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Papers by Geoffrey Smith

Journal of Archaeological Science: Reports, 2017

In recent years, source provenance studies employing portable X-ray fluorescence (pXRF) technolog... more In recent years, source provenance studies employing portable X-ray fluorescence (pXRF) technology have become commonplace in archaeology; however, they are not without critiques. Concerns center on the capability of instruments to produce valid results and researchers' abilities to accurately interpret those results and make correct source assignments. In this paper, we focus on the latter issue with a look towards statistical means of assigning artifacts to obsidian types using data provided by pXRF spectrometers. Using a sample of 677 obsidian artifacts from the northwestern Great Basin, we evaluate the ability of various approaches (principal components, cluster, and discriminant function analyses) to correctly assign artifacts to particular obsidian types. These multivariate methods generally work well to separate artifacts into different groups (i.e., obsidian types); however, they are less well-suited to assign individual artifacts to an obsidian source or type. We therefore tested the ability of the statistical program Fordisc, commonly used in forensic anthropology, to assign individual artifacts to specific geochemical obsidian sources or types. Our results indicate that Fordisc made accurate source assignments. Furthermore, because Fordisc provides probability values for different possible matches, it offers an advantage over other methods.

American Antiquity, 2016

Beads manufactured from marine shells originating along the Pacific Coast have been found at nume... more Beads manufactured from marine shells originating along the Pacific Coast have been found at numerous sites in the western United States. Because they were conveyed across substantial distances and widely exchanged during ethnographic times, researchers generally assume that shell beads were also traded prehistorically. By examining the spatial and temporal distribution of beads, researchers have reconstructed prehistoric exchange networks. In this report, we present stable isotope data and accelerator mass spectrometer (AMS) radiocarbon dates for six Callianax (previously Olivella) biplicata beads from the LSP-1 rockshelter in southcentral Oregon. Most of the beads were deposited during the early Holocene during a series of short-term occupations and the shells used to manufacture them were procured along the northern California, Oregon, or Washington coasts. Cuentas manufacturadas a partir de valvas de moluscos marinos han sido halladas en numerosos sitios del oeste de los Estados Unidos de América. Debido a que han sido transportados a distancias significativas y ampliamente intercambiados durante tiempos etnográficos, los investigadores han asumido que las cuentas de valvas han sido también intercambiado en momentos prehistóricos. Examinando la distribución espacial y temporal de las cuentas, algunos investigadores han reconstruido las redes de intercambio. En este trabajo presentamos datos de isótopos estables y fechados radiocarbónicos (AMS) para seis cuentas realizadas en valvas de Callianax biplicata (anteriormente denominadas Olivella) procedentes del abrigo rocoso LSP-1 en el centro-sur de Oregon. Los resultados indican que las cuentas fueron depositadas durante el Holoceno temprano, cuando LSP-1 fue utilizado durante una serie de ocupaciones de corto plazo. Por lo tanto, son las cuentas de concha marina más antiguas

Journal of Archaeological Science, 2011

Based on source provenance data derived from Paleoindian artifacts in the Great Basin, most resea... more Based on source provenance data derived from Paleoindian artifacts in the Great Basin, most researchers agree that early groups were mobile and far-ranging; however, current explanations of the behavior reflected by those data differ. Some models portray Paleoindians as residentially-mobile foragers while others portray them as wetland-tethered collectors reliant upon logistical forays. We consider the types of hunter-gatherer behavior that could produce trends in the X-ray fluorescence data from three Paleoindian assemblages in northwest Nevada, where abundant high quality obsidian essentially allows us to hold the effects of raw material availability constant between sites. We conclude that while it is difficult to differentiate between residential and logistical mobility using technological and sourcing data alone, we can nevertheless begin to understand the relative time-averaged importance of particular locations on the landscape and why such places attracted Paleoindians.

American Antiquity, 2010

Mobility is a common theme in Paleoindian research throughout North America including in the Grea... more Mobility is a common theme in Paleoindian research throughout North America including in the Great Basin. One recent model based on results from the X-ray fluorescence (XRF) analysis of Paleoindian artifacts holds that early groups occupied geographically discrete foraging territories throughout the Great Basin during the terminal Pleistocene/early Holocene, ca. 11,500–7500 radiocarbon years ago (14C B.P.), that covered between 46,000 and 107,000 km2. While this model is innovative, its implications regarding Paleoindian mobility are difficult to reconcile with our knowledge of foraging populations. In this article, I evaluate the model using XRF data for 260 Paleoindian projectile points from northwest Nevada. The results fail to support the hypothesis that a single, expansive foraging territory once covered the western Great Basin. However, when compared to a sample of 1,085 projectile points from later periods (ca. 700014C B.P. to the historic era), data from the Paleoindian samp...

Journal of Archaeological Science, 2011

Like Paleoindian populations elsewhere in North America, Pre-Archaic groups in the Great Basin ar... more Like Paleoindian populations elsewhere in North America, Pre-Archaic groups in the Great Basin are assumed to have been highly mobile and far ranging. This view is commonly based on analyses of lithic technology and source provenance studies. While these approaches have added to our knowledge of Pre-Archaic lifeways, they have rarely focused on occupation span – an aspect of hunter–gatherer

PaleoAmerica, 2019

ABSTRACT We review some of the current problems and prospects in ongoing Western Stemmed Traditio... more ABSTRACT We review some of the current problems and prospects in ongoing Western Stemmed Tradition (WST) studies and highlight recent discoveries at important sites in the Intermountain West. While the region has traditionally not been the focus of peopling of the Americas studies, it has received considerable attention in recent years due to the discovery of WST points and other artifacts in Clovis-aged deposits. Fieldwork at sites in Oregon, Idaho, Nevada, and Utah has produced WST assemblages dated to the terminal Pleistocene and early Holocene and generated new fine-grained datasets capable of addressing longstanding questions about WST technology, chronology, and subsistence. Collectively, these efforts have helped to refocus North American Paleoindian studies on the Intermountain West and the role that it played in the peopling of the Americas.

American Antiquity, 2013

Typological cross-dating is the primary means by which archaeological sites are placed into chron... more Typological cross-dating is the primary means by which archaeological sites are placed into chronological frameworks. This approach relies on the assumption that artifacts at undated sites—usually projectile points—are coeval with similar artifacts found at Other, dated sites. While typological cross-dating is necessary in regions dominated by open-air lithic scatters, the approach can be problematic when undated and dated sites are separated by significant distances. Here, we present radiocarbon dates on projectile points with organic hafting material still attached or found within organic storage bags. Our results provide unequivocal ages for various morphological projectile point types at several Great Basin locales and should be useful to researchers seeking local age estimates for those point types, which often involves relying on chronological data from more distant sites. The results also highlight potential issues with uncritically applying typological cross-dating using typ...

Proceedings of the National Academy of Sciences, 2012

Ancient cultural changes have often been linked to abrupt climatic events, but the potential that... more Ancient cultural changes have often been linked to abrupt climatic events, but the potential that climate can exert a persistent influence on human populations has been debated. Here, independent population, temperature, and moisture history reconstructions from the Bighorn Basin in Wyoming (United States) show a clear quantitative relationship spanning 13 ka, which explains five major periods of population growth/decline and ∼45% of the population variance. A persistent ∼300-y lag in the human demographic response conforms with either slow (∼0.3%) intrinsic annual population growth rates or a lag in the environmental carrying capacity, but in either case, the population continuously adjusted to changing environmental conditions.

Journal of Archaeological Science, 2014

One of the principal ways that researchers date archaeological sites is by using temporally diagn... more One of the principal ways that researchers date archaeological sites is by using temporally diagnostic projectile points as index fossils; however, this practice has not been widely employed to date rock art sites. We use this approach here to test the hypothesis that the Great Basin Carved Abstract (GBCA) petroglyph style found in the northern Great Basin was produced by Paleoindians. Using frequencies of projectile points at 55 GBCA sites, we demonstrate that Paleoindian points are significantly overrepresented there relative to their occurrence on the general landscape, providing evidence that Great Basin populations produced rock art sometime during the Terminal Pleistocene/Early Holocene (TP/EH), w12,500e8000 radiocarbon years ago. Additionally, we examine several environmental variables at GBCA sites and propose a model of Paleoindian land-use in the northern Great Basin that highlights seasonal visits to uplands to procure geophytes (i.e., root crops).

Journal of Archaeological Science, 2009

In this paper, we expand upon a prior study [Surovell, T.A., Brantingham, P.J., 2007. A note on t... more In this paper, we expand upon a prior study [Surovell, T.A., Brantingham, P.J., 2007. A note on the use of temporal frequency distributions in studies of prehistoric demography. Journal of Archaeological Science 34, 1868-1877.] that explored the problem of taphonomic bias. Taphonomic bias refers to the tendency for younger things to be over-represented relative to older things in the archaeological record due to the operation of destructive processes like erosion and weathering. Using a database of radiocarbon dated volcanic deposits from Bryson, R.U., Bryson, R.A., Ruter, A. [2006. A calibrated radiocarbon database of late Quaternary volcanic eruptions. Earth Discussions 1, 123-124.], we develop an empirical model of taphonomic bias. In contrast to our prior study in which we modeled taphonomic bias as an exponential function wherein the likelihood of site loss remains constant through time, we argue that the probability of site destruction actually decreases with site age. We further demonstrate how this model can be used to correct temporal frequency distributions and extract demographic histories. We illustrate this approach using databases of radiocarbon dates from rockshelter and open-air sites in the Bighorn Basin, Wyoming, USA, and mammoths and humans in Siberia, Russia.

Journal of Archaeological Science, 2013

Great Basin populations during the PleistoceneeHolocene Transition (PHT) are often characterized ... more Great Basin populations during the PleistoceneeHolocene Transition (PHT) are often characterized as being mobile and focused on wetlands; however, the factors that influenced where Paleoindians selected residential campsites are poorly understood. Using predictions derived from optimal foraging-based patch choice models and GIS reconstructions of the PHT landscape, some researchers have argued that occupations in smaller wetlands should have been shorter than occupations in larger wetlands but such arguments have rarely been evaluated using empirical data. The PHT lithic record provides an opportunity to evaluate the relationship between wetland size and occupation span by applying Kuhn's (1995) concept of technological provisioning. Kuhn expects more mobile populations to provision individuals and more sedentary populations to provision places and suggests that: (1) a strategy of provisioning individuals should be reflected by a high proportion of more extensively used artifacts made on non-local raw materials; and (2) a strategy of provisioning places should be reflected by a high proportion of less extensively used artifacts made on local raw materials. We apply the technological provisioning concept to lithic assemblages from two of the Parman localities, extensive PHT sites in the northwestern Great Basin, and compare local and nonlocal artifacts to determine if Paleoindians shifted from provisioning individuals while moving to/from the sites to provisioning the place while occupying them. There is no relationship between artifact transport distance and artifact use intensity. We interpret these findings as evidence that Paleoindians did not alter their provisioning strategies while occupying the Parman localities, likely because occupations were brief within a small wetland poorly-suited to support groups for long periods.

North American Archaeologist, 2012

We present source provenance data from a sample of obsidian projectile points and unmodified flak... more We present source provenance data from a sample of obsidian projectile points and unmodified flakes from Paiute Creek Shelter (PCS), a site in Nevada's Black Rock Desert that was first occupied 4,700 calendar years ago (cal BP). Significant differences between the source profiles of earlier (pre-1,450 cal BP) and later (post-1,450 cal BP) occupations suggest that toolstone procurement strategies changed over time at PCS. Before 1,450 cal BP, there was a heavy reliance on local toolstone directly procured from nearby sources. Although local toolstone remained important after 1,450 cal BP, non-local toolstone became more common at PCS, highlighting increased interactions with neighboring populations. The shift in toolstone use at PCS is but one of many changes in the archaeological record of the northwestern Great Basin after 1,500 cal BP.

Journal of Archaeological Science: Reports, 2017

In recent years, source provenance studies employing portable X-ray fluorescence (pXRF) technolog... more In recent years, source provenance studies employing portable X-ray fluorescence (pXRF) technology have become commonplace in archaeology; however, they are not without critiques. Concerns center on the capability of instruments to produce valid results and researchers' abilities to accurately interpret those results and make correct source assignments. In this paper, we focus on the latter issue with a look towards statistical means of assigning artifacts to obsidian types using data provided by pXRF spectrometers. Using a sample of 677 obsidian artifacts from the northwestern Great Basin, we evaluate the ability of various approaches (principal components, cluster, and discriminant function analyses) to correctly assign artifacts to particular obsidian types. These multivariate methods generally work well to separate artifacts into different groups (i.e., obsidian types); however, they are less well-suited to assign individual artifacts to an obsidian source or type. We therefore tested the ability of the statistical program Fordisc, commonly used in forensic anthropology, to assign individual artifacts to specific geochemical obsidian sources or types. Our results indicate that Fordisc made accurate source assignments. Furthermore, because Fordisc provides probability values for different possible matches, it offers an advantage over other methods.

American Antiquity, 2016

Beads manufactured from marine shells originating along the Pacific Coast have been found at nume... more Beads manufactured from marine shells originating along the Pacific Coast have been found at numerous sites in the western United States. Because they were conveyed across substantial distances and widely exchanged during ethnographic times, researchers generally assume that shell beads were also traded prehistorically. By examining the spatial and temporal distribution of beads, researchers have reconstructed prehistoric exchange networks. In this report, we present stable isotope data and accelerator mass spectrometer (AMS) radiocarbon dates for six Callianax (previously Olivella) biplicata beads from the LSP-1 rockshelter in southcentral Oregon. Most of the beads were deposited during the early Holocene during a series of short-term occupations and the shells used to manufacture them were procured along the northern California, Oregon, or Washington coasts. Cuentas manufacturadas a partir de valvas de moluscos marinos han sido halladas en numerosos sitios del oeste de los Estados Unidos de América. Debido a que han sido transportados a distancias significativas y ampliamente intercambiados durante tiempos etnográficos, los investigadores han asumido que las cuentas de valvas han sido también intercambiado en momentos prehistóricos. Examinando la distribución espacial y temporal de las cuentas, algunos investigadores han reconstruido las redes de intercambio. En este trabajo presentamos datos de isótopos estables y fechados radiocarbónicos (AMS) para seis cuentas realizadas en valvas de Callianax biplicata (anteriormente denominadas Olivella) procedentes del abrigo rocoso LSP-1 en el centro-sur de Oregon. Los resultados indican que las cuentas fueron depositadas durante el Holoceno temprano, cuando LSP-1 fue utilizado durante una serie de ocupaciones de corto plazo. Por lo tanto, son las cuentas de concha marina más antiguas

Journal of Archaeological Science, 2011

Based on source provenance data derived from Paleoindian artifacts in the Great Basin, most resea... more Based on source provenance data derived from Paleoindian artifacts in the Great Basin, most researchers agree that early groups were mobile and far-ranging; however, current explanations of the behavior reflected by those data differ. Some models portray Paleoindians as residentially-mobile foragers while others portray them as wetland-tethered collectors reliant upon logistical forays. We consider the types of hunter-gatherer behavior that could produce trends in the X-ray fluorescence data from three Paleoindian assemblages in northwest Nevada, where abundant high quality obsidian essentially allows us to hold the effects of raw material availability constant between sites. We conclude that while it is difficult to differentiate between residential and logistical mobility using technological and sourcing data alone, we can nevertheless begin to understand the relative time-averaged importance of particular locations on the landscape and why such places attracted Paleoindians.

American Antiquity, 2010

Mobility is a common theme in Paleoindian research throughout North America including in the Grea... more Mobility is a common theme in Paleoindian research throughout North America including in the Great Basin. One recent model based on results from the X-ray fluorescence (XRF) analysis of Paleoindian artifacts holds that early groups occupied geographically discrete foraging territories throughout the Great Basin during the terminal Pleistocene/early Holocene, ca. 11,500–7500 radiocarbon years ago (14C B.P.), that covered between 46,000 and 107,000 km2. While this model is innovative, its implications regarding Paleoindian mobility are difficult to reconcile with our knowledge of foraging populations. In this article, I evaluate the model using XRF data for 260 Paleoindian projectile points from northwest Nevada. The results fail to support the hypothesis that a single, expansive foraging territory once covered the western Great Basin. However, when compared to a sample of 1,085 projectile points from later periods (ca. 700014C B.P. to the historic era), data from the Paleoindian samp...

Journal of Archaeological Science, 2011

Like Paleoindian populations elsewhere in North America, Pre-Archaic groups in the Great Basin ar... more Like Paleoindian populations elsewhere in North America, Pre-Archaic groups in the Great Basin are assumed to have been highly mobile and far ranging. This view is commonly based on analyses of lithic technology and source provenance studies. While these approaches have added to our knowledge of Pre-Archaic lifeways, they have rarely focused on occupation span – an aspect of hunter–gatherer

PaleoAmerica, 2019

ABSTRACT We review some of the current problems and prospects in ongoing Western Stemmed Traditio... more ABSTRACT We review some of the current problems and prospects in ongoing Western Stemmed Tradition (WST) studies and highlight recent discoveries at important sites in the Intermountain West. While the region has traditionally not been the focus of peopling of the Americas studies, it has received considerable attention in recent years due to the discovery of WST points and other artifacts in Clovis-aged deposits. Fieldwork at sites in Oregon, Idaho, Nevada, and Utah has produced WST assemblages dated to the terminal Pleistocene and early Holocene and generated new fine-grained datasets capable of addressing longstanding questions about WST technology, chronology, and subsistence. Collectively, these efforts have helped to refocus North American Paleoindian studies on the Intermountain West and the role that it played in the peopling of the Americas.

American Antiquity, 2013

Typological cross-dating is the primary means by which archaeological sites are placed into chron... more Typological cross-dating is the primary means by which archaeological sites are placed into chronological frameworks. This approach relies on the assumption that artifacts at undated sites—usually projectile points—are coeval with similar artifacts found at Other, dated sites. While typological cross-dating is necessary in regions dominated by open-air lithic scatters, the approach can be problematic when undated and dated sites are separated by significant distances. Here, we present radiocarbon dates on projectile points with organic hafting material still attached or found within organic storage bags. Our results provide unequivocal ages for various morphological projectile point types at several Great Basin locales and should be useful to researchers seeking local age estimates for those point types, which often involves relying on chronological data from more distant sites. The results also highlight potential issues with uncritically applying typological cross-dating using typ...

Proceedings of the National Academy of Sciences, 2012

Ancient cultural changes have often been linked to abrupt climatic events, but the potential that... more Ancient cultural changes have often been linked to abrupt climatic events, but the potential that climate can exert a persistent influence on human populations has been debated. Here, independent population, temperature, and moisture history reconstructions from the Bighorn Basin in Wyoming (United States) show a clear quantitative relationship spanning 13 ka, which explains five major periods of population growth/decline and ∼45% of the population variance. A persistent ∼300-y lag in the human demographic response conforms with either slow (∼0.3%) intrinsic annual population growth rates or a lag in the environmental carrying capacity, but in either case, the population continuously adjusted to changing environmental conditions.

Journal of Archaeological Science, 2014

One of the principal ways that researchers date archaeological sites is by using temporally diagn... more One of the principal ways that researchers date archaeological sites is by using temporally diagnostic projectile points as index fossils; however, this practice has not been widely employed to date rock art sites. We use this approach here to test the hypothesis that the Great Basin Carved Abstract (GBCA) petroglyph style found in the northern Great Basin was produced by Paleoindians. Using frequencies of projectile points at 55 GBCA sites, we demonstrate that Paleoindian points are significantly overrepresented there relative to their occurrence on the general landscape, providing evidence that Great Basin populations produced rock art sometime during the Terminal Pleistocene/Early Holocene (TP/EH), w12,500e8000 radiocarbon years ago. Additionally, we examine several environmental variables at GBCA sites and propose a model of Paleoindian land-use in the northern Great Basin that highlights seasonal visits to uplands to procure geophytes (i.e., root crops).

Journal of Archaeological Science, 2009

In this paper, we expand upon a prior study [Surovell, T.A., Brantingham, P.J., 2007. A note on t... more In this paper, we expand upon a prior study [Surovell, T.A., Brantingham, P.J., 2007. A note on the use of temporal frequency distributions in studies of prehistoric demography. Journal of Archaeological Science 34, 1868-1877.] that explored the problem of taphonomic bias. Taphonomic bias refers to the tendency for younger things to be over-represented relative to older things in the archaeological record due to the operation of destructive processes like erosion and weathering. Using a database of radiocarbon dated volcanic deposits from Bryson, R.U., Bryson, R.A., Ruter, A. [2006. A calibrated radiocarbon database of late Quaternary volcanic eruptions. Earth Discussions 1, 123-124.], we develop an empirical model of taphonomic bias. In contrast to our prior study in which we modeled taphonomic bias as an exponential function wherein the likelihood of site loss remains constant through time, we argue that the probability of site destruction actually decreases with site age. We further demonstrate how this model can be used to correct temporal frequency distributions and extract demographic histories. We illustrate this approach using databases of radiocarbon dates from rockshelter and open-air sites in the Bighorn Basin, Wyoming, USA, and mammoths and humans in Siberia, Russia.

Journal of Archaeological Science, 2013

Great Basin populations during the PleistoceneeHolocene Transition (PHT) are often characterized ... more Great Basin populations during the PleistoceneeHolocene Transition (PHT) are often characterized as being mobile and focused on wetlands; however, the factors that influenced where Paleoindians selected residential campsites are poorly understood. Using predictions derived from optimal foraging-based patch choice models and GIS reconstructions of the PHT landscape, some researchers have argued that occupations in smaller wetlands should have been shorter than occupations in larger wetlands but such arguments have rarely been evaluated using empirical data. The PHT lithic record provides an opportunity to evaluate the relationship between wetland size and occupation span by applying Kuhn's (1995) concept of technological provisioning. Kuhn expects more mobile populations to provision individuals and more sedentary populations to provision places and suggests that: (1) a strategy of provisioning individuals should be reflected by a high proportion of more extensively used artifacts made on non-local raw materials; and (2) a strategy of provisioning places should be reflected by a high proportion of less extensively used artifacts made on local raw materials. We apply the technological provisioning concept to lithic assemblages from two of the Parman localities, extensive PHT sites in the northwestern Great Basin, and compare local and nonlocal artifacts to determine if Paleoindians shifted from provisioning individuals while moving to/from the sites to provisioning the place while occupying them. There is no relationship between artifact transport distance and artifact use intensity. We interpret these findings as evidence that Paleoindians did not alter their provisioning strategies while occupying the Parman localities, likely because occupations were brief within a small wetland poorly-suited to support groups for long periods.

North American Archaeologist, 2012

We present source provenance data from a sample of obsidian projectile points and unmodified flak... more We present source provenance data from a sample of obsidian projectile points and unmodified flakes from Paiute Creek Shelter (PCS), a site in Nevada's Black Rock Desert that was first occupied 4,700 calendar years ago (cal BP). Significant differences between the source profiles of earlier (pre-1,450 cal BP) and later (post-1,450 cal BP) occupations suggest that toolstone procurement strategies changed over time at PCS. Before 1,450 cal BP, there was a heavy reliance on local toolstone directly procured from nearby sources. Although local toolstone remained important after 1,450 cal BP, non-local toolstone became more common at PCS, highlighting increased interactions with neighboring populations. The shift in toolstone use at PCS is but one of many changes in the archaeological record of the northwestern Great Basin after 1,500 cal BP.