Sediment core PTLN‐PC1 was collected September 2013 in sequential 1‐m sections using a 5‐cm‐diameter Colinvaux‐Vohnout Livingstone‐type rod‐operated piston corer (Geocore, Columbus, Ohio). Each section was sealed in the field and refrigerated at 4 °C until core splitting and subsampling.

Thirteen macrofossils were pulled from the core and were pretreated with an acid‐base‐acid procedure according to the protocol in Brock et al. (2010) to remove extraneous organic materials. Accelerator mass spectrometry 14C dating was performed by DirectAMS in Bothell, WA, United States.

Data Processing Description

The modern age control (youngest age, at depth = 81 cm) was converted from fraction modern to 14C years using the pMC.age() function in the Bacon age‐modeling software package (Blaauw and Christen, 2011). This produced a 90.3% confidence interval for the calibrated age estimate of −0.04611 to −0.05081 ka BP, or CE 1996–2001 (plus a small chance (4.6%) of −0.00831 to −0.00808 ka BP, or CE 1958); this age is anomalously young and clearly an outlier based on comparison with a nearby universal core, prompting its removal. All other dates were calibrated using IntCal2013 (Reimer et al., 2013) and the Clam 2.2 software package (Blaauw, 2010).

BCO-DMO Processing: modified parameter names (replaced "." with underscores; changed "14C_raw" to "raw_14C" because column names cannot start with numbers)

Data Files

File
T_Lake_PC1_Chronology.csv (Comma Separated Values (.csv), 710 bytes) MD5:12233e485ca1458cf6b48cc846895c8a Primary data file for dataset ID 771658

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1241247

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
Palau_lakes		2010-08-21	Small boats - CRRF	Michael N. Dawson (Principal Investigator) Julian P. Sachs (Principal Investigator)	data info

Instruments

Accelerator Mass Spectrometer

Supplied Name: Accelerator mass spectrometry

Supplied Description:

Accelerator mass spectrometry 14C dating was performed by DirectAMS in Bothell, WA, United States.

Instrument Type

Generic Name: Accelerator Mass Spectrometer

Acronym: AMS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB17/

Generic Description:

An AMS measures "long-lived radionuclides that occur naturally in our environment. AMS uses a particle accelerator in conjunction with ion sources, large magnets, and detectors to separate out interferences and count single atoms in the presence of 1x1015 (a thousand million million) stable atoms, measuring the mass-to-charge ratio of the products of sample molecule disassociation, atom ionization and ion acceleration." AMS permits ultra low-level measurement of compound concentrations and isotope ratios that traditional alpha-spectrometry cannot provide. More from Purdue University: http://www.physics.purdue.edu/primelab/introduction/ams.html

Piston Corer

Supplied Name: Colinvaux‐Vohnout Livingstone‐type rod‐operated piston corer

Supplied Description:

Colinvaux‐Vohnout Livingstone‐type rod‐operated piston corer (Geocore, Columbus, Ohio). Hand-operated sediment coring device.

Instrument Type

Generic Name: Piston Corer

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/51/

Generic Description:

The piston corer is a type of bottom sediment sampling device. A long, heavy tube is plunged into the seafloor to extract samples of mud sediment. A piston corer uses a "free fall" of the coring rig to achieve a greater initial force on impact than gravity coring. A sliding piston inside the core barrel reduces inside wall friction with the sediment and helps to evacuate displaced water from the top of the corer. A piston corer is capable of extracting core samples up to 90 feet in length.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
Labcode	sample identification used by 14C laboratory	unitless	sample
depth_top	composite depth, top of 1 cm interval associated with fossil	centimeters (cm)	depth_core
mat_dated	material dated	unitless	sample_descrip
raw_14C	conventional radiocarbon age, relative to 1950	years	C14_age
raw_14C_err	standard error, radiocarbon age	years	C14_age
calib_14C_95_lo	calibrated age, 95% confidence interval lower bound	years	C14_age
calib_14C_95_up	calibrated age, 95% confidence interval upper bound	years	C14_age