In Pluvial Lakes of the Estancia Valley, Central New Mexico

Home , Lake Estancia

The occurrence and paleolimnologic significance of cutthroat trout (Oncorhynchus clarki) in pluvial lakes of the Estancia Valley, central New Mexico

FREDERICK W. BACHHUBER Department of Geoscience, University of Nevada, Las Vegas, Las Vegas, Nevada 89154-4010

ABSTRACT INTRODUCTION annual rainfall of less than 30 cm. Potential evaporation is estimated at 152 cm per year Cutthroat trout (Oncorhynchus clarki) The Estancia Valley is a closed topographic (Harbour, 1958), producing a deficit-water fossils in the Quaternary-age lacustrine sedi- basin in the eastern Basin and Range physio- budget of 122 cm annually. The extreme deficit- ment of the Estancia Valley provide insight graphic province near the geographic center of water budget precludes the occurrence of natu- into the paleolimnologic history of the valley. the state of New Mexico (Fig. 1). The highest ral perennial water bodies within the lower- The presence of fish is evidence that a pluvial elevations (above 3,050 m) within the wa- elevation parts of the valley. system overflowed into the Pecos River watershed are along the western rim in the Man- A series of late Holocene-age, playa-floored tershed. Most likely, the overflow occurred zano Mountains, whereas the lowest elevations deflation basins is incised in the floor of the during the expansion of Early Lake Estancia, (1,842 m) are along the central topographic axis. Estancia Valley (Fig. 1). The deflation basins are an Illinoian or pre-IUinoian pluvial lake Within the low-elevation area, mean annual cut into Quaternary-age sediment, exposing a known only in subcrop. Once established in temperature approximates 10 °C with a mean complex stratigraphic sequence that reflects the Estancia watershed, trout occupied headwater streams and only intermittently migrated and resided in developing lake systems. The headwater streams served as refugia through the Sangamon(?) and early and middle Wisconsin time when a fresh-water lake did not exist in the valley. With the ad- vent of full-pluvial conditions during the late Wisconsin, trout migrated from headwater streams into the first of three fresh-water phases of Late Lake Estancia. On two occa- sions, climate shifted to warmer and drier conditions, causing significant lake-level drawdown. Salinity increased and trout were eliminated from the lake, only to be reintro- duced during the next fresh-water phase. Near the close of the late Wisconsin, Late Lake Estancia waned and desiccated, but headwater streams remained as fish refugia. Following the interpluvial episode, the basin again filled, culminating in Lake Willard, considered to be of latest Wisconsin age. With evolution into a fresh-water body, trout migrated into a lake environment for the last time. Ensuing hot/dry conditions brought about the desiccation of Lake Willard and severely impacted the headwater streams. This factor, in possible combination with human fishing activity, led to the elimination of fish from the Estancia Valley after a con- tinuous occupation of at least 130,000 yr. Figure 1. Index map of the Estancia Valley in central New Mexico, indicating present major river systems (left), distribution of modern playas, and location of playa E-28 and E-22 (right).

Geological Society of America Bulletin, v. 101, p. 1543-1551, 5 figs., December 1989.

1543

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major climatic change with well-delineated is exposed along the flanks of the numerous de- (Bachhuber and McClellan, 1977; Bachhuber, pluvial and interpluvial intervals. The pluvial in- flation basins located near the topographic axis 1982), this part of the section represents various tervals contain Oncorhynchus clarki (cutthroat of the valley. The most deeply incised deflation depositional environments including brackish- trout; formerly recognized as the genus Salmo) basin, E-28 (Fig. 1), contains 11 m of sediment water paludal, shallow saline, and hypersaline fossils. The presence of O. clarki in the Quater- that represents (1) the upper 1.5 m of an early to lacustrine. It is now clear that the sequence con- nary record of the valley extends the geographic middle Wisconsin section, (2) Late Lake Estan- tains the uppermost part of a middle Wisconsin range of the trout and provides insight into the cia of late Wisconsin age, (3) a late Wisconsin section and a late Wisconsin littoral facies of the paleoecologic and paleolimnologic history of the interpluvial episode, and (4) Lake Willard, a earliest expansion of Late Lake Estancia. The area. latest Wisconsin pluvial stand. Subsurface sam- littoral facies is subdivided into two units (Fig. The geomorphic evidence of a pluvial sys- ples collected at the base of the E-28 section 3), the lower of which contains an abundance of tem within the valley has been recognized since with a bucket auger extend the early to middle foraminifers, indicating that embryonic Late the turn of the century (Keyes, 1903). Meinzer Wisconsin section to a total thickness of 10.5 m. Lake Estancia was a shallow saline body. The (1911) described a series of well-preserved Water-well data (Titus, 1969) indicate that this middle Wisconsin portion of the exposed section wave-cut cliffs, terraces, beaches, spits, and bars. section rests on 17 m of Sangamon(?)-age allu- is characterized by an abundance of Ruppia The highest shoreline features described by vium and dune deposits and 7 m of Illinoian(?)- maritima (ditchgrass) and charophytes (stone- Meinzer are 35 m below the present topographic age lacustrine sediment. wort) as well as foraminifers, all indicators of sill in the southeast part of the basin. The sill, at brackish to saline conditions. Ruppia achenes a minimum elevation of 1,932 m (Hawley and Pre-pluvial Sediment have been dated at 35,650 +3000/-2180 yr B.P. others, 1982), is a broad, gently sloping saddle (A-4903) and from a correlative section at that separates the Estancia Valley from the Pinos The lower 3 m of the exposed stratigraphic >33,000 yr B.P. (A-1001). The radiocarbon Wells basin. The location of the highest strand- section at E-28 consists of interbedded clay, silt, dates suggest that the lower exposed portion of line below the sill led Meinzer and other re- and gypsarenite. Referred to as the "pre-pluvial the "pre-pluvial phase" sediment predates the searchers (Leopold, 1951; Harbour, 1958) to phase" of Late Lake Estancia in earlier work climatic change responsible for the growth of conclude that the pluvial lake did not overflow Late Lake Estancia and represents depositional and never evolved into a fresh-water body. environments different from that which led to the eventual expansion of the lake during late Later work in the basin (Lyons, 1969; Titus, LATE HOLOCENE Wisconsin time. 1969) suggests that a pluvial system was much Depth (no/"^ Dune Deposits & Deflation deeper and greater in areal extent than originally 0 An 11-m-deep subsurface section was ex- proposed. Both researchers reported shoreline LATE WISCONSIN tracted with a bucket auger, sampling at 10-cm features elevationally higher than those reported Pluvial-lake & intervals. Preliminary work (Bachhuber, 1987, o a Interpluvial Deposits by Meinzer (1911). Titus, in particular, de- 3 1988) indicates that the subsurface section is sed- scribed a wave-cut cliff and beach association at imentologically and biostratigraphically similar an elevation of 1,939 m, or 7 m above the topo- .1 0 MIDDLE WISCONSIN to that of the previously described "pre-pluvial graphic sill. Bachhuber (1971) also recognized Paludal & Saline- phase." Ruppia and charophytes are present possible shoreline features near the elevation of lacustrine Deposits throughout the section, and foraminifers are the sill. These features, together with those de- EARLY WISCONSIN abundant in discrete stratigraphic horizons. Alluvium & Saline- scribed by Lyons and Titus, are termed "older lacustrine Deposits Even though chronologic control is lacking, the shoreline features" in contrast to the "younger 20 upper radiocarbon dates and extrapolated depo- shoreline features," which are described by sition rates suggest an early Wisconsin age for Meinzer (1911). The older shoreline sequences the lower part of the section. Significantly, from are highly dissected and widely scattered along what appears to be an early through middle SANGAMON (?) the eastern margin of the watershed. In contrast, Wisconsin subsurface section, there is no record 30 Alluvium & the younger shoreline sequences are prominently Dune Deposits of a fresh-water body within the Estancia developed on most interior slopes surrounding Valley. the valley. Although individual "older shoreline fea- Late Lake Estancia ILLINOIAN (?) 40 tures" may be questionable as to origin, the Pluvial-lake Deposits geomorphic evidence suggests that a lake stand (EARLY LAKE ESTANCIA) The "pre-pluvial phase" sediment is overlain reached the topographic sill and overflowed into by intercalated thick-bedded, flint-gray clay and adjacent basins and, ultimately, into an exter- thin-bedded silty clay, silt, and gypsarenite with TERTIARY (?) nally drained river system. This contention is Alluvium the interval capped by a 2.5-m massive-bedded, supported by the presence of trout remains 50 • flint-gray clay. The sediment represents the late within the Quaternary sediment of the valley. Wisconsin-age Late Lake Estancia pluvial system. On the basis of sedimentology and biostra- PRE-TERTIARY STRATIGRAPHY Bedrock tigraphy, the Late Lake Estancia interval (Fig. 3) is subdivided into five phases: (1) an initial fresh- Outcrop and subcrop data indicate that the Figure 2. Generalized stratigraphic section water phase, (2) the first partial drawdown Estancia Valley contains a Quaternary record of Quaternary and pre-Quaternary deposits phase, (3) a middle fresh-water phase, (4) the that may extend as far back as Illinoian time of the Estancia Valley, derived from outcrop second partial drawdown phase, and (5) a final (Fig. 2). A late Quaternary stratigraphic section and subcrop data. fresh-water phase. The middle fresh-water phase

CO INFERRED * 1983), makes the date questionable. I believe CO tn SALINITY (TDS) r » S that the 20,040 yr B.P. date preceding the final ¡5 S « WATER DEPTH (m) K fresh-water phase better fits the regional Depth (m) S ° O "TU chronology. Willard Soil Estancia Playa Complex

Lake Willard The Late Lake Estancia sediment is overlain by finely intercalated, red to brown silt and clay and white, fine- to medium-grained gypsarenite. Estancia Playa Inclined bedding, laminae truncations, and cut- Complex and-fill structures are common. This unit, referred to as the "Estancia Playa Complex" (Fig. 3), represents deposition in a shallow, broad Late Lake Estancia playa developed on the Late Lake Estancia desiccation surface. Sedimentation occurred in * final freshwater response to intermittent flooding of the lacus- phase trine plain. Although radiocarbon dates have not been obtained from the unit. Bachhuber (1982) considered that the Estancia Playa Complex * second partial marked the close of late Wisconsin glacio- drawdown phase pluvial conditions in the Estancia Valley. A new * middle freshwater phase _ radiocarbon date on the overlying Lake Willard sediment, however, suggests that the Estancia * first partial Playa Complex may instead represent an epi- drawdown phase sode of desiccation within the upper part of late * initial freshwater Wisconsin time. phase * littoral fades brackish S" Lake Willard

saline - 9 The sediment of the Estancia Playa Complex is vertically transitional with the flint-gray clay Middle Wisconsin -1 0 of the Lake Willard unit (Fig. 3). The gradual Paludal and Saline — >33,000 change in sediment character indicates that basin 35,650 Lakes Interval flooding and the ephemeral lakes characteristic -1 1 of the Estancia Playa Complex became more * = anomalous ? X =Cylherissa lacustris persistent, with eventual evolution into the Lake Willard pluvial stand. Similar to Late Lake Es- Figure 3. Quaternary stratigraphic section of playa E-28 (see Fig. 1) with composite biostrat- tancia, the embryonic phase of Lake Willard igraphic column showing distribution of five key taxa. Also included are the inferred salinity contains an assemblage of foraminifers, indicat- and water depth of various pluvial and interpluvial episodes. ing that the lake evolved from an initial saline condition (in the range of 25°/0o to 35°/oo TDS) to a fresh-water stand (Bachhuber and McClel- and one of the partial drawdown phases were charophytes, and brackish-water ostracodes are lan, 1977). Until recently, radiocarbon dates not previously recognized (Bachhuber and abundant. The presence of Ruppia, especially, were not available directly from the Lake Wil- McClellan, 1977; Bachhuber, 1982). indicates that salinity of the partial drawdown lard sediment, but Bachhuber (1982) estimated The three fresh-water phases and, presumed- phases was higher than that of the bracketing that maximum development was reached in late ly, deeper-water phases, of the Late Lake Estan- fresh-water phases. The salinity tolerance of the early Holocene time, about 8,000 yr ago. A re- cia interval are flint-gray clay units, the first and submerged-aquatic plant is broad, but its associ- cently obtained radiocarbon date suggests that last of which have an abundance of fresh-water ation with saline lakes is consistent in all species Lake Willard could represent the last pluvial gastropods and pelecypods. The initial fresh- known (Verhoeven, 1979; Husband and Hick- peak of the late Wisconsin. The accelerator date water phase also contains an abundance of tiger- man, 1985). Ruppia achenes from the second on 50 mg (1,700 adult ostracode valves) of salamander bones (Ambystoma tigrinum) that partial drawdown phase have been dated at Candona rawsoni from the middle of the Lake were radiocarbon dated at 24,300 ± 560 yr B.P. 12,400 ± 450 (GX-1637) and 20,040 + 240 yr Willard section indicates 12,460 + 135 yr B.P. (AA-1868). This marks the beginning of Wis- B.P. (AA-1867). The 12,400 yr B.P. date was (Beta-25819, ETH-4155). This date may coin- consin glacio-pluvial conditions in the Estancia obtained on seeds that had an unexpectedly low cide with the highest lake level of Lake Willard. Valley. carbon yield relative to total sample weight. The high stand was followed by gradual drawdown and eventual desiccation. Ensuing playa The two intervening partial drawdown phases This, in addition to the date placing the Estancia sedimentation and eolian activity on the Lake are marked by a high gypsarenite and silt con- Valley pluvial system out of phase with other Willard lacustrine plain resulted in the forma- tent. Mollusks are absent, whereas Ruppia, regional systems (Smith and Street-Perrott,

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tion of the Willard soil, a 1-m-thick, indurated- With recently obtained subcrop data and the its major tributary, the Pecos River (Smith, gypsarenite cap. I now consider the Willard soil finding of fish in all the developmental phases of 1984) (Fig. 1). This allopatric form may have as marking the close of late Wisconsin pluvial Late Lake Estancia and especially in Lake Wil- the closest affinity to the Estancia Valley popula- conditions. lard, a new paleolimnologic model is presented tion. Behnke (1988, personal commun.), how- herein. ever, has speculated that the Estancia fish may BIOSTRATIGRAPHY OF be a descendant of an extinct middle Pleistocene FISH REMAINS TAXONOMY AND HISTORIC (ca. 700,000 yr B.P.) cutthroat trout found in the DISTRIBUTION OF FISH San Luis Valley, Colorado (Rogers and others, Fish bones were first found in the Estancia 1985). If this is the case, then the Estancia form sediment by J. Piatt Bradbury in 1966. Since Hundreds of isolated bones, mainly ribs and has no direct lineage with, and is much older Bradbury's discovery, numerous bones, such as vertebrae, have been removed from the Estancia than, any of the four major subspecies of cut- skull fragments, ribs, vertebrae, jaw remnants, section, but only one species of fish seems to throat now recognized (Behnke, 1988). and teeth, have been sieved and picked from the have inhabited Late Lake Estancia and Lake lacustrine clay and silt. The bones are generally Willard. This species has been identified as On- PALEOECOLOGY disarticulated and widely scattered through the corhynchus clarki (cutthroat trout) by W. J. sediment matrix, but concentrations are found Koster (1969, personal commun.). The initial Ecologic data on Oncorhynchus clarki sug- along sandy bedding planes. A number of com- identification was based on bone comparison gest that the fossil occurrence of the species by plete skeletons were found but, owing to the with modern specimens of O. clarki The identi- itself is not a sensitive indicator of paleoecologic highly friable nature of the sediment upon dry- fication was confirmed by G. R. Smith (1977, conditions. In general, trout are envisioned to ing, none could be removed intact from the field. personal commun.), who examined much of the occupy cold, fresh-water lakes and rivers, but O. Vertebrae and ribs from one fish skeleton were Estancia collection, comparing bones with all clarki, in particular, is reported under thermal dated at 11,740 ± 900 yr B.P. (A-1002). In view native western trout. The collection includes and saline-alkalinity conditions that vary of the regional chronology of other high-water many distinctive bones that are virtually identi- significantly. stands and the overlying Lake Willard date of cal to those of recent O. clarki 12,460 yr B.P., the fish bone date is question- Smith (1977, personal commun.) noted that Temperature able. The specimen used for radiocarbon dating distinctive characters for separating the Estancia was at least 27 cm long (a part of the skull was fossils from O. aguabonita (golden trout), O. In Pyramid Lake, northwestern Nevada, the missing). The preservation of this particular apache (Arizona trout), and O. gairdneri (rain- "sink" for the Truckee River, and in the Pleisto- specimen is remarkable because the bone mate- bow trout) include the prominent ventro-medial cene Lake Lahontan basin (Benson and Thomp- rial is not evidently altered, and a dark, organic- ridge of the dentary, the slender preopercle, and son, 1987), O. clarki henshawi formed the base rich outline delineates the general form of the the extreme post-ventral angle of the opercular of an important commercial and recreational fish. Skin fragments are preserved, with the scale arm of the hyomandibular. The maxilla of the fishery. Pyramid Lake is a warm monomictic pattern and structure clearly evident. The part of Estancia form lacks the prominent median dor- lake in a climatic setting similar to that of the the skeleton not used for radiocarbon dating is sal groove and the anteriorly directed premaxil- Estancia Valley today. Profundal water temper- deposited at the New Mexico Museum of Natu- lary process of O. gilae (Gila trout). ature of the lake is relatively constant at 6 °C, ral History, Albuquerque (NMMNH 32), along It is critical to differentiate the Estancia fish but surface-water temperature rises to 23 °C by with a representative collection of Estancia Val- remains especially from O. apache and O. gilae. the end of summer (Galat and others, 1981). ley fish (NMMNH 33 through 35). Both are closely related to O. clarki and pres- Even though the higher temperature is consid- Fish remains have now been found in four ently are found in drainage systems relatively ered to be lethal to trout, they can occupy the stratigraphic levels: (1) the initial fresh-water near, but west of, the Estancia Valley. The his- colder parts of the hypolimnion during the phase, (2) middle fresh-water phase, (3) the final toric distribution of O. apache and O. gilae is the summer. Behnke (1981), however, observed an fresh-water phase (all of Late Lake Estancia), upper headwaters of the Salt, Little Colorado, unnamed subspecies of cutthroat in a Humboldt and (4) Lake Willard. Only in part are these and Gila (Fig. 1) Rivers of Arizona and western River headwater stream (north-central Nevada) fresh-water stands defined by the presence of New Mexico (Rinne, 1980a, 1980b). If the Es- with temperature as high as 25.5 °C. The obser- cutthroat trout. In earlier work (Bachhuber, tancia remains had proved to be either species, vation demonstrates that at least one subspecies 1982), fish were reported from only two strati- implications for lake drainage and fish migration of cutthroat trout can be eurythermal. graphic horizons that correlate with the initial would be significantly different. The high temperature tolerance of modern fresh-water phase and the final fresh-water The identification of Oncorhynchus clarki in cutthroat trout, therefore, seems to give little di- phase of Late Lake Estancia. No fish bones were Estancia Valley Quaternary sediment extends, rect insight into the temperature conditions of found in Lake Willard sediment. On the basis of but does not significantly alter, the geographic Late Lake Estancia and Lake Willard. Nonethe- these reported occurrences of fish, a model was range of the fish, because it has the widest histor- less, along with other paleontologic evidence, at presented in which Late Lake Estancia over- ic distribution of any western trout. Anadromous the time of deepest lake development, Late Lake flowed during the initial fresh-water phase, with forms are found along the Pacific coast from Estancia and Lake Willard were probably cold- a possible second overflow occurring during the California to Alaska. Nonanadromous, allopat- water bodies. Marine foraminifers found in the final fresh-water phase. Even though Bachhuber ric forms occupy headwater areas of interior and early, saline, developmental phase of both lakes (1971) recognized that the geomorphic evidence externally drained basins from Alberta through imply that the summer temperature was 9.7 °C does not directly support a late Wisconsin over- California to New Mexico (Behnke, 1980). In lower than the present (Bachhuber and McClel- flow episode, the apparent need to have lake areas adjacent to the Estancia Valley, native lan, 1977). The magnitude of temperature de- overflow for the establishment of fish led to the populations of cutthroat trout (O. clarki vagina- pression suggested by foraminifers is consistent miscalculation of timing of the overflow event. lis) are in the headwaters of the Rio Grande and with that proposed by Galloway (1970, 1983)

and Brakenridge (1978). If this condition, which range of tolerance for modern populations. Cut- ring when alkalinity levels reach 0.5°/oo to was present during the expansion of the lakes, throat trout commonly exist in infrahaline bod- 1.0°/oo. Cutthroat trout in Walker Lake, how- prevailed through later developmental phases, ies, but they also are in Pyramid Lake, with a ever, have adapted to 3.5°/oo bicarbonate alka- then metalimnion temperature would have been TDS of about 5°/oo, and in Walker Lake (also linity and a sulfate-ion level of 2.5°/oo (Galat and lower than 10 °C during the summer months. located in northwestern Nevada in the Pleisto- others, 1985). According to Galat and others Certainly, temperatures were much below the cene Lake Lahontan basin), with a TDS of (1985), the sulfate-ion level, in particular, may lethal limit for O. clarki, although as both lakes 12°/oo (Galat and others, 1985). The problem of be the most important limiting factor. Even waned, temperature increases may have had an establishing a saline-tolerant limit for cutthroat though cutthroat trout are tolerant of high salin- adverse effect on fish populations. trout is complicated further by recognition that ity and high specific-ion levels in fluctuating fish appear to be limited more by specific-ion lakes, the sulfate-ion concentration may be the Salinity levels than by salinity per se. R. J. Behnke factor that controls their apparent distribution in (1988, personal commun.) has indicated that the pluvial systems of the Estancia Valley. In addition to cold-water environments, trout high carbonate-bicarbonate and sulfate-ion lev- There is no reason to believe that the Estancia also are generally considered to be residents of els interfere with the excretory and physiological trout occupied water conditions beyond the fresh-water bodies, but there is a considerable processes of fresh-water fishes,wit h stress occur- range of modern populations. In fact, based on

ESTANCIA VALLEY AND SURROUNDING AREA

Inferred Area! Extent: pool elev.

] Early Lake Estancia; 1939 m

] Late Lake Estancia: 1897 m

?1870 m Figure 4. Inferred areal extent of Early Lake Es- tancia, Late Lake Estan- cia, and Lake Willard at the time of highest lake level for each episode. Early Lake Estancia maximum development indicates overflow across the topographic sill, into the Pinos Wells and Encino basins and ultimately into the Pecos River drainage system (see Fig. 1). Line A to D is the location of the long profile of Figure 5.

Contour interval 100 feet up to 6400 teet

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other paleontologic evidence, it appears that the Estancia form, for the most part, was more re- Feet stricted than are modern populations. The 6400" presence of O. clarki in the three fresh-water phases of Late Lake Estancia and Lake Willard suggests that water chemistry was in the range of infrahaline to slightly saline. This is supported by the presence of a fresh-water assemblage of 6200- mollusks, ostracodes, and Pediastrum and other algae (Bachhuber, 1971) in a flint-gray clay indicative of deep water. The fresh-water stands of 8 km Late Lake Estancia and Lake Willard are in great contrast to the early saline developmental 6000- 5 mi phases (indicated by foraminifers) of both lakes and the two brackish-saline partial drawdown phases (indicated by Ruppia) of Late Lake Es- tancia. Fish bones are absent in all of these presumed saline phases. Although fish fossils have not been found in the partial-drawdown phases, the adaptability of modern cutthroat trout sug- cene time. Trout could have entered the Illinoian(?) Pluvial and Lake Overflow gests that their presence in these sections would Estancia basin and become established in head- not be unwarranted. Likewise, the presence of water streams at any time prior to basin closure. Originally, Bachhuber (1982) equated over- trout stratigraphically above documented in- If migration occurred in the middle Pleistocene, flow with the first fossil occurrence of fish in the frahaline stages of Late Lake Estancia and Lake then the Estancia fish are probable descendants initial fresh-water phase of Late Lake Estancia. Willard is consistent with this adaptability. Only of the extinct (ca. 700,000 yr B.P.) San Luis If Late Lake Estancia had overflowed, then the in the uppermost stratigraphic parts of both Valley form (Rogers and others, 1985). This hy- spillway would have been over the topographic lakes are fish bones again absent. It is assumed pothesis dictates that a relict fish population sill located along the southeast margin of the that the waning phases had evolved into highly would have existed in the Estancia Valley wa- basin (Figs. 4 and 5). Drainage would have con- saline end members, or the sulfate-ion level had tershed from at least the middle Pleistocene into tinued into the adjacent Pinos Well basin, increased to the lethal point for cutthroat. The Holocene time. Because bone morphology of the thence into the Encino basin, and finally into latter contention is partly supported by the pres- Estancia trout is virtually identical with that of either Pintada Canyon (Bachhuber, 1982) or a ence of Limnocythere staplini, an ostracode that modern cutthroat trout, this hypothesis seems topographic sag located east of the present city typically lives in carbonate-depleted, high-sul- unlikely. Genetic isolation of this duration of Encino (Kelley, 1972). In either direction, fate, saline waters (Forester, 1983). should have produced significant morphological drainage from the Encino basin would eventual- variation. It is not known whether bone mor- ly join the Pecos River. PALEOLIMNOLOGY phology of the Estancia fish is comparable with The general outlet route into the Pecos River the extinct San Luis Valley form. This has yet to is still considered herein to be the direction of The presence of fish in what is presently a be tested. lake overflow, but I no longer believe that over- closed physiographic basin poses a paleolimno- Another possibility for fish introduction into a flow occurred during the late Wisconsin. Haw- logical problem, but regardless of the numerous closed basin is via drainage-divide transfer or ley and others (1982) noted that surficial imaginative dispersal mechanisms proposed, headwater-stream diversion. This mechanism, deposits associated with some of the "older "most fish occur where they do because they or initiated by headward erosion or landsliding, is shoreline features" have prominent horizons of their ancestors swam there" (Koster, 1957, p. 1). well documented (Hubbs and others, 1974) and clay and soil-carbonate accumulation. Accord- It is the geologist who most often questions this is responsible for the distribution of some allo- ing to Hawley and others (1982), the degree of assertion; yet, it is the geologist who provides the patric fish populations in the Great Basin. soil development indicates that lake expansion data that make the concept axiomatic (see Stream diversion can happen at any time, but to the topographic sill probably last occurred in Hubbs and Miller, 1948). The only viable the highest incidence should occur when streams pre-Wisconsin time at least 130,000 yr ago. This mechanism for the introduction of fish to the have a high perennial discharge. In the presently is indirectly supported by the early to middle Estancia Valley is by swimming via either a arid Estancia Valley, this would coincide with Wisconsin record obtained from the Estancia through-flowing fluvial system predating basin times of full glacio-pluvial climatic conditions. Valley (Bachhuber, 1987, 1988), which has no closure, a headwater-stream diversion, or a lake Therefore, if trout entered the Estancia basin by indication of a fresh-water stand. If overflow did overflow. The question is not whether the fish stream diversion, then the most likely time of not occur during late Wisconsin time, and if swam into the basin, but rather the timing and arrival would be during Ulinoian(?) or late Wis- there are no indications of fresh-water bodies in route of introduction. consin time. the early to middle Wisconsin, then overflow It is clear that from late Miocene to probably The introduction of fish into the Estancia Val- most likely occurred during the expansion of early Pleistocene time, the Estancia Valley had a ley by either an early through-flowing fluvial Early Lake Estancia, a pluvial system described through-flowing fluvial system into the Encino system or by headwater-stream diversion cannot by Titus (1969) from test-hole data. The Early area and the ancestral Pecos/Brazos River net- be refuted with present geologic or paleonto- Lake Estancia section consists of from 6 to 7 m work (Kelley, 1972; Hawley, 1984). Through- logic data. I believe, however, that a stronger of tan to gray silty clay and thin-sand stringers. flow was broken, however, by middle Pleisto- case can be made for lake overflow. Titus did not assign an age to Early Lake Estan-

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Sill 190S m

— 1850 Late Lake Estancia sediment

Early Lake Estancia sediment IB IC ID

Figure 5. Long profile through the Estancia Valley to the Encino basin (A to D, Fig. 4). Maximum lake-level elevations of Early Lake Estancia, Late Lake Estancia, and Lake Willard and Early Lake Estancia overflow into the Pecos River drainage system are indicated. Maximum lake depths cited in text are based on lake-level elevations and sediment-column elevations indicated in the figure. (Note overlap where figure parts join.)

cia, but in stratigraphic context, it appears that it of 1,939 m, producing the wave-cut cliff/beach lation. Other fish species may not have survived, is no younger than Illinoian in age, with the association described by Titus (1969) but still however. One of the paradoxes of the late Wis- overlying Medial Sand (Titus, 1969) being no not dated or definitely shown to be a shoreline consin lakes is that they have a highly diverse younger than Sangamon in age. This general feature. At this stand, the lake would have had a biota but only one species of fish. Hundreds of chronology better fits the timing of overflow minimum depth of 125 m and covered an area identifiable bones have been found, and so the proposed by Hawley and others (1982) than of 2,340 km2. The total lake pool, including the monospecific occurrence is not an artifact of does a late Wisconsin overflow. The ramifica- flooded Pinos Wells and Encino basins, encom- specimen collection. The presence of O. clarki tion of this hypothesis is that cutthroat trout en- passed 2,860 km2 (Fig. 4). The glacio-pluvial only is a function of either this species being the tered the Estancia Valley, via the Pecos River climate responsible for the growth of Early Lake only successful immigrant into the basin, per- system, considerably before the late Wisconsin Estancia likely gave rise to a fully integrated, haps owing to a series of small waterfalls negoti- pluvial maximum. perennial-stream network draining out of the able by trout but not by other indigenous fishes, Although paleontologic evidence is lacking in Manzano and Sandia Mountains (Fig. 4). This or being the only survivor of Sangamon(?) cli- support of Early Lake Estancia overflow, there assumption is made because cutthroat is an obli- mate. This paradox would be resolved by find- is indirect evidence that the lake was a fresh- gate stream spawner, and the existence of peren- ing fish remains in Early Lake Estancia sedi- water body, a condition that would have pre- nial streams was a requirement for the mainte- ment, especially if more than one species occurs. vailed during overflow. In the E-28 bucket- nance of a resident population in the lake. auger samples, stratigraphically above the Early Consequently, with spawners entering the rivers Early to Middle Wisconsin Subpluvial Lake Estancia sediment and of probable early during the spring, a resident riverine population through middle Wisconsin age, low densities of would invariably be established. This is a pre- Cutthroat trout not only survived the warm/ fresh-water ostracodes are associated with an requisite for the long-term survival of the fish in dry climate of the Sangamon(?) interpluvial epi- abundance of foraminifers and Ruppia. Because the watershed. sode in headwater streams, but also the cold/dry both organisms are indicative of a shallow, sa- climate (Bachhuber, 1987) of the early through line lake, the ostracodes must have been re- Sangamon(?) Interpluvial middle Wisconsin interval. The paleontologic worked from an older but elevationally higher, evidence indicates that the floor of the Estancia basin-margin, fresh-water facies. From what is Near the close of the Illinoian(?), Early Lake Valley was covered by persistent brackish, saline presently known of the subsurface stratigraphy Estancia likely evolved into a saline body, and and hypersaline lakes throughout the period. of the valley, Early Lake Estancia sediment the lacustrine fish population was eliminated. Because evidence of an early or middle Wiscon- could be the only contributor of the fresh-water Eventually, Early Lake Estancia desiccated, as sin fresh-water pluvial system is lacking, trout ostracodes. shown by the presence of the Medial Sand, a must have remained in headwater-stream On the basis of the apparent fresh-water na- 17-m-thick alluvial and eolian unit reported by refugia. ture of Early Lake Estancia and the geomorphic Titus (1969) from subcrop data. Apparently, the evidence, I believe that cutthroat trout entered warm, dry climate of the Sangamon(?) was not Late Wisconsin Pluvial the basin during an Early Lake Estancia over- severe enough to eliminate completely the high- flow event and established a resident lacustrine elevational headwater streams. These streams, With the onset of late Wisconsin pluvial con- population. When the lake overflowed, Early even if reduced to small intermittent segments, ditions, the last saline lake of the middle Wis- Lake Estancia water level reached an elevation retained their reproductively viable trout popu- consin expanded and evolved into an infrahaline

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body. Perennial streams became fully integrated, Late Lake Estancia desiccated near the close Early Lake Estancia, salinity and water tempera- and O. clarki migrated into Late Lake Estancia of the late Wisconsin pluvial maximum. The ture most likely increased to the lethal limit, and from headwater réfugia, establishing a lacustrine lacustrine plain was subaerially exposed but in- the resident lacustrine-trout population was population after a hiatus of at least 100,000 yr. termittently flooded, with the resultant accumu- eliminated. By this time, a resident riverine pop- The sediment thickness of the initial fresh-water lation of playa sediment. On the basis of the ulation was established in headwater streams, phase suggests that trout resided in the lake for a 12,460 yr B.P. date from overlying sediment, the permitting the long-term survival of trout in the relatively short time. As the lake level dropped, desiccation event and subsequent deposition of Estancia Valley. The riverine population sur- dissolved-ion concentration increased (Fig. 3). the Estancia Playa Complex sediment occurred vived in headwater streams through the warm/ Fish were eliminated from the lake, whereas during a period of aridity in the latter part of late dry interpluvial climate of the Sangamon(?) (al- Ruppia proliferated. The climatic shift responsi- Wisconsin time. luvial and eolian deposition) and implied ble for the first partial drawdown phase most Following deposition of the Estancia Playa cold/dry subpluvial climate of early and middle likely had a significant effect on lake chemistry, Complex sediment, the basin began to fill, in- Wisconsin time (shallow saline-lake deposition). sedimentologic processes, and water tempera- itially with a saline body populated by forami- At the close of the middle Wisconsin (prior to ture, but the network of headwater streams re- nifers. Additional expansion culminated in the 24,000 yr ago), a climatic shift into cold/moister tained a resident trout population. These popula- Lake Willard pluvial stand. Cutthroat trout mi- conditions initiated the development and expan- tion centers became the nuclei for reintroduction grated, for the last time, into the lake from the sion of pluvial Late Lake Estancia. My assertion of trout into the Late Lake Estancia middle surrounding highland streams. Fish bones asso- that there was an actual increase in precipitation fresh-water phase and, later, into the final fresh- ciated with mollusks and the ostracode C. lacus- is based on work in progress on the early and water phase and, eventually, into Lake Willard. tris indicate an initial infrahaline phase, but this middle Wisconsin section where cold conditions Because the middle fresh-water phase does condition was short lived. Salinity most likely appear to produce only shallow saline lakes. In not have an assemblage of mollusks, this sug- soon increased, high enough to eliminate mol- order for a saline lake to expand into a deep gests that the expanding lake freshened enough lusks and C. lacustris but not to the toxic level fresh-water system, the added dimension of in- for the establishment of trout, but did not neces- for fish. Fish are present throughout much of the creased precipitation must be invoked. sarily evolve into an infrahaline body. Following remaining section represented by Lake Willard. Three fresh-water phases separated by partial the apparent short-term freshening of the middle It is difficult to determine the maximum size drawdown phases are recognized in the Late fresh-water phase, salinity again increased to the and depth of Lake Willard because shoreline Lake Estancia stratigraphic section. Multiple point where fish could no longer survive. This features cannot be unequivocally attributed to phases attest to the climatic instability of the marks the second partial drawdown phase char- the lake. Nonetheless, at E-22 (the easternmost time period, with full pluvial conditions being acterized again by the establishment of Ruppia. playa, see Fig. 1), the Lake Willard flint-gray interrupted by warmer or drier conditions. The For a third time, the lake expanded and fresh- clay, typical of the more interior playa sections, three fresh-water phases contain cutthroat trout ened and was populated by trout. This was the becomes laterally sandy and thinly bedded, and remains, indicating that headwater streams beginning of the final fresh-water phase. The more than half of the section is represented by a served as distribution centers for reintroduction presence of mollusks and ostracodes suggests littoral sand facies. The shallow-water facies of fish after each partial drawdown phase, the that an infrahaline condition existed early during suggests that the shoreline did not extend east- last of which occurred about 20,000 yr ago. I the final fresh-water phase, but this condition erly much beyond the E-22 section and thus, believe that Late Lake Estancia reached its was maintained for only a short period. Mol- water depth was considerably less than that of greatest size and depth during the final fresh- lusks and Cytherissa lacustris, a distinctive Late Lake Estancia. If the lake rose to Harbour's water phase, although this condition also could fresh-water ostracode (Fig. 3), disappear from "B" shorelines (1958), then the lake would have have been reached during the initial fresh-water the record, but fish continue, indicating a possi- stood at an elevation of about 1,870 m. This phase. ble evolution to higher salinity, but relatively appears to be a reasonable extrapolation, based A major climatic shift (prior to 12,500 yr low sulfate-ion or carbonate-bicarbonate levels. on the E-22 stratigraphic section, even though ago) resulted in the desiccation of Late Lake This condition prevailed through much of the the "B" shorelines could be Late Lake Estancia Estancia. At this time, subaerial sediment, rep- stratigraphie interval represented by the final recessional features. At this level, the lake would resented by the Estancia Playa Complex, ac- fresh-water phase. have been 20 m deep (Fig. 3), with a surface cumulated on the Late Lake Estancia lacustrine 2 The final fresh-water phase was the time of area covering 610 km (Fig. 4). plain. Interpluvial climatic conditions were maximum lake development during the late warm and/or dry, but not extreme enough to Wisconsin. The lake level rose to an elevation of PALEOCLIMATIC IMPLICATIONS alter severely headwater streams within the Es- 1,897 m, creating the highest "younger shoreline AND SUMMARY tancia Valley watershed. These streams must feature" described by Meinzer (1911). At this have retained a reproducing trout population, as time, Late Lake Estancia was about 50 m deep The presence of Oncorhynchus clarki fossils was the case during the Sangamon(?), early and and oligotrophic (Fig. 3), covering a surface area in the Estancia Valley suggests that a pluvial middle Wisconsin, and the partial drawdown 2 of 1,170 km (Fig. 4). Significantly, the late lake level reached and overflowed the topo- phases of Late Lake Estancia of late Wisconsin Wisconsin high lake level was 35 m below the graphic sill (Fig. 5). I believe that overflow time. topographic sill and overflow could not occur. across the sill and ultimately into the Pecos Basin flooding became more persistent during Infrahaline to slightly saline conditions were River was associated with Illinoian(?)-age Early the latter phase of Estancia Playa Complex dep- maintained by reduced summer temperature Lake Estancia (at least 130,000 yr ago), a plu- osition. A climatic shift to pluvial conditions and probably a slight increase in precipitation vial system known only in subcrop and possible initiated the expansion of Lake Willard from an (see Smith and Anderson, 1982). shoreline features. During the waning stages of initial shallow, saline phase and finally into a

Hawley, J. W., 1984, The Ogallala Formation in eastern New Mexico, in fresh-water body. At the time of lake freshening and confirmed the identification of the fish re- Proceedings, Ogallala Aquifer Symposium II, Lubbock, June 1984: (about 12,500 yr ago), trout again migrated into mains. R. J. Behnke, J. W. Hawley, A. G. Syl- Lubbock, Texas, Texas Tech University Water Resources Research Center, p. 157-176. the lake basin, establishing a lacustrine popula- vester, and two anonymous reviewers provided Hawley, J. W., Foster, R. W., Broadhead, R., and Love, D. W., 1982, Road- log segment I-B: Tijeras Canyon to Abo Canyon via Estancia and tion. Lake Willard may have existed into Holo- critical editorial comments. Their dedication to Manzano, in Grambling, J. A., and Wells, S. G., eds., Albuquerque cene time. the review process is appreciated. Funding for country II: New Mexico Geological Society Field Conference, 33rd, Guidebook, p. 8-24. The desiccation of Lake Willard during the four radiocarbon dates was provided by the Hubbs, C. L., and Miller, R. R., 1948, The zoological evidence: Correlation between fish distribution and hydrographic history in the desert basins early Holocene epoch brought pluvial condi- University of Nevada, Las Vegas, Research of western United States, in The Great Basin, with emphasis on glacial tions to a close in the Estancia Valley. During Council. Susan Harvey, Fred Formwalt, and and postglacial times: University of Utah Bulletin 38, p. 17-166, Hubbs, C. L., Miller, R. R., and Hubbs, L. C., 1974, Hydrographic history and the middle and late Holocene, various episodes Candido Alarid generously permitted access to relict fishes of the north-central Great Basin: California Academy of Sciences Memoirs, v. 7,259 p. of soil and dune formation and a subpluvial their properties. This study and continuing work Husband, B. C., and Hickman, M., 1985, Growth and biomass allocation of event are recognized, but the climatic trend was would not be possible without their cooperation. Ruppia occidentals in three lakes, differing in salinity: Canadian Jour- nal of Botany, v. 63, p. 2004-2014. toward aridity. The present valley-floor topog- Kelley, V, C., 1972, Geology of the Fort Sumner sheet, New Mexico: New Mexico Bureau of Mines and Mineral Resources Bulletin 98, 51 p. raphy, consisting of deflation basins and asso- REFERENCES CITED Keyes, C. R., 1903, Ephemeral lakes: American Journal of Science, v. 16. ciated parabolic dunes that postdate 4660 ± 170 p. 377-378. Bachhuber, F. W., 1971, Paleolimnology of Lake Estancia and the Quaternary Koster, W. J., 1957, Guide to the fishes of New Mexico: Albuquerque. New yr B.P. (GX-13321), is a product of hot/dry history of the Estancia Valley, central New Mexico [Ph.D. thesis]: Al- Mexico, University of New Mexico Press, 116 p. buquerque, New Mexico, University of New Mexico, 238 p. Leopold, L. B., 1951, Pleistocene climate in New Mexico: American Journal of conditions probably more extreme than at pres- 1982, Quaternary history of the Estancia Valley, central New Mexico, Science, v. 249, p. 152-168. ent (the parabolic dunes are now stabilized). in Grambting, J. A., and Wells, S. G„ eds., Albuquerque country II: Lyons, T. R., 1969, A study of the Paleo-Indian and Desert Culture complexes New Mexico Geological Society Field Conference, 33rd, Guidebook, of the Estancia Valley area, New Mexico [Ph.D. thesis]: Albuquerque, From a watershed perspective, these conditions p. 343-346. New Mexico, University of New Mexico, 355 p. 1987, An early to mid-Wisconsin climatic record from the Estancia Meinzer, O. E., 1911, Geology and water resources of Estancia Valley. New were extreme enough to impact severely not Valley, central New Mexico: Geological Society of America Abstracts Mexico; with notes on ground-water conditions in adjacent parts of only the valley floor but also the stream network with Programs, v. 19, p. 577. central New Mexico: U.S. Geological Survey Water-Supply Paper 275, 1988, Paléontologie analysis of an early through middle Wisconsin 89 p. flowing from the surrounding highlands. The section from the Estancia Valley, central New Mexico: Geological So- Rinne, J. N., 1980a, Salmo apache, in Lee, D.S., and others, eds„ Atlas of ciety of America Abstracts with Programs, v. 20, p. 206. North American freshwater fishes: North Carolina State Museum of short, low-volume perennial streams and springs Bachhuber, F. W., and McClellan, W. A., 1977, Paleoecology of marine Natural History, North Carolina Biological Survey Publication that exist today do not contain fish, and there is Foraminifera in the pluvial Estancia Valley, central New Mexico: 1980-12, p. 104. Quaternary Research, v. 7, p. 254-267. 1980b, Salmo gilae, in Lee, D. S., and others, eds., Atlas of North no historic report of fish from within the Estan- Behnke, R. J., 1980, Salmo clarki, in Lee, D. S., and others, eds., Atlas of North American freshwater fishes: North Carolina State Museum of Natural American freshwater fishes: North Carolina State Museum of Natural History, North Carolina Biological Survey Publication 1980-12, p. 107. cia Valley watershed. Therefore, the climatic History, North Carolina Biological Survey Publication 1980-12, p. 105. Rogers, K. L., Repenning, C. A., Forester, R. M., Larson, E. L,, Hall, S. A., conditions that produced the deflation basins 1981, Systematic and zoogeographical interpretation of Great Basin Smith, G. R., Anderson, E., and Brown, T. J., 1985, Middle Pleistocene trouts, in Naiman, R. J., and Soltz, D. L., eds., Fishes in North Ameri- (Late Irvingtonian: Nebraskan) climate changes in southcentral Colo- and dunes were also the demise of or played a can deserts: New York, John Wiley & Sons, p. 95-124. rado: National Geographic Research, v. 1, p. 535-563. 1988, Phylogeny and classification of cutthroat trout, in Gresswell, Smith, G. I., and Street-Perrott, F. A., 1983, Pluvial lakes of the western United major role in the elimination of the Estancia R. E., ed., Status and management of Interior stocks of cutthroat trout: States, in Porter, S. C, ed., Late Quaternary environments of the United Valley fish population, not only from waning American Fisheries Society Symposium, v. 4, p. 1-7. Slates, Volume 1, The late Pleistocene: Minneapolis, Minnesota, Uni- Benson, L., and Thompson, R. S., 1987, The physical record of lakes in the versity of Minnesota Press, p. 190—212. Lake Willard, but also from the watershed as a Great Basin, in Ruddiman, W. F., and Wright, H. E., Jr., eds., North Smith, L. N., and Anderson, R. Y., 1982, Pleistocene-Holocene climate of the America and adjacent oceans during the last déglaciation: Boulder, Estancia basin, central New Mexico, in Grambling, J. A., and Wells, whole. Either these extreme climatic conditions Colorado, Geological Society of America, The Geology of North Amer- S. G., eds., Albuquerque country II: New Mexico Geological Society were not in evidence at any other time since the ica, v. K-3, p. 241-260. Field Conference, 33rd, Guidebook, p. 343-346. Brakenridge, G. R., 1978, Evidence for a cold dry full-glacial climate in the Smith, R. H., 1984, Native trout of North America: Portland, Oregon, Frank introduction of fish to the valley, or the fish American Southwest: Quaternary Research, v. 9, p. 22-40. Amato Publications, 144 p. Forester, R. M., 1983, Relationship of two lacustrine ostracode species to solute Titus, F. B., 1969, Late Tertiary and Quaternary hydrogeology of the Estancia population was decimated by the arrival of pre- composition and salinity; Implications for paleohydrochemistry: Geol- basin, central New Mexico [Ph.D. thesis]: Albuquerque, New Mexico, historic people. ogy, v. II, p. 435-438. University of New Mexico, 179 p, Galat, D. L, Lider, E. L., Vigg, S„ and Robertson, S. R., 1981, Limnology of a Verhoeven, J.T.A., 1979, The ecology of Ruppia-dommied communities in large deep North American terminal lake, Pyramid Lake, Nevada, western Europe; I. Distribution of Ruppia representatives in relation to U.S.A.: Hydrobiologia, v. 82, p. 281-317. their autecology: Aquatic Botany, v. 6, p. 197-268. ACKNOWLEDGMENTS Galat, D. L„ Post, G„ Keefe, T. J., and Bouck, G. R., 1985, Histological changes in the gill, kidney and liver of Lahontan cutthroat trout, Salmo clarki henshawi, living in lakes of different salinity-alkalinity: Journal of Fish Biology, v. 27, p. 533-552. I am indebted to William J. Koster, the grand Galloway, R. W., 1970, The full-glacial climate in the southwestern United gentleman of New Mexico fishes. He has taught States: Association of American Geographers Annals, v. 60, p. 245-256. me more important things than science. Special 1983, Full-glacial southwestern United States: Mild and wet or cold and dry: Quaternary Research, v. 19, p. 236-248. thanks are due Gerald R. Smith, who did a de- Harbour, J., 1958, Microstratigraphic and sedimentational studies of an early MANUSCRIPT RECEIVED BY THE SOCIETY FEBRUARY 23,1988 tailed examination of the Estancia fish collection man site near Lucy, New Mexico [M.S. thesis]: Albuquerque, New REVISED MANUSCRIPT RECEIVED JUNE 7, 1989 Mexico, University of New Mexico, 111 p. MANUSCRIPT ACCEPTED JUNE 13,1989

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