Mazuva ano Homo sapiens vakapinda muhuwandu hukuru hweshanduko ye ecosystem, asi zvakaoma kuona kwakabva kana mhedzisiro yekutanga maitiro aya.Archaeology, geochronology, geomorphology, uye paleoenvironmental data kubva kuchamhembe kweMalawi inonyora hukama huripo pakati pekuvapo kwemaforoji, sangano reecosystem, uye alluvial fan formation muLate Pleistocene.Mushure mezana ramakore rechi20, yakaomeswa system yeMesolithic artifacts uye alluvial fans yakaumbwa.Makore 92 000 apfuura, munzvimbo yepaleo-ecological, pakanga pasina analogue mune yakapfuura 500,000-gore rekodhi.Data yezvinocherwa mumatongo uye ongororo huru yekuronga inoratidza kuti moto wepakutanga wakagadzirwa nevanhu wakadzoreredza zvirambidzo zvemwaka pakubatidza, zvichikanganisa kuumbwa kwezvinomera uye kukukurwa.Izvi, zvakasanganiswa nekuchinja kwemvura kunofambiswa nemamiriro ekunze, zvakazoita kuti pave neshanduko yezvakatipoteredza kuenda kunzvimbo yekutanga yekugadzira pre-agricultural landscape.
Vanhu vemazuva ano vane simba vanokurudzira shanduko yeecosystem.Kwezviuru zvemakore, vakashandura nharaunda zvakanyanya uye nemaune, zvichimutsa gakava pamusoro pekuti uye sei yekutanga-inotongwa nevanhu ecosystem yakabuda (1).Uchapupu hunowedzera hwezvokuchera matongo uye hwemagariro hunoratidza kuti kune nhamba huru yekubatana kwepakati pakati peforiji nenharaunda yavo, izvo zvinoratidza kuti maitiro aya ndiwo hwaro hwekushanduka kwemarudzi edu (2-4).Fossil uye genetic data inoratidza kuti Homo sapiens yaivepo muAfrica makore angangoita 315,000 apfuura (ka).Nhoroondo yezvokuchera matongo inoratidza kuti kuoma kwemaitiro anoitika munyika yose kwakawedzera zvakanyanya munguva yakapfuura inenge 300 kusvika 200 ka spans.Kuguma kwePleistocene (Chibanian) (5).Kubva patakasimukira semhuka, vanhu vakatanga kuvimba nehunyanzvi hwekuvandudza tekinoroji, kurongeka kwemwaka, uye kudyidzana kwakaoma munharaunda kuti kubudirire.Hunhu uhwu hunoita kuti titore mukana wezvaimbogara zvisingagarwi kana kuti zvakanyanyisa nharaunda nezviwanikwa, saka nhasi uno vanhu ndivo vega mhuka dzepasi rose (6).Moto wakaita basa guru pakushandurwa uku (7).
Biological mhando dzinoratidza kuti kuchinjika kwechikafu chakabikwa kunogona kuteverwa kumashure angangoita 2 miriyoni makore apfuura, asi hazvina kusvika pakupera kweMiddle Pleistocene apo humbowo hwakajairwa hwekuchera matongo hwekutonga moto hwakaonekwa (8).Mhepo yegungwa ine marekodhi eguruva kubva munzvimbo yakakura yeAfrica kondinendi inoratidza kuti mumamiriyoni emakore apfuura, iyo yepamusoro ye elemental kabhoni yakaonekwa mushure me 400 ka, kunyanya panguva yekuchinja kubva kuinterglacial kuenda kune glacial nguva, asi zvakare yakaitika Panguva. Horocene (9).Izvi zvinoratidza kuti pamberi pe400 ka, moto muSouth Africa yeSahara wakanga usina kujairika, uye zvipo zvevanhu zvaive zvakakosha muHolocene (9).Moto mudziyo unoshandiswa nevafudzi muHolocene yose kurima nekuchengetedza mafuro (10).Nekudaro, kuona kumashure uye ecological kukanganisa kwekushandiswa kwemoto nevavhimi-vaunganidzi mukutanga Pleistocene kwakanyanya kuoma (11).
Moto unonzi chishandiso cheinjiniya chekushandisa zviwanikwa mune zvese ethnography uye zvekuchera matongo, kusanganisira kuvandudza mararamiro ekudzoka kana kugadzirisa mbishi.Zviitwa izvi zvinowanzoenderana nekuronga veruzhinji uye zvinoda ruzivo rwakawanda rwezvakatipoteredza (2, 12, 13).Kupisa kwemamiriro ekunze kunogonesa vavhimi-vanotora kuti vadzinge mhuka, kudzora tumbuyu, uye kuwedzera kubereka kwekugara (2).Pa-saiti moto unokurudzira kubika, kupisa, kudzivirira mhuka, uye kubatana kwevanhu (14).Nekudaro, mwero wekuti muvhimi-munhongi moto anogona kugadzirisa zvakare zvikamu zvenzvimbo, senge chimiro chenharaunda yezvipenyu uye mamiriro ekunze, hazvina kujeka (15, 16).
Pasina dhata rekare rekuchera matongo uye geomorphological uye kuenderera mberi kwezvakatipoteredza zvinyorwa kubva kunzvimbo dzakawanda, kunzwisisa kusimukira kwekuchinja kwevanhu kunokonzerwa nemamiriro ekunze kunonetsa.Zvinyorwa zvenguva refu zvedhipoziti yedhamu kubva kuGreat Rift Valley kuSouthern Africa, zvakasanganiswa nezvinyorwa zvekare zvekuchera matongo munzvimbo iyi, zvinoita kuti ive nzvimbo yekuongorora kukanganiswa kwezvakatipoteredza kunokonzerwa nePleistocene.Pano, isu tinoshuma nezve archeology uye geomorphology yenzvimbo yakakura yeStone Age kumaodzanyemba-pakati peAfrica.Zvadaro, takaibatanidza nepaleoenvironmental data inotangira> 600 ka kuti tione humbowo hwekutanga hwekubatanidza hwemafambiro evanhu uye shanduko yezvipenyu mumamiriro emoto wakaitwa nevanhu.
Takapa zera rakanga risati rambotaurwa pamubhedha waChitimwe muRuwa rweKaronga, riri kumucheto kuchamhembe kweMalawi kuchamhembe kweAfrica Rift Valley (Mufananidzo 1) (17).Mibhedha iyi inoumbwa nevhu dzvuku alluvial mafeni uye rwizi sediments, kufukidza anenge 83 mativi makiromita, ane mamiriyoni matombo zvigadzirwa, asi hapana akachengetedzwa Organic zvisaririra, akadai mapfupa (Supplementary chinyorwa) (18).Our optically excited light (OSL) data kubva kuPasi rekodhi (Figure 2 uye Tables S1 kusvika kuS3) yakagadzirisa zera remubhedha weChitimwe kuLate Pleistocene, uye zera rekare re alluvial fan activation uye kuvigwa kwematombo zera rinenge 92 ka ( 18, 19).The alluvial and river Chitimwe layer inofukidza madziva nenzizi dze Pliocene-Pleistocene Chiwondo layer kubva pa low-angle unconformity (17).Aya madhipoziti ari mufault wedge iri kumucheto kwedhamu.Kumisikidzwa kwavo kunoratidza kudyidzana pakati pemadziva ekushanduka uye zvikanganiso zvinoshanda zvichipinda muPliocene (17).Kunyangwe tectonic chiito chingave chakanganisa nzvimbo yedunhu uye piedmont mutserendende kwenguva yakareba, chiitiko chekukanganisa munzvimbo iyi chinogona kunge chakadzikira kubva kuMiddle Pleistocene (20).Mushure me ~ 800 ka uye kusvika nguva pfupi mushure me100 ka, iyo hydrology yeLake Malawi inonyanya kutungamirirwa nemamiriro ekunze (21).Naizvozvo, hapana yeiyi ndiyo chete tsananguro yekuumbwa kwealuvial mafeni muLate Pleistocene (22).
(A) Nzvimbo yechiteshi cheAfrica inoenderana nekunaya kwemazuva ano (asterisk);bhuruu inonyorova uye tsvuku inooma (73);bhokisi riri kuruboshwe rinoratidza Lake Malawi nenzvimbo dzakatenderedza MAL05-2A uye MAL05-1B Nzvimbo yepakati / 1C core (pepuru dot), apo nzvimbo yeKaronga inoratidzirwa seyakasvibirira, uye nzvimbo yemubhedha weLuchamange inoratidzwa. sebhokisi jena.(B) Nzvimbo yekuchamhembe yeMalawi basin, inoratidza hillshade topography inoenderana neMAL05-2A core, yakasara Chitimwe mubhedha (brown patch) uye nzvimbo yekuchera yeMalawi Early Mesolithic Project (MEMSAP) (yellow dot) );CHA, Chaminade;MGD, musha weMwanganda;NGA, Ngara;SS, Sadara South;VIN, mufananidzo weraibhurari yezvinyorwa;WW, Beluga.
OSL yepakati zera (mutsara mutsvuku) uye kukanganisa kwe1-σ (25% grey), mazera ese eOSL ane chekuita nekuitika kwe in situ artifacts muKaronga.Zera rinoenderana neyakapfuura 125 ka data inoratidza (A) kernel density fungidziro yeese OSL mazera kubva alluvial fan sediments, zvichiratidza sedimentary/alluvial fan accumulation (cyan), uye dhamu rekuvaka patsva padanho remvura zvichibva pane chikuru chechikamu chekuongorora (PCA) maitiro eAquatic mafossils uye authigenic zvicherwa (21) (blue) kubva kuMAL05-1B/1C core.(B) Kubva paMAL05-1B/1C core (dema, kukosha kuri pedyo ne7000 ine asterisk) uye iyo MAL05-2A core (grey), maverengero e macromolecular kabhoni pagiramu akajairwa neredhiyo yekunyungudika.(C) Margalef mhando kupfuma index (Dmg) kubva MAL05-1B/1C core fossil mukume.(D) Mazana emukume kubva kuCompositae, miombo woodland neOlea europaea, uye (E) Mazana emukume kubva kuPoaceae nePodocarpus.Yese data yemukume inobva kuMAL05-1B/1C core.Nhamba dziri kumusoro dzinonongedzera kune yega OSL samples yakatsanangurwa muTables S1 kusvika S3.Musiyano mukuwanikwa kwedata uye kugadziriswa unokonzerwa nekusiyana kwesampling nguva uye kuwanikwa kwezvinhu mukati mepakati.Mufananidzo S9 inoratidza maviri macro kabhoni marekodhi akashandurwa kuita z-zvibodzwa.
(Chitimwe) Kugadzikana kwemamiriro ezvinhu mushure mekugadzirwa kwefani kunoratidzwa nekuumbwa kwevhu dzvuku uye ivhu rinogadzira carbonates, iyo inovhara sediments-shaped sediments yenharaunda yose yekudzidza (Supplementary text uye Tafura S4).Kuumbwa kweLate Pleistocene alluvial fans muLake Malawi Basin hakungogumiri munzvimbo yeKaronga.Makiromita angangoita 320 kumaodzanyemba kwakadziva kumabvazuva kweMozambique, terrestrial cosmogenic nuclide deep profile ye 26Al uye 10Be inodzikamisa kuumbwa kwemubhedha weLuchamange wevhu dzvuku kusvika pa119 kusvika 27 ka (23).Uku kurambidzwa kwezera kwakakura kunopindirana nenhoroondo yedu yeOSL yechikamu chekumadokero kweLake Malawi Basin uye inoratidza kuwedzera kwevateveri vedunhu muLate Pleistocene.Izvi zvinotsigirwa nedata kubva kudhamu core rekodhi, izvo zvinoratidza kuti iyo yepamusoro sedimentation mwero inoperekedzwa ne240 ka, iyo ine yakanyanya kukosha paca.130 uye 85 ka (zvinyorwa zvekuwedzera) (21).
Humbowo hwekutanga hwekugariswa kwevanhu munzvimbo iyi hune chekuita nevhu rekwaChitimwe rakaonekwa pa ~92 ± 7 ka.Mhedzisiro iyi yakavakirwa pa605 m3 yezvicherwa zvakacherwa kubva ku14 sub-centimeter space control yekuchera matongo uye 147 m3 yemarara kubva ku46 magomba ekuchera matongo, anodzorwa vertical kusvika 20 cm uye akatwasuka akadzorwa kusvika 2 metres (Supplementary text to Figures) Pamusoro pezvo, takaongororawo makiromita 147.5, takaronga makomba makumi mana ekuongorora geological, uye tikaongorora zvinopfuura zviuru makumi matatu nezvisere zvetsika kubva pamakumi matanhatu acho (Matafura S5 neS6) (18).Iyi tsvakurudzo yakakura uye matongo anoratidza kuti kunyange zvazvo vanhu vekare vaisanganisira vanhu vekare vemazuva ano vangave vakagara munzvimbo inenge 92 ka yapfuura, kuunganidza kwesediments kwakabatana nekumuka uye kugadzikana kweLake Malawi hakuna kuchengetedza uchapupu hwezvokuchera matongo kusvikira Kuumba Chitimwe mubhedha.
Data yezvokuchera matongo inotsigira fungidziro yekuti mukupera kweQuaternary, kuwedzera kwefan-shape uye zviitiko zvevanhu kuchamhembe kweMalawi zvaivepo muhuwandu hukuru, uye zvisaririra zvetsika zvaive zvemhando dzemamwe mativi eAfrica ane hukama nevanhu vemazuva ano.Zvizhinji zvezvigadzirwa zvakagadzirwa ne quartzite kana quartz matombo erwizi, ane radial, Levallois, chikuva uye random core kuderedza (Mufananidzo S4).Morphological diagnostic artifacts anonyanya kuverengerwa kuMesolithic Age (MSA) -specific Levallois-mhando tekinoroji, angangoita 315 ka muAfrica kusvika parizvino (24).Mubhedha wepamusoro-soro weChitimwe wakagara kusvika pakutanga kweHolocene, uine zviitiko zvishoma zveLate Stone Age, uye wakawanikwa uine hukama nemushakabvu Pleistocene neHolocene hunter-gatherers muAfrica yose.Kusiyana neizvi, tsika dzematombo ematombo (zvakadai sematurusi makuru ekucheka) anowanzobatanidzwa neEarly Middle Pleistocene haawanzoitiki.Iko kwakaitika izvi, zvakawanikwa muMSA-ine sediments mukupedzisira Pleistocene, kwete mumatanho ekutanga ekuisa (Table S4) (18).Kunyangwe iyo saiti yaivepo pa ~ 92 ka, iyo yakanyanya kumiririra nguva yezviitiko zvevanhu uye alluvial fan deposition yakaitika mushure ~ 70 ka, inotsanangurwa zvakanaka neseti yeOSL mazera (Mufananidzo 2).Isu takasimbisa iyi pateni ne25 yakabudiswa uye 50 yakambove isina kudhindwa OSL mazera (Mufananidzo 2 uye Tables S1 kusvika S3).Izvi zvinoratidza kuti kubva pahuwandu hwemakore makumi manomwe neshanu ekutemerwa, makumi manomwe akadzoserwa kubva kumarara mushure me70 ka.Mufananidzo 2 unoratidza mazera makumi mana ane chekuita ne-in-situ MSA artifacts, maererano nemhombe paleoenvironmental zviratidzo zvakaburitswa kubva pakati peMAL05-1B/1C yepakati basin (25) uye yakambodhindirwa MAL05-2A yekumusoro basin centre yedhamu.Marasha (padhuze nefani inogadzira OSL zera).
Tichishandisa ruzivo rutsva kubva mukucherwa kwematongo e phytoliths uye micromorphology yevhu, pamwe neruzivo rweveruzhinji pamusoro pefossil pollen, marasha makuru, zvisaririra zvemumvura uye zvicherwa zveuthigenic kubva pakati peMalawi Lake Drilling Project, takavakazve hukama hwevanhu veMSA neLake Malawi.Tora mamiriro ekunze nemamiriro ekunze enguva imwe cheteyo (21).Vamiririri vaviri vekupedzisira ndivo hwaro hwekuvaka patsva kudzika kwedhamu kubva kune anopfuura 1200 ka (21), uye inofananidzwa nemukume uye macrocarbon samples akaunganidzwa kubva panzvimbo imwechete pakati pe ~ 636 ka (25) munguva yakapfuura. .Iwo akareba macores (MAL05-1B uye MAL05-1C; 381 uye 90 m zvakateerana) akaunganidzwa anenge 100 makiromita kumaodzanyemba kwakadziva kumabvazuva kwenzvimbo yeprojekti yekuchera matongo.Nheyo pfupi (MAL05-2A; 41 m) yakaunganidzwa makiromita angangoita makumi maviri nemashanu kumabvazuva kweRwizi rweRukulu rweNorth (Mufananidzo 1).Iyo MAL05-2A core inoratidza pasi paleoenvironmental mamiriro munzvimbo yeKalunga, nepo MAL05-1B/1C core isingagamuchire yakananga rwizi kupinza kubva kuna Kalunga, saka inogona kuratidza zvirinani mamiriro edunhu.
Deposition rate yakanyorwa muMAL05-1B/1C composite drill core yakatanga kubva pa240 ka uye yakawedzera kubva paavhareji yenguva yakareba yakakosha ye0.24 kusvika 0.88 m/ka (Mufananidzo S5).Kuwedzera kwekutanga kune hukama nekuchinja kwechiedza chezuva che orbital, izvo zvinokonzeresa shanduko yakakwira-amplitude munharaunda yedhamu panguva ino (25).Nekudaro, kana iyo orbital eccentricity inodonha mushure me85 ka uye mamiriro ekunze akagadzikana, iyo subsidence rate ichiri yakakwirira (0.68 m / ka).Izvi zvakapindirana nerekodha yepasi reOSL, iyo yakaratidza humbowo hwakakura hwekuwedzera kwe fan fan mushure meanenge 92 ka, uye yaienderana nedata rekufungidzira rinoratidza kuwirirana kwakanaka pakati pekukukurwa nemoto mushure me85 ka (Supplementary text uye Tafura S7).Tichifunga nezvekukanganisa kweiyo inowanikwa geochronological control, hazvibviri kutonga kana iyi seti yehukama inoshanduka zvishoma nezvishoma kubva mukufambira mberi kweiyo nzira yekudzokorodza kana kuputika nekukurumidza kana ichisvika pane yakakosha.Zvinoenderana neiyo geophysical modhi yebheseni yekushanduka-shanduka, kubva kuMiddle Pleistocene (20), rift yekuwedzera uye yakabatana subsidence yadzikira, saka haisiriyo chikonzero chikuru cheyakakura yekugadzira fan iyo isu takanyanya kufunga mushure me92 ka.
Kubva kuMiddle Pleistocene, mamiriro ekunze anga ari chinhu chikuru chekutonga kwemvura yegungwa (26).Kunyanya, kusimudzwa kwebheseni rekuchamhembe kwakavhara nzira yekubuda nayo.800 ka yekudzika dziva kusvika yasvika pachikumbaridzo chepamusoro pekubuda kwemazuva ano (21).Iri kumucheto kwekumaodzanyemba kwedhamu, nzvimbo iyi yekubudisira yaipa muganhu wepamusoro wemvura yedhamu panguva yekunaya kwemvura (kusanganisira nhasi), asi yakabvumira bheseni kuvhara sezvo mvura yemudhamu yakaderera munguva yakaoma (27).Kuvakwa patsva kwechikamu chedhamu kunoratidza kuchinjika kwakaoma uye kunyorova kutenderera munguva yakapfuura 636 ka.Zvinoenderana neuchapupu hunobva kufossil pollen, nguva yekusanaya kwemvura yakanyanyisa (> 95% kuderedzwa kwemvura yakazara) yakabatana nekudziya kwezuva kwezhizha kwakakonzera kuwedzera kwezvinomera zvemugwenga, nemiti inongogumira kunzira dzemvura dzisingaperi (27).Idzi (dziva) dzakaderera dzine hukama nepollen spectra, zvichiratidza huwandu hwehuswa (80% kana kupfuura) uye xerophytes (Amaranthaceae) nekudhura kwemuti taxa uye kuderera kwese kupfuma kwemarudzi (25).Kusiyana neizvi, dhamu racho parinosvika pamwero wemazuva ano, zvinomera zvakada kufanana nemasango emumakomo eAfrica zvinowanzosvika kumahombekombe egungwa [anenge mamita 500 pamusoro pegungwa ( masl)].Nhasi, masango emakomo eAfrica anongoonekwa mudiki diki diki pamusoro pe1500 masl (25, 28).
Nguva ichangopfuura yekusanaya kwemvura yakaitika kubva pa104 kusvika ku86 ka.Mushure meizvozvo, kunyangwe dhamu rakadzokera kumamiriro epamusoro, masango emiombo akavhurika ane huwandu hukuru hwemakwenzi nemishonga yemishonga zvakave zvakajairika (27, 28).Sango remuAfrica rinonyanya kukosha iPodocarpus pine, iyo haina kumbobvira yawana kukosha kwakafanana neyakapfuura dhamu repamusoro mushure me85 ka (10.7 ± 7.6% mushure me85 ka, nepo dhamu rakafanana risati rasvika 85 ka 29.8 ± 11.8% )Indekisi yeMargalef (Dmg) inoratidzawo kuti hupfumi hwekare hwe85 ka hwakaderera ne43% pane hwakambogara hwakasimba mudhamu (2.3 ± 0.20 uye 4.6 ± 1.21, zvichiteerana), semuenzaniso, pakati pe420 ne345 ka (Supplementary. zvinyorwa uye nhamba S5 uye S6) (25).Pollen samples kubva panenge nguva.88 kusvika 78 ka inewo chikamu chepamusoro cheCompositae pollen, iyo inogona kuratidza kuti zvinomera zvakakanganiswa uye zviri mukati mekukanganisa kwezuva rekare apo vanhu vakagara munzvimbo.
Isu tinoshandisa maitiro emamiriro ekunze anomaly (29) kuongorora iyo paleoecological uye paleoclimate data yemacores akacheneswa pamberi uye mushure me85 ka, uye kuongorora hukama hwezvakatipoteredza pakati pezvinomera, kuwanda kwezvipenyu, uye kunaya kwemvura uye fungidziro yekubvisa iyo inferred yakachena mamiriro ekunze.Dhiraivha baseline mode ye ~ 550 ka.Iyi inharaunda yakashandurwa inokanganiswa nekunaya kwemvura uye moto unozadza mudhamu, izvo zvinoratidzwa nekushaikwa kwemarudzi uye misanganiswa yezvinomera.Mushure mekuoma kwekupedzisira, mamwe masango chete akadzoka, kusanganisira zvikamu zvisingatsvi zvemasango emumakomo eAfrica, zvakadai semafuta emuorivhi, uye zvikamu zvisingatsvi mumasango anogara achipisa, akadai seCeltis (Supplementary text and Figure S5) ( 25).Kuti tiedze iyi hypothesis, takaenzanisa mazinga emvura yegungwa anobva kune ostracode uye authigenic mineral substitutes sezvimiririra zvakasiyana-siyana (21) uye zvakasiyana-siyana zvakadai semarasha uye pollen zvinogona kukanganiswa nekuwedzera kwemoto (25).
Kuti titarise kufanana kana musiyano pakati pemisanganiswa iyi panguva dzakasiyana, takashandisa mukume kubva kuPodocarpus (evergreen tree), uswa (uswa), uye muorivhi (chikamu chisingadziviriri moto chemasango emakomo eAfrica) pakuongorora kukuru (PCoA), uye miombo (chikamu chikuru chemasango nhasi).Nekuronga PCoA panzvimbo yakapindirwa inomiririra dhamu redziva pakaumbwa musanganiswa wega wega, takaongorora kuti musanganiswa wepollen unochinja sei maererano nekunaya uye kuti hukama uhu hunochinja sei mushure me85 ka (Mufananidzo 3 uye Mufananidzo S7).Pamberi pe85 ka, masampuli-akavakirwa-giramu akaunganidzwa akananga kumamiriro akaoma, nepo podocarpus-based samples akaunganidzwa akananga kumvura.Kusiyana neizvi, masampula mushure me85 ka akaunganidzwa nemasamples akawanda asati asvika 85 ka uye ane mavhareji akasiyana siyana, zvichiratidza kuti maumbirwo awo haana kujairika kune akafanana mamiriro ekunaya.Nzvimbo yavo muPCoA inoratidza simba reOlea uye miombo, zvose zviri zviviri zvinofarirwa pasi pemamiriro ezvinhu anowanzopisa moto.Mumasampuli mushure me85 ka, Podocarpus pine yaingove yakawanda mumasampuli matatu akateedzana, izvo zvakaitika mushure menguva pakati pe78 ne79 ka yakatanga.Ikoku kunokarakadza kuti pashure pokuwedzera kwokutanga kwokunaya kwemvura, sango rinoratidzika kuva rakanaya kwenguva pfupi risati raputsika pakupedzisira.
Poindi imwe neimwe inomiririra sampu yemukume pane imwe nguva, uchishandisa chinyorwa chekuwedzera uye muenzaniso wezera muMufananidzo 1. S8.Iyo vector inomiririra kutungamira uye gradient yekuchinja, uye refu vector inomiririra yakasimba maitiro.Nzvimbo yepasi inomiririra mwero wemvura yedhamu semumiriri wekunaya kwemvura;bhuruu yakasviba yakakwirira.Avhareji kukosha kwePCoA chimiro kukosha inopihwa iyo data mushure me85 ka (dhaimani dzvuku) uye data rese kubva kune akafanana dziva mazinga pamberi pe85 ka (yero diamondi).Uchishandisa iyo data ye636 ka yese, iyo "simulated lake level" iri pakati -0.130-σ uye -0.198-σ padyo neavhareji eigenvalue yedhamu level PCA.
Kuti tidzidze hukama pakati pemukume, dhamu remvura uye marasha, takashandisa nonparametric multivariate analysis of variance (NP-MANOVA) kuenzanisa iyo yose "zvakatipoteredza" (inomiririrwa ne data matrix yepollen, mvura yegungwa uye marasha) zvisati zvaitika. uye mushure mekuchinja kwe85 ka.Takaona kuti kusiyanisa uye covariance inowanikwa mune iyi data matrix ndeye nhamba yakakosha misiyano isati yasvika uye shure kwe85 ka (Tafura 1).
Yedu yepasi paleoenvironmental data kubva kune phytoliths nevhu riri kumucheto kweWest Lake rinoenderana nekududzira kunobva pane yedhamu proxy.Izvi zvinoratidza kuti pasinei nekuwanda kwemvura yedhamu racho, nzvimbo yacho yakashandurwa kuita nzvimbo ine masango akavhurika nemasango ane miti, sezvazvinoita nhasi (25).Nzvimbo dzese dzakaongororwa phytoliths kumucheto kwekumadokero kwebheseni mushure me ~ 45 ka uye inoratidza huwandu hukuru hwevhavha yearboreal inoratidza mamiriro emvura.Nekudaro, vanotenda kuti mazhinji emulch ari muchimiro chemasango akavhurika akafukidzwa neshenjere nehuswa hwekuvhunduka.Maererano ne data ye phytolith, miti yemichindwe isingadziviriri moto (Arecaceae) inongowanikwa pamhenderekedzo yegungwa, uye haiwaniki kana kuti haipo munzvimbo dzekuchera matongo dzemukati (Table S8) (30).
Kazhinji kutaura, kunyorova asi kwakavhurika mamiriro ekupedzisira Pleistocene anogona zvakare kutorwa kubva pasirestrial paleosols (19).Dongo reLagoon uye ivhu remuchadenga carbonate kubva kunzvimbo yekuchera matongo yeMwanganda Village inogona kurondwa kumashure kusvika ku40 kusvika ku28 cal ka BP (yaimbove yakagadziriswa Qian'anni) (Tafura S4).Iyo carbonate ivhu pamubhedha weChitimwe inowanzoita nodular calcareous (Bkm) uye argillaceous uye carbonate (Btk) zvidimbu, izvo zvinoratidza nzvimbo yekugadzikana kwe geomorphological uye kunonoka kugadzikana kubva kune inosvika kure alluvial fan Inenge 29 cal ka BP (Supplementary. chinyorwa).Ivhu rakanyungudutswa, rakaomeswa laterite (lithic rock) rakaumbwa pazvisaririra zvemafeni ekare rinoratidza nzvimbo yakavhurika (31) uye kunaya kwakasimba kwemwaka (32), zvichiratidza kuenderera mberi kwemamiriro aya panzvimbo.
Tsigiro yebasa remoto mushanduko iyi inobva kune akapetwa macro charcoal records ezvibooreso cores, uye kupinda kwemarasha kubva kuCentral Basin (MAL05-1B/1C) kwakawedzera kubva pamusoro.175 makadhi.Nhamba huru yezvikwiriso zvinotevera pakati pezvinenge.Mushure me135 uye 175 ka uye 85 uye 100 ka, nzvimbo yegungwa yakadzoka, asi sango nehupfumi hwemhando hazvina kupora (Supplementary text, Figure 2 uye Figure S5).Ukama huri pakati pemarasha ekuputika uye kubatwa kwemagineti kwezvidziva zvegungwa zvinogonawo kuratidza mapatani enguva refu yemoto nhoroondo (33).Shandisa data kubva kuLyons et al.(34) Lake Malawi yakaramba ichiparadza nzvimbo yakatsva mushure me85 ka, iyo inoreva kuwirirana kwakanaka (Spearman's Rs = 0.2542 uye P = 0.0002; Tafura S7), nepo zvinyoro zvekare zvinoratidza hukama hwakasiyana (Rs = -0.2509 uye P < 0.0001).Mubheseni rekuchamhembe, iyo mupfupi MAL05-2A musimboti ine yakadzama yekufambidzana anchor poindi, uye mudiki Toba tuff i ~ 74 kusvika 75 ka (35).Kunyange zvazvo isina maonero enguva refu, inogamuchira zvinyorwa zvakananga kubva mubheseni umo data yezvokuchera matongo inotorwa.Zvinyorwa zvemazimbe ebheseni rekuchamhembe zvinoratidza kuti kubva kuToba crypto-tephra chiratidzo, kuiswa kwemazimbe anotyisa kwakawedzera zvishoma nezvishoma panguva iyo humbowo hwekuchera matongo hunowanzo (Mufananidzo 2B).
Humbowo hwemoto wakaitwa nevanhu hunogona kuratidza kushandiswa nemaune pachikero chenyika, kupararira kwevanhu kunokonzera kupisa kwakawanda kana kukuru panzvimbo, kuchinjwa kwehuni nekukohwa masango, kana musanganiswa wezviitwa izvi.Vavhimi vemazuva ano vanoshandisa moto kuti vashandure mibairo yekutsvaga (2).Zviito zvavo zvinowedzera kuwanda kwemhuka, kuchengetedza nzvimbo yemosaic, uye kuwedzera kupisa kwakasiyana uye heterogeneity yematanho ekutevedzana (13).Moto wakakoshawo kune zviitiko zvepa-saiti sekudziya, kubika, kudzivirira, uye kushamwaridzana (14).Kunyangwe misiyano midiki mukuiswa kwemoto kunze kwekurova kwemheni yechisikigo inogona kushandura masango ekutevedzana, kuwanikwa kwemafuta, uye mwaka wekupfura.Kuderedzwa kwechifukidziro chemuti uye miti yepasi ndiyo inonyanya kuwedzera kukukurwa, uye kurasikirwa kwemarudzi akasiyana-siyana munzvimbo ino kwakabatana zvikuru nekurasikirwa kwemasango emakomo eAfrica (25).
Muzvinyorwa zvekuchera matongo pamberi peMSA isati yatanga, kutonga kwevanhu kwemoto kwakanyatsosimbiswa (15), asi kusvika ikozvino, kushandiswa kwayo sechigadziro chekugadzirisa nzvimbo kwakanyorwa chete mumamiriro mashomanana ePaleolithic.Izvi zvinosanganisira nezve muAustralia.40 ka (36), Highland New Guinea.45 ka (37) chibvumirano cherunyararo.50 ka Niah Cave (38) in lowland Borneo.Munyika dzeAmerica, vanhu pavakatanga kupinda mumhoteredzo iyi, kunyanya munguva yakapfuura 20 ka (16), kupisa kwemoto kwakaonekwa sechinhu chikuru mukugadziriswazve kwenharaunda dzezvirimwa nemhuka.Izvi mhedziso dzinofanirwa kubva pauchapupu hwakakodzera, asi muchiitiko chekupindirana kwakananga kwekuchera matongo, geological, geomorphological, uye paleoenvironmental data, iyo causality nharo yakasimbiswa.Kunyange zvazvo marine core data yemvura yegungwa yeAfrica yakambopa humbowo hwekuchinja kwemoto munguva yakapfuura inenge 400 ka (9), pano tinopa humbowo hwesimba revanhu kubva kune zvakakosha zvekuchera matongo, paleoenvironmental, uye geomorphological data sets.
Kuzivikanwa kwemoto wakaitwa nevanhu muzvinyorwa zvepaleoenvironmental zvinoda humbowo hwemabasa emoto uye shanduko yenguva kana nzvimbo yezvinomera, zvichiratidza kuti shanduko idzi hadzina kufanotaurwa nemamiriro ekunze ega, uye kupindirana kwenguva / nzvimbo pakati pekuchinja kwemamiriro emoto uye shanduko mumunhu. zvinyorwa (29) Pano, humbowo hwekutanga hwekupararira kweMSA uye kuumbwa kwe fan fan muLake Malawi basin kwakaitika panenge pakutanga kwekurongeka kukuru kwezvinomera zvedunhu.85 makadhi.Kuwanda kwemarasha muMAL05-1B/1C musimboti kunoratidza maitiro edunhu ekugadzirwa kwemarasha uye kuiswa, panosvika zana nemakumi mashanu ka kana zvichienzaniswa nemamwe 636 ka rekodhi (Figure S5, S9, uye S10).Iyi shanduko inoratidza kukosha kwakakosha kwemoto kuumba kuumbwa kweiyo ecosystem, iyo isingagoni kutsanangurwa nemamiriro ekunze chete.Mumamiriro emoto chaiwo, kubatidza mheni kunowanzoitika pakupera kwemwaka wakaoma (39).Zvisinei, kana huni hwakaoma zvakakwana, moto unoitwa nevanhu unogona kubatidzwa chero nguva.Pachiyero chechiitiko, vanhu vanogona kuramba vachichinja moto nekunhonga huni kubva pasi pesango.Mhedzisiro yemhando ipi neipi yemoto wakaitwa nevanhu ndewekuti une mukana wekukonzera kudyiwa kwemiti yakawanda, inogara gore rose, uye pachikero chose.
MuSouth Africa, kubvira 164 ka (12), moto waishandiswa kupisa matombo ekugadzira maturusi.Kare kubvira 170 ka (40), moto waishandiswa sechombo chekubika machubhu ane sitachi, uchishandiswa zvizere moto munguva dzekare.Prosperous Resources-Inowanzoitika Scenery (41).Kupisa kwenzvimbo kunoderedza chivharo che arboreal uye chishandiso chakakosha chekuchengetedza nzvimbo dzeuswa uye masango, izvo zvinotsanangudza zvinhu zvemagariro-anopindirana nevanhu (13).Kana chinangwa chekushandura zvinomera kana hunhu hwemhuka chiri kuwedzera kupisa kunoitwa nevanhu, saka hunhu uhwu hunomiririra kuwedzera kwekuoma kwekutonga nekuisa moto nevanhu vemazuvano vekare kana vachienzaniswa nevanhu vekutanga, uye zvinoratidza kuti hukama hwedu nemoto hwakapfuura. kuchinja mukutsamirana (7).Ongororo yedu inopa imwe nzira yekunzwisisa shanduko mukushandiswa kwemoto nevanhu muLate Pleistocene, uye kukanganisa kwekuchinja uku pamamiriro avo nenzvimbo.
Kuwedzera kwemafafitera eLate Quaternary alluvial munzvimbo yeKaronga kunogona kukonzerwa nekusanduka kuri kuita kupisa kwemwaka nemwaka pasi pemamiriro ekunaya kwemvura yakakwira kudarika avhareji yekunaya kwemvura, izvo zviri kukonzera kukukurwa kwegomo.Iyo nzira yechiitiko ichi inogona kunge iri mhinduro yemvura-yemwero inofambiswa nekuvhiringidzika kunokonzerwa nemoto, kukukurwa kwakawedzera uye kwakasimba kwechikamu chepamusoro chemvura, uye kuwedzera kwealuvial mafeni munzvimbo yepiedmont pedyo neLake Malawi.Kuita uku kunogona kusanganisira kushandura zvimiro zvevhu kuti zvideredze kupinza, kuderedza kushata kwepamusoro, uye kuwedzera kuyerera nekuda kwekusanganiswa kwemamiriro ekunze emvura uye kuderedzwa kwechifukidziro chearboreal (42).Kuvepo kwesediments kunotanga kuvandudzwa nekubvisa chifukidziro, uye nekufamba kwenguva, simba revhu rinogona kuderera nekuda kwekupisa uye kuderedzwa kwemidzi.Kuputika kwevhu repamusoro kunowedzera sediment flux, iyo inogadziriswa ne fan-shaped kuunganidza pasi pemvura uye inokurumidza kuumbwa kwevhu dzvuku pane fan-shaped.
Zvinhu zvakawanda zvinogona kudzora maitiro emamiriro emamiriro emoto, mazhinji acho anoshanda mukati menguva pfupi (42-44).Chiratidzo chatinosanganisa pano chiri pachena pachiyero chemireniyamu.Ongororo uye mamiriro ekushanduka kwemamiriro ekunze anoratidza kuti nekukanganisika kwezvinomera kunokonzerwa nemoto wemusango wakadzokororwa, chiyero che deudation chachinja zvakanyanya pamireniyamu nguva chiyero (45, 46).Kushaikwa kwezvinyorwa zvefossil zvemudunhu zvinofambirana nekuchinja kunoonekwa mumarekodha emarasha nezvinomera kunotadzisa kuvakwa patsva kwemaitiro ehunhu hwevanhu uye shanduko yezvakatipoteredza pakuumbwa kwenharaunda dzinodya sora.Zvisinei, mhuka huru dzinogara munzvimbo dzakavhurika dzinoita basa mukudzichengetedza uye kudzivirira kupinda kwemiti yemiti (47).Uchapupu hwekuchinja muzvikamu zvakasiyana zvezvakatipoteredza hazvifaniri kutarisirwa kuitika panguva imwe chete, asi hunofanira kuonekwa sehuwandu hwehuwandu hwemigumisiro inogona kuitika kwenguva yakareba (11).Tichishandisa nzira yemamiriro ekunze anomaly (29), tinoona basa revanhu sechinhu chakakosha chekufambisa mukuumba mamiriro ekuchamhembe kweMalawi panguva yeLate Pleistocene.Nekudaro, izvi zvinokonzeresa zvinogona kunge zvichibva pane zvakamboitika, zvishoma zviri pachena nhaka yekudyidzana kwevanhu nenharaunda.Chimiro chemarasha chakaonekwa mu paleoenvironmental rekodhi zuva rekutanga rekuchera matongo risati rasvika rinogona kusanganisira chikamu cheanthropogenic chisingakonzeri shanduko yezvakatipoteredza seyakanyorwa gare gare, uye haibatanidzi madhipoziti akakwana kuratidza nechivimbo basa revanhu.
Mapfupi sediment cores, akadai seaya ari pedyo neMasoko Lake Basin muTanzania, kana kuti mapfupi sediment cores muLake Malawi, anoratidza kuti huturu hwehuswa nehuswa hwachinja, izvo zvinonzi zvakaitika makore makumi mana nemashanu apfuura.Kuchinja kwemamiriro ekunze kweka (48-50).Zvakadaro, kungotarisisa kwenguva refu kwechinyorwa chemukume cheLake Malawi > 600 ka, pamwe chete nemamiriro ekare ezvekuchera matongo pedyo nayo, zvinokwanisika kunzwisisa mamiriro ekunze, zvinomera, marasha, uye mabasa evanhu.Kunyange zvazvo vanhu vangangoonekwa kuchamhembe kweLake Malawi basin isati yasvika 85 ka, inenge 85 ka, kunyanya mushure me70 ka, inoratidza kuti nzvimbo inoyevedza yekugara kwevanhu mushure mokunge nguva yekupedzisira yekusanaya kwemvura yapera.Panguva ino, kushandiswa kutsva kana kwakanyanyisa / kushandiswa kwemoto nevanhu zviri pachena kunosanganiswa nekushanduka kwemamiriro ekunze kuti vagadzirise hukama hwezvakatipoteredza> 550-ka, uye pakupedzisira vakagadzira nzvimbo yepakutanga yezvekurima (Mufananidzo 4).Kusiyana nenguva dzakapfuura, sedimentary yenzvimbo inochengetedza iyo MSA saiti, inova basa rehukama hunodzokororwa pakati pezvakatipoteredza (kugovera zviwanikwa), maitiro evanhu (maitiro ekuita), uye activation fan (deposition/ saiti kuvigwa).
(A) Nezve.400 ka: Hapana vanhu vanogona kuonekwa.Mamiriro ehunyoro akafanana nemazuva ano, uye dhamu racho rakakwirira.Yakasiyana, isiri-moto inodzivirira arboreal kavha.(B) Pamusoro pe100 ka: Hapana chinyorwa chekuchera matongo, asi kuvapo kwevanhu kunogona kuonekwa kuburikidza nekuwanda kwemarasha.Mamiriro akaoma zvikuru anoitika munzvimbo dzakaoma dzemvura.Iro dombo rinowanzo buritswa uye madhiri epamusoro ane mashoma.(C) Inenge 85 kusvika ku60 ka: Mvura yegungwa inowedzera nekuwedzera kwekunaya.Kuvapo kwevanhu kunogona kuwanikwa kuburikidza nekuchera matongo mushure me 92 ka, uye mushure me 70 ka, kupiswa kwenzvimbo dzakakwirira uye kuwedzera kwealuvial fans kuchatevera.Pave nezvinomera zvishoma zvakasiyana-siyana, zvisingatsva nemoto.(D) Inenge 40 kusvika ku20 ka: Kuiswa kwemazimbe ezvakatipoteredza mubheseni rekuchamhembe kwakawedzera.Kuumbwa kwe alluvial fans kwakaenderera mberi, asi kwakatanga kupera simba pakupera kwenguva iyi.Kana ichienzaniswa neyekare rekodhi ye636 ka, dhamu redziva rinoramba rakakwirira uye rakagadzikana.
Iyo Anthropocene inomiririra kuunganidzwa kwemaitiro ekuvaka-niche akagadziridzwa kwezviuru zvemakore, uye chiyero chayo chakasiyana neazvino Homo sapiens (1, 51).Mumamiriro ezvinhu emazuva ano, nekutanga kwekurima, nzvimbo dzakagadzirwa nevanhu dzinoramba dziripo uye dzichiwedzera, asi dziri kuwedzera kwemaitiro akaiswa panguva yePleistocene, pane kubviswa (52).Mashoko anobva kuchamhembe kweMalawi anoratidza kuti nguva yekushandura ecological inogona kurebeswa, yakaoma uye ichidzokororwa.Uhu hukero hweshanduko hunoratidza ruzivo rwakaoma rwezvakatipoteredza rwevanhu vekare vemazuva ano uye hunoratidza kushanduka kwavo kune marudzi edu ane simba pasi rose nhasi.
Zvinoenderana neprotocol yakatsanangurwa naThompson et al., pa-saiti kuferefeta uye kurekodha kwezvinhu zvakagadzirwa uye cobblestone maitiro panzvimbo yekuongorora.(53).Kuiswa kwegomba rekuedza uye kucherwa kwenzvimbo huru, kusanganisira micromorphology uye phytolith sampling, yakatevera protocol yakatsanangurwa naThompson et al.(18) uye Wright et al.(19).Yedu geographic information system (GIS) mepu yakavakirwa paMalawi geological survey mepu yedunhu inoratidza kuwirirana kwakajeka pakati peChitimwe Beds nenzvimbo dzekuchera matongo (Figure S1).Nguva iri pakati pemakomba ekuongorora matongo neanochera matongo munharaunda yeKaronga ndeekutora muenzaniso wakakura kwazvo wemumiriri (Mufananidzo S2).Geomorphology yeKaronga, geological age uye ongororo yezvinocherwa mumatongo inosanganisira nzira ina huru dzeongororo yenzvimbo dzinoti: ongororo yevanofamba netsoka, makomba ekuongorora matongo, makomba ebvunzo dze geological uye macherwa ane udzame enzvimbo.Pamwe chete, maitiro aya anobvumira sampling yekuratidzwa kukuru kwemubhedha weChitimwe kuchamhembe, nechepakati, uye kumaodzanyemba kweKaronga (Mufananidzo S3).
Kuongorora kwepa-saiti uye kurekodha kwezvigadzirwa uye maumbirwo ematombo ematombo panzvimbo yeongororo yevanofamba netsoka yakatevera gwara rakatsanangurwa naThompson et al.(53).Iyi nzira ine zvinangwa zvikuru zviviri.Yokutanga ndeyekuziva nzvimbo dzakasakara zvisaririra zvetsika, uye wozoisa makomba ebvunzo dzekuchera matongo munzvimbo idzi kudzorera zvisaririra zvetsika mu situ kubva munzvimbo yakavigwa.Chinangwa chechipiri ndechekunyora zviri pamutemo kugoverwa kwezvinhu, maitiro avo, uye hukama hwavo nekwakabva zvinhu zvematombo zviri pedyo (53).Mubasa iri, chikwata chevanhu vatatu chakafamba chinhambwe chemamita maviri kusvika matatu kwehwerengedzo yemakiromita 147.5 mutsetse, vachiyambuka mibhedha mizhinji yeChitimwe yakadhonzwa (Table S6).
Basa rakatanga rakanangana neChitimwe Mibhedha kuti riwedzere kucherechedzwa kwemasamples ezvigadzirwa, uye kechipiri rakanangana nezvikamu zvemitsetse mirefu kubva kumahombekombe egungwa kuenda kunzvimbo dzakakwirira dzinodimbura mativi akasiyana siyana.Izvi zvinosimbisa maonero akakosha ekuti zvinhu zvakawanikwa pakati penzvimbo dzakakwirira dzekumadokero nemahombekombe egungwa zvinongoenderana nemubhedha weChitimwe kana zvimwe zvichangobva kuitika zveLate Pleistocene neHolocene sediments.Iyo artefacts inowanikwa mune mamwe madhipoziti isiri-saiti, yakatamiswa kubva kune dzimwe nzvimbo munzvimbo, sezvinoonekwa kubva mukuwanda kwazvo, saizi, uye dhigirii remamiriro ekunze.
Gomba rekuchera matongo panzvimbo uye kucherwa kwenzvimbo huru, kusanganisira micromorphology uye phytolith sampling, yakatevera protocol yakatsanangurwa naThompson et al.(18, 54) uye Wright et al.(19, 55).Chinangwa chikuru ndechekunzwisisa kugovaniswa kwepasi pevhu kwezvigadzirwa uye madhiri emhando yefan munzvimbo yakakura.Zvigadzirwa zvinowanzovigwa zvakadzika munzvimbo dzese muChitimwe Mibhedha, kunze kwekumicheto, uko kukukurwa kwatanga kubvisa pamusoro pevhu.Munguva yekuferefeta zvisina kurongwa, vanhu vaviri vakapfuura nepaChitimwe Beds, iyo yairatidzwa semamepu pamepu yehurumende yeMalawi.Vanhu ava pavakasangana nemapendekete etsvina yeChitimwe Bed, vakatanga kufamba nechekumucheto, kwavaikwanisa kuona zvinhu zvakanyura kubva muvhu.Nekurerekera zvakacherwa zvichikwira zvishoma (3 kusvika 8 m) kubva pane zviri kushingaira kukoromora, kuchera kunogona kuratidza nzvimbo yavo ye-in-situ maererano nevhu rine mazviri, pasina kudiwa kwekuchera kwakadzama nedivi.Makomba ebvunzo anoiswa kuitira kuti ave 200 kusvika 300 metres kubva kune inotevera gomba riri pedyo, nokudaro achitora shanduko muChitimwe mubhedha sediment uye artifacts mairi.Mune zvimwe zviitiko, gomba rekuyedza rakaburitsa saiti yakazove nzvimbo yekuchera yakazara.
Makomba ese ebvunzo anotanga aine sikweya ye1 × 2 m, akatarisana nekuchamhembe-kumaodzanyemba, uye anocherwa muzvikamu zvisingaite zvemasendimita makumi maviri, kunze kwekunge ruvara, magadzirirwo, kana zviri mukati mesediment zvachinja zvakanyanya.Nyora sedimentology uye ivhu zvinhu zvezvinhu zvose zvakacherwa, izvo zvinopfuura zvakaenzana kuburikidza ne 5 mm yakaoma sieve.Kana iyo deposition yakadzika ikaramba ichipfuura 0.8 kusvika 1 m, rega kuchera mune imwe yemamita maviri emamita uye ramba uchichera mune imwe, nekudaro uchigadzira "nhanho" kuitira kuti iwe ugone kupinda mukati makadzika matete.Zvadaro ramba uchichera kusvikira dombo rasvika, zvishoma 40 cm yearcheologically sterile sediments iri pasi pehuwandu hwezvigadzirwa, kana kuchera kunenge kusina kuchengetedzeka (kudzika) kuti uenderere mberi.Mune zvimwe zviitiko, kudzika kwekuisa kunoda kuwedzera gomba rekuyedza kusvika kune chetatu square mita uye kupinda mugero mumatanho maviri.
Geological test pits dzakamboratidza kuti Chitimwe Mibhedha inowanzoonekwa pamepu dze geological nekuda kwekusiyana kwayo neruvara rutsvuku.Kana zvinosanganisira hova dzakakura uye nzizi sediments, uye alluvial fan sediments, hazviwanzo kuratidzika zvitsvuku (19).Geology Gomba rekuyedzwa rakacherwa segomba rakapfava rakagadzirirwa kubvisa madhaka akasanganiswa epamusoro kuratidza madhaka epasi pevhu.Izvi zvinodikanwa nekuti mubhedha weChitimwe wakakukurwa kuita chikomo cheparabolic, uye pane madonhwe akadonha pamateru, ayo kazhinji haaite masikirwo akajeka kana kucheka.Saka macherwa aya akaitwa pamusoro pemubhedha waChitimwe, pamwe paive nepanoroverana pasi pemubhedha waChitimwe nemubhedha wePliocene Chiwondo waiva pazasi, kana kuti akaitika paida kunyorwa misi (55).
Kuchera kwakazara kwekuchera matongo kunoitwa munzvimbo dzinovimbisa nhamba huru ye-in-situ matombo emidziyo magungano, kazhinji akavakirwa pamakomba ebvunzo kana nzvimbo uko nhamba huru yezvisaririra zvetsika inogona kuoneka ichidonha kubva pamateru.Zvisaririra zvetsika zvakacherwa zvakawanikwa kubva kune sedimentary zvikamu zvakacherwa zvakasiyana mune sikweya ye1 × 1 m.Kana iyo density yezvigadzirwa zvakakwirira, iyo yekuchera unit ndeye 10 kana 5 cm spout.Zvese zvigadzirwa zvematombo, fossil mapfupa uye ocher zvakadhirowewa panguva yekuchera kukuru kwega kwega, uye hapana muganhu wehukuru.Saizi yescreen ndeye 5mm.Kana zvisaririra zvetsika zvikawanikwa panguva yekuchera matongo, vanozopihwa yakasarudzika bar kodhi yekudhirowa nhamba yekuwana, uye nhamba dzekuwanikwa munhevedzano imwe chete dzinozopihwa kune zvakasefa zvakawanikwa.Zvisaririra zvetsika zvinoiswa chiratidzo neingi isingaperi, inoiswa mumabhegi ane mavara emuenzaniso, uye yakasungirirwa pamwe chete nezvimwe zvisaririra zvetsika kubva kumashure akafanana.Mushure mekuongorora, zvisaririra zvetsika zvese zvinochengetwa muCultural and Museum Center yeKaronga.
Kuchera kwese kunoitwa maererano nemaitiro echisikigo.Izvi zvakakamurwa kuita spits, uye kupfira kunoenderana neiyo artifact density (semuenzaniso, kana iyo artifact density yakadzikira, kupfira kunenge kwakakwira).Ruzivo rwekumashure (semuenzaniso, zvivakwa zvepasi, hukama hwemashure, uye kucherechedzwa kwekukanganisa uye density yezvigadzirwa) zvinorekodhwa muDatabhesi reKuwana.Yese data yekubatanidza (somuenzaniso, zvakawanikwa zvakadhirowewa muzvikamu, kukwidziridzwa kwechirevo, makona masikweya, uye samples) zvinobva paUniversal Transverse Mercator (UTM) coordination (WGS 1984, Zone 36S).Panzvimbo huru, mapoinzi ese anorekodhwa uchishandisa Nikon Nivo C akateedzana 5 ″ yakazara chiteshi, iyo yakavakirwa pane yemunharaunda grid padyo sezvinobvira kuchamhembe kweUTM.Nzvimbo yekona yekuchamhembe kwakadziva kumadokero kwenzvimbo yega yega yekuchera uye nzvimbo yenzvimbo yega yega yekuchera Huwandu hwemavhu hunopihwa muTafura S5.
Chikamu che sedimentology uye ivhu sainzi maitiro eese akacherwa mayuniti akarekodhwa pachishandiswa United States Agricultural Part Class Programme (56).Sedimentary zvikamu zvinotsanangurwa zvichibva pakukura kwezviyo, angularity, uye hunhu hwekurara.Cherechedza kusanganisa kusina kujairika uye kukanganisa kunobatanidza nesediment unit.Kukura kwevhu kunoonekwa nekuunganidza sesquioxide kana carbonate muvhu repasi.Underground weathering (semuenzaniso, redox, kuumbwa kweasara manganese nodules) inowanzorekodhwawo.
Nzvimbo yekuunganidzira yeOSL samples inotarwa pahwaro hwekufungidzira kuti ndedzipi facies dzinogona kuburitsa fungidziro yakavimbika yezera rekuvigwa sediment.Panzvimbo yekuenzanisira, migero yakacherwa kuratidza iyo authigenic sedimentary layer.Unganidza ese masampuli anoshandiswa kufambidzana neOSL nekuisa chubhu yesimbi isina kujeka (inenge 4 cm mudhayamita uye inosvika 25 cm pakureba) muchidimbu.
OSL yekufambidzana inoyera saizi yeboka remaerekitironi akavharirwa mumakristasi (akadai sequartz kana feldspar) nekuda kwekusangana nemwaranzi yeionizing.Mazhinji emwaranzi iyi anobva mukuora kweradioactive isotopes mumhoteredzo, uye chidimbu chidiki chezvimwe zvikamu munzvimbo dzinopisa dzinoonekwa muchimiro chemwaranzi yepasi.Maerekitironi akabatwa anoburitswa kana kristaro yaiswa muchiedza, inoitika panguva yekufambisa (zeroing chiitiko) kana murabhoritari, apo mwenje unoitika pane sensor inogona kuona mafotoni (semuenzaniso, photomultiplier chubhu kana kamera ine charger. coupling device) Chikamu chepasi chinobuda kana erekitironi yadzokera pasi.Quartz zvidimbu zvine saizi iri pakati pe150 ne250 μm inopatsanurwa nekusefa, asidhi kurapwa uye density kupatsanurwa, uye anoshandiswa sediki aliquots (<100 particles) akaiswa pamusoro pearuminiyamu ndiro kana kudhirowa mutsime 300 x 300 mm Munhu zvidimbu zvinoongororwa pane pani yealuminium.Mushonga wakavigwa unowanzo fungidzirwa uchishandisa imwe aliquot regeneration method (57).Pamusoro pekuongorora dhamu remwaranzi inogamuchirwa nezviyo, kufambidzana kweOSL kunodawo kuenzanisa mwero wedoro nekuyera huwandu hweradionuclide muchikamu chesample yakaunganidzwa uchishandisa gamma spectroscopy kana neutron activation ongororo, uye kuona iyo cosmic dose referenzi sampuli Nzvimbo uye kudzika kweiyo. kuvigwa.Kutemerwa kwezera rekupedzisira kunowanikwa nekugovanisa dosi yekuvigwa nechiyero chedosi.Zvisinei, kana pane kuchinja kwepimo yakayerwa netsanga imwe chete kana boka rezviyo, muenzaniso wenhamba unodiwa kuti uone chiyero chakakodzera chakavigwa chinoshandiswa.Chiyero chakavigwa chinoverengerwa pano uchishandisa iyo yepakati era modhi, mune imwe aliquot kufambidzana, kana mune imwe-chete kufambidzana, uchishandisa inogumira musanganiswa modhi (58).
Marabhoritari matatu akazvimirira akaita ongororo yeOSL yechidzidzo ichi.Iyo yakadzama nzira dzemunhu parabhoritari yega yega inoratidzwa pazasi.Kazhinji, tinoshandisa regenerative dose method to apply OSL dating to small aliquots (makumi ezviyo) pane kushandisa single grain analysis.Izvi ndezvokuti panguva yekuedza kwekukura patsva, chiyero chekudzorera chemuenzaniso muduku chakaderera (<2%), uye chiratidzo cheOSL hachina kuzara pachiyero chechiratidzo chechisikigo.Iro inter-laboratory consistency yekutsunga zera, kuwirirana kwemigumisiro mukati uye pakati pezvakaedzwa stratigraphic profiles, uye kuwirirana nekududzirwa kwe geomorphological ye14C yemakore e carbonate rocks ndiyo nheyo huru yekuongorora uku.Murabhoritari yega yega yakaongorora kana kuita chibvumirano chezviyo chimwe chete, asi yakazvimiririra kuti yaisakodzera kushandiswa muchidzidzo ichi.Iyo yakadzama nzira uye mapuroteni ekuongorora anoteverwa nerabhoritari yega yega anopihwa mune zvekuwedzera zvinhu uye nzira.
Zvigadzirwa zvematombo zvakawanikwa kubva mukucherwa kwakadzorwa (BRU-I; CHA-I, CHA-II, uye CHA-III; MGD-I, MGD-II, uye MGD-III; uye SS-I) yakavakirwa pane metric system uye mhando. maitiro.Pima huremu uye saizi huru yechinhu chimwe nechimwe (uchishandisa sikero yedhijitari kuyera huremu i0.1 g; uchishandisa Mitutoyo digital caliper kuyera zviyero zvese i0.01 mm).Zvese zvisaririra zvetsika zvinoiswawo maererano neyakagadzirwa zvinhu (quartz, quartzite, flint, nezvimwewo), saizi yezviyo (yakanaka, yepakati, yakaoma), kufanana kwehukuru hwezviyo, ruvara, rudzi rwecortex uye kufukidzira, mamiriro ekunze / kutenderera kutenderera uye giredhi rehunyanzvi. (yakakwana kana kupatsanurwa) Macores kana flakes, flakes / makona zvidimbu, sando matombo, magirinedhi nezvimwe).
Nheyo inopimwa nekureba kwayo;hupamhi hwepamusoro;hupamhi ndeye 15%, 50%, uye 85% yehurefu;kunonyanyisa ukobvu;ukobvu i15%, 50%, uye 85% yehurefu.Zviyero zvakaitwawo kuongorora huwandu hwezvinhu zvepakati pehemispherical tissues (radial uye Levallois).Ese ari maviri asina kusimba uye akatyoka macores anoiswa maererano neiyo nzira yekugadziridza (imwe chikuva kana multi-platform, radial, Levallois, nezvimwewo), uye mavanga asina kuchena anoverengerwa pa ≥15 mm uye ≥20% yehurefu hwepakati.Macores ane 5 kana mashoma 15 mm mavanga anoiswa se "random".Iko cortical coverage yehupamhi hwepakati pese inonyorwa, uye iyo yakaenzana cortical kufukidzwa kwerutivi rumwe norumwe inonyorwa pamucheto wehemispherical tissue.
Pepa rinopimwa pamwe chete nehurefu hwaro;hupamhi hwepamusoro;hupamhi ndeye 15%, 50%, uye 85% yehurefu;kunonyanyisa ukobvu;ukobvu i15%, 50%, uye 85% yehurefu.Rondedzera zvimedu maererano nezvikamu zvakasara (proximal, pakati, distal, kupatsanurwa kurudyi uye kupatsanurwa kuruboshwe).Kurebesa kunoverengwa nekupatsanura hurefu hwakanyanya nehupamhi hwehupamhi.Eresa hupamhi hwepuratifomu, ukobvu, uye ekunze kwepuratifomu kona yeisina kurongeka uye proximal zvidimbu zvimedu, uye rongedza mapuratifomu zvinoenderana nedhigirii rekugadzirira.Rekodha cortical kufukidzwa uye nzvimbo pane ese zvimedu uye zvimedu.Iyo distal mipendero yakakamurwa zvichienderana nerudzi rwekugumisa (munhenga, hinge, uye yekumusoro forogo).Pachidimbu chakazara, rekodha nhamba uye nzira yevanga pane rapfuura.Kana wasangana, rekodha nzvimbo yekushandura uye invasiveness zvinoenderana neprotocol yakagadzwa naClarkson (59).Zvirongwa zvekugadzirisa zvakatangwa kune mazhinji emusanganiswa wekuchera kuti uongorore nzira dzekudzorera uye saiti deposition kutendeseka.
Zvigadzirwa zvematombo zvakadzorerwa kubva kumakomba ekuedza (CS-TP1-21, SS-TP1-16 uye NGA-TP1-8) inotsanangurwa maererano nechirongwa chakareruka kupfuura kuchera kunodzora.Pachinhu chimwe nechimwe, hunhu hunotevera hwakarekodhwa: mbishi, saizi yechikamu, cortex kufukidzwa, saizi giredhi, mamiriro ekunze / kumucheto kukuvadzwa, zvigadzirwa zvehunyanzvi, uye kuchengetedza zvidimbu.Zvinyorwa zvinotsanangurwa zvekuongorora maitiro emaflakes uye cores akanyorwa.
Mabhuroko akazara e sediment akachekwa kubva muzvikamu zvakafumurwa mukuchera uye migero ye geological.Matombo aya akaiswa panzvimbo nemabhandiji epurasita kana pepa rechimbuzi uye tepi yekurongedza, ndokuzoendeswa kuGeological Archaeology Laboratory yeYunivhesiti yeTubingen kuGermany.Ikoko, sampuli yakaomeswa pa40 ° C kwemaawa makumi maviri nemana.Zvadaro vanorapwa pasi pevacuum, vachishandisa musanganiswa wepolyester resin isina kukurudzirwa uye styrene muchiyero che7: 3.Methyl ethyl ketone peroxide inoshandiswa sechinhu chinokonzera, resin-styrene musanganiswa (3 kusvika 5 ml / l).Kana musanganiswa we resin waita gelled, kupisa sampuli pa 40 ° C kwemaawa makumi maviri nemana kuti uomese zvachose musanganiswa.Shandisa saha kucheka sampuli yakaomeswa kuita 6 × 9 cm zvidimbu, uzvinamire pane girazi slide uye uzvikuya kuhupamhi hwe30 μm.Zvimedu zvakazoitika zvakaongororwa uchishandisa flatbed scanner, uye yakaongororwa uchishandisa ndege polarized light, cross-polarized light, oblique chiitiko chiedza, uye blue fluorescence neziso rakashama uye magnification (× 50 kusvika × 200).Izwi uye tsananguro yezvikamu zvitete zvinotevera zvinongedzo zvakaburitswa naStoops (60) uye Courty et al.(61).Iyo ivhu inoumba carbonate nodules inounganidzwa kubva pakadzika> 80 cm inochekwa nepakati kuitira kuti hafu igone kupihwa pamuviri uye inoitwa muzvidimbu zvitete (4.5 × 2.6 cm) uchishandisa yakajairwa stereo maikorosikopu uye petrographic maikorosikopu uye cathodoluminescence (CL) Research maikorosikopu. .Kudzora kwemhando dze carbonate kwakanyatso kuchenjerera, nokuti kuumbwa kwevhu-kuumba carbonate kunoenderana nepamusoro pemvura yakagadzikana, asi kuumbwa kwepasi pasi carbonate kunozvimiririra pamusoro pepamusoro kana ivhu.
Samples dzakacherwa kubva pachekwa pamusoro pevhu-inogadzira carbonate nodules uye nehafu kuti ongororo dzakasiyana.FS yakashandisa yakajairwa stereo uye petrographic maikorosikopu yeGeoarchaeology Working Group uye CL maikorosikopu yeExperimental Mineralogy Working Group kudzidza zvimedu zvitete, zvese zviri muTübingen, Germany.Iwo radiocarbon dating sub-samples akadhirowa pachishandiswa madhiri chaiwo kubva kunzvimbo yakatarwa inosvika zana ramakore.Imwe hafu yemanodule ndeye 3 mm mudhayamita kudzivirira nzvimbo dzine kunonoka recrystallization, rich mineral inclusions, kana shanduko huru muhukuru hwe calcite crystals.Iyo yakafanana protocol haigone kuteverwa kune iyo MEM-5038, MEM-5035 uye MEM-5055 A samples.Mienzaniso iyi inosarudzwa kubva kune yakasununguka sediment samples uye idiki kwazvo kuti ichekwe nepakati kuti iite zvidimbu zvitete.Nekudaro, zvidzidzo zvakatetepa-chikamu zvakaitwa pane inoenderana micromorphological samples dzepadyo sediments (kusanganisira carbonate nodules).
Takaendesa 14C kufambidzana samples kuCentre for Applied Isotope Research (CAIS) paYunivhesiti yeGeorgia, Athens, USA.Iyo carbonate sampu inopindirana ne100% phosphoric acid mumudziyo wakabviswa unobuda kuita CO2.Kucheneswa kwakadzika-tembiricha kweCO2 samples kubva kune zvimwe zvinogadzirwa zvigadzirwa uye catalytic kutendeuka kuita graphite.Chiyero chegraphite 14C/13C chakayerwa pachishandiswa 0.5-MeV accelerator mass spectrometer.Enzanisa chiyero chemuenzaniso nereshiyo yakayerwa neoxalic acid I yakajairwa (NBS SRM 4990).Carrara marble (IAEA C1) inoshandiswa semashure, uye travertine (IAEA C2) inoshandiswa seyechipiri chiyero.Mhedzisiro yacho inoratidzwa sechikamu chekabhoni yemazuva ano, uye zuva rakataurwa risingaverengeki rinopihwa mumakore eradiocarbon (BP makore) gore ra1950 risati rasvika, vachishandisa 14C hafu yeupenyu hwemakore 5568.Iko kukanganisa kunonzi 1-σ uye inoratidza kukanganisa kwenhamba uye yekuedza.Zvichibva pa δ13C kukosha kwakayerwa neisotopu ratio mass spectrometry, C. Wissing yeBiogeology Laboratory muTubingen, Germany, yakashuma zuva rekukamurwa kweisotopu, kunze kweUGAMS-35944r yakayerwa paCAIS.Sample 6887B yakaongororwa mune duplicate.Kuti uite izvi, dhiraivha yechipiri sub-sample kubva kune nodule (UGAMS-35944r) kubva kune sampling nzvimbo inoratidzwa pane yekucheka pamusoro.Iyo INTCAL20 calibration curve (Tafura S4) (62) yakashandiswa kumaodzanyemba kwehemisphere yakashandiswa kugadzirisa kupatsanurwa kwemhepo kwemasampuli ose kusvika ku14C kusvika ku2-σ.