Howard J Spero
Biographic Data
| ID | 92626 |
|---|---|
| NAME | Howard J Spero |
| GIVEN NAMES | Howard J |
| FAMILY NAME | Spero |
| SIGNATURE | SPERO H J |
| AFFILIATIONS | University of California, Davis |
| ORCID | 0000-0001-5465-8607 |
| VERIFIED | Yes |
| TOTAL WORKS | 9 |
| TOTAL CITATIONS | 48 |
| AUTHOR COUNT | 9 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 2005 |
| LATEST PUBLICATION YEAR | 2025 |
| H-INDEX | 4 |
Late Holocene Landscape Use, Site Seasonality, and Settlement Patterns in San Francisco, California
Isotopic and provenance analysis of Neolithic and Bronze Age shell disc beads from Ban Non Wat, north-east Thailand
Small, disc-shaped shell beads are recorded as mortuary offerings in many Neolithic and Bronze Age burials in Southeast Asia. Yet the provenance of these artefacts is often obscure, as production processes involve the removal of diagnostic morphological features, negating taxonomic classification. Here, the authors report on the combined isotopic and morphological analysis of a subset of shell beads from the site of Ban Non Wat in north-east Thai…
Isotopic Evidence of Sources for Central California Olivella Beads
Without the large bead production sites present on the Channel Islands, the origin of Olivella beads in central California has been largely speculative. Stable isotope analysis of shell carbonate provides a useful test of source, production, and distribution hypotheses by providing information about the environment of shell formation. We reassess results of previous stable isotope sourcing studies and employ a cluster analysis that suggests most …
Staple, Feasting, or Fallback Food? Mussel Harvesting Among Hunter-Gatherers in Interior Central California
Shells are a visible component of archaeological middens in Central California. While coastal and bay shore sites are often dominated by shells, these food items were sometimes hauled many kilometers from their collection points and are found in appreciable numbers in inland sites as well. Using oxygen and carbon stable isotope data from 44 Mytilus sp. (mussel) shells, we reconstruct shellfish seasonality harvesting at one inland site dating to t…
Millennial-scale variations in western Sierra Nevada precipitation during the last glacial cycle MIS 4/3 transition
Dansgaard–Oeschger (D–O) cycles had far-reaching effects on Northern Hemisphere and tropical climate systems during the last glacial period, yet the climatic response to D–O cycles in western North America is controversial, especially prior to 55 ka. We document changes in precipitation along the western slope of the central Sierra Nevada during early Marine Oxygen Isotope Stages (MIS) 3 and 4 (55–67 ka) from a U-series dated speleothem record fr…
Seasonality of Late Prehistoric Clamming on San Francisco Bay: Oxygen Isotope Analyses of Macoma nasuta Shells from a Stege Mound, CA-CCO-297
Using oxygen isotope ratios in terminal growth rings, we estimate the month of harvest of 32 Macoma nasuta shells from a single component Late Phase II (450–200 cal BP) assemblage from CA-CCO-297. Results suggest that clamming occurred throughout the year, but was most pronounced during two pulses in early summer and early winter. We relate the former to longer daylight in early summer that facilitated access to tidal flats and clamming, while th…
Stable isotope reconstructions of shellfish harvesting seasonality in an estuarine environment: Implications for Late Holocene San Francisco Bay settlement patterns
Stable Isotope Provenance Analysis of Olivella Shell Beads From the Los Angeles Basin and San Nicolas Island
Production of marine shell beads in island and coastal settings was an important activity in prehistory, with important political and economic ties. Currently, there are few methods to track beads to their locus of production. Examining the spatial distribution of bead types provides one method of doing so. Chemical and stable isotopic methods provide an additional and independent means of testing hypotheses generated by spatial distributions. We…
Provenance analysis of Olivella biplicata shell beads from the California and Oregon Coast by stable isotope fingerprinting
Stable isotope reconstructions of shellfish harvesting seasonality in an estuarine environment: Implications for Late Holocene San Francisco Bay settlement patterns
Provenance analysis of Olivella biplicata shell beads from the California and Oregon Coast by stable isotope fingerprinting
Stable Isotope Provenance Analysis of Olivella Shell Beads From the Los Angeles Basin and San Nicolas Island
Production of marine shell beads in island and coastal settings was an important activity in prehistory, with important political and economic ties. Currently, there are few methods to track beads to their locus of production. Examining the spatial distribution of bead types provides one method of doing so. Chemical and stable isotopic methods provide an additional and independent means of testing hypotheses generated by spatial distributions. We…
Seasonality of Late Prehistoric Clamming on San Francisco Bay: Oxygen Isotope Analyses of Macoma nasuta Shells from a Stege Mound, CA-CCO-297
Using oxygen isotope ratios in terminal growth rings, we estimate the month of harvest of 32 Macoma nasuta shells from a single component Late Phase II (450–200 cal BP) assemblage from CA-CCO-297. Results suggest that clamming occurred throughout the year, but was most pronounced during two pulses in early summer and early winter. We relate the former to longer daylight in early summer that facilitated access to tidal flats and clamming, while th…
Isotopic and provenance analysis of Neolithic and Bronze Age shell disc beads from Ban Non Wat, north-east Thailand
Small, disc-shaped shell beads are recorded as mortuary offerings in many Neolithic and Bronze Age burials in Southeast Asia. Yet the provenance of these artefacts is often obscure, as production processes involve the removal of diagnostic morphological features, negating taxonomic classification. Here, the authors report on the combined isotopic and morphological analysis of a subset of shell beads from the site of Ban Non Wat in north-east Thai…
Provenance analysis of Olivella biplicata shell beads from the California and Oregon Coast by stable isotope fingerprinting
Stable Isotope Provenance Analysis of Olivella Shell Beads From the Los Angeles Basin and San Nicolas Island
Production of marine shell beads in island and coastal settings was an important activity in prehistory, with important political and economic ties. Currently, there are few methods to track beads to their locus of production. Examining the spatial distribution of bead types provides one method of doing so. Chemical and stable isotopic methods provide an additional and independent means of testing hypotheses generated by spatial distributions. We…
Stable isotope reconstructions of shellfish harvesting seasonality in an estuarine environment: Implications for Late Holocene San Francisco Bay settlement patterns
Millennial-scale variations in western Sierra Nevada precipitation during the last glacial cycle MIS 4/3 transition
Dansgaard–Oeschger (D–O) cycles had far-reaching effects on Northern Hemisphere and tropical climate systems during the last glacial period, yet the climatic response to D–O cycles in western North America is controversial, especially prior to 55 ka. We document changes in precipitation along the western slope of the central Sierra Nevada during early Marine Oxygen Isotope Stages (MIS) 3 and 4 (55–67 ka) from a U-series dated speleothem record fr…
Seasonality of Late Prehistoric Clamming on San Francisco Bay: Oxygen Isotope Analyses of Macoma nasuta Shells from a Stege Mound, CA-CCO-297
Using oxygen isotope ratios in terminal growth rings, we estimate the month of harvest of 32 Macoma nasuta shells from a single component Late Phase II (450–200 cal BP) assemblage from CA-CCO-297. Results suggest that clamming occurred throughout the year, but was most pronounced during two pulses in early summer and early winter. We relate the former to longer daylight in early summer that facilitated access to tidal flats and clamming, while th…
Staple, Feasting, or Fallback Food? Mussel Harvesting Among Hunter-Gatherers in Interior Central California
Shells are a visible component of archaeological middens in Central California. While coastal and bay shore sites are often dominated by shells, these food items were sometimes hauled many kilometers from their collection points and are found in appreciable numbers in inland sites as well. Using oxygen and carbon stable isotope data from 44 Mytilus sp. (mussel) shells, we reconstruct shellfish seasonality harvesting at one inland site dating to t…
Isotopic Evidence of Sources for Central California Olivella Beads
Without the large bead production sites present on the Channel Islands, the origin of Olivella beads in central California has been largely speculative. Stable isotope analysis of shell carbonate provides a useful test of source, production, and distribution hypotheses by providing information about the environment of shell formation. We reassess results of previous stable isotope sourcing studies and employ a cluster analysis that suggests most …
Isotopic and provenance analysis of Neolithic and Bronze Age shell disc beads from Ban Non Wat, north-east Thailand
Small, disc-shaped shell beads are recorded as mortuary offerings in many Neolithic and Bronze Age burials in Southeast Asia. Yet the provenance of these artefacts is often obscure, as production processes involve the removal of diagnostic morphological features, negating taxonomic classification. Here, the authors report on the combined isotopic and morphological analysis of a subset of shell beads from the site of Ban Non Wat in north-east Thai…
Late Holocene Landscape Use, Site Seasonality, and Settlement Patterns in San Francisco, California
Archaeology (9 works) · Geography (9 works) · Isotope Analysis in Ecology (9 works) · Archaeology and ancient environmental studies (8 works) · Geology (7 works) · Oceanography (5 works) · Bay (4 works) · Ecology (4 works) · Geology and Paleoclimatology Research (4 works) · Isotope analysis (4 works)