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/lp/de-gruyter/carbon-isotopic-composition-of-earlydiagenetic-methane-variations-with-0O4TLdt1bF
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- de Gruyter
- Copyright
- Copyright © 2015 by the
- ISSN
- 2300-7559
- eISSN
- 2300-7559
- DOI
- 10.1515/physica-2015-0003
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Abstract
e de strate t e a ua y e et a e i res sedi e ts tw akes M sz e (E P a d) a d Skrzy ka ( P a d) T e erti a radie t i 13 a ues aried wide y r a ut -4 5 (-1 ) i ate su er 1 3 t a ut 2 5 (-1 ) i ate wi ter, i t e u er st sedi e t r i es a ut 3- eters i e t T ese erti a s a are t y are t due t idati r te erature a es, ut rat er t t e i er radie t t e d w ward de rease r du ti rates ia t e a eti a id er e et a e a d tati at way rat er t a ia t e C 2- 2 at way T e r du ti 13 a ues are t e i est duri su er w i e t e west duri wi ter, re e t13 C i wi ter, ate ed es e ia y duri sur a e sa i T e d w ward radie t autu a d, at reater de t s, i ate su er resu ts r is t e e ri e t t e residua re urs rs et a e, red i a t y C 2 Keywords: ar is t e ud et , is t e, et a e, ake, sedi e t, dia e esis, ree use e e t, M. ORION DR SE , S. A AS, T. PIE OS 1. INTRODUCTION Metha e pr ducti is a i p rta t part the a car cyc i (e. . Crai a d Ch u 1 82, hai a d Ras usse 1 83, Stee e et a . 1 8 ) a d etha e ic pathways are deter i ed y c e isti r a ic atter, water, a d acteria acti ity. The wi act rs ha e ee pr ed r pr p sed t a ect etha e esis a d etha e u r atura wet a ds: (1) sa i ity (De Lau e et a . 1 83), (2) erti izati paddy s i ( ada 1 0), (3) s i red p te tia (Cicer e et a . 1 83, S e s a d R ssewa 1 8, ( utrie t a d r a ic c te t sur ace s i s a d their thick ess ( arriss a d Se acher 1 81). (5) su strate a d ati e e d-pr duct c (De Lau e et a . 1 8 ), ( ) p a t type a d its physi ica state ( e ti ati rate, a e, hei ht Dacey a d u 1 , Dacey 1 81, Cicer e et a . 1 83, Se acher et a . 1 85), a d ( ) pri ary pr ducti ( hiti a d Cha t 1 3). I additi a y e ter a act rs ike (1) wi d speed (Se acher et a . 1 83), (2) at spheric pressure (Mats a d Like s 1 0), (3) isture c te t r water e e ( arriss et a . 1 82, S e s a d R sswa 1 8, a d ( te perature (Baker-B cker et a . 1 , S e s a d R sswa 1 84, Se acher et a . 1 8 ) ay c tr the etha e u r atura wet a ds. I this paper we rep rt seas a s i ertica pr i es i c a d car is t pic c p siti etha e. Basi the ther dy a ics, a i p icit assu pti c u d e appare t y ade that car is t pe racti ati act r etwee the etha e precurs rs a d etha e as, depe ds te perature. L ica y, at the wer te perature the ake e ir e t, the racti ati act r c u d e e pected t e ar er. Other act rs c tr i is t pe c p siti etha e are is t pe rati i su strates ( etha e precurs rs) a d etha e c su pti y icr ia idati . I atura reshwater syste s, the er e tati acetate, C 3COO C 4 CO2 (Barker 1 3 ), a d the reducti car di ide, CO2 4 2 C 4 0), are the ai etha e ic pathways. Based up 2O (Takai 1 reshwater paddy s i i cu ati e peri e ts, the e d e er 13C a ue etha e pr duced r acetate dissi i ati is -3 a d the 13C a ue C 4, r CO2/ 2 was esti ated t e - t - 0 (Su i t a d ada 1 3). There re, cha es i the re ati e rati s etha e r ati pathways ay ead t te p ra a d spatia s the 13C a ue i C 4, th u h a ra ic atter precurs r ay sh w h e e us car is t pic c p siti . 13 It has ee sh w that, i atura c diti s, diur a s i s e cases d es ut, usua y d es t c rresp d t the diur a s water r sedi e ts te perature, ut rather c rresp ds t the a u da ce a d is t pe characteristics the etha e precurs rs with e i i e r e etha e idati ( drysek 1 5, 1 ). There re, u k w act r(s) sti re ai r CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE atura c diti s reshwater akes syste s, ecause ack i r ati spatia a d te p ra s etha e esis i reshwater sedi e ts, particu ar y i akes (e. . te ate et a . 1 84, hiticar et a . 1 8 ). It was u d rece t y that 13 a ues reshwater etha e te ds t ec e re e ati e with depth the water c u a d depth sedi e ts ( drysek et a . 1 4, drysek 1 , 2005a). C se ue t y, e ay state that data pu ished i pre i us w rks ay t ir y represe t is t pic c p siti t ta etha e e itted r reshwater sedi e ts. There re, the a s the prese t study are: 1) t tai ew data C 4 e erated r akes with respect t spatia a d te p ra distri uti s, 2) etter u dersta di the echais s etha e esis, 3) t pr ide ew data r is t pic ass a a ces car cyc i i ear y dia e esis i reshwater syste s a d ree h use ases u . 2. MATERIALS AND MET ODS 2.1. STUD AREA Metha e was sa p ed i tw akes, e i Easter a ther i ester P a d. A ake i Easter P a d, cated ca. 50 k NE r Lu i (5 .4 N, 23.1 E), was se ected i this study as the ai sa p i site. It e s t the re i the cz a dawa Lake a d. The water a a ce c ear y sh ws that this re i is sh rt water. Mea precipitati , a y years easured, is 5 0 a d e ap rati is 450 . A ut 110 is ru which 52 akes the u der r u d ru . S a per ea i ity a d water capacity P eist ce e dep sits u der yi the ake a d the act that the area is at, with a d ze r s eters a i u re ati e hei ht, are the reas s that the water e e is t deep a d the sur ace is swa py ( i at et a . 1 1). Lake M sz e is i its i a sta e the ake de e p e t, it is surr u ded y peat- s, swa ps a d arshes. It is a dystr phic, ery sha w ( a . depth 0.8 ), s a (0.1 k 2) ake. N seas a s i the water e e has ee ser ed. The tt is ery at a d practica y ree r a y acr phytes. A the a k the ake ar u d is c ered y a ati peat- . The sedi e ts are e tre e y s t a d c p sed ear e c usi e y in situ r a ic atter detritus (C r i the dry sedi e t is a ut 5 ). M. ORION DR SE , S. A AS, T. PIE OS FIG. 1. Map sh wi the cati s scribed i : drysek (1 5, 1 ,1 sa p ed akes i P a d. Sa p i ). sites are de- Occasi a y sa p i ha e bee carried ut a s i Lake Skrzy ka (52.15 N, 1 .0 E, ca. 30 k s uthward r P z a , P a d). Lake Skrzy ka is a . 2.0 eters depth a d sh ws ear ide tica i ica a d hydr ica character as Lake M sz e, but is situated i uch ess arshy re i . 2.2. SAMPLIN AND IELD OBSERVATIONS I rder t reduce the i ue ce diur a s ( drysek 1 4, 1 5) each sa p i ca pai was carried ut 12:00 a d 3:00 PM. Vertica sa p i pr i e was d e by se ue tia a itati deeper z es sedi e t by ea s a sca ed (with 1 c accuracy) padd e. The depth water i the sa p i sites was 0.5 . The isua y esti ated sa p i depth res uti was appare t y better tha 5 c . Bubb es were btai ed r sub er ed sedi e ts by a itati , a d the trapped by a i erted u e 20 c i dia eter i t a ass b tt e i ed with as- ree water. The upper st ayer sedi e t was a itated irst, u ti a the etha e had appare t y bee re eased. The , the e t, deeper z e sedi e ts was stirred, a d i each subse ue t z e the thick ess the stirred sedie ts was arr wer. This pr cedure appare t y pre e ted c ta i ati etha e r a i e z e by etha e r a ther er ayi z e. Sa p i ti e bubb e ases was usua y t er tha 2 i utes. S e water re ai ed i the b tt e. The b tt es were sea ed with a buty rubber cap a d a a u i u sea , a d the sa p es were i ediate y treated with C 2. B tt es with sa p es were st red i a re ri erat r (34 C) i a i erted p siti . E peri e ts with a a ysis repeated at di ere t ti es r se era ti es pr ed that the e th the peri d r which sa p es were he d be re they were a a yzed did t i ue ce resu ts. M re er, it was pr ed pre i us y that sa p es c ected at the sa e ti e r the sa e depth water c u , r the sa e depth sedi e ts (025 c ) a d r reas ab y si i ar sedi e ts, but at CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE di ere t sa p i stati s, sh wed the sa e 13C resu ts withi a a ytica err r which was r 0.05 t 0.2 ( drysek et a1. 1 4, drysek 1 4, 1 5). Vertica pr i es te perature i sedi e ts were easured with a precisi 0.1 C, usi a 3- eter ther c up e pr be ade by Czaki . 2.3. ANAL TICAL TEC NIQUES ith ecu ar sie es, a dry-ice-etha i ture, a d i uid itr e , the etha e was cry e ica y puri ied u der acuu r ther hydr e a d carb c tai i ases. Subse ue t y, the etha e, t ether with hydr e a d carb - ree ases was passed thr u h a c pper ide ur ace (850 00 C) twice. The pr ducts btai ed, 2O a d CO2, were separated cry e ica y. Carb is t pe a a yses were ade a di ied MI-1305 ass spectr eter with dua i et ( a as, 1 ) a d h e- ade detecti syste s ( a as a d Sk rzy ski, 1 80). The is t pe rati s are e pressed as 13C a ues re ati e t the PDB sta dard, usi a ass spectr etric c paris w rki CO2 as with CO2 prepared r NBS 1 a d NBS 22 sta dards. The i ter a precisi btai ed was 0.05 . The repr ducibi ity is t pe preparati was r 0.05 t 0.2 ). The che ica c p siti sa p e ases was a a yzed by TCD as chr at raphy ( E wr chr at raph S04 ) a d the c te t r a ic atter ( C r ) was a a yzed by Di ere tia Ther a A a ysis a d Ther ra i etry ( Deri at raph 1500D ). 3. RESULTS A data ha e bee prese ted i i ures. Sy b s, i each i ure represe ti the sa e ake, c rresp ds t the sa e pr i e. Si ce te perature is the act r c tr i is t pe e ects, te perature easure e ts i the sedi e ts pr i es ha e bee carried ut. I the spri 1 3, pr i es te perature ( i . 2a) i Lake M sz e te d t decrease t sedie t depth 0.8 , a d the i crease at the reater depths. I the ear y a d ate su er 1 3, the te perature sedi e ts decreases d w wards. S e e tra te perature pr i es, which are t acc pa ied by as sa p i , are sh w i i . 2a. we er, i ery ate su er, i the Lake Skrzy ka sedie ts, the hi hest te perature has bee u d at the depth ab ut 0. ( i . 2b). I the autu 1 3 the te perature te ded t i crease t sedi e t depth 1.3 , a d the decreased at reater depth. I the wi ter 1 4 the te perature i creased d w wards. Sa p i i 2.0 .2 (Lake M sz e) a d 3.05.23 (Lake Skrzy ka) ha e t bee ass ciated with te perature easure e ts. M. ORION DR SE , S. A AS, T. PIE OS FIG. 2a. Te perature s i ertica pr i es i the Lake M sz e sedi e ts (E P a d), each p i t c rresp ds t the as sa p i i ter a , te perature was easured i 10 c ertica i ter a s. A the sy b s i each i ure represe ti Lake M sz e re er t the sa e pr i e. S e additi a te perature pr i es has bee sh w here, but they are t represe ted by sa p es. FIG. 2b. Te perature s i ertica pr i es i the Lake Skrzy ka sedi e ts ( P a d), each p i t c rresp ds t the as sa p i i ter a , te perature has bee easured i 10 c i ter a s. A sy b s i each i ure represe ti Lake Skrzy ka c rresp ds t the sa e pr i e. CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE FIG. 3a. Vertica s a d seas a cyc e i the ertica c i the Lake M sz e sedi e ts. s i FIG. 3b. Vertica s a d seas a cyc e i the ertica c i the Lake Skrzy ka sedi e ts. s i Metha e c i bubb es aried r 1 t 0 i the prese t i esti ati s ( i . 3ab, ab). CO2 c stituted r ess tha 1 t ab ut 8 ( i . ab), but d i a t y itr e c stituted the ther c p e ts, r se - M. ORION DR SE , S. A AS, T. PIE OS era t ab ut 80 the ase us bubb es. O y trace a u ts ther ases were detected. I e era , bubb e e erati by sedi e ts weak y ary a the pr i es, the etha e c te t duri su er was hi h i c trast t that duri c d seas s ( i . 3ab). I s e pr i es, especia y take i the spri a d autu ( i . 3ab) the bubb es r id-depth z es which are re ati e y rich i etha e. The west c etha e has bee ted i the deepest part the c d seas s pr i es ( i . 3a). Si pr i es the carb is t pe c p siti etha e i sedi e ts r Lake M sz e are sh w i i . 4a, a d the ur ther pr i es are sh w i i . 4b (Lake Skrzy ka). I Lake M sz e, sa p i stati s were ab ut 1 r 13 the ar i the ake. A e era tre d decreasi C a ues with i creasi depth was bser ed i the pr i es take i 2.0 .2 , 3.05.01, 3.08.30 (Lake M sz e, i . 4a). This patter see s t c rresp d t sedi e ts te perature, especia y whe k the pr i es i : the su er ( i . 4ab) upper part the pr i e the ate spri ( 3.05.23, i . 4b) - the upperst parts sedi e ts are a ready war ( i . 2a), a d wer part the pr i e the ear y autu ( 2.0 .2 , 3.14.11 i . 4a) the deeper sedi e ts are sti war ( 3.14.1 1, i . 2a). I Lake M sz e duri sa p i i 3.1 1.14 a d 4.02.11 the ake was r ze (10 a d 15 c ice c er, respecti e y). These pr i es sh wed tre ds 13 i creasi C a ues with i creasi depth ( i . 4a). FIG. 4a. Vertica s a d seas a cyc e i the ertica a ue i the Lake M sz e sedi e ts. si CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE FIG. 4b. Vertica s a d seas a cyc e i the ertica a ue i the Lake Skrzy ka sedi e ts. si Duri wi ter etha e e erati r the upper 1 was s w that y se era i i iters as ha e bee re eased due t a itati the sedi e ts (whereas i the sa e p ace duri the su er the sa e u e sedi e t re eased appr i ate y th usa d ar er u e the as). Thus, the upper st sa p e the 4.02.11 pr i e represe ts etha e r as wide a i ter a sedi e ts as 0.0 t 1.2 . The autu 1 3 a d 1 4 pr i es e hibited a rather hi h 13C a ue as c pared t that i the ate spri a d ear y su er pr i es, but the hi hest a ues were sh w by the ate su er sa p es a d the west a ue by the ate wi ter sa p e. 4. DISCUSSION A EIN O SEDIMENTS AND ISOTOPE RACTIONATION A ENERAL OVERVIE I e era , re ati e y si p e, wecu ar wei ht c p u ds, such as structura carb hydrates a d pr tei -beari ateria s, are re easi y deraded tha the c p e p y eric c p u ds such as the i i w dy a d e er e t a uatic p a ts (M re 1 , etze 1 5, ya a et a . 1 , ea M. ORION DR SE , S. A AS, T. PIE OS a d I es 1 8. r e a p e, Be (1 ) i cubated ded s i a aer bica y a d u d that uc se a d pept e were de raded t etha e a d carb di ide uch aster tha ce u se, a th u h the t ta u es etha e a d carb di ide e e tua y pr duced r the three substrates were r u h y the sa e. Si i ar y, a a ateria is dec p sed t etha e a d carb di ide ab ut 10 ti es aster tha is i ce u ses (Be er et a . 1 8. There re, etha e pr ducti sh u d decrease with sedi e t aturati . I act, tube i cubati s sh wed that the rate etha e pr ducti i reshwater ake sedi e ts decreased r a i u a ues at sur ace t ear y zer at depths 40 t 0 c . Likewise, t ta r a ic carb decreased r sur icia a ues (5 t 2 ) at 40 t 0 c with urther decreases with depth ( ya a et a . 1 , ya a 1 0). B air a d Carter (1 2) esti ated the carb is t pe racti ati act r duri etha e pr ducti i a ic ari e sedi e ts t be 1.032. They ha e sh w that the 13C a ue etha e pr duced r acetate is re e ati e 13 tha the C a ue the ethy r up the acetate. rzycki et a . (1 8 ) ha e u d that the carb is t pe di ere ce the ethy carb acetate a d etha e is 2 . The 13C a ue C 4 pr duced r acetate u der steady state c diti s was esti ated t be si i ar t that ethy carb acetate (43 t -30 ) i su ate dep eted reshwater areas a d the i tra ecu ar is t pe distributi acetate was -43 t -30 r ethy carb a d -24 t -15 r carb y carb (Su i t a d ada 1 3). It was rep rted a s that, i the CO2-C 4 syste , the racti ati is 1.04 at 3 C ( rzycki et a . 1 8 ) a d ra es wide y depe de t bacteria species r e a p e, at 45 C the racti ati act r aries at east r 1.045 t 1.0 1 ( a es et a . 1 8). Metha e pr duced r ther substrates tha carb di ide a d acetate, c u d be c assiied as a third r up (Ore a d et a . 1 82) but we d t ha e e ide ce that 13 a d its c u d be di ere t r the a ue r etha e pr duced r carb di ide a d acetate. T this r up pathways ay be r e a p e, the pr ducti a d c su pti the ethy r up ethi i e a d di ethysu phide, ethy ated a i es, etha , etha , be z ate, reducti carb ide, r ate, etc. ( i d er a d Br ck 8ab, ei er a d eikus 1 8, Patters a d espe 1 , Ore a d et a . 1 82). we er, y u der certai specia c diti s this third r up etha e ic pathways d es p ay a i p rta t r e. i et a . (1 83) rep rted that 35.1 1.1 etha e esis ccurri i s urries su ate-rich i tertida sedi e ts was r tri ethy a i e, whereas L ey a d u (1 83) deter i ed that 15 a d 5 t ta etha e esis i w su ate ake sedi e ts c u d be acc u ted r ethy a i es a d etha , respecti e y. The act r i iti acetate er e tati is the pr ducti rate acetate, whereas the CO2/ 2 pr ducti C 4 ay be c tr ed by 2 tra s er (C rad a d Babbe 1 8 ). we er, t be re speci ic, the act r i iti acetate CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE dissi i ati is the a ai abi ity acetate. Acetate pr ducti rate ca be ery hi h, but y a itt e racti is c erted t etha e. I hydr e is pr duced i substa tia a u ts by bacteria a d diss ciati water, a d ikewise the CO2 c i water is re ati e y hi h, these ay e ha ce etha e esis ia the CO2/ 2 reducti i the upper st h riz s sedie ts. The abu da ces y e a d ther p te tia y i p rta t e ectr accept rs supp rti the dec p siti r a ic atter a s depe d the rates icr bia acti ities that are, i tur , c tr ed by i ht a d te perature resu ti r day- i ht s ( drysek 1994, drysek et a . 199 ). M re er, the di ere t echa is bi e ic etha e pr ducti ca resu t i a wide ra e is t pic c p siti especia y withi i i eters t ce ti eters the sedi e t-water i ter ace. I e era , the c s CO2 a d acetate i ari e sedi e ts i crease a d decrease d w ward, respecti e y (Cri a d Marte s 198 ). B th r ss acetate pr ducti rate a d acetate c i sedi e ts is the hi hest i the sur ace ayer (02 c ) a d it is se era ti es wer at depth 8-10 c , a th u h the acetate idati rate with depth, eed t be better c ari ied (Christe se 1984, Miche s et a . 1989). 14 C i cubati e peri e ts de strated that acetate c i sedie ts decreased substa tia y a ter i cubati peri ds (Miche s et a . 1989). Acetate tur er is hi h ear the sur ace, but it is u sure i acetate dissi i ati si i ica t y e ceed the rate CO2/ 2 reducti , because 2 pr ducti is the hi hest ear the sur ace as we . Despite that this p i t is t we d cu e ted i the iterature, because the u certai ties a d p te tia arti acts ass ciated with the 14C-tracer acetate tur er easure e ts, s e e ide ces, a ri the p i t that acetate dissi i ati is re ati e y re i p rta t i the 13 sur icia sedi e ts, c es r C e peri e ts. Na e y, the si i ar situati was c ear y bser ed i paddy s i -water i cubati studies, a d the 13 a ue was a use u i dicat r r assessi the c tributi acetate er e tati t the t ta pr ducti etha e: the hi h 13C 4 a ues c rresp ded t a hi her c tributi the acetate pr cess (Su i t a d ada 1993). PRO ILES ANAL ED e specu ate that the i put resh r a ic atter i t sedi e ts, i the e d su er, c u d s i ht y e ha ce the pr ducti acetic acid a d pr ide the hi her 13C a ues r etha e. C se ue t y, the ate su er/ear y autu etha e c u d sh w the re p siti e 13C a ue i the a ua cyc e. I act, hi hest 13 a ues ( i . 4a) a d isua y ud ed hi hest etha e pr ducti were bser ed duri ate su er a d ear y autu . Abu da t bubb e etha e is easi y a d e icie t y btai ed by i ited stirri sedi e t duri su er, whereas w a u ts bubb e etha e are btai ed i si i ar c diti s by e te si e stirri sedi e ts duri wi ter. This bser ati c rre- M. ORION DR SE , S. A AS, T. PIE OS ates we with a ua s ebu iti (Marte s et a . 198 , Cha t a d Marte s 1988, Burke et a . 1988, drysek et a . 1994, edrysek 199 ) a d te perature seas a s ( i . 2a). B th ebu iti a d te perature are the west duri wi ter a d the hi hest duri su er. This resu t is caused pr bab y by the act that etha e is ess s ub e at wer te perature (Cha t et a . 1992) a d by a ishi y w pr ducti etha e duri wi ter ( drysek 199 ). I as uch as ri i e etati acr phytes is ike y t be critica i a ecti etha e esis (e. . erard a d Cha t 1993), because partia c su pti etha e by idati ca si i ica t y shi t hydr e a d carb is t pic rati s p siti e y i the residua etha e ( yaku et a . 19 9, Barker a d ritz 1981, C e a et a . 1981). r this reas i ur sa p i stati s sub er ed r e er ed acr phytes were prese t withi se era eters. Therere, the decrease i 13 with i creasi depth i sedi e ts ( i . 4ab) was p ssib y caused either by acti e etha e c su pti c se t the sur ace a d/ r by hi her c tributi acetic acid er e tati ear the sur ace ayers a d a re ati e y reater c tributi by the CO2/ 2 reducti i deeper parts sedi e ts. we er, a ic c diti s were bser ed ust se era ce ti eters be w the water-sedi e t i ter ace, a d the su ate c i p re waters was c se t zer ( drysek 2005b). Thus, atter pr cess, reater c tributi by the CO2/ 2 pathway i deeper parts sedi e ts, is ike y e phasized here, si ce the p siti e depth- 13C c rre ati i sedi e ts c u d t p ssib y be a resu t aryi de rees bacteria idati trapped etha e. N ethe ess, despite a aer bic c diti s, idati sh u d t be e ected, a d there re re acts sh u d be c sidered. It c cer especia y re ati s etha e c a d 13 a ue. Decrease i etha e c i e era d es t c rre ate t 13 a ues ( i . 5ab) a e ati e c rre ati sh u d be bser ed i idati was the d i a t act r c tr i 13 C a ue. O the ther ha d, tw pr i es 93.05.01 a d 94.02.11 sh w si i ica t e ati e c rre ati ( i . 5a) which ay su est appare t idati e ect. we er, these tw pr i es are c tradicti e. Na e y, i the pr i e 94.02.11 appare t y the st idized etha e (hi h 13C a ue) c rresp ds t the deep part the pr i e, but i the pr i e 93.05.01 appare t y the st idized etha e (hi h 13C a ue) c rresp ds t the sur icia part the pr i e. It w u d i p y that idati has re ati t depth i the sedi e ts which, the ther ha d, is crucia r idati p te tia , su ate c etc. Additi a y, the e tre e y ar e s i the 13C a ues i the pr i e 93.08.30 d es t c rresp d t a y re arkab e i the C 4 c ( i . 5a). M reer, a e ati e c rre ati i the CO2-C 4 syste sh u d be bser ed i idati was i p rta t si k etha e, but c trary, a p siti e c rre ati ( i . b) r c rre ati has bee bser ed ( i . a). CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE FIG. 5a. C rre ati 13 i the Lake M sz e sedi e ts. FIG. 5b. C rre ati c the Lake Skrzy ka sedi e ts. a d M. ORION DR SE , S. A AS, T. PIE OS FIG. 6a. C rre ati c CO2 i the Lake M sz e sedi e ts. bubb e FIG. 6b. C rre ati c CO2 i the Lake Skrzy ka sedi e ts. bubb e CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE FIG. 7a. C rre ati M sz e sedi e ts. O2 i the Lake FIG. 7b. C rre ati Skrzy ka sedi e ts. O2 i the Lake M. ORION DR SE , S. A AS, T. PIE OS FIG. 8a. C rre ati a d te perature sedi e ts i Lake M sz e. FIG. 8b. C rre ati Skrzy ka. a d te perature sedi e ts i Lake CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE we er, i Lake M sz e, a i crease i CO2 c i bubb es r y p siti e y c rre ate with 13 a ues ( i . a). M re er, the su er pr i e 93.0 .1 ( i . a), a d especia y pr i es the e d the su er i.e. 93.08.30 ( i . a) a d i Lake Skrzy ka the pr i e 93.09.08 ( i . b) sh w a p siti e c rre ati i the CO2- 13 syste . This is i a ree e t with a e pected e ect etha e idati as i p rta t act r c tr i 13 C etha e. we er, the sa e pr i es are discussed be w, as it sh ws a p siti e c rre ati i the te perature- 13 syste ( i . 8ab) a d as it was pr ed ab e, etha e i these pr i es has t bee idized. M re er, i c trast t Lake Skrzy ka ( i . b), besides the e ti ed ab e pr i es, a p siti e c rre ati i the CO2- 13 syste , i Lake M sz e, is bser ed ( i . a). This syste see s rather c p e , the DIC p is re ati e y ar e, a d a y pr cesses, t re ated t etha e esis, are resp sib e r carb cyc i i the ake sedi e ts. Thus, pr bab y ther act r(s), c i cide ta y acti i the sa e directi , c u d be resp sib e r this CO2- 13 c rre ati . Pr bab y te perature c u d be the crucia act r, as the wi ter a d autu pr i es sh w e ati e r CO2- 13 c rre ati ( i . a). I su ary, 13 we su est that the C-dep eted etha e at depth i ht re ect a reater c tributi etha e esis ia the carb di ide reducti pathway. Cha es i the re ati e rates etha e-pr duci pathways are uch re pr bab e tha idati , a d sh u d be e pected. Na e y, a ter the acetate reeased i the sha wer sedi e ts was e hausted thr u h etha e pr ducti , etha e esis c u d sti pr ceed i the deeper ayer, usi CO2 deri ed r r a ic a d i r a ic s urces. Resu ts btai ed by Su i t a d ada (1995) c i ce that i c trast t acetate i reshwater sedi e ts, at depth, the hydr e substrates r CO2 reducti are sti prese t whe the easi y de raded ra ic c p u ds (acetate precurs rs) ha e bee practica y uti ized. ere, a i p icit assu pti c u d be a s ade that acetate di usi withi the atura e ir e t was e i ib e, s that a acetate pr duced withi a i e stratu was i ediate y c su ed by reacti such as C 4 er e tati , su ate reducti , s rpti r ther pr cesses (S re se et a . 1981, Christe se 1984, Miche s et a . 1989, drysek 2005a). Sebacher et a . (198 ) u d that etha e u r A aska wet a ds did t c rre ate we with peat thick ess. It w u d be w rth t e ti that this i di was c siste t with ur bser ati s, based isua ud e t ade i this study, a d pr bab y resu ts r the act that the der (deeper) sedi e ts are t as pr ducti e i ter s etha e as the y u er e. I the M sz e Lake sedi e ts, it has bee bser ed that ai y the t p 23 eters r a ic rich sedi e ts pr duced C 4, a d be w 1.5 the a u t as bubb es reeased r sedi e ts dra atica y decreased. Ob i us y, bubb e i e t ries wi atura y decrease with depth as the sedi e t c pacts a d bubb es are rced upward. O the ther ha d, hi her pressure at depth i creases ar i p M. ORION DR SE , S. A AS, T. PIE OS e t ry the sedi e t i terstices. we er, a y c rrecti s r this act r are ar bey d the sc pe this w rk, as the ai p i t here are s the 13 12 C/ C rati i etha e. A yway, i 94.02.11 isua y ud ed hi hest pr ducti etha e was at the depth ab ut 1 , a d it was ery i ited i the sur icia z es where the te perature was ab ut 2 C ( i . 2a). M st pr bab y the te perature i the upper i ter a was t w t de e p a acti e etha e esis. Pr i es 94.02.11 a d deeper parts 93.11.14 a d 93.08.30 pr i es, sh w e ati e 13 -depth c rre ati ( i . 4a). The seas a i ertica pr i es the 13 a ues i Lake M sz e ( i . 4a) d t a ways c rre ate we with the c rresp di seas a te perature i sedie ts ( i . 2a), h we er, a e era tre d p siti e c rre ati te perature sedi e ts a d 13C a ues ha e bee bser ed i the tw akes studied ( i . 8ab). I e era , the c rre ati i the te perature- 13 syste is bser ed y whe we c sider a resu ts r se era sa p i acti s, but t i a separate pr i e ( i . 8a). The e cepti is the su er pr i e 93.0 .1 ( i . 8a), a d especia y pr i es the e d the su er i.e. 93.08.30 ( i . 8a) a d 93.09.08 ( i . 8b). I Lake M sz e the d w ward si i ica t i crease i te perature c rresp ds t a e i ib e d w ward decrease i 13 a ues i the upper st part the 93.11.14 13 pr i e ( i . 13 2a, 4a). The te perature a d a ue aries i the sa e directi . I the deeper part the sa e pr i e, the d w ward a ishi y s a decrease i te perature c rresp ds t the d w ward re arkab e i crease i 13 a ues. I this case, the te perature a d 13 a ue aries i the pp site directi s. O the ther ha d, the d w ward i crease i the te perature sedi e ts i 94.02.11 c rresp ds t d w ward i crease i 13 a ues. The te perature a d 13 a ue a ai cha es i the sa e directi . The 93.05.01 te perature pr i e sh ws, i the i ter a 0 t ab ut 0.8 , a d w ward decrease, a d be w ca. 0.8 , d w ward i crease te perature, but the 13 a ue i this pr i e sh ws y a d w ward decrease, b th ab e the 0.8 a d be w 0.8 . There re, te perature a d 13 a ues ary i depe de t y. e ce pr bab y direct re ati e ists te perature a d 13 a ues. we er, e re case c u d be c sidered. Shi ts tw separate 13 te perature pr i es a d the tw c rresp di C pr i es are i c siste t. r e a p e, the te perature pr i e 93.0 .1 is ery c se t the 93.08.30 13 pr i es ( i . 2a the ri ht side the p t) but the c rresp di C pr 13 i e 93.0 .1 is ery c se t the C pr i es 93.05.01, 92.09.2 a d e e 94.02.11 ( i . 4a the e t side the p t). It c tradicts t the i p rta ce 13 te perature as a act r c tr i a ue i ertica pr i es i sedi e ts. Thus, a ther echa is tha te perature , pr bab y direct y i ue ces the bser ed is t pic patter . CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE At hi her te perature su er the rate dec p siti r a ic atter i te perate c i ate is appare t y hi her tha duri c der seas s. The sedi e ts studied are c p sed st y r a ic detritus. Te perature the Lake M sz e sedi e ts aried r 2 C duri wi ter t 18 C duri su er. Thus, i the sur icia ayers the sedi e ts i the akes studied, CO2 a d acetic acid, a d i the deeper re i s st y CO2, appare t y are pr duced st e icie t y at the e d su er whe i the wh e pr i e te perature is the hi hest. There re, duri this seas the p rewater is saturated with respect t etha e precurs rs. It was bser ed by Cha t a d Marte s (1988) that, due t te perature-c tr ed s ubi ity a d te perature-depe de t di usi etha e, i e t ries sedi e tary as bubb es were se era ti es hi her duri su er tha i wi ter. Thus, the bser ed i Lake M sz e re i te si e bubb e pr ducti a d hi her 13 a ues i the su er as c pared t th se i wi ter, were the resu t t y re i te si e bacteria acti ity at hi her te perature but a s i ited di usi at hi her te perature. O the ther ha d, it ca be e pected that te perature decreases resu ts i wer c etha e precurs rs with st pr bab y si i ica t is t pe e ect. Acetate tur s er s rapid y (days) that at the e d the wi ter, there sh u d be a ishi y w residua p e t er r war er seas s. Likewise, despite that the CO2 (bicarb ate) p is re ati e y ar e, it ay be i ited i the deepest part the sedi e t, where the sedi e t is re c pact a d bacteria idati is appare t y suppressed due t wer te perature. e ce, the hi hest 13Ce rich e ts were bser ed i the deepest parts the wi ter a d ate autu pr i es. This de ay a s e p ai the wer decreasi radie ts the 13 a ues at reater depths (93.05.0 , 93.0 .1 a d 93.08.30). Likewise, the surprisi i crease the 13 a ues i the deepest part (be w 3 ) the 93.08.30 pr i e ay be e p ai ed by the i ited p CO2 at this depth, acti e etha e esis, a d wer di usi . There re, it ca be pr p sed that, the deeper seated CO2 ets is t pica y hea y as re C 4 is pr duced due t CO2 pathway, a d c se ue t y C 4 ets hea ier t . he s e 13Ce riched CO2 a d C 4 di use upwards it ay resu t 13C-e rich e t i the carb p i the er yi e e s. we er, uch re studies w u d be re uired t this p i t. I the ater sta e dia e esis, acetate a d CO2 ay ri i ate r di ere t c p u ds represe ti di ere t is t pic rati s, supp sed y e riched i hea y carb is t pes. Thus, the ertica i 13 t y re ects the acetate/carb di ide pathways a d ki etic e rich e t i 13C the residua precurs rs etha e, but a s the is t pe characteristics the precurs rs acetate a d carb di ide. urther studies wi be re uired this p i t t . 2Particu ar y the s i the CO2/ CO3 /CO3 ar rati s due t i creasi pressure d w ward withi the sedi e t, te perature a d p a d their p te tia i ue ce the 13C/12C is t pic rati s i the reduced CO2 (the etha e precur- M. ORION DR SE , S. A AS, T. PIE OS s r) sh u d be c sidered. Such studies c u d pr ide a s a i p rta t basis which a pa e e ir e ta rec structi based ertica s carb is t pe c p siti carb -beari c p u ds sedi e ts ( r a ic atter, carb ates) ca be de e ped. 5. CONCLUSIONS 1. I reshwater sedi e ts, isua y ud ed etha e pr ducti decreased with i creasi depth i sedi e ts a d radua y ceased at a depth ab ut 23 eters. I the sedi e ts studied, be w ab ut 3 , substa tia a u ts etha e were pr duced r re eased duri su er. The depth ear zer pr ducti r re ease was ab ut 2 duri wi ter. There re, etha e u ay t c rre ate with sedi e t thick ess, i the sedi e ts i the prese t ie ds are uch re tha 3 i thick ess. 2. I the sedi e ts studied, te perature a d idati are, i e era , t the act rs direct y resp sib e r the is t pic si ature etha e. 3. It is pr p sed that the CO2/ 2 pathway beca e re i p rta t with i creasi depth i sedi e ts, a d etha e esis ia acetic acid er e tati decreased with i creasi depth i sedi e ts. At depths be w 1 the CO2/ 2 pathway e c usi e y d i ates. Pr bab y, ther pathways etha e esis, such as ia etha a d ethy a i es (which is e i ib e r the is t pic p i t iew) a s decrease with depth. S e idati etha e at sha wer depths c u d ccur but e era y it is t the pri ary reas r the bser ed patter . 4. Duri su er at the depth ab ut 3 a d duri wi ter i the e tire pr i e, the pr ducti etha e precurs rs pr bab y decreases t a ishi y w a ues. we er, because c ti ui etha e esis, a ki etic e rich e t i hea y is t pes the residua carb p is resp sib e r the bser ed radua d w ward decrease the radie t 13C is t pe dep eti etha e. i a y, this pr cess resu ts i d w ward i crease the is t pe rati s etha e at the depth ab ut 3 duri su er, a d be w the depth ab ut 1 duri ate autu -wi ter. AC NO LED MENTS The auth rs wish t e press their ratitude t M.S. i us, . S k wski, . pata, . dzie , a d R. Stry ecki r their he p with sa p i a d is t pe preparati s a d t T. Durakiewicz r his ki d he p with c ecti s e iterature. The auth rs are rate u r a critica readi the a uscript a d c e ts t Derek a d ey a d especia y t Dr. N. B air. CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE Tha ks are due t Pr ess r A ieszka a uszka, U ie ce, r care u re iew the sub itted ersi . This study was supp rted by the State C ittee r Scie ti ic Research, pr ect . 2PO4 04528 (P a d), ra ts S a d IN U r., a d IAI. RE ERENCES 1. 2. 3. 4. 5. . . 8. 9. 10. 11. 12. 13. 14. 15. 1 . Baker-B cker A., D hue T.M., a d Ma cy . . (19 ) Methane flux from wetland areas, Te us 29, 245-250. Barker .A. (193 ) On the Biochemistry of methane fermentation, Arch. Micr bi . 7, 420-438. Barker . . a d ritz P. (1981) Carbon isotope fractionation during microbial methane oxidation, Nature 293, 289-291. Be R. . (19 9) Studies on the decomposition of organic matter in flooded soils, S i Bi . Bi che . 1, 105-11 . Be er R., Maccubi A.E., a d ds R.E. (198 Anaerobic biodegradation of lignin polysaccharide components of lingocellulose and synthetic lignin by sediment microflora, App . E ir . Micr bi . 47, 998-1004. B air N.E. a d Carter R .D. (1992) The carbon isotope biogeochemistry of acetate from a methanogenic marine sediment, e chi . C s chi . Acta 56, 124 -1258. Burke R.A., Marte s C.S., a d Sacket .M. (1988) Seasonal von of D/H and 13 12 C/ C ratios of microbial methane in surface sediments, Nature 332, 829-831. Cha t .P. a d Marte s S. (1988) Seasonal vons in ebullitive flux and carbon isotopic composition of methane in tidal freshwater estuary, ba Bi e che . Cyc es 2, 289-298. Cha t .P., Marte s C.S., e ey C.A., Cri P.M. a d Sh wers . . (1992) Methane Transport Mechanisms and Isotopic Fractionation in Emerged Macrophytes of an Alaskan Tundra Lake, . e phys. Res. 97, 1 81-1 88. Christe se D. (198 Determination of substrates oxidized by sulphate reduction in intact cores of marine sediments. Li . Ocea r. 29, 198-192. Cicer e R. ., Shetter .D., De wiche C.C. (1983) Seasonal von of methane flux from a California rice paddy, . e phys. Res. 88, 1022-11024. C e a D.D., Risatti .B., a d Sch e M. (1981). Fractionation of carbon and hydrogen isotopes by methane-oxidizing bacteria, e chi . C s chi . Acta 45, 1033-103 . C rad R., a d Babbe M. (1989) Effect of dilution on methanogenesis, hydrogen turnover and interspecies hydrogen transfer in anoxic paddy soil, EMS Micr bi . Ec . 62, 21-2 . Crai ., a d Ch u C.C. (1982) Methane: the record in polar ice cores, ephys. Res. Lett. 9, 44 -481. Cri P.M. a d Marte s C.S. (198 ) Methane production from bicarbonate and acetate in an anoxic marine sediment, e chi . C s chi . Acta 50, 2089-209 . Dacey . . . (1981) How aquatic plants ventilate, Ocea us 24, 43-51. M. ORION DR SE , S. A AS, T. PIE OS 1 . Dacey . . ., a d u M. . (I9 9) Methane efflux from lake sediments through water lilies, Scie ce 203, 1253-1255. 18. a es L.M., ayes .M., a d u sa us R.P. (19 8) Methane-producing bacteria: natural fractionations of the stable carbon isotopes, e chi . Cas chi . Acta 42, 1295-129 . 19. erard . a d Cha t . (1993) Quantification of methane oxidation in the rhizosphere of emergent aquatic macrophytes: defining upper limits, Bi e che istry 23, 9-9 . 20. a as S. (19 9) An automatic inlet system with pneumatic changeover valves for isotope ratio mass spectrometer, . Phys. E.: Sci. I str. 12, 418-420. 21. a as S., a d Sk rzy ski . (1980) An inexpensive device for digital measurements of isotopic ratios, . Phys. E. : Sci. I str. 13, 34 -349. 22. arriss R.C. a d Sebacher D.I. (1981) Methane flux in forested freshwater swamps of the southeastern United States, e phys. Res. Lett. 8, 1002-1004. 23. arriss R.C., Sebacher D.I., a d Day R. .P. (1982) Methane flux in the Great Dismal Swamp, Nature 297, 3- 4. 24. ea O. . a d I es P. (198 Carbon and energy flow in terrestrial ecosystems: relevance to microflora, i : K u M. ., a d Reddy C.A. (eds.), Current Perspectives in Microbial Ecology, A er. S c. Micr bi ., ashi t DC, pp. 394-404. 25. drysek M.O. (199 Carbon isotope evidence for diurnal vons in methanogenesis in freshwater lake sediments, i : M.O. drysek (ed.), Extended Abstracts of Isotope Workshop II, 25-2 May 1994, Ksi Cast e, P a d., pp. 8., I ter ati a Is t pe S ciety a d U i ersity r c aw. 2 . drysek M.O. (1995) Carbon isotope evidence for diurnal vons in methanogenesis in freshwater lake sediments, e chi . C s chi . Acta, 59, 55 -5 1. 2 . drysek M.O. (199 ) Spatial and temporal vons in carbon isotope ratio of early-diagenetic methane from freshwater sediments: methanogenic pathways, Acta U i ersitatis Vratis a ie sis Prace e icz -Mi era icz e, (M raph), . 3, pp. 1-110. 28. drysek M.O. (2005a) Depth of the water column in relation to carbon isotope ratios in methane in freshwater sediments, e ica Quartere y, 49 (2), 151-1 4. 29. drysek M.O. (2005b) S-O-C isotopic picture of sulphate-methane-carbonate system in freshwater lakes. E ir e ta Che istry Letters 3 (, 100-112. 30. drysek M.O., a as S., ada E., S k wski K., i us M.S., Takai ., a d Radwa S. (199 Carbon isotope evidence for seasonal and spatial vons of methanogenesis during early diagenesis in freshwater lake sediments, Poland, i : M.O. drysek (Ed.) Extended Abstracts of Isotope Workshop II, 25-2 May 1994, Ksi Cast e, P a d., pp. 9- 3., I ter ati a Is t pe S ciety a d U i ersity r c aw. 31. drysek M.O., a as S., ada E., B prakup S., Ueda S., Vi ar s r P. a d Takai . (199 ) Early-diagenetic Methane from Various Tropical Freshwater Sediments: Molecular and Carbon Isotope Vons in One Dial Cycle, A . S c. e .P . 67, 93-101. 32. Khai M.A.K., a d Ras usse R. (1983) Sources, sinks and seasonal cycles of atmospheric methane, . e phys. Res. 88, 5131-5144. CARBON ISOTOPIC COMPOSITION O EARL -DIA ENETIC MET ANE 33. Ki .M., K u M. ., a d L ey D.R. (1983) Metabolism of acetate, methanol, and methylated amines in intertidal sediments of Lowes Cove, Maine, App . E ir . Micr bi . 45, 1848-1853. 34. K ya a T, Nashi ura M., a d Matsuda 1-1. (19 9) Early diagenesis of organic matter in lacustrine sediments in terms of methane fermentation, e icr bi . . 1, 31 1-32 . 35. K ya a T. (1990) Gases in lakes, their production mechanism and degassing (CH4 and 1-12) of the Earth., i : Geochemistry of gaseous elements and compounds, Thephrastus Pub ishi Pr prietary C ., SA. (Let.), Athe s, pp. 2 1-335. 3 . Krzycki .A., Ke ea ky .R., De ir M. ., a d eikus . . (198 ) Stable carbon isotope fractionation by Methanosarcina barkeri during methanogenesis from acetate, methanol and carbon dioxide-hydrogen, App . E ir . Micr bi . 53, 259 -2599. 3 . L ey D.R. a d K u M. . (1983) Methanogenesis from methanol and methylamines and acetogenesis from hydrogen and carbon dioxide in the sediments of an euthrophic 1akes, App . E ir . Micr bi . 45, 1310-1315. 38. Marte s C.S., B air E.N., ree C.D. a d des Marais D. . (198 ) Seasonal Vons in the Stable Carbon Isotopic Signature of Biogenic Methane in a Coastal Sediment, Scie ce 223, 1300-1303. 39. Mats M.D. a d Like s .E. (1990) Air pressure and methane fluxes, Nature 347, 18- 19. 40. Miche s A.R., ac bs M.E., Scra t , a d Macki .E. (1989) Modeling of distribution of acetate in anoxic estuarine sediments, Li . Ocea r. 34, 4 5 . 41. M re L.R. (19 9) Geomicrobiology and geomicrobiological attack on sediment organic matter, i : E i t ., a d Murphy M.T. . (eds.) Organic Geochemistry, Spri er, New rk, pp. 2 5-303. 42. Ore a d R.S., Marsi-i L.M., P ci S. (1982) Methane production and simultaneous sulphate reduction in anoxic salt marsh sediments, Nature 296, 143145. 43. Patters .A. a d espe R.B. (19 9) Trimethylamine and methylamine as growth substrates for rumen bacteria and Methanosarcina barkeri, Curr. Micr bid. 3, 9-83. 44. Sebacher D.I., arriss R.C., a d Bart ett K.B. (1983) Methane flux across the airwater interface: air velocity effects, Te us 35B, 103-109. 45. Sebacher D.I., arriss R.C., a d Bart ett K.B. (1985) Methane emission to the atmosphere through aquatic plants, .E ir . Qua . 14, 40-4 . 4 . Sebacher D.I., arriss R.C., Bart ett K.B., Sebacher S.M., a d rice S.S. (198 ) Atmospheric methane sources: Alaskan tundra bogs, an alpine fen, and subarctic boreal marsh, Te us 38B, 1-10. 4 . S re se ., Christe se D., a d r e se B (1981) Volatile fatty acids and hydrogen as substrates of sulphate reducing bacteria in anaerobic marine sediments, App . E ir . Micr bi . 42, 5-11. M. ORION DR SEK, S. A AS, T. PIE KOS 48. Stee e L.P., raser P. ., Ras usse R.A., Kha i M.A.K., C wat T. ., a d Th i K. . (198 ) The global distribution of methane in the troposphere, . At s. Che . 5, 125-1 1. 49. Su i t A. a d ada E. (1993) Carbon isotopic composition of bacterial methane in a soil incubation experiment: Contributions of acetate and CO2/H2, e chi . C s chi . Acta 57, 4015-402 . 50. Su i t A. a d ada E. (1995) Hydrogen isotopic composition of bacterial methane: CO2/H2 reduction and acetate fermentation, e chi . C s chi . Acta 59, 1329-133 . 51. S e s B . a d R ssewa T. (198 In situ methane production from acid peat in plant communities with different moisture regimes in a subarctic mire, Oik s 43, 341-350. 52. Takai . (19 0) The mechanism of methane fermentation in flooded paddy soil, S i Sci. P a t Nutr. 6, 238-244. 53. ada E. (1990) Carbon isotopic studies of global methane production with emphasis on paddy fields, i : Course-book of Isotope Geology (ed. M.O. drysek), pp. 141-149, r c aw U i ersity a d C ittee Mi era Sci. 54. ei er P. . a d Zeikus . . (19 8) Acetate metabolism in Methanosarcina barkeri, Arch. Micr bi . 119, 1 5-182. 55. etze R. . (19 5) Limnology, Sau ders, Phi ade phia. 5 . hiticar M. ., aber E., a d Sch e M. (198 ) Biogenic methane formation in marine and freshwater environments: CO2 reduction vs. acetate fermentation: Isotope evidence, e chi . C s chi . Acta 50, 93- 09. 5 . hiti . . a d Cha t .P. (1993) Primary production control of methane emission from wetlands, Nature 364, 94- 95. 58. i at T., Micha czyk Z., Turczy ski M., a d ciech wski .K. (1991) The cz a dawa Lakes, Studies D cu e tati Ce ter Physi raphy, . I ., Zak ad Nar d wy i . Oss i skich, r c aw arszawaKraków, P ish Acade y Scie ces. 59. te ate I., hiticar M. ., a d Sch e M. (198 Carbon and hydrogen isotope composition of bacterial methane in a shallow freshwater lake, Li . Ocea r. 29, 985-992. 0. Zi d er S. . a d Br ck T.D. (19 8a) Production of methane and carbon dioxide from methane thiol and dimethylsulfide by anaerobic lake sediments, Nature 273, 22 -228. 1. Zi d er S. . a d Br ck T.D. (19 8b) Methane, carbon dioxide and hydrogen sulfide production from the terminal methiol group of methionine by anaerobic lake sediments, App . E ir . Micr bi . 35, 344-352. 2. Zyaku A.M., B dar V.A., a d Nas araye B.B. (19 9) Fractionation of stable carbon isotopes of methane in process of microbiological oxidation, e khi iya, pp. 29 -29 .
Journal
Annales UMCS, Physica – de Gruyter
Published: Mar 1, 2015