are aecyparis does grow today in bogs local environment with scanty vegetation. dominated by sedge pollen, justifying its and forest openings (Neiland, 1971) but Micralymma brevilingue is also relatively designation as a sedge peat. It may be never in alpine or subarctic regions (Flulten, abundant (Table 3). According to my ear- analogous to the subsurface peats charac- 1968). Hence, it would be entirely unex- lier comments, this means either that the teristic of many contemporary tundra areas pected in the type of environment indicated site of deposition was near marine shoreline (Brown, 1969). Following formation of the by peat 1 fossils. For this reason, I suspect or that substrate conditions differed from peat, climate on the northern part of the that the original identification was those found at contemporary inland tundra Seward Peninsula warmed enough to cause erroneous. sites. If the latter, there is no clear evidence, thaw of ice wedges and accompanying slumping of unit 2 sediments (note ice- wedge pseudomorph, Fig. 6B, and slumped LEFT WINGS of Tachinus apterus Makl. sediments at station 5, Fig. 4). During or contemporary shortly after this period of interglacial Pt. Barrow, Alas. thawing, erosion truncated the upper portions of unit 2, including the ice-wedge pseudomorph. In contemporary tundra areas, subsurface peats form primarily as a result of solifluction (Brown, 1969). Thus if peat 2 is a subsurface peat, it implies that a

0 a8 solifluction phase occurred late in the dep- I / o.o ^ o osition of unit 2 sediments, before degrada- + ^a 900^0-» o A A^^ » 0 o^e'o tion of the ice wedge. • ^--fof o e 9,0- • A A -F A A^ A O O • O % + +D4 4GI 4 V°SOO • Inmachuk Formation -f û a 4- a a' i " Most of the pollen data for this unit come A • A -F' += C0NTEMP. from a series of samples taken at the ex- fossil S 10-67 D+A'D QA % T A = S-6 posure between stations 2 and 3 (Figs. 7 AL I A A Q • 0 T LEFT I = S-5 A -^Q i -(- oo • ELYTRON and 8). The sample series does not extend * = S-12 A'D A Û -F- A to the uppermost portion of the Inmachuk TT 0 = S 10-67 • = S 13-67 unit because the sediments there are folded, p possibly by solifluction, which makes determination of the vertical position of the LENGTH (In mm) samples impossible. The bulk macrofossil Figure 15. Interassemblage comparisons of elytral size and wings in Tachinus apterus. Assemblages S—13—67 and sample, S—12, does include the upper folded S-10-67 from Cape Deceit Formation (unit 2), S—12 from Inmachuk Formation, S-5 and S-6 from Deering silts but none of the organic sediments Formation (units 1 and 2, respectively). See Figure 5 and text for probable age of assemblages. Line A, regression of length on width for S-6 elytra (n = 73, Y = 15.9 + 0.55X). Line B, regression of length on width for S-10-67 elytra composing peat 3. (n = 76, V = 18.0 + 0.45X). "st." in illustration = stigma. Low percentages of Picea pollen indicate

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tundra conditions, a conclusion supported Peat 3. Most of the samples from the taining an extremely high percentage of by the dominance in S—12 (Table 3) of fos- peaty silts of this unit contain high per- alder pollen, may signify, however, that al- sils of obligate tundra insects and presence centages of Salix pollen, undoubtedly due der; were at times locally abundant and al- of Micralymma brevilingue fossils in the to an abundance of willows in the former ways present within the Cape Deceit region. coarse residue of pollen sample 86—69 (Fig. local environment. But all samples, includ- Insect fossils from the D. henseli zone ing those not seriously biased by Salix (assemblage S—1, Table 3) suggest a local Mesic to xeric local conditions are indi- (125—68, Fig. 8) contain low percentages of environment that was grassy and scantily cated by the abundance of Amara alpina spruce pollen, and one sample yielded vegetated. According to the plant mac- fossils. Some small ponds must have existed fragments of the beetle, Amara alpina — rofossil record, Potentilla and cruciferous near Cape Deceit because a few fossils of good evidence of tundra. plants were also locally abundant. aquatic insects (Colymbetes and Donacia), During or shortly after deposition of peat Some articulated insect fossils from S—1 tadpole shrimp, mollusks, and ostracods 3, solifluction mobilized Inmachuk and in (within the henseli zone) occur in calcare- also occur in the assemblage (Fig. 15, Table some cases uppermost Cape Deceit sedi- ous cemented silt peds. In one case, frag- 3). But compared to fossils of terrestrial in- ments (Fig. 6F). The angular unconformity ments of the parasitic wasp Macrocentris sects, those from aquatic animds are rare. between the Inmachuk and Deering Forma- innuitorum were found cemented in the The S-12 insect assemblage contains sev- tions is testimony for a phase of erosion fol- same ped with parts of the probable host — eral features common to younger assem- lowing this solifluction episode. a lepidopteran larva. Preservation of such blages such as S—1 and S-6 (Fig. 7) but an ephemeral host-parasite association in missing in assemblages from the Cape De- Deering Formation the peds shows that cementation took place ceit Formation. One of these is the paucity Peat 4. Taken together, the pollen and near the soil surface only shortly after death of Cryobius fossils; the other is the relative plant macrofossils (Figs. 9, 10, 11) show of the animals. This would be extremely un- abundance of fossils of leafhoppers that both black and white spruces as well as likely to occur in the acidic soils charac- (Hardya youngi in the case of S—12, Table arboreal birches grew near Deering during terizing most present-day tundra regions. 3). The latter probably signifies drier, more peat 4 time. The climate must have been Thus I believe that during S-l time, soil pH grassy local conditions than exist at Cape significantly warmer than at present. Car- was higher, perhaps approaching the values Deceit now. Such conditions could have penter ants (Camponotus herculeanus) found in contemporary grassland and been inimical for most species of Cryobius. occur in the woody peat exposed at station steppe soils. The resultant unleached soils The abundance of leafhoppers in S—12 8 and show not only :hat the area was may have favored Micralymma brevilingue, may also reflect steppelike regional condi- forested but that dry sites suitable for nest- foss .ls of which are abundant in S—1. tions; however, alternate fossil evidence ing existed at the Cape. But the insect as- supporting such a conclusion is either lack- semblage also includes one articulated fossil ing or equivocal. of the tundra beetle, Pterostichus Pollen samples from the upper part of the parasimilis, implying perhaps that tree Inmachuk Formation are distinguished cover was intermittent, as in present-day from those lower in the unit by their higher forest-tundra ecotonal regions. percentages of Betula and Sphagnum and Unit 1. Sample 57—69 from a peaty lower percentages of Salix and Artemisia. horizon above peat 4 (previously consid- But this shift of frequencies is correlated ered part of peat 4 by Guthrie and with changes in sediment texture — sand at Matthews, 1971) contains macrofossils of the base of the sample sequence to silt at the spruce but surprisingly little spruce pollen. top — making the pollen fluctuations This sample may represent the situation, analogous to vegetational changes observed postulated earlier, in which deteriorating in contemporary flood-plain successional climate in a region containing spruce causes sequences, where sediment type strongly interruptions of sexual reproduction and influences the composition of plant com- hence reduced pollen production before all munities. (Bliss and Cantlon, 1957; Vier- of the trees die out. The congeliturbation eck, 1966). Hence the distinction between structures existing in the sands immediately upper and lower Inmachuk samples may be below 57—69 and above peat 4 may mark due largely to local environmental con- the first pulse of cold climate after forma- straints. If so, paleoenvironmental conclu- tion of the peat. Note (section on Pollen, sions based on the similarity of upper Cape Ecologic and Taxonomic Notes) that it is Deceit and lower Inmachuk spectra are this unit that has yielded a sample contain- probably spurious because the samples rep- ing pollen of a polyploid grass. Climatic resent different depositional environments. stress and substrate instability, both of Comparison of spectra from upper Cape which may have been prevalent during dep- Deceit Formation silts with spectra from osition of the sands, have been suggested Scale Bor = 0.5mm silts in the upper Inmachuk Formation pro- as the causes of polyploidy among arctic Figure 16. Dorsal and lateral views of male genitalia vides a better index of regional climatic plants (Bliss, 1971; Johnson and Packer, of Ch.-ysolina species, "fig." = flagellum. A. Chrysolina change. It shows that climate during In- 1967). cf. cavigera (Sahib.), sample S-l 3-67 (Cape Deceit Formation, unit 2). B. Chrysolina cf. rufilabris (Faid.) machuk time may have been slightly The D. henseli zone at the base of unit 1 sp. C, sample S-l (Deering Formation, unit 1). C. warmer (higher Betula percentages) than is poorly documented palynologically. The Chrysolina cf. rufilabris (Faid.), sp. B, sample S-6 during late Cape Deceit time but somewhat few samples that were examined do indi- (Deering Formation, unit 2). D. Chrysolina rufilabris colder (lower Alnus percentages) than at (Faid. I, contemporary specimen, V. Udukunsk, Oden- cate tundra conditions, but with fewer al- vall (ill collections of Zoological Museum, University of present. ders than at present. Sample 58-69, con- Helsirici).

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Carbonate-cemented silt peds were found character of basal peaty sediments seems to macrofossils from S—6 (Fig. 11) contains in sediments of assemblages S—12 and S—6, have resulted primarily through truncation about 20 percent grass "seeds"—more and even though they did not contain ar- of a continuous peat horizon by than in any other assemblage. Most of them ticulated fossils as in the case of S-l, their solifluction. are from an upland species of bluegrass significance with respect to soil chemistry is Pollen sample 102-68 (Fig. 9) from the (.Poa). probably the same. basal peat has little environmental Unless the low percentage of alder pollen A grassy tundra with shrub birches con- significance because it is obviously biased is due to aridity, climate during deposition tinued to persist, at least locally, during by overrepresentation of grass pollen. Re- of the clayey silts was colder than at pres- deposition of the portion of unit 1 im- maining peat 5 spectra contain very high ent. But it was neither too cold nor too dry mediately above the D. henseli zone. Per- Alnus percentages and considering the con- for the growth of dwarf birches because centages of grass and Sphagnum are slightly straints imposed by the alder values, rela- seeds of Betula nana occur in Assemblage higher than in samples from lower in the tively high percentages of spruce pollen. S-6 (Fig. 11) and Betula pollen is abundant unit, but the significance of this is difficult During this time alders were probably in most pollen samples (Figs. 9, 10). Low to assess because of paucity of supporting growing in interfluve areas such as Cape De- arctic zone 4 type tundra is implied by other macrofossil evidence. Indeed, aside from ceit, which implies that climate was some- plant macrofossils from S-6; therefore, the the frost cracks, one of the chief charac- what milder than now. The region was not regional climate was probably no colder teristics of the silts within this increment is forested, although the presence of than in present-day northern or far western their lack of organic detritus (only 1.5 £ of Leptothorax canadensis in peat 5 (Fig. 13) Alaska. residue >0.635 mm per 350 kg of sedi- and 10 percentPicea pollen in sample 19-67 Peat 6. Percentages of Betula are much ment). The few macrofossils that were ob- indicates that spruce tree line may have been higher in peat 6 than in the underlying tained are relatively well preserved, and closer to Deering than at present (Fig. 10). clayey silts. This could reflect greater local pollen preservation is no worse than in The tundra environment at Cape Deceit abundance of shrub birches due to favor- other parts of the exposure; thus, it is un- may have been very much like that of the able substrate conditions (that is, moss in- likely that the inorganic character of the present (S—5, Table 3). For example stead of accumulating silt; Viereck, 1966) sediments owes to postdepositional weath- Cryobius fossils are abundant, particularly and (or) invasion of tree birches from the ering. The only other explanation is that the the species, P. parasimilis, a common in- east. The latter would imply warmer cli- silts are sterile because they accumulated habitant of richly vegetated tundra. The mate. McCulloch and Hopkins (1966) have rapidly in a very scantily vegetated local en- many fossils of P. nivalis call for thick turf shown that climate was warmer and that vironment. This is also the implication of cover as at present. Unlike other assem- tree birches did grow farther west than the frost cracks. blages leafhopper fossils are nearly absent, Deering at about the time when peat 6 was Alder percentages rise abruptly in the and arthropod fossils indicative of open forming. Unfortunately, the evidence from upper sample from the frost crack unit, arid poorly vegetated sites, for example, peat 6 is equivocal on this matter because since the shift is not correlated with any ob- Lepidophorus lineaticollis, Tarentula, no birch macrofossils were found, and an vious lithologic change (as in the case of the Chiloxanthus stellatus, and Amara alpina, attempt to separate the Betula pollen into Inmachuk sequence), I assume it reflects a are relatively rare. tree and shrub varieties using criteria estab- real increase in the regional abundance of Unit 2. The Upper or Late Wisconsin lished by Birks (1968) proved inconclusive. alders — in other words, ameliorating part of unit 2 consists of clayey silts. The The blocky moss peat that caps the Cape climate. presence of aquatic or shore-dwelling in- Deceit exposure yielded a pollen spectrum Peat 5. Peat 5 is here considered (contrary sects and aquatic or near aquatic plants (for similar to Deering surface samples. But be- to Guthrie and Matthews, 1971) to include example, Hippuris, Ranunculus trich- cause this peat is not dated, all that can be not only the nodular peat immediately above ophyllus) in the macrofossil assemblage concluded is that vegetation similar to that inorganic silts of unit 1 but also the overlying (Fig. 11, Table 3) shows that deposition oc- of the present did not originate at Deering frost-disturbed organic silts at the base of curred in a pond, possibly one of thermokarst until after initial formation of peat 6 about unit 2 (Fig. 6E). At some parts of the expo- origin. 9,000 yr ago. sure, there is slight evidence for an Despite some lateral variability, due unconformity between the underlying unit 1 perhaps to rebedded pollen from peat 5, all DISCUSSION silts and basal peat 5 sediments. spectra from the clayey silts at the two At station 8 a zone of discolored arid major sample sites (stations 1 and 8) con- Related Paleoenvironmental slightly leached silts occurs immediately tain high percentages of grass and Information below the nodular peat horizon (Fig. 6E). It Artemisia pollen. These two characteristics It is important that the conclusions pre- probably represents an incipient soil distinguish them from all other pollen sented above be viewed in the light of the formed early in the deposition of peat 5. spectra in the Cape Deceit sequence and are paleoecological data already at hand. Such Humates are concentrated at the base of the by themselves adequate reason for suggest- data are discussed below in order of the leached zone (position of sample 103-68, ing that the regional environment at Deer- geographical region from which they come. Fig. 6E), possibly marking the position of a ing was grassy or steppelike during the England. The most detailed studies on static permafrost table. If so, depth of sea- latest Pleistocene. Along with many obli- Quaternary insects have been carried out by sonal thawing during initial peat 5 deposi- gate tundra species, the insect assemblage G. R. Coope and his associates in England tion would have been approximately 30 cm (Table 3, S—6) includes species that now (Coope, 1970, for review). But because En- — somewhat less than in similar Cape De- occur only in grassland areas outside of gland is far removed from Alaska, presently ceit terrain at present. Alaska (Athysanella, Anomalon) and others within a temperate rather than subarctic or The uppermost peaty silts of peat 5 have that are characteristic of xeric sites arctic zone, and contains a contemporary evidently been disturbed by a phase of (Lepidophorus lineaticollis, Harpalus am- fauna much different from that of Alaska, solifluction coinciding with or postdating putatus, Amara alpina, Ptersotichus most of the studies performed there war- their deposition. At station 8 the nodular soperi). In addition the assemblage of plant rant little consideration here. One excep-

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tion is a recent paper (Coope and Brophy, evidence — something not yet available for blages from the Eva Creek exposure near 1972) in which the sensitivity of fossil in- Alaska. Fairbanks (Matthews, 1968). An updated sects and fossil pollen as paleoclimatic indi- Thus, here I employ several types of evi- taxa list from that report is presented in cators is tested. It shows, through detailed dence with the hope that collectively they Table 5. Note that it includes fossils of the comparison of the results achieved by using will yield a more detailed picture than presently allopatric species, Micralymma the two methods, that fossil insects are in would be gained by use of any single brevilingue and Harpalus amputatus. some cases the more accurate index of method alone. Pollen analysis is given Recall that occurrence of these two species climatic change. Even though this report is primary emphasis because considerations in assemblage S—6 at Cape Deceit is con- also based on the use of several types of of time and fossil abundance dictate that it sidered to be partial evidence of steppelike evidence for documentation of the paleoen- alone can provide information on the entire conditions. Guthrie (1968a) has previously vironmental record, it is in no way a test of Cape Deceit sedimen tary sequence. suggested that such an environment the relative merits of each approach. Such a Interior Alaska. The only other pub- characterized the late Pleistocene of interior test depends on a large mass of previously lished study on Alaskan Quaternary insects Alaska. Moreover, pollen samples from in- gathered and substantiated paleoclimatic deals with several Wisconsin age assem- terior Alaska (Matthews, 1970, 1974c) also imply existence of steppelike conditions in latest Wisconsin time, and an insect as- Imuruk Lake Core I semblage of very latest Wisconsin age at Eva Creek (J. V. Matthews, Jr., unpub. data) is, like assemblage S—6 from the Deer- ing Formation, dominated by fossils of the beetles Morychus and Lepidophorus lineaticollis. All these facts show that the steppe-tundra environment at Deering was not unique to that area. 8000 bp. ^-•o Western Alaska. Imuruk Lake, located Holocene L" approximately 50 km south of Cape Deceit ' I0700bp.-' (Fig. 2), is the site of the most detailed pol- K len studies yet conducted in Alaska (Colin- I2000bp- vaux, 1964; Colbaugh, 1968). Although it >34000bp. is inland from the coast and 300 m higher in elevation, its proximity to Cape Deceit and the fact that both sites presently possess a similar contemporary pollen rain suggest that both also have had similar vegetational Intermediate Terrace histories. If so, then the Imuruk record (Fig. 17) is valuable for comparison with the conclusions presented here. However for several reasons, such comparisons are not as easily drawn as might be expected. For example, the Imuruk sequence likely does not represent as much time as that of Cape Deceit because the basal formation at the latter site predates the middle Pleistocene, whereas the Imuruk lake basin is formed of mid-Pleistocene basalts (Hopkins, 1963) that were not reached by any of the Imuruk cores (Colinvaux, 1964). Moreover, I believe (contrary to Colinvaux, 1964, 1967) that the base of the longest Imuruk core is no older than the early Illinoian,4 which if

4 I would interpret the lower 5 m of the core to represent all of Illinoian time instead of "Yarmouth" plus Illinoian as in Figure 17 and Colinvaux (1964). His correlation shows the Illinoian increment of the core to be Picea, Artemisia less than 2% much shorter than the Wisconsin increment, just the opposite of what is expected if glaciers and associated C-14 dales for Intermediate zones of aeolian deposition were nearer Imuruk Lake Terrace: 9900bp. at during Illinoian than Wisconsin time (Fig. 2). I agree Graniie Bay; 7400 bp. at with Colinvaux that the lower part of the core, in which Salix Bay spruce peaks occur (Zones A to G), is not likely to represent forested conditions at Imuruk; however, I dis- agree with his contention that these zones represent an each division = 20% interglacial environment essentially like that of the present. The critical point in his interpretation is the Figure 17. Generalized pollen diagram from Imuruk Lake (modified from Colinvaux, 1964; Colbaugh, 1968). significance of spruce peaks in Zones A to G. He consid- Dates for zonal boundaries in core 1 are from Colbaugh (1968). Core 1 samples are lacustrine silts and clays, ers them to have similar implication as the spruce whereas zone M samples are autochthonous and allochthonous peats. fluctuations in Zone i and L, but I doubt this because the

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true places further constraints on compari- during this warm period. While it lasted, 3. Sediments from immediately below son of the two paleoecological sequences. It spruces no doubt moved north in the river clayey silts of unit 2 at Cape Deceit contain also must be realized, when attempting to valleys south of Imuruk Lake and contrib- high percentages of alder pollen, like sam- compare the two sequences, that Imuruk uted the spruce pollen seen in samples from ples from Imuruk Zone i, and unlike sam- represents essentially continuous deposi- Imuruk Zone L (Colbaugh, 1968; Fig. 17). ples from Zone J (Fig. 17). For reasons tion, whereas a few major and probably 2. Pollen samples from at least the upper stated earlier, I believe that the lower part many minor depositional hiatuses are pres- part of the clayey silt zone in unit 2 (Deer- of Unit 2 (Deering Formation) at station 8 ent at Cape Deceit. Finally, because the ing Formation) are equivalent in age to does correlate with Sangamon Zone i at sediments at Cape Deceit are primarily col- those from Imuruk Zone K (Figs. 5, 17); Imuruk. This, of course, implies that a large luvial (while those at Imuruk are primarily however, I interpret them differently than part of Wisconsin time is not represented in lacustrine), some of the distinctions and Colinvaux (1964) does for Zone K. Both he the sequence at station 8. Pollen spectra (or) similarities between the two pollen rec- and Livingstone (1955) view fossil spectra from the basal sediments of unit 2 at station ords may be a function of local rather than of the Zone K type as comparable to sur- 1 (erroneously equated with peat 5 in regional vegetational and climatic face pollen spectra from contemporary Guthrie and Matthews, 1971) are more conditions. birch-dominated tundra, even though the similar to those from Imuruk J2, suggesting With these caveats in mind, one can now fossil samples contain higher percentages of that the hiatus is not so great at that part of examine some of the similarities and dis- both Artemisia and grass than surface sam- the exposure. Alternatively, peat 5 and as- similarities of the Imuruk and Cape Deceit ples from such sites. I believe that Zone K sociated organic sediments with high alder records. and unit 2 pollen spectra represent a percentages might be equated with a mid- 1. None of the samples from the upper steppelike tundra environment, albeit one Wisconsin interstadial. But pollen data part of the Deering Formation yield pollen with more birches than existed on the Sew- from those sediments reveal a spruce tree spectra with high spruce values such as ard Peninsula earlier in Wisconsin time line closer to Deering than at present, those in Zone L at Imuruk, despite the fact (see Zone J3 at Imuruk; Fig. 17). whereas interstadial pollen from Imuruk that high percentages of Picea in that zone are attributed to westward advance of TABLE 6. SUMMARY OF QUATERNARY ENVIR0W1ENTAL HISTORY AT CAPE DECEIT, ALASKA spruce along the north shore of Seward

Peninsula (Colbaugh, 1968; D. M. Hop- Stratigraphie Unit Paleoenvironment kins, written commun., 1969). The expla- Late Holocene Deering Fm., Unit 2, Tundra like present; dwarf birches wide spread; alders in valleys nation for this discrepancy may be that sample 72-67 or other protected sites. Thick moss peat forms at Cape Deceit. spruce tree line did not, in fact, advance Climate like present Early Holocene Deering Fm., Unit 2 Tundra. Birches (dwarf?) abundant; spruce treeline perhaps significantly toward Deering during the (circa 9000 yrs BP) and Peat 6 closer to Deering than now. Climate slightly warmer than at early Holocene. In this context, note :hat present (McCulloch and Hopkins, 1966) (a) the recent conclusion by D. M. Hopkins Late Wisconsin Deering Fm., Unit 2 Steppe-tundra. Poa, Artemisia, potentllla locally abundant. (12000-13000 yrs BP) (upper part) Prairie insects at Deering; grazing ungulates on Seward Peninsula. (written commun., 1971) that a previous Climate arid, colder; but not too cold for growth of dwarf birch

report of spruce fossils in early Holocene Early Wisconsin? Deering Fm., basal Herbaceous tundra; locally grassy with crucifers. Climate colder sediments around Kotzebue Sound (McCul- Unit 2 (station 1) than present loch and Hopkins, 1966) is in error, and (b) Sangamon (Pelukian) Deering Fm., Peat 5 Tundra like present; but alders growing in interfluve areas. interglacial and basal Unit 2 at Spruce treeline closer to Deering than today. Solifluction. unpublished pollen spectra by C. S. station 8 Climate warmer but too cold for spruces

Schweger (1971) that fail to record a peak Deering Fm., upper Herbaceous tundra (grassy?); with some dwarf birches. Alders Unit 1 rare until immediately before formation of Peat 5. Local vegeta- of spruce pollen in early Holocene sedi- tion cover low. Climate as now or colder; locally arid ments at Cape Blossom, near Kotzebue. Deering Fm., henseli Herbaceous tundra (grassy?). Dwarf birches present; alders at Zone times locally abundant but generally rare. Substrate pH higher. That a phase of early Holocene warming Climate as now or colder did occur is nevertheless indicated by evi- Pre-Illinoian inter- Deering Fm., Peat 4 Open forest. White spruce, black spruce and arboreal birch at dence of regional thawing (McCulloch and glacial (Kotzebuan?) Cape Deceit. Locally swampy. Climate warmer; like present inte- Hopkins, 1966) and westward movement rior Alaska but less continental in the Kotzebue Sound region of other Pre-Illinioan glacial Inmachuk Fm. (including Tundra. Dwarf birches present; alders rare, potentilla and Peat 3) grasses locally abundant. Willows and Artemisia present during boreal plants and animals (Hopkins, 1972; deposition of lower sands; willows present during formation of Peat 3. Solifluction during or after Peat 3 formation. Climate C. S. Schweger, oral commun., 1971). probably colder

Slowing silt deposition and peat formation "Cromerian"* inter- Inmachuk/Cape Deceit Forested? Erosional interval with thawing and slumping of frozen (peat 6) at Cape Deceit may have occurred glacial hiatus sediments. Climate warmer than now "Cromerian" glacial Cape Deceit Fm., Unit 2 Herbaceous tundra; probably not grassy. Alders and birches rare. Locally plant cover low but Potentilla abundant. Soliftuction(?) spruce peaks in the lower zones differ in at least two during formation of Peat 2. Climate colder than at present. ways from those above. First, they are not, like the Permafrost exists at Deering upper spruce peaks, associated with high percentages of "Cromerian" inter- Cape Deceit Fm., Peat 1 Forest-tundra. Larches present at Cape Deceit; spruce rare or alder pollen; therefore, they almost certainly do not rep- gl aci al ? absent. Regional treeline very near to Deering. Locally swampy. resent a shrub-tundra environment near tree line as at Climate warmer than present but evidently not warm enough for present. Second, the lower spruce peaks, unlike the growth of spruce upper ones, are associated in the core with zones of sand "Cromerian" glacial Cape Deceit Fm., Unit 1 Tundra like present. Dwarf birches and alders present. Sedges (not illustrated in Fig. 17; see Colinvaux, 1964). The or interglacial and potentilla at times locally abundant. Solifluction during early phase of deposition. Climate like the present at Cape significance of this fact is not clear, but it could mean Deceit that high spruce percentages reflect nothing more than overrepresentation of allochthonous pollen during a "Cromerian" interglacial Cape Deceit Fm., Unit 1, Forest or forest-tundra. Spruces growing at or near Cape Deceit sample 79-68 and alders locally abundant (in interfluve areas). Climate time of very low local pollen production and rapid warmer, possibly like present Interior Alaska (aeolian?) sedimentation. Thus, a tundra environment Cape Deceit Fm. Tundra? Mechanical weathering of metalImestone bedrock at Cape containing dwarf birches and possessing few aiders and Deceit. Climate periglaclal? no spruce may have existed at Deering during all of the

time represented by Zones A to H. If so, this entire sec- * See text concerning the use of the European term, "cromerian." tion of the core probably represents only Illinoian time.

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Zone J2 (Fig. 17) and the lower part of the to growth of alders in interfluve areas evolution (if any) among existing groups of Epiguruk exposure on the Kobuk River (where they are presently absent) because of closely related species — those most likely (Fig. 2; C. S. Schweger, oral commun., warmer climate (Petrov, 1967). A similar to have undergone some evolutionary 1971) imply that mid-Wisconsin spruce tree explanation is given for high alder per- change during the time span of Cape Deceit line was farther away from Deering than at centages in peat 5. But in Chukotka an deposition. Lack of specific determinations present. Clearly, if peat 5 is of interstadial alder-rich tundra environment apparently for many of the plant fossils listed in Figure age, it does not represent the same intersta- also existed in interfluve areas during the 11 and in the pollen diagrams also hinders dial that is recorded at Imuruk and Amguem interglacial, which is equivalent to assessment of possible plant evolution. Epiguruk. the North American mid-Wisconsin (Pet- The abundance of identifiable insect fos- 4. For reasons mentioned above, com- rov, 1967). sils from Cape Deceit provides a sounder parison of pre-Sangamon portions of the Studies of Quaternary insects are just basis for assessment of the part insects have environmental record at Cape Deceit and now getting under way in eastern Siberia played in phyletic ecosystem evolution. But Imuruk is difficult. If Colinvaux's correla- (A. V. Sher, 1973, written commun.). A most fossils that could be identified to tion is accepted (Fig. 17), then Deering preliminary effort (Matthews, 1974a) species are referred to extant species, and Formation unit 1 spectra differ from II- shows, as does the Cape Deceit evidence, those listed as being near (cf.) a contempo- linoian spectra at Imuruk by possession of that certain closely related species of tundra rary species may just as likely represent an much lower Artemisia and higher Betula insects, for example, Amara alpina and A. undescribed extant species as an extinct percentages. However, if the entire lower bokori, evolved before the middle Pleis- one. According to Table 3, even closely re- portion of the Imuruk sequence (Zones A to tocene. lated species, such as Amara alpina and A. H, Fig. 17) is of Illinoian age, as I suggest, bokori, had apparently diverged from their then the distinction between Illinoian age Ecosystem Evolution presumed common ancestor before latest spectra at Cape Deceit and Imuruk is not so The object of this study is to document early Pleistocene time. This seems to be true pronounced. Still, Zone H samples at Im- Quaternary environmental change in the also for many species of the Cryobius com- uruk do contain higher Artemisia percent- Deering—Cape Deceit area (Table 6 for plex. The only definite evidence of phyletic ages than any from unit 1. Perhaps this summary) and to infer, when possible, insect evolution at Cape Deceit is progres- means that sediments equivalent in age to paleoenvironmental conditions in the larger sive wing reduction in Tachinus apterus, a zone H are absent at Cape Deceit. Seward Peninsula region. Fossils from any very minor change considering the long Siberia and Chukotka. Paleoecological one time period within the Cape Deceit se- period of time involved. Thus, fossil evi- data from the eastern U.S.S.R. are relevant quence represent part of a formerly func- dence presented here supports Coope's to the Cape Deceit study. Pollen and mac- tioning ecosystem. Moreover, since most of (1970) conclusion that evolution of insects rofossils from sediments of the Begunov the fossil evidence presented here relates di- has proceeded very slowly, much slower in and Olyor suites in the Kolymian basin rectly or indirectly to tundra environments, fact than is thought by entomologists who (Katz and others, 1970; Matthews, 1974a; this paper is really a partial record of the have dealt with evolutionary and Sher, 1971) show, like Cape Deceit data, evolution of the terrestrial tundra ecosys- phylogenetic problems from the standpoint that hypoarctic tundra already existed in tem at Deering. of relations and distribution of the contem- central Beringia by the early Pleistocene. Ecosystem evolution is defined here as a porary fauna (Ball, 1963; Ross, 1965; Barr, The northernmost areas of the U.S.S.R. and long-term shift in composition and 1969). However, the evidence presented North America may have been lowland dynamics of an ecosystem due ultimately to here pertains chiefly to Coleoptera. Rates of tundra as early as the Pliocene (Matthews, climatic change. This study shows only evolution may well have been faster in 1974b). changes in composition of the system. It is other orders or in other regions (Downes, Petrov (1967) suggests that the pollen inferred that these involved changes in the 1965). spectra from the Chukotkan marine dynamics of the system. The large number of extant Cryobius Pinakul' sequence indicate climatic condi- Changes in the biotic portion of the sys- species from the oldest levels of the Cape tions more severe than at present, a contrast tem occur in two ways: (1) in situ evolution Deceit sequence is surprising. Ball (1963) to an alternate view (Hopkins, 1974) that of plant and animal taxa within the system originally assumed that the subgenus correlates it with the Einahuhtan intergla- — "phyletic ecosystem evolution," and (2) achieved its present diversity largely cial of western Alaska (Hopkins, 1967b). shifts in the relative abundance of taxa al- through speciation in Pleistocene refugia, Domination of Bryales spores, one of the ready existing within the system or sub- ye;: the duration of isolation in such areas facts cited in support of cold climate during stitution by taxa from other contem- was short compared to the longevity of Pinakul' time, could, in my opinion, be the poraneously functioning ecosystems— some of the species listed in Table 3. De- result of differential preservation and con- "nonphyletic ecosystem evolution." spite the close relation of species in the centration of spores in the marine sedimen- Phyletic Ecosystem Evolution. Phyletic Cryobius complex, diversification must tary environment. According to the correla- ecosystem evolution at Cape Deceit is have occurred earlier (Ball, 1969), possibly tion suggested in Figure 5 and Hopkins' illustrated by changes in the early in the Pleistocene or during the (1974) conclusion concerning the climatic Predicrostonyx-Dicrosronyx small mam- Pliocene when lowland tundra habitat was significance of the Pinakul' suite, the Cape mal lineage of microtine rodents (Guthrie first forming in the Northern Hemisphere Deceit Formation predates Pinakul' sedi- and Matthews, 1971). presumably a re- (Hopkins and others, 1971; Matthews, ments. sponse to changing tundra conditions dur- 1974b). At that time the tundra environ- The Val'katlen sequence of Chukotka is ing the last 400,000 to 900,000 yr. ment would not have been continuous equivalent to the Pelukian of Alaska (Hop- Cape Deceit fossils provide no evidence across the Holarctic, as at present, and dif- kins, 1972, 1974; Petrov and Khoreva, of in situ plant evolution. But neither do the ferent tundra-adapted Cryobius species 1968). Dominance of alder pollen in assemblages listed in Figure 11 include could have evolved from existent boreal Val'katlen lacustrine deposits on the north many fossils of leaves or floral parts, which lineages in each of the disjunct tundra re- side of the Gulf of Anadyr is probably due would be required in order to document gions. Initial radiation of Cryobius in the

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new tundra environment probably hap- mation indicate that both the local and re- assume that they are irrelevant to the study pened quickly, but once most terricolous gional environments were more xeric and of tundra ecosystems. But this is not so, for niches in any one tundra region had been grassy than contemporary tundra. Frenzel paleoecological studies such as this one filled, further speciation would have pro- (1968) refers to such an environment as show not only that tundra ecosystems have ceeded very slowly. Finally when, in middle steppe-tundra, and its existence at Deering changed through time, but also that the Pleistocene time, lowland tundra became during Late Wisconsin time agrees with évi- present tundra environment of unglaciated continuous across Holarctica, Cryobius dence presented by Guthrie (1968a), Yurt- areas of Alaska is quite different from the species that had evolved earlier in disjunct sev (1963,1972), and Neilson (1968). But a environment of only 10,000 yr ago. There- tundra regions would have intermingled steppe-tundra environment there as late as fore, it seems appropriate that workers and become widespread. The result is the 12,400 B.P. contradicts Hopkins (1972), interested in the contemporary tundra complex contemporary Cryobius fauna. who regards other data from Imuruk Lake ecosystem and its functioning take into ac- Though this explanation is largely a and Kotzebue Sound to indicate a shift to count the growing body of knowledge con- scenario, it is beginning to have a factual shrub birch-dominated tundra around cerning its history. basis through current work on Pliocene and 13,000 yr ago. Dwarf birches did occur at Compared to the Pleistocene fauna, the late Tertiary northern insect assemblages Deering 12,400 yr ago, but this does not present Holarctic insect fauna is im- (Hopkins and others, 1971; Matthews, rule out survival of steppelike conditions. In poverished. With reference to vertebrates, 1974b). Moreover, it explains both the fact, Imuruk pollen Zone K shows this by this fact has been clear to paleontologists close relation of Cryobius species and their its relatively higher Artemisia and grass for a long time, but it has not been con- apparent longevity. Other groups of closely percentages than occur in surface samples sidered by entomologists, who until re- related arctic animals and plants may have from contemporary tundra with shrub cently were forced to work without the per- had a similar evolutionary history. birches. That steppelike conditions were spective offered by fossils. Ross (1970), in Nonphyletic Ecosystem Evolution. not restricted to the Deering area in latest his excellent paper on the origins of the Since the early Pleistocene, most ecosystem Wisconsin time is also indicated by fossils prairie leafhopper fauna, acknowledges this evolution at Deering has been primarily of of the grazing ungulates, Bison, Mam- problem when he states that, "during the the nonphyletic type — involving almost no muthus, and Equus from sites near Imuruk Pleistocene, patterns of prairie leafhopper in situ evolution of the members of the bio tic Lake (Larsen, 1968; Colinvaux, 1964). evolution, dispersal, and extinction have portion of the system. Table 6 indicates en- Steppe conditions may have been more wide- been much more complex than the rela- vironmental changes that occurred at Deer- spread on Seward Peninsula earlier in Wis- tively simple patterns outlined . . .". The ing since initial deposition of the Cape Deceit consin time; however, this part of the record occurrence of grassland conditions in large Formation. For most of that time, the Deer- is apparently missing at Cape Deceit. areas of Pleistocene Alaska and Siberia, a ing area was evidently the site of a function- In spite of some differences in the se- fact not likely to have been foreseen by the ing tundra ecosystem, but on at least three quence at Cape Deceit and Imuruk, both study of the contemporary fauna alone, cer- occasions, tree line existed at or west of Deer- sequences indicate development of grassy tainly confirms this statement. ing. At the time of the last (Sangamon) inter- steppelike tundra, culminating in late Pleis- Finally, some of the specific environmen- glacial, it stood nearer to Deering than at tocene time. The explanation for this trend tal evidence discussed here relates to a time present. is obscure, but it calls for regional aridity when man is definitely known to have been During the peat 1 interglacial, larches and possibly a more severe temperature re- in Alaska (Larsen, 1968; McKennan and formed tree line in the Deering area. Why gime during the late Pleistocene. The record Cook, 1968), thereby giving archaeologists this should have been so in the early Pleis- from the midcontinent of the United States an insight on the type of environment in tocene and not now is unclear. Assuming (Taylor, 1965) and the record of Eurasia which humans lived and hunted. It should the larch fossils are of L. laricina, then the (Giterman and Golubeva, 1967; Frenzel, be obvious from this report that compari- present restricted Alaskan distribution of 1968; Grichuk, 1971) also show that late son of former man-occupied Alaskan envi- that species may be a consequence of the Pleistocene climate was the most severe. ronments with present-day Alaskan treeless severe climate during one of the late Pleis- The maximum extension toward Alaska of sites may be misleading. tocene cold periods. the Eurasian cold steppe environment also Fossils show that the former tundra envi- occurred during latest Pleistocene time ACKNOWLEDGMENTS ronment at Deering sometimes differed (Grichuk, 1971). G. E. Ball, L. C. Bliss, R. C. Fox, C. S. significantly from that of the present. The The fact that steppe-tundra conditions Schweger, J. A. Westgate (University of Al- problem arises in determining whether such existed throughout most of unglaciated berta), G. R. Coope (University of Birming- differences were of local or regional extent. Alaska during the late Pleistocene (Guthrie, ham, England), and D. M. Hopkins (U.S. Insects and plant fossils from unit 2 of the 1968a; Matthews, 1970, 1974c) has impor- Geological Survey) read and offered com- Cape Deceit Formation indicate an envi- tant implications for a variety of biological ments on this paper. ronment quite different from that of the specialists. For example, the present tundra H. B. Leech (California Academy of Sci- present, but some differences may be owing ecosystem in Alaska is being intensively ences), E. C. Becker, J. M. Campbell, W. J. to local depositional conditions. For exam- studied under the auspices of the Interna- Brown, H. F. Howden, H. Teske, W.R.M. ple, continuing deposition of silt would tional Biological Program (IBP). A wealth Mason, K.G.A. Hamilton (Entomology Re- favor an abundance of Artemisia and hin- of data has been accumulated and is being search Institute, Ottawa), H. Silfverberg der growth of mosses and dwarf birches, used to construct mathematical models of (University of Helsinki), C. H. Lindroth which often root in mosses (Viereck, 1966), the tundra ecosystem. Implicit in this ap- (University of Lund, Sweden), and G. E. therefore partly explaining low Betula pol- proach is that only quantitative data may Ball helped with identification of certain len percentages. On the other hand, low be used, and because the types of informa- specimens or loaned comparative material. percentage of alder pollen in unit 2 proba- tion discussed here and in other paleoen- D. F. Kakachka (Forest Products Labora- bly means colder regional climate. vironmental studies are not readily ex- tory, Wisconsin) identified Larix wood Fossils from unit 2 of the Deering For- pressed numerically, it becomes very easy to from the Cape Deceit Formation.

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Residents of Deering, especially Gilbert Berggren, G., 1969, Atlas of seeds and small Haven, Yale Univ. Press, p. 359-380. Karmun, Johnathan Moto, Thomas Barr, fruits of northwest European plant species .970, Interpretation of Quaternary insect and Chris Jones offered help and hospital- with morphological descriptions, Pt. 2. fossils, in Smith, R. F., and Mittler, T. E., ity during the field portion of th is study. Cyperaceae: Stockholm, Swedish Natl. Sci. sds., Annual review of entomology, Vol. Research Council, 68 p. 15: Palo Alto, Calif., Ann. Rev. Sci., Inc., p. Financial assistance was provided by the Berglund, B. E., and Dige-feldt, C., 1970, A 97-120. Department of Geology (University of Al- paleoecological stucy cf late-glacial lake at Coope, G. R., and Brophy, J. A., 1972, Late gla- berta), International Nickel Company of Torreberga, Scania, south Sweden: Oikos, :ial environmental changes indicated by a Canada, Boreal Institute (University of Al- v. 21, p. 98-128. Coleopteran succession from north Wales: berta), and the Otto Geist Fund (University Bertsch, K., 1941, Ein Bestimmungsbuch zur Boreas, v. l,p. 97-147. of Alaska). Pflanzenkunde der Vorgeschichtlichen Zeit. Dogra, P. D., 1967, Seed sterility and distur- Handbücher der Praktischen Vor- bances in embryogeny in conifers with par- geschichtsforsch ung: Stuttgart, Hans ticular reference to seed testing and tree REFERENCES CITED Reinerth, 247 p. breeding in Pinaceae: Studia Forestalia Agadzhanyan, A. K., 1971, Lemmings of the Beug, H. J., 1961, Leitfaden der Pollenbestim- Suecica, v. 45, 97 p. Dnieper Glaciation on the Russian Plain mung für Mitteleuropa und angrenzende Downes, J. A., 1965, Adaptations of insects in (translation from Russian): Akad. Nauk Gebiete: Stuttgart, Gustav Fischer Verlag, the arctic: Ann. Rev. Entomology, v. 10, p. SSSR Doklady, v. 201, p. 208-211. 63 p. 257-274. 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