solvent extraction, bleaching, and alkaline hydrolysis, removed noncellulose organic components
solvent extraction, bleaching, and alkaline hydrolysis, removed noncellulose organic components
solvent extraction, bleaching, and alkaline hydrolysis, removed noncellulose organic components
About 10 to 15 specimens were selected from each 1cm sample. Each shell was cracked open and sonicated in methanol to remove degreesnegrained particles that degreesll the chambers. Cleaned shell fragments were treated with 15% H2O2 for 1 hour to remove organic matter, dried, and ground to a homogenous powder.
About 10 to 15 specimens were selected from each 1cm sample. Each shell was cracked open and sonicated in methanol to remove degreesnegrained particles that degreesll the chambers. Cleaned shell fragments were treated with 15% H2O2 for 1 hour to remove organic matter, dried, and ground to a homogenous powder.
About 10 to 15 specimens were selected from each 1cm sample. Each shell was cracked open and sonicated in methanol to remove degreesnegrained particles that degreesll the chambers. Cleaned shell fragments were treated with 15% H2O2 for 1 hour to remove organic matter, dried, and ground to a homogenous powder.
Sieved and cleaned following Xia et al. 1997
Sieved and cleaned following Xia et al. 1997
Sieved and cleaned following Xia et al. 1997
Sieved and cleaned following Xia et al. 1997
Prior to TIC and d18O analyses, each sample was combined withdeionize d water, shaken and centrifuged for 15 min at 20,000 rpm using a Sorval Superspeed RC2B.1 After centrifugation, the conductivity of the supernatant was measured and the supernatant discarded. This procedure was repeated until the conductivity of the supernatant was o3 times the conductivity of Boulder, Colorado, tap water. The sample was then freeze dried and homogenized with a mortar and pestle.
Prior to TIC and d18O analyses, each sample was combined withdeionize d water, shaken and centrifuged for 15 min at 20,000 rpm using a Sorval Superspeed RC2B.1 After centrifugation, the conductivity of the supernatant was measured and the supernatant discarded. This procedure was repeated until the conductivity of the supernatant was o3 times the conductivity of Boulder, Colorado, tap water. The sample was then freeze dried and homogenized with a mortar and pestle.
Prior to TIC and d18O analyses, each sample was combined withdeionize d water, shaken and centrifuged for 15 min at 20,000 rpm using a Sorval Superspeed RC2B.1 After centrifugation, the conductivity of the supernatant was measured and the supernatant discarded. This procedure was repeated until the conductivity of the supernatant was o3 times the conductivity of Boulder, Colorado, tap water. The sample was then freeze dried and homogenized with a mortar and pestle.
15% H2O2, ultrasonic cleaning, methanol rinse
15% H2O2, ultrasonic cleaning, methanol rinse
15% H2O2, ultrasonic cleaning, methanol rinse
and most ofthe carbonate macro fossil samples were processed on a preparation  line described by Buchardt (1977); less than 200um
and most ofthe carbonate macro fossil samples were processed on a preparation  line described by Buchardt (1977); less than 200um
and most ofthe carbonate macro fossil samples were processed on a preparation  line described by Buchardt (1977); less than 200um
1cm3 samples from core
1cm3 samples from core
1cm3 samples from core
the Holocene was sampled more intensively (every 0.5 cm), 4 cm intervals from 3000 cal. BP to the present, and at 1 cm intervals prior to 8200 cal. BP; Optically pure diatomite was obtained by oxidation (H2O2) to remove organics, an acid wash (10% HCl) to remove carbonates and gravity settling to remove small amounts of clay. The hydrous layer of the diatoms was stripped by outgassing during a prefluorination.
the Holocene was sampled more intensively (every 0.5 cm), 4 cm intervals from 3000 cal. BP to the present, and at 1 cm intervals prior to 8200 cal. BP; Optically pure diatomite was obtained by oxidation (H2O2) to remove organics, an acid wash (10% HCl) to remove carbonates and gravity settling to remove small amounts of clay. The hydrous layer of the diatoms was stripped by outgassing during a prefluorination.
the Holocene was sampled more intensively (every 0.5 cm), 4 cm intervals from 3000 cal. BP to the present, and at 1 cm intervals prior to 8200 cal. BP; Optically pure diatomite was obtained by oxidation (H2O2) to remove organics, an acid wash (10% HCl) to remove carbonates and gravity settling to remove small amounts of clay. The hydrous layer of the diatoms was stripped by outgassing during a prefluorination.
Piston cores were split, described, and one half of the core was slab sampled at 1-cm intervals. The boxcore was extruded vertically and sampled every 0.5 cm. Samples were washed in deionized water, oven dried, and homogenized prior to coulometric and isotopic analyses [Yuan, 2003]
Piston cores were split, described, and one half of the core was slab sampled at 1-cm intervals. The boxcore was extruded vertically and sampled every 0.5 cm. Samples were washed in deionized water, oven dried, and homogenized prior to coulometric and isotopic analyses [Yuan, 2003]
Piston cores were split, described, and one half of the core was slab sampled at 1-cm intervals. The boxcore was extruded vertically and sampled every 0.5 cm. Samples were washed in deionized water, oven dried, and homogenized prior to coulometric and isotopic analyses [Yuan, 2003]
Piston cores were split, described, and one half of the core was slab sampled at 1-cm intervals. The boxcore was extruded vertically and sampled every 0.5 cm. Samples were washed in deionized water, oven dried, and homogenized prior to coulometric and isotopic analyses [Yuan, 2003]
Piston cores were split, described, and one half of the core was slab sampled at 1-cm intervals. The boxcore was extruded vertically and sampled every 0.5 cm. Samples were washed in deionized water, oven dried, and homogenized prior to coulometric and isotopic analyses [Yuan, 2003]
Piston cores were split, described, and one half of the core was slab sampled at 1-cm intervals. The boxcore was extruded vertically and sampled every 0.5 cm. Samples were washed in deionized water, oven dried, and homogenized prior to coulometric and isotopic analyses [Yuan, 2003]
five shells of the spinose morphotype of P. coronatus were selected and crushed to open internal chambers, cleaned, and fragments re-picked prior to pretreatment...Gastropod shells were broken open and sonically cleaned to remove fine-grained particles from internal chambers...All carbonate samples were soaked in ~15% H2O2 for 30 min to remove organic matter and then rinsed with methanol. The methanol was removed with a syringe, and samples were dried in an oven at 508C for 24 h. Gastropods and Chara samples were ground to a homogeneous powder and ostracods were analyzed whole. Approximately 50?100 Ag of carbonate was loaded into individual reaction vessels for isotopic analysis
five shells of the spinose morphotype of P. coronatus were selected and crushed to open internal chambers, cleaned, and fragments re-picked prior to pretreatment...Gastropod shells were broken open and sonically cleaned to remove fine-grained particles from internal chambers...All carbonate samples were soaked in ~15% H2O2 for 30 min to remove organic matter and then rinsed with methanol. The methanol was removed with a syringe, and samples were dried in an oven at 508C for 24 h. Gastropods and Chara samples were ground to a homogeneous powder and ostracods were analyzed whole. Approximately 50?100 Ag of carbonate was loaded into individual reaction vessels for isotopic analysis
five shells of the spinose morphotype of P. coronatus were selected and crushed to open internal chambers, cleaned, and fragments re-picked prior to pretreatment...Gastropod shells were broken open and sonically cleaned to remove fine-grained particles from internal chambers...All carbonate samples were soaked in ~15% H2O2 for 30 min to remove organic matter and then rinsed with methanol. The methanol was removed with a syringe, and samples were dried in an oven at 508C for 24 h. Gastropods and Chara samples were ground to a homogeneous powder and ostracods were analyzed whole. Approximately 50?100 Ag of carbonate was loaded into individual reaction vessels for isotopic analysis
five shells of the spinose morphotype of P. coronatus were selected and crushed to open internal chambers, cleaned, and fragments re-picked prior to pretreatment...Gastropod shells were broken open and sonically cleaned to remove fine-grained particles from internal chambers...All carbonate samples were soaked in ~15% H2O2 for 30 min to remove organic matter and then rinsed with methanol. The methanol was removed with a syringe, and samples were dried in an oven at 508C for 24 h. Gastropods and Chara samples were ground to a homogeneous powder and ostracods were analyzed whole. Approximately 50?100 Ag of carbonate was loaded into individual reaction vessels for isotopic analysis
five shells of the spinose morphotype of P. coronatus were selected and crushed to open internal chambers, cleaned, and fragments re-picked prior to pretreatment...Gastropod shells were broken open and sonically cleaned to remove fine-grained particles from internal chambers...All carbonate samples were soaked in ~15% H2O2 for 30 min to remove organic matter and then rinsed with methanol. The methanol was removed with a syringe, and samples were dried in an oven at 508C for 24 h. Gastropods and Chara samples were ground to a homogeneous powder and ostracods were analyzed whole. Approximately 50?100 Ag of carbonate was loaded into individual reaction vessels for isotopic analysis
five shells of the spinose morphotype of P. coronatus were selected and crushed to open internal chambers, cleaned, and fragments re-picked prior to pretreatment...Gastropod shells were broken open and sonically cleaned to remove fine-grained particles from internal chambers...All carbonate samples were soaked in ~15% H2O2 for 30 min to remove organic matter and then rinsed with methanol. The methanol was removed with a syringe, and samples were dried in an oven at 508C for 24 h. Gastropods and Chara samples were ground to a homogeneous powder and ostracods were analyzed whole. Approximately 50?100 Ag of carbonate was loaded into individual reaction vessels for isotopic analysis
five shells of the spinose morphotype of P. coronatus were selected and crushed to open internal chambers, cleaned, and fragments re-picked prior to pretreatment...Gastropod shells were broken open and sonically cleaned to remove fine-grained particles from internal chambers...All carbonate samples were soaked in ~15% H2O2 for 30 min to remove organic matter and then rinsed with methanol. The methanol was removed with a syringe, and samples were dried in an oven at 508C for 24 h. Gastropods and Chara samples were ground to a homogeneous powder and ostracods were analyzed whole. Approximately 50?100 Ag of carbonate was loaded into individual reaction vessels for isotopic analysis
five shells of the spinose morphotype of P. coronatus were selected and crushed to open internal chambers, cleaned, and fragments re-picked prior to pretreatment...Gastropod shells were broken open and sonically cleaned to remove fine-grained particles from internal chambers...All carbonate samples were soaked in ~15% H2O2 for 30 min to remove organic matter and then rinsed with methanol. The methanol was removed with a syringe, and samples were dried in an oven at 508C for 24 h. Gastropods and Chara samples were ground to a homogeneous powder and ostracods were analyzed whole. Approximately 50?100 Ag of carbonate was loaded into individual reaction vessels for isotopic analysis
five shells of the spinose morphotype of P. coronatus were selected and crushed to open internal chambers, cleaned, and fragments re-picked prior to pretreatment...Gastropod shells were broken open and sonically cleaned to remove fine-grained particles from internal chambers...All carbonate samples were soaked in ~15% H2O2 for 30 min to remove organic matter and then rinsed with methanol. The methanol was removed with a syringe, and samples were dried in an oven at 508C for 24 h. Gastropods and Chara samples were ground to a homogeneous powder and ostracods were analyzed whole. Approximately 50?100 Ag of carbonate was loaded into individual reaction vessels for isotopic analysis
none
none
none
Samples collected from core
Samples collected from core
Samples collected from core
Individual laminae for top 900 years then 5 year bulk samples
Individual laminae for top 900 years then 5 year bulk samples
Individual laminae for top 900 years then 5 year bulk samples
Sieving 250�m
Sieving 250�m
Sieving 250�m
N/A
N/A
N/A
sediment had been bleached to  remove organic matter and sieved at 63 um to remove ostracodes.
sediment had been bleached to  remove organic matter and sieved at 63 um to remove ostracodes.
sediment had been bleached to  remove organic matter and sieved at 63 um to remove ostracodes.
We sampled the sediments contiguously at 3-year intervals for the past 250 years and at 5-year intervals for the remainder of the past 3100 years.
We sampled the sediments contiguously at 3-year intervals for the past 250 years and at 5-year intervals for the remainder of the past 3100 years.
We sampled the sediments contiguously at 3-year intervals for the past 250 years and at 5-year intervals for the remainder of the past 3100 years.
Bulk sediment samples were taken from core C/E for isotope analyses at 0.5-cm increments for the uppermost 16.5 cm (32 field-extruded samples; Glew, 1988; Glew et al., 2001), at 1-cm increments from 16.5-cm depth to the White River Ash at 64-cm depth, and at 2-cm increments from 64- to 144-cm depth for a total of 121 samples. The bulk sediment samples were wet sieved through nested screens (63, 125, 250-mm), collected separately and freeze dried. At least five individual Chara stem encrustations (1?3 mm each in length) were picked from the dried fractions, examined for purity, homogenized and sub- sampled for CO2 extraction
Bulk sediment samples were taken from core C/E for isotope analyses at 0.5-cm increments for the uppermost 16.5 cm (32 field-extruded samples; Glew, 1988; Glew et al., 2001), at 1-cm increments from 16.5-cm depth to the White River Ash at 64-cm depth, and at 2-cm increments from 64- to 144-cm depth for a total of 121 samples. The bulk sediment samples were wet sieved through nested screens (63, 125, 250-mm), collected separately and freeze dried. At least five individual Chara stem encrustations (1?3 mm each in length) were picked from the dried fractions, examined for purity, homogenized and sub- sampled for CO2 extraction
Bulk sediment samples were taken from core C/E for isotope analyses at 0.5-cm increments for the uppermost 16.5 cm (32 field-extruded samples; Glew, 1988; Glew et al., 2001), at 1-cm increments from 16.5-cm depth to the White River Ash at 64-cm depth, and at 2-cm increments from 64- to 144-cm depth for a total of 121 samples. The bulk sediment samples were wet sieved through nested screens (63, 125, 250-mm), collected separately and freeze dried. At least five individual Chara stem encrustations (1?3 mm each in length) were picked from the dried fractions, examined for purity, homogenized and sub- sampled for CO2 extraction
1cm3 of material every 10cm down core
1cm3 of material every 10cm down core
1cm3 of material every 10cm down core
contiguous 1cm samples from the core
contiguous 1cm samples from the core
contiguous 1cm samples from the core
every 0.5cm down core (15 years)
every 0.5cm down core (15 years)
every 0.5cm down core (15 years)
sample was  homogenized  prior to division into aliquots for isotope and diatom  analyses; Sediment for isotopic analysis was reacted with 2% sodium hypochlorite to remove organic matter and rinsed five times. The sediment was then sieved at 63 mm to remove ostracodes, shell material, and charaphyte sheaths. The flowthrough from the sieve was collected, freezedried, homogenized, and analyzed for carbon and oxygen isotopes
sample was  homogenized  prior to division into aliquots for isotope and diatom  analyses; Sediment for isotopic analysis was reacted with 2% sodium hypochlorite to remove organic matter and rinsed five times. The sediment was then sieved at 63 mm to remove ostracodes, shell material, and charaphyte sheaths. The flowthrough from the sieve was collected, freezedried, homogenized, and analyzed for carbon and oxygen isotopes
sample was  homogenized  prior to division into aliquots for isotope and diatom  analyses; Sediment for isotopic analysis was reacted with 2% sodium hypochlorite to remove organic matter and rinsed five times. The sediment was then sieved at 63 mm to remove ostracodes, shell material, and charaphyte sheaths. The flowthrough from the sieve was collected, freezedried, homogenized, and analyzed for carbon and oxygen isotopes
sample was  homogenized  prior to division into aliquots for isotope and diatom  analyses; Sediment for isotopic analysis was reacted with 2% sodium hypochlorite to remove organic matter and rinsed five times. The sediment was then sieved at 63 mm to remove ostracodes, shell material, and charaphyte sheaths. The flowthrough from the sieve was collected, freezedried, homogenized, and analyzed for carbon and oxygen isotopes
all recognisable coarse shells and shell fragments handpicked from sediment sample prior to analysis
all recognisable coarse shells and shell fragments handpicked from sediment sample prior to analysis
all recognisable coarse shells and shell fragments handpicked from sediment sample prior to analysis
5cm sampling interval down the core
5cm sampling interval down the core
5cm sampling interval down the core
XRD, SEM; calcite layer composed almost only by rhomboedric calcite crystals, 5?15 ?m long
XRD, SEM; calcite layer composed almost only by rhomboedric calcite crystals, 5?15 ?m long
XRD, SEM; calcite layer composed almost only by rhomboedric calcite crystals, 5?15 ?m long
Disagregation of 12g sediment by H2O2 for 48 hours, sieved at 100�m in tap water, ethanol wash and dry
Disagregation of 12g sediment by H2O2 for 48 hours, sieved at 100�m in tap water, ethanol wash and dry
Disagregation of 12g sediment by H2O2 for 48 hours, sieved at 100�m in tap water, ethanol wash and dry
0.5cmthick samples
0.5cmthick samples
0.5cmthick samples
Homogenized 1 cm subsamples were pretreated for isotope analysis by 24 h digestion in ~45 ml of 2.5% sodium hypochlorite, then sieved (125 ?m) to remove ostracode shells and other coarse materials
Homogenized 1 cm subsamples were pretreated for isotope analysis by 24 h digestion in ~45 ml of 2.5% sodium hypochlorite, then sieved (125 ?m) to remove ostracode shells and other coarse materials
Homogenized 1 cm subsamples were pretreated for isotope analysis by 24 h digestion in ~45 ml of 2.5% sodium hypochlorite, then sieved (125 ?m) to remove ostracode shells and other coarse materials
Homogenized 1 cm subsamples were pretreated for isotope analysis by 24 h digestion in ~45 ml of 2.5% sodium hypochlorite, then sieved (125 ?m) to remove ostracode shells and other coarse materials
Homogenized 1 cm subsamples were pretreated for isotope analysis by 24 h digestion in ~45 ml of 2.5% sodium hypochlorite, then sieved (125 ?m) to remove ostracode shells and other coarse materials
Homogenized 1 cm subsamples were pretreated for isotope analysis by 24 h digestion in ~45 ml of 2.5% sodium hypochlorite, then sieved (125 ?m) to remove ostracode shells and other coarse materials
Samples collected from core
Samples collected from core
contiguous 0.5permil1.0cm intervals; analyses, samples were washed through a 109mm mesh, and 15 Charastem encrustations were manually selected from the residue except in samples that yielded fewer stems. The encrustations were bleached in 3% NaOCl solution, rinsed four times in doubly distilled water, airdried, and ground to powder.
contiguous 0.5permil1.0cm intervals; analyses, samples were washed through a 109mm mesh, and 15 Charastem encrustations were manually selected from the residue except in samples that yielded fewer stems. The encrustations were bleached in 3% NaOCl solution, rinsed four times in doubly distilled water, airdried, and ground to powder.
contiguous 0.5permil1.0cm intervals; analyses, samples were washed through a 109mm mesh, and 15 Charastem encrustations were manually selected from the residue except in samples that yielded fewer stems. The encrustations were bleached in 3% NaOCl solution, rinsed four times in doubly distilled water, airdried, and ground to powder.
Ostracods samples pretreated with 3% H2O2, then samples were split using a microsplitter.
Ostracods samples pretreated with 3% H2O2, then samples were split using a microsplitter.
Ostracods samples pretreated with 3% H2O2, then samples were split using a microsplitter.
Sieving at 63degreesm, 5% NaOCl bleaching
Sieving at 63degreesm, 5% NaOCl bleaching
Sieving at 63degreesm, 5% NaOCl bleaching
3cm intervals down core
3cm intervals down core
3cm intervals down core
Sieving 250�m
Sieving 250�m
Sieving 250�m
Sediment samples were washed in 10% HCl to eliminate biogenic and mineral carbonates, freeze-dried, and gently dry-sieved using a 500-mm mesh. The sieving step removes the larger organic fragments, which have a greater potential to be derived from in-washed terrestrial material, while concentrating the fine organic fraction, derived primarily from zooplankton faecal pellets that deliver aquatic organic matter directly to the sediments (Edwards 1993). The fine-grained fraction was then processed through additional steps to remove non-cellulose organic components and minerogenic matter, including solvent extraction, bleaching, alkaline hydrolysis, oxyhydroxide leaching, and sodium polytungstate density separation
Sediment samples were washed in 10% HCl to eliminate biogenic and mineral carbonates, freeze-dried, and gently dry-sieved using a 500-mm mesh. The sieving step removes the larger organic fragments, which have a greater potential to be derived from in-washed terrestrial material, while concentrating the fine organic fraction, derived primarily from zooplankton faecal pellets that deliver aquatic organic matter directly to the sediments (Edwards 1993). The fine-grained fraction was then processed through additional steps to remove non-cellulose organic components and minerogenic matter, including solvent extraction, bleaching, alkaline hydrolysis, oxyhydroxide leaching, and sodium polytungstate density separation
Sediment samples were washed in 10% HCl to eliminate biogenic and mineral carbonates, freeze-dried, and gently dry-sieved using a 500-mm mesh. The sieving step removes the larger organic fragments, which have a greater potential to be derived from in-washed terrestrial material, while concentrating the fine organic fraction, derived primarily from zooplankton faecal pellets that deliver aquatic organic matter directly to the sediments (Edwards 1993). The fine-grained fraction was then processed through additional steps to remove non-cellulose organic components and minerogenic matter, including solvent extraction, bleaching, alkaline hydrolysis, oxyhydroxide leaching, and sodium polytungstate density separation
Samples collected from core
Samples collected from core
Samples collected from core
Samples collected from core
Samples collected from core
Samples collected from core
0.5 cm increments
0.5 cm increments
0.5 cm increments
Core samples
Core samples
Core samples
N/A
N/A
N/A
every 5cm downcore
every 5cm downcore
every 5cm downcore
Sediment sampleswere disaggregated for approximately 24 h in 7% H2O2 solution and sieved
at 63 μm to isolate authigenic (i.e., precipitated in-lake) carbonate material
and to limit contamination by biogenic carbonate shell material. The captured
<63 μm fraction of the sediment was settled from rinse water and then
centrifuged, and the remaining liquid was decanted. The resulting fine grained
 carbonate sediment was bleached (using a 50% bleach, 50% water
 solution), rinsed three times using deionized water, freeze-dried, and homogenized
using an agate mortar and pestle.
Sediment sampleswere disaggregated for approximately 24 h in 7% H2O2 solution and sieved
at 63 μm to isolate authigenic (i.e., precipitated in-lake) carbonate material
and to limit contamination by biogenic carbonate shell material. The captured
<63 μm fraction of the sediment was settled from rinse water and then
centrifuged, and the remaining liquid was decanted. The resulting fine grained
 carbonate sediment was bleached (using a 50% bleach, 50% water
 solution), rinsed three times using deionized water, freeze-dried, and homogenized
using an agate mortar and pestle.
Sediment sampleswere disaggregated for approximately 24 h in 7% H2O2 solution and sieved
at 63 μm to isolate authigenic (i.e., precipitated in-lake) carbonate material
and to limit contamination by biogenic carbonate shell material. The captured
<63 μm fraction of the sediment was settled from rinse water and then
centrifuged, and the remaining liquid was decanted. The resulting fine grained
 carbonate sediment was bleached (using a 50% bleach, 50% water
 solution), rinsed three times using deionized water, freeze-dried, and homogenized
using an agate mortar and pestle.
every 2cm in the upper 10cm and then every 4-6cm downcore
every 2cm in the upper 10cm and then every 4-6cm downcore
every 2cm in the upper 10cm and then every 4-6cm downcore
"continuous intervals of 0.25 cm from 0 to 5 cm depth,   at 1.0 cm intervals from 5 to 69 cm depth and at spaced   intervals of 2.0 cm from 69 to 300 cm depth"
"continuous intervals of 0.25 cm from 0 to 5 cm depth,   at 1.0 cm intervals from 5 to 69 cm depth and at spaced   intervals of 2.0 cm from 69 to 300 cm depth"
"continuous intervals of 0.25 cm from 0 to 5 cm depth,   at 1.0 cm intervals from 5 to 69 cm depth and at spaced   intervals of 2.0 cm from 69 to 300 cm depth"
"continuous intervals of 0.25 cm from 0 to 5 cm depth,   at 1.0 cm intervals from 5 to 69 cm depth and at spaced   intervals of 2.0 cm from 69 to 300 cm depth"
"continuous intervals of 0.25 cm from 0 to 5 cm depth,   at 1.0 cm intervals from 5 to 69 cm depth and at spaced   intervals of 2.0 cm from 69 to 300 cm depth"
"continuous intervals of 0.25 cm from 0 to 5 cm depth,   at 1.0 cm intervals from 5 to 69 cm depth and at spaced   intervals of 2.0 cm from 69 to 300 cm depth"
Ostracods samples pretreated with 3% H2O2, then samples were split using a microsplitter.
Ostracods samples pretreated with 3% H2O2, then samples were split using a microsplitter.
Ostracods samples pretreated with 3% H2O2, then samples were split using a microsplitter.
Sample preparation followed methods described in De Deckker (1982)
Sample preparation followed methods described in De Deckker (1982)
Sample preparation followed methods described in De Deckker (1982)
Sediment samples were disaggregated for approximately 24 h in 7% H2O2 solution and sieved at 63 μm to isolate authigenic (i.e., precipitated in-lake) carbonate material and to limit contamination by biogenic carbonate shell material. The captured <63 μm fraction of the sediment was settled from rinse water and then centrifuged, and the remaining liquid was decanted. The resulting fine grained carbonate sediment was bleached (using a 50% bleach, 50% water solution), rinsed three times using deionized water, freeze-dried, and homogenizedsing an agate mortar and pestle.
Sediment samples were disaggregated for approximately 24 h in 7% H2O2 solution and sieved at 63 μm to isolate authigenic (i.e., precipitated in-lake) carbonate material and to limit contamination by biogenic carbonate shell material. The captured <63 μm fraction of the sediment was settled from rinse water and then centrifuged, and the remaining liquid was decanted. The resulting fine grained carbonate sediment was bleached (using a 50% bleach, 50% water solution), rinsed three times using deionized water, freeze-dried, and homogenizedsing an agate mortar and pestle.
Sediment samples
were disaggregated for approximately 24 h in 7% H2O2 solution and sieved
at 63 μm to isolate authigenic (i.e., precipitated in-lake) carbonate material
and to limit contamination by biogenic carbonate shell material. The captured
<63 μm fraction of the sediment was settled from rinse water and then
centrifuged, and the remaining liquid was decanted. The resulting fine grained
 carbonate sediment was bleached (using a 50% bleach, 50% water
 solution), rinsed three times using deionized water, freeze-dried, and homogenized
using an agate mortar and pestle.
Sediment samples
were disaggregated for approximately 24 h in 7% H2O2 solution and sieved
at 63 μm to isolate authigenic (i.e., precipitated in-lake) carbonate material
and to limit contamination by biogenic carbonate shell material. The captured
<63 μm fraction of the sediment was settled from rinse water and then
centrifuged, and the remaining liquid was decanted. The resulting fine grained
 carbonate sediment was bleached (using a 50% bleach, 50% water
 solution), rinsed three times using deionized water, freeze-dried, and homogenized
using an agate mortar and pestle.
Pisidiidae shell fragments (between 1 and 5) were crushed and treated with H2O2 for 30 min to remove organic material. The samples were then rinsed three times with deionized water. Aliquots (*100 lg) were weighed for isotopic analysis
Pisidiidae shell fragments (between 1 and 5) were crushed and treated with H2O2 for 30 min to remove organic material. The samples were then rinsed three times with deionized water. Aliquots (*100 lg) were weighed for isotopic analysis
Pisidiidae shell fragments (between 1 and 5) were crushed and treated with H2O2 for 30 min to remove organic material. The samples were then rinsed three times with deionized water. Aliquots (*100 lg) were weighed for isotopic analysis
Aggregates of ~30 adult ostracod carapaces of the genus Physocypria, with no evidence of corrosion, were isolated from sediment for oxygen isotope analysis at 1?2 cm intervals. Ostracod valves were soaked in 15 % H2O2, cleaned ultrasonically in deionized water, rinsed with methanol and dried at 60�C for 12 hours
Aggregates of ~30 adult ostracod carapaces of the genus Physocypria, with no evidence of corrosion, were isolated from sediment for oxygen isotope analysis at 1?2 cm intervals. Ostracod valves were soaked in 15 % H2O2, cleaned ultrasonically in deionized water, rinsed with methanol and dried at 60�C for 12 hours
Aggregates of ~30 adult ostracod carapaces of the genus Physocypria, with no evidence of corrosion, were isolated from sediment for oxygen isotope analysis at 1?2 cm intervals. Ostracod valves were soaked in 15 % H2O2, cleaned ultrasonically in deionized water, rinsed with methanol and dried at 60�C for 12 hours
Samples collected from core
Samples collected from core
Samples collected from core
Shells collected from sediment core
Shells collected from sediment core
Shells collected from sediment core
N/A
N/A
N/A
N/A
N/A
N/A
sieving 0.062-2 mm fraction, washing in DI water
sieving 0.062-2 mm fraction, washing in DI water
sieving 0.062-2 mm fraction, washing in DI water
Samples were dried at 50 degrees C for 24 h
Samples were dried at 50 degrees C for 24 h
Samples were dried at 50 degrees C for 24 h
Individual laminae for top 900 years then 5 year bulk samples
Individual laminae for top 900 years then 5 year bulk samples
1cm thick samples from core
1cm thick samples from core
1cm thick samples from core
Samples collected from core
Samples collected from core
Samples collected from core
Samples freeze dried and sieved
Samples freeze dried and sieved
d180 values (relative to the PDB standard) in the TIC fraction, in hand-picked carbonate crystals,
d180 values (relative to the PDB standard) in the TIC fraction, in hand-picked carbonate crystals,
d180 values (relative to the PDB standard) in the TIC fraction, in hand-picked carbonate crystals,
Individual gastropod shells were also picked from every 1-cm interval for stable isotopic analysis. Single specimens of Pyrgophorus coronatus were separated from the sieved 1400 mm fraction under 101 magnification. Gastropod shells were soaked in 15% H2O2 to remove organic matter cleaned and sonicated in deionized water, and ultimately rinsed with methanol before drying. Individual gastropod shells were ground to a fine powder using a mortar and pestle
Individual gastropod shells were also picked from every 1-cm interval for stable isotopic analysis. Single specimens of Pyrgophorus coronatus were separated from the sieved 1400 mm fraction under 101 magnification. Gastropod shells were soaked in 15% H2O2 to remove organic matter cleaned and sonicated in deionized water, and ultimately rinsed with methanol before drying. Individual gastropod shells were ground to a fine powder using a mortar and pestle
Individual gastropod shells were also picked from every 1-cm interval for stable isotopic analysis. Single specimens of Pyrgophorus coronatus were separated from the sieved 1400 mm fraction under 101 magnification. Gastropod shells were soaked in 15% H2O2 to remove organic matter cleaned and sonicated in deionized water, and ultimately rinsed with methanol before drying. Individual gastropod shells were ground to a fine powder using a mortar and pestle
Individual gastropod shells were also picked from every 1-cm interval for stable isotopic analysis. Single specimens of Pyrgophorus coronatus were separated from the sieved 1400 mm fraction under 101 magnification. Gastropod shells were soaked in 15% H2O2 to remove organic matter cleaned and sonicated in deionized water, and ultimately rinsed with methanol before drying. Individual gastropod shells were ground to a fine powder using a mortar and pestle
contiguous 1cm samples from pit
contiguous 1cm samples from pit
contiguous 1cm samples from pit
cleaned of organic material using 15% H2O2, then washed with deionized water, rinsed in methanol, and dried. Gastropods were cleaned in the same manner, except that specimens were additionally cleaned by sonication...Multiple (5) gastropod shells were ground to a fine powder with a mortar and pestle and a portion of the pulverized aragonite was loaded into stainless steel carrying boats for isotopic analysis.Multiple individuals, each living approximately one year, were used to average shortterm (i.e. yearly) changes in lake conditions.
cleaned of organic material using 15% H2O2, then washed with deionized water, rinsed in methanol, and dried. Gastropods were cleaned in the same manner, except that specimens were additionally cleaned by sonication...Multiple (5) gastropod shells were ground to a fine powder with a mortar and pestle and a portion of the pulverized aragonite was loaded into stainless steel carrying boats for isotopic analysis.Multiple individuals, each living approximately one year, were used to average shortterm (i.e. yearly) changes in lake conditions.
cleaned of organic material using 15% H2O2, then washed with deionized water, rinsed in methanol, and dried. Gastropods were cleaned in the same manner, except that specimens were additionally cleaned by sonication...Multiple (5) gastropod shells were ground to a fine powder with a mortar and pestle and a portion of the pulverized aragonite was loaded into stainless steel carrying boats for isotopic analysis.Multiple individuals, each living approximately one year, were used to average shortterm (i.e. yearly) changes in lake conditions.
For stable isotope analysis, each 1 cm subsample was disaggregated by soaking in 3% H2O2 and subsequently sieved at 250 mm. The .250 mm fraction was collected on filter paper, dried at 60�C and transferred to glass scintillation vials. Ostracods and gastropods were separated from the matrix using a dissecting microscope at 10 � magnification. Adult specimens of the ostracod Cytheridella boldi were picked from the sieved 425?500 mm fraction, Heterocypris communis were picked from the 351?500 mm fraction, and Cypria obtusa were picked from the 250?300 mm fraction. Specimens of the gastropod Pyrgophorus sp. were separated from the sieved .1000 mm fraction. Ostracod valves were cleaned of organic material using 15% H2O2, then washed in deionized water, rinsed in methanol, and dried. Gastropods were cleaned in the same manner, except that specimens were cleaned further by sonication. Samples consisting of many monospecific ostracod carapaces (|15 C. boldi, |20 H. communis, |25 C. obtusa) were loaded into a stainless-steel carrying boat, crushed with a glass rod dipped in methanol and allowed to dry overnight. Numerous monospecific ostracod valves were used to constitute a sample to reduce variance that might result from running single, short-lived individuals whose isotopic signatures might reflect short-term (i.e., seasonal) water-column temperature and salinity conditions (Heaton et al., 1995)
For stable isotope analysis, each 1 cm subsample was disaggregated by soaking in 3% H2O2 and subsequently sieved at 250 mm. The .250 mm fraction was collected on filter paper, dried at 60�C and transferred to glass scintillation vials. Ostracods and gastropods were separated from the matrix using a dissecting microscope at 10 � magnification. Adult specimens of the ostracod Cytheridella boldi were picked from the sieved 425?500 mm fraction, Heterocypris communis were picked from the 351?500 mm fraction, and Cypria obtusa were picked from the 250?300 mm fraction. Specimens of the gastropod Pyrgophorus sp. were separated from the sieved .1000 mm fraction. Ostracod valves were cleaned of organic material using 15% H2O2, then washed in deionized water, rinsed in methanol, and dried. Gastropods were cleaned in the same manner, except that specimens were cleaned further by sonication. Samples consisting of many monospecific ostracod carapaces (|15 C. boldi, |20 H. communis, |25 C. obtusa) were loaded into a stainless-steel carrying boat, crushed with a glass rod dipped in methanol and allowed to dry overnight. Numerous monospecific ostracod valves were used to constitute a sample to reduce variance that might result from running single, short-lived individuals whose isotopic signatures might reflect short-term (i.e., seasonal) water-column temperature and salinity conditions (Heaton et al., 1995)
For stable isotope analysis, each 1 cm subsample was disaggregated by soaking in 3% H2O2 and subsequently sieved at 250 mm. The .250 mm fraction was collected on filter paper, dried at 60�C and transferred to glass scintillation vials. Ostracods and gastropods were separated from the matrix using a dissecting microscope at 10 � magnification. Adult specimens of the ostracod Cytheridella boldi were picked from the sieved 425?500 mm fraction, Heterocypris communis were picked from the 351?500 mm fraction, and Cypria obtusa were picked from the 250?300 mm fraction. Specimens of the gastropod Pyrgophorus sp. were separated from the sieved .1000 mm fraction. Ostracod valves were cleaned of organic material using 15% H2O2, then washed in deionized water, rinsed in methanol, and dried. Gastropods were cleaned in the same manner, except that specimens were cleaned further by sonication. Samples consisting of many monospecific ostracod carapaces (|15 C. boldi, |20 H. communis, |25 C. obtusa) were loaded into a stainless-steel carrying boat, crushed with a glass rod dipped in methanol and allowed to dry overnight. Numerous monospecific ostracod valves were used to constitute a sample to reduce variance that might result from running single, short-lived individuals whose isotopic signatures might reflect short-term (i.e., seasonal) water-column temperature and salinity conditions (Heaton et al., 1995)
For stable isotope analysis, each 1 cm subsample was disaggregated by soaking in 3% H2O2 and subsequently sieved at 250 mm. The .250 mm fraction was collected on filter paper, dried at 60�C and transferred to glass scintillation vials. Ostracods and gastropods were separated from the matrix using a dissecting microscope at 10 � magnification. Adult specimens of the ostracod Cytheridella boldi were picked from the sieved 425?500 mm fraction, Heterocypris communis were picked from the 351?500 mm fraction, and Cypria obtusa were picked from the 250?300 mm fraction. Specimens of the gastropod Pyrgophorus sp. were separated from the sieved .1000 mm fraction. Ostracod valves were cleaned of organic material using 15% H2O2, then washed in deionized water, rinsed in methanol, and dried. Gastropods were cleaned in the same manner, except that specimens were cleaned further by sonication. Samples consisting of many monospecific ostracod carapaces (|15 C. boldi, |20 H. communis, |25 C. obtusa) were loaded into a stainless-steel carrying boat, crushed with a glass rod dipped in methanol and allowed to dry overnight. Numerous monospecific ostracod valves were used to constitute a sample to reduce variance that might result from running single, short-lived individuals whose isotopic signatures might reflect short-term (i.e., seasonal) water-column temperature and salinity conditions (Heaton et al., 1995)
For stable isotope analysis, each 1 cm subsample was disaggregated by soaking in 3% H2O2 and subsequently sieved at 250 mm. The .250 mm fraction was collected on filter paper, dried at 60�C and transferred to glass scintillation vials. Ostracods and gastropods were separated from the matrix using a dissecting microscope at 10 � magnification. Adult specimens of the ostracod Cytheridella boldi were picked from the sieved 425?500 mm fraction, Heterocypris communis were picked from the 351?500 mm fraction, and Cypria obtusa were picked from the 250?300 mm fraction. Specimens of the gastropod Pyrgophorus sp. were separated from the sieved .1000 mm fraction. Ostracod valves were cleaned of organic material using 15% H2O2, then washed in deionized water, rinsed in methanol, and dried. Gastropods were cleaned in the same manner, except that specimens were cleaned further by sonication. Samples consisting of many monospecific ostracod carapaces (|15 C. boldi, |20 H. communis, |25 C. obtusa) were loaded into a stainless-steel carrying boat, crushed with a glass rod dipped in methanol and allowed to dry overnight. Numerous monospecific ostracod valves were used to constitute a sample to reduce variance that might result from running single, short-lived individuals whose isotopic signatures might reflect short-term (i.e., seasonal) water-column temperature and salinity conditions (Heaton et al., 1995)