Karl Laumbach

Two C3/C4 vegetative boundaries and an expanding/contracting Chihuahuan Desert during the past 4000 yr at the Cañada Alamosa Archaeological Project Area, New Mexico

Carbon isotopic measurement (δ13C) as an indicator of C3 or C4 vegetation preserved in soil organic matter and pedogenic carbonate is an important tool for reconstructing paleoclimate. However, while δ13C values of C4 plants (−14‰) generally indicate warm-season grass, δ13C value...