CCZO -- Soil Geochemistry -- 70-m deep borehole -- Calhoun Long-Term Soil Experiment -- (2010)

OVERVIEW

Description/Abstract

Samples were collected from Steve Stone’s property which is adjacent to the Calhoun Long-term forest plots (see map below - click on 'Overview Maps' tab). Three continuous mineral soil cores were collected from 0-14 m with a Geoprobe in Steve Stone’s hardwood forest (“Core Locations” in map). These surficial samples were collected from this location because contemporary vegetation, aerial photography dating back to 1938, and soil profile morphology indicated that European agriculture had minimally affected soils in this hardwood forest. Samples deeper than 14 m were collected from Steve Stone’s pasture, approximately 30 m away from the “core locations”, during the installation of a groundwater well by a private contractor (Gill Drilling Services inc.). Samples from 14-18 m were collected with a three-wing bit auger while samples from 18-67 m were collected with a roller-cone bit. After collection all samples were air-dried, and samples from 0-18 m were sieved to 2 mm.

Texture was measured by the pipette method on 20 g of sample. Soil pH was measured with a continuous flow electrode in deionized water and in 0.01 M CaCl2 with a soil:solution ratio of 0.5 and a 15 minute extraction time. Exchangeable acidity was extracted with 1M KCl (soil:solution=0.002, 30 minute extraction) and titrated to 8.2 with 0.02 M NaOH. Exchangeable calcium, magnesium, potassium, and sodium were extracted with 1 M NH4OAc (soil:solution=0.05, 30 minute extraction) and measured by Atomic Absorption Spectrophotometry. Total aluminum, beryllium, calcium, manganese, silicon, titanium, and zirconium were measured by Inductively coupled plasma atomic emission spectroscopy while total iron, magnesium, phosphorus, potassium, and sodium were measured by Atomic Absorption Spectrophotometry following LiBO2 fusion of pulverized and oxidized (30 minutes at 800 C) subsamples (0.1 g sample, 0.4 g LiBO2, 13 minutes at 1000 C). “Free”-iron and “free”-beryllium (Mehra & Jackson, 1958, DOI: 10.1346/CCMN.1958.0070122) were measured by Atomic Absorption Spectrophotometry after extraction with 1 M NH2OH·HCl in 1 M HCl (soil:solution=0.05, 4 hours at 90 C). Meteoric Beryllium-10 was extracted by KHF and NaSO4 fusion and 10Be/9Be isotopic ratios were measured by accelerator mass spectrometry. Total carbon and nitrogen were measured by combustion on a CE Elantech Flash EA 1112 Elemental Analyzer.

Creator/Author

Bacon, A.R.|Richter, Daniel deB.

CZOs

Calhoun

Contact

Allan R. Bacon, 1745 McCarty Drive, University of Florida, Gainesville, FL, 32611, USA. Daniel deB. Richter, 308 Research Drive, Duke University, Durham, NC, 27708, USA.

Subtitle

Sampling depths of 0-18 m and 30-67 m

SUBJECTS

Disciplines

Biogeochemistry|Geochemistry / Mineralogy|Soil Science / Pedology

Topics

Soil Geochemistry

Subtopic

70-m deep borehole

Keywords

Soil|Regolith|Subsoil|Granite|Geochemistry|Residence Time|Totals|Soil Properties|Carbon|Nitrogen|Meteoric beryllium-10|Cosmogenic Nuclides|Calhoun CZO

Variables

Soil_texture|Soil_pH_water|Soil_pH_CaCl2|Soil_KCl_acidity|Soil_exchangeable_Ca|Soil_exchangeable_Mg|Soil_exchangeable_K|Soil_exchangeable_Na|Iron|Magnesium|Phosphorus|Potassium|Sodium|Beryllium|Calcium|Manganese|Silicon|Titanium|Zirconium|Free_beryllium|Free_iron| 10Be_meteoric|carbon|nitrogen

Variables ODM2

Beryllium-10|Calcium|Carbon dioxide|Iron|Magnesium|Manganese|Nitrogen|Phosphorus, total|Potassium, total|Silicon|Sodium, dissolved|Acidity, exchange|pH|Soil texture|Titanium|Zirconium

TEMPORAL

Date Start

2010-06-18

Date End

2010-11-19

SPATIAL

Field Areas

Calhoun Long-Term Soil-Ecosystem Plots and Reference Areas

Location

Calhoun Long-Term Soil Experiment

North latitude

34.606646999999995

South latitude

34.606646999999995

West longitude

-81.723906

East longitude

-81.723906

REFERENCE

Publications of this data

Bacon, Allan R., Daniel deB. Richter, Paul R. Bierman, and Dylan H. Rood (2012). Coupling meteoric 10Be with pedogenic losses of 9Be to improve soil residence time estimates on an ancient North American interfluve. Geology 40 (9): 847–850 http://dx.doi.org/10.1130/G33449.1

CZO ID

4673