Homo sapiens igezweho yagize uruhare runini mu guhindura urusobe rwibinyabuzima, ariko biragoye kumenya inkomoko cyangwa ingaruka zambere ziyi myitwarire.Ubucukumbuzi, geochronologiya, geomorphologiya, hamwe n’ibidukikije bya paleoen ibidukikije biva mu majyaruguru ya Malawi byerekana isano iri hagati yo kuba hari aborozi, ishyirahamwe ry’ibidukikije, hamwe n’abafana ba alluvial muri Late Pleistocene.Nyuma yikinyejana cya 20, hashyizweho uburyo bwuzuye bwibikoresho bya Mesolithique nabafana ba alluvial.Imyaka 92.000 irashize, mubidukikije bya paleo-ibidukikije, nta analogue yabayeho mumyaka 500.000 ishize.Ibyataburuwe mu matongo hamwe n’isesengura ry’ibanze byerekana ko umuriro wakozwe n'abantu hakiri kare kugabanya ibihe byagenwe byo gutwikwa, bikagira ingaruka ku bimera n’isuri.Ibi, bifatanije n’imihindagurikire y’imvura iterwa n’ikirere, amaherezo byatumye habaho ihinduka ry’ibidukikije ahantu nyaburanga mbere y’ubuhinzi.
Abantu ba kijyambere ni abateza imbere imbaraga zo guhindura ibidukikije.Mu myaka ibihumbi, bahinduye ibidukikije cyane kandi babigambiriye, bitera impaka zerekeye igihe nuburyo bwa mbere urusobe rwibinyabuzima rwiganjemo abantu rwagaragaye (1).Ibimenyetso byinshi bya kera byubucukumbuzi n’amoko byerekana ko hari umubare munini wimikoranire yisubiramo hagati yabashumba n’ibidukikije, ibyo bikaba byerekana ko iyo myitwarire ari ishingiro ry’ihindagurika ry’ibinyabuzima byacu (2-4).Ibisigazwa by’ibinyabuzima na genetike byerekana ko Homo sapiens yabayeho muri Afurika hashize imyaka 315.000 (ka).Ibyataburuwe mu matongo byerekana ko imyitwarire igoye ku mugabane wa Afurika yiyongereye cyane mu bihe byashize hafi 300 kugeza 200 ka.Iherezo rya Pleistocene (Chibanian) (5).Kuva tugaragara nk'ubwoko, abantu batangiye kwishingikiriza ku guhanga udushya mu ikoranabuhanga, gahunda y'ibihe, n'ubufatanye bugoye kugira ngo batere imbere.Iyi mico idushoboza kwifashisha ibidukikije ndetse nubutunzi bikabije bidatuwe, bityo rero muri iki gihe abantu ni ubwoko bwinyamanswa yonyine ku isi (6).Umuriro wagize uruhare runini muri iri hinduka (7).
Ingero z’ibinyabuzima zerekana ko guhuza n’ibiryo bitetse bishobora guturuka ku myaka nibura miliyoni 2 ishize, ariko kugeza igihe Pleistocene yo hagati yarangirije niho hagaragaye ibimenyetso bisanzwe by’ubucukuzi bw’umuriro (8).Inyanja y'inyanja ifite ivumbi ryaturutse mu gace kanini k'umugabane wa Afurika yerekana ko mu myaka miriyoni ishize, impinga ya karubone yibanze yagaragaye nyuma ya ka ka 400, cyane cyane mu gihe cyo kuva mu bihugu bitandukanye bikagera mu kirere, ariko nanone byabaye mu gihe Holocene (9).Ibi birerekana ko mbere ya 400 ka, umuriro muri Afrika yo munsi yubutayu bwa Sahara utari usanzwe, kandi uruhare rwabantu rwagize uruhare runini muri Holocene (9).Umuriro nigikoresho gikoreshwa nabashumba muri Holocene muguhinga no kubungabunga ibyatsi (10).Ariko rero, gutahura inkurikizi n'ingaruka z’ibidukikije byo gukoresha umuriro n’abaterankunga bahiga muri Pleistocene yo hambere biragoye (11).
Umuriro witwa igikoresho cyubwubatsi bwo gukoresha umutungo haba muri etnografiya na archeologiya, harimo kuzamura imibereho cyangwa guhindura ibikoresho fatizo.Ibi bikorwa mubisanzwe bifitanye isano nigenamigambi rusange kandi bisaba ubumenyi bwinshi bwibidukikije (2, 12, 13).Ahantu nyaburanga hashobora gutuma abahiga-bahiga birukana umuhigo, kurwanya udukoko, no kongera umusaruro w’imiturire (2).Umuriro ku rubuga uteza imbere guteka, gushyushya, kurinda inyamaswa, no kubana neza (14).Nyamara, urugero urwego rw’abahiga-bahiga rushobora kongera guhuza ibice bigize imiterere, nkimiterere y’umuryango w’ibidukikije hamwe n’ubutaka, ntibisobanutse neza (15, 16).
Hatariho amakuru ya kera yubucukuzi na geomorphologiya hamwe nibidukikije bikomeza kuva ahantu henshi, gusobanukirwa iterambere ryimihindagurikire y’ibidukikije iterwa n’abantu ni ikibazo.Inyandiko ndende zo kubitsa mu biyaga ziva mu kibaya kinini cya Rift muri Afurika yepfo, zifatanije n’inyandiko za kera za kera za kera muri ako gace, bituma iba ahantu ho gukora iperereza ku ngaruka z’ibidukikije zatewe na Pleistocene.Hano, turatanga raporo kuri archeologiya na geomorphologie yubutaka bwagutse bwibuye muri Afrika yepfo.Noneho, twabihuje namakuru ya paleoen ibidukikije akwirakwiza> 600 ka kugirango tumenye ibimenyetso byambere bihuza byerekana imyitwarire yumuntu no guhindura urusobe rwibinyabuzima murwego rwumuriro wakozwe n'abantu.
Twatanze imyaka ntarengwa yo kumenyekanisha uburiri bwa Chitimwe mu Karere ka Karonga, iherereye mu majyaruguru y’amajyaruguru ya Malawi mu majyepfo ya Afurika Rift Valley (Ishusho 1) (17).Ibi bitanda bigizwe nubutaka butukura alluvial nubutaka bwimigezi, bingana na kilometero kare 83, burimo miriyoni yibicuruzwa byamabuye, ariko nta bisigazwa by’ibinyabuzima byabitswe, nkamagufwa (Inyandiko yinyongera) (18).Amakuru yacu yishimye cyane (OSL) kuva mubitabo byisi (Igicapo cya 2 na Imbonerahamwe S1 kugeza kuri S3) yahinduye imyaka yigitanda cya Chitimwe kuri Late Pleistocene, kandi imyaka ishaje cyane yo gukora abafana ba alluvial no gushyingura amabuye ni 92 ka ( 18, 19).Igice cya alluvial n'umugezi Chitimwe bitwikira ibiyaga n'inzuzi zo mu gice cya Pliocene-Pleistocene Chiwondo uhereye ku mfuruka ntoya (17).Ibyo bibitse biherereye mu kayira kegereye ikiyaga.Imiterere yabyo yerekana imikoranire hagati yimihindagurikire yikiyaga namakosa akomeye agera muri Pliocene (17).Nubwo ibikorwa bya tectonic bishobora kuba byaragize ingaruka kumiterere yakarere no mumisozi miremire kuva kera, ibikorwa byamakosa muri kano karere bishobora kuba byaragabanutse kuva Pleistocene yo hagati (20).Nyuma ya ~ 800 ka kandi kugeza nyuma gato ya 100 ka, hydrology yikiyaga cya Malawi iterwa ahanini nikirere (21).Kubwibyo, nta na kimwe muri ibyo aricyo gisobanuro cyonyine cyo gushiraho abafana ba alluvial muri Late Pleistocene (22).
(A) Aho sitasiyo nyafurika iherereye ugereranije nimvura igezweho (inyenyeri);ubururu butose kandi umutuku wumye (73);agasanduku k'ibumoso kerekana ikiyaga cya Malawi hamwe n’ibice bikikije MAL05-2A na MAL05-1B Ahantu hambere / 1C (akadomo k'umuyugubwe), aho agace ka Karonga kagaragazwa nk'icyatsi kibisi, kandi aho uburiri bwa Luchamange bugaragara nk'agasanduku k'umweru..CHA, Chaminade;MGD, umudugudu wa Mwanganda;NGA, Ngara;SS, Sadara y'Amajyepfo;VIN, ishusho y'ibitabo by'ibitabo;WW, Beluga.
Imyaka ya OSL hagati (umurongo utukura) hamwe nikosa rya 1-σ (25% imvi), imyaka yose ya OSL ijyanye no kugaragara mubintu byabereye i Karonga.Imyaka ugereranije namakuru 125 ya kera yerekana (A) igereranya ryubunini bwikigereranyo cyimyaka yose ya OSL uhereye kumyanda ya alluvial, byerekana abafana / alluvial kwirundanya kwabafana (cyan), hamwe no kwiyubaka kurwego rwamazi yikiyaga hashingiwe kubisesengura ryibanze (PCA) biranga indangagaciro Amazi ibisigazwa by'amabuye y'agaciro na authigenic minerval (21) (ubururu) kuva muri MAL05-1B / 1C....Amakuru yimitsi yose aturuka muri MAL05-1B / 1C.Imibare iri hejuru yerekana urugero rwa OSL rwihariye rurambuye muri Imbonerahamwe S1 kugeza kuri S3.Itandukaniro muburyo bwo kuboneka no gukemura biterwa nuburyo butandukanye bwo gutoranya no kuboneka kubintu muri rusange.Igicapo S9 cerekana macro ebyiri za karubone zahinduwe kuri z-amanota.
.Ishirwaho ryabafana ba Late Pleistocene alluvial mu kibaya cyikiyaga cya Malawi ntabwo rigarukira mu gace ka Karonga.Ibirometero bigera kuri 320 mu majyepfo yuburasirazuba bwa Mozambike, isi ya cosmogenic nuclide yuburebure bwa 26Al na 10Be igabanya imiterere yigitanda cya Luchamange cyubutaka butukura bwa alluvial kugeza kuri 119 kugeza 27 ka (23).Uku kubuza imyaka myinshi guhuza na OSL yakurikiranye nigihe cyiburengerazuba bwikibaya cyikiyaga cya Malawi kandi byerekana kwaguka kwabafana ba alluvial bo mukarere muri Late Pleistocene.Ibi bishyigikirwa namakuru yaturutse mu kiyaga cy’ibiyaga bigari, byerekana ko igipimo cyo hejuru cy’ibimera kijyana na ka 240, gifite agaciro gakomeye kuri ca.130 na 85 ka (inyandiko yinyongera) (21).
Ibimenyetso byambere byerekana gutura kwabantu muri kariya gace bifitanye isano nubutaka bwa Chitimwe bwagaragaye kuri ~ 92 ± 7 ka.Ibisubizo bishingiye kuri 605 M3 ya D3 yacukuwe kuva kuri 14 Umwanya wa Cent-Cent-santimeologiya na 147 ya m3 ya kera Twongeyeho, twakoze ubushakashatsi kuri kilometero 147.5, dutegura ibyobo 40 byo gupima geologiya, tunasesengura ibisigisigi by’umuco birenga 38.000 muri 60 muri byo (Imbonerahamwe S5 na S6) (18).Iperereza ryimbitse n’ubucukuzi byerekana ko nubwo abantu ba kera harimo n’abantu ba mbere bo muri iki gihe bashobora kuba barabaye muri ako gace nko mu myaka 92 ishize, ikusanyirizo ry’imyanda ijyanye no kuzamuka hanyuma gutuza ikiyaga cya Malawi nticyabitse ibimenyetso by’ubucukuzi kugeza igihe bibaye ku buriri bwa Chitimwe.
Ibyataburuwe mu matongo bishyigikira umwanzuro w'uko mu mpera za Quaternary, kwaguka kw'abafana n'ibikorwa by'abantu mu majyaruguru ya Malawi byabayeho ku bwinshi, kandi ibisigisigi by’umuco byari iby'ibindi bice by'Afurika bifitanye isano n'abantu bo muri iki gihe.Ibicuruzwa byinshi bikozwe mu mabuye y’inzuzi ya quartzite cyangwa quartz, hamwe na radiyo, Levallois, urubuga no kugabanya intoki zidasanzwe (Ishusho S4).Ibikoresho byo gusuzuma indwara ya Morphologique biterwa ahanini na Mesolithic Age (MSA) -ubuhanga bwihariye bwa Levallois, bumaze nibura ka 315 muri Afrika kugeza ubu (24).Igitanda cyo hejuru cya Chitimwe cyakomeje kugeza Holocene yo hambere, gikubiyemo gake cyane ibyabaye bitinze, kandi wasangaga bifitanye isano na nyakwigendera Pleistocene na Holocene bahiga muri Afurika.Ibinyuranye, imigenzo yibikoresho byamabuye (nkibikoresho binini byo gutema) mubisanzwe bifitanye isano na Pleistocene yo hambere ntibisanzwe.Aho ibyo byabereye, wasangaga muri MSA irimo imyanda irimo nyakwigendera Pleistocene, ntabwo byari mu ntangiriro yo kubitsa (Imbonerahamwe S4) (18).Nubwo urubuga rwabayeho kuri ~ 92 ka, igihe cyagaragaye cyane mubikorwa byabantu no guta abafana ba alluvial byabaye nyuma ya ~ 70 ka, bisobanuwe neza nurutonde rwimyaka ya OSL (Ishusho 2).Twemeje ubu buryo hamwe na 25 byasohotse na 50 mbere ya OSL itarasohoka (Ishusho 2 na Imbonerahamwe S1 kugeza S3).Ibi byerekana ko mubisobanuro 75 byimyaka 75, 70 byakuwe mubutaka nyuma ya 70 ka.Igishushanyo cya 2 cyerekana imyaka 40 ijyanye n’ibikoresho bya MSA biri, ugereranije n’ibipimo nyamukuru by’ibidukikije byashyizwe ahagaragara kuva hagati mu kibaya cyo hagati cya MAL05-1B / 1C (25) hamwe n’ikibaya cy’amajyaruguru cya MAL05-2A kitarashyirwa ahagaragara.Amakara (yegeranye numufana utanga imyaka ya OSL).
Twifashishije amakuru mashya yavuye mu bucukuzi bw'ibyataburuwe mu matongo ya phytoliths na micromorphologie y'ubutaka, hamwe n'amakuru rusange yerekeranye n'amababi y’ibimera, amakara manini, ibisigazwa byo mu mazi ndetse n'amabuye y'agaciro ya authigenic duhereye ku mushinga wo gucukura ikiyaga cya Malawi, twongeye kubaka umubano wa MSA n'ikiyaga cya Malawi.Koresha ikirere n'ibidukikije mugihe kimwe (21).Ibikoresho bibiri byanyuma nibyo shingiro ryingenzi ryo kongera kubaka ubujyakuzimu bwikiyaga ugereranije na ka zirenga 1200 (21), kandi bigahuzwa nintangangore za polen na macrocarubone byakusanyirijwe ahantu hamwe murwego rwa ~ 636 ka (25) kera .Ibirometero birebire (MAL05-1B na MAL05-1C; 381 na 90 m) byakusanyirijwe nko mu birometero 100 mu majyepfo yuburasirazuba bwiburasirazuba bwumushinga wubucukuzi.Intangiriro ngufi (MAL05-2A; m 41) yakusanyirijwe nko mu birometero 25 mu burasirazuba bw'umugezi wa Rukulu y'Amajyaruguru (Ishusho 1).Intangiriro ya MAL05-2A iragaragaza imiterere y’ibidukikije ku isi mu gace ka Kalunga, mu gihe intangiriro ya MAL05-1B / 1C itakira imigezi iturutse i Kalunga, bityo irashobora kwerekana neza imiterere y’akarere.
Igipimo cyo kubitsa cyanditswe muri MAL05-1B / 1C compte ya drill core yatangiriye kuri 240 ka kandi yiyongera kuva ku kigereranyo kirekire cyigihe kingana na 0.24 igera kuri 0,88 m / ka (Ishusho S5).Ubwiyongere bwambere bujyanye nimpinduka zumucyo wizuba rya orbital, bizatera impinduka nini-amplitude murwego rwikiyaga muriki gihe (25).Nyamara, iyo orbital eccentricity igabanutse nyuma ya 85 ka kandi ikirere kikaba gihamye, umubare wubwiyongere uracyari hejuru (0,68 m / ka).Ibi byahuriranye na OSL yo ku isi, yerekanaga ibimenyetso byinshi byerekana ko abafana ba alluvial yagutse nyuma ya ka ka 92, kandi byari bihuye namakuru yanduye yerekana isano iri hagati yisuri n'umuriro nyuma ya 85 ka (Inyandiko yinyongera na Imbonerahamwe S7).Urebye ikosa ryikurikiranabikorwa rya geochronologie iboneka, ntibishoboka kumenya niba iyi mibanire yimibanire igenda ihinduka gahoro gahoro kuva aho inzira igarukira cyangwa igaturika vuba mugihe igeze ahakomeye.Ukurikije imiterere ya geofiziki yubwihindurize bwibase, kuva Pleistocène yo hagati (20), kwaguka kwagabanutse hamwe no kugabanuka bifitanye isano byagabanutse, ntabwo rero arimpamvu nyamukuru yatumye gahunda yo gushinga abafana twiyemeje cyane cyane nyuma ya 92 ka.
Kuva Pleistocene yo hagati, ikirere nicyo kintu nyamukuru kigenzura amazi y’ikiyaga (26).By'umwihariko, kuzamura ikibaya cyo mu majyaruguru byafunze gusohoka bihari.800 ka kugirango yimbure ikiyaga kugeza igeze ku burebure bwurwego rwo gusohoka bigezweho (21).Iri soko riherereye mu majyepfo y’ikiyaga, iryo soko ryatanze urugero ntarengwa rw’amazi y’ikiyaga mu gihe cy’amazi menshi (harimo n’uyu munsi), ariko yemerera ikibaya gufunga kuko amazi y’ikiyaga yagabanutse mu gihe cyumye (27).Kwiyubaka kurwego rwikiyaga byerekana guhinduranya byumye kandi bitose mugihe cyashize 636 ka.Dukurikije ibimenyetso byatanzwe n’imyanda y’ibimera, ibihe by’amapfa bikabije (> 95% byagabanutse ku mazi yose) bifitanye isano n’izuba ryinshi ry’izuba byatumye kwaguka kw’ibimera byo mu butayu, ibiti bikaba bigarukira ku nzira y’amazi ahoraho (27).Izi ntera (ikiyaga) zifitanye isano nudusimba twinshi, byerekana igice kinini cyibyatsi (80% cyangwa birenga) na xerofitike (Amaranthaceae) byishyuye tagisi yibiti hamwe nubutunzi bwibinyabuzima muri rusange (25).Ibinyuranye na byo, iyo ikiyaga cyegereye urwego rugezweho, ibimera bifitanye isano rya bugufi n’amashyamba yo muri Afurika yo mu misozi ubusanzwe bigera ku kiyaga cya metero zigera kuri 500 hejuru y’inyanja (masl)].Muri iki gihe, amashyamba yo muri Afurika yo mu misozi agaragara gusa mu tuntu duto duto hejuru ya masl 1500 (25, 28).
Igihe cy’amapfa gikabije cyabaye kuva 104 kugeza 86 ka.Nyuma yibyo, nubwo urwego rwikiyaga rwasubiye mubihe byiza, ishyamba rya miombo rifunguye hamwe n’ibiti byinshi n’ibimera byabaye rusange (27, 28).Amatagisi akomeye yo muri Afurika yo mu misozi ni pine ya Podocarpus, itigeze isubira mu gaciro kangana n’ikiyaga cyahoze hejuru nyuma ya 85 ka (10.7 ± 7,6% nyuma ya 85 ka, mu gihe urwego rw’ikiyaga rusa mbere ya 85 ka ari 29.8 ± 11.8% ).Indangantego ya Margalef (Dmg) irerekana kandi ko ubukire bwubwoko bwa ka ka 85 ishize buri munsi ya 43% ugereranije n’ikiyaga kinini cyahozeho (2.3 ± 0,20 na 4,6 ± 1.21), urugero, hagati ya 420 na 345 ka (Inyongera inyandiko n'imibare S5 na S6) (25).Ingero zanduye kuva mugihe hafi.88 kugeza kuri 78 ka nayo irimo ijanisha ryinshi ryimyanda ya Compositae, ishobora kwerekana ko ibimera byahungabanye kandi biri mumakosa yibihe byashize igihe abantu bigaruriye ako karere.
Twifashishije uburyo budasanzwe bw’ikirere (29) kugira ngo dusesengure amakuru ya paleoecologique na paleoclimate ya cores zacukuwe mbere na nyuma ya 85 ka, tunasuzuma isano iri hagati y’ibidukikije hagati y’ibimera, ubwinshi bw’ibinyabuzima, n’imvura ndetse na hypothesis yo gukuraho ihanurwa ry’imihindagurikire y’ikirere.Gutwara uburyo bwibanze bwa ~ 550 ka.Iyi ecosystem yahinduwe yibasiwe n’imvura n’imvura yuzuyemo ibiyaga n’umuriro, ibyo bikaba bigaragarira mu kubura amoko n’ibimera bishya.Nyuma yigihe cyizuba giheruka, gusa ibintu bimwe na bimwe byamashyamba byagaruwe, harimo ibice birwanya umuriro byamashyamba yo mumisozi yo muri Afrika, nkamavuta ya elayo, hamwe nibice bitarwanya umuriro byamashyamba yibihe bishyuha, nka Celtis (Inyandiko yinyongera nishusho S5) ( 25).Kugirango dusuzume iyi hypothesis, twerekanye urugero rw'amazi yo mu kiyaga akomoka kuri ostracode hamwe na minisiteri ya minisiteri ya authigenic nk'ibihinduka byigenga (21) hamwe n'ibihinduka biterwa n'amakara n'amababi bishobora guterwa no kwiyongera k'umuriro (25).
Kugirango tumenye isano cyangwa itandukaniro riri hagati yibi bihe bitandukanye, twakoresheje amabyi ava muri Podocarpus (igiti cyatsi kibisi), ibyatsi (ibyatsi), na elayo (ibice bitarwanya umuriro byamashyamba yo mumisozi yo muri Afrika) kugirango dukore isesengura nyamukuru (PCoA), na miombo (igice kinini cyibiti byamashyamba uyumunsi).Mugutegura PCoA hejuru yubuso bugereranya urwego rwikiyaga mugihe buri guhuza kwakozwe, twasuzumye uburyo guhuza amabyi bihinduka kubijyanye nimvura nuburyo iyi mibanire ihinduka nyuma ya 85 ka (Ishusho 3 nishusho S7).Mbere ya 85 ka, ingero zishingiye ku kibonezamvugo zegeranijwe zerekeza ku gihe cyumye, mu gihe ingero zishingiye kuri podocarpus zegeranijwe zerekeza ku bihe bitose.Ibinyuranyo, ibyitegererezo nyuma ya 85 ka byegeranye hamwe na sample nyinshi mbere ya 85 ka kandi bifite agaciro kagereranijwe, byerekana ko imiterere yabyo idasanzwe mubihe byimvura.Umwanya wabo muri PCoA ugaragaza imbaraga za Olea na miombo, byombi bikundwa mubihe bikunze kwibasirwa numuriro.Mu byitegererezo nyuma ya 85 ka, pinusi ya Podocarpus yari nyinshi gusa mu byitegererezo bitatu bikurikiranye, byabaye nyuma y’intera iri hagati ya 78 na 79 ka.Ibi birerekana ko nyuma yubwiyongere bwambere bwimvura, ishyamba risa nkaho ryakize mbere gato yuko risenyuka.
Buri ngingo igereranya icyitegererezo kimwe cyimyanya mugihe runaka, ukoresheje inyandiko yinyongera hamwe nimyaka yimyaka mumashusho 1. S8.Inzitizi yerekana icyerekezo nicyiciro cyimpinduka, naho icyerekezo kirekire kigaragaza icyerekezo gikomeye.Ubuso bwibanze bugereranya urwego rwamazi yikiyaga nkuhagarariye imvura;ubururu bwijimye buri hejuru.Impuzandengo yimiterere yibiranga PCoA itangwa kumibare nyuma ya 85 ka (diyama itukura) hamwe namakuru yose kuva kurwego rwikiyaga kimwe mbere ya 85 ka (diyama yumuhondo).Ukoresheje imibare ya 636 ka yose, "urwego rwikiyaga rwigana" ruri hagati ya -0.130-σ na -0.198-σ hafi ya eigenvalue igereranijwe kurwego rwikiyaga PCA.
Kugirango twige isano iri hagati yintanga, urwego rwamazi yikiyaga namakara, twakoresheje isesengura rinyuranye ritandukanye ryibintu bitandukanye (NP-MANOVA) kugirango tugereranye "ibidukikije" muri rusange (bigereranywa na matrix yamakuru ya pollen, urwego rwamazi yikiyaga namakara) mbere na nyuma ya 85 ka inzibacyuho.Twabonye ko itandukaniro hamwe na covariance biboneka muri aya makuru matrike ari itandukaniro rinini mu mibare mbere na nyuma ya 85 ka (Imbonerahamwe 1).
Ibidukikije bya paleoen ibidukikije byo ku isi biva kuri phytoliths nubutaka ku nkombe yikiyaga cyiburengerazuba bihuye nubusobanuro bushingiye kuri prokisi yikiyaga.Ibi byerekana ko nubwo amazi menshi y’ikiyaga, ubusitani bwahinduwe ahantu nyaburanga higanjemo ubutaka bw’amashyamba bwimeza ndetse n’ibyatsi byo mu ishyamba, nkuyu munsi (25).Ibibanza byose byasesenguwe kuri phytoliths kuruhande rwiburengerazuba bwikibase ni nyuma ya ~ 45 ka kandi byerekana umubare munini wigifuniko cya arboreal cyerekana ibihe bitose.Icyakora, bizera ko ibyatsi byinshi biri muburyo bwishyamba ryimeza ryuzuyemo imigano nubwatsi bwubwoba.Dukurikije imibare ya phytolith, ibiti by'imikindo bidashobora kwihanganira umuriro (Arecaceae) bibaho ku nkombe z'ikiyaga gusa, kandi ntibisanzwe cyangwa ntibiboneka ahantu hacukuwe kera (Imbonerahamwe S8) (30).
Muri rusange, imiterere itose ariko ifunguye mugihe cya nyuma ya Pleistocene irashobora no gutondekwa kuri paleosol yo ku isi (19).Ibumba rya Lagoon n'ibishanga bya karubone biva mu bucukuzi bw'ibyataburuwe mu Mudugudu wa Mwanganda birashobora kuboneka kuva kuri 40 kugeza kuri 28 ya ka ka BP (mbere yahinduwe na Qian'anni) (Imbonerahamwe S4).Ubutaka bwa karubone muburiri bwa Chitimwe mubisanzwe ni nodular calcareous (Bkm) hamwe na argillaceous na karubone (Btk), byerekana aho ihagaze rya geomorphologique ihagaze hamwe no gutinda gahoro kuva kumufana wa alluvial agera kuri 29 cal ka BP (Inyongera inyandiko).Ubutaka bwangirika, bukomeye latite (urutare rwa lithic) bwakozwe ku bisigisigi byabafana ba kera byerekana imiterere yimiterere yimiterere (31) nubushyuhe bukabije bwibihe (32), byerekana ingaruka zikomeje kuba kuri ibi bihe.
Inkunga y'uruhare rw'umuriro muri iyi nzibacyuho ituruka ku makara makara abiri yamakara yerekana amakarito, kandi kwinjiza amakara mu kibaya cyo hagati (MAL05-1B / 1C) muri rusange byiyongereye kuva hafi.Amakarita 175.Umubare munini wimpinga ukurikira hagati yikigereranyo.Nyuma ya 135 na 175 ka na 85 na 100 ka, urwego rwikiyaga rwongeye gukira, ariko amashyamba nubukire bwubwoko ntibwongeye gukira (Inyandiko yinyongera, Ishusho 2 nishusho S5).Isano iri hagati y’amakara n’ikwirakwizwa rya magnetiki y’imisozi y’ibiyaga irashobora kandi kwerekana imiterere y’amateka maremare y’umuriro (33).Koresha amakuru yo muri Lyons n'abandi.. 0.0001).Mu kibaya cyo mu majyaruguru, intoki ngufi ya MAL05-2A ifite ingingo yimbitse yo gukundana, kandi umuto muto wa Toba ni ~ 74 kugeza 75 ka (35).Nubwo idafite icyerekezo kirekire, yakira ibitekerezo bivuye mubibaya aho amakuru yubucukuzi yaturutse.Amakara y’amakara y’ikibaya cy’amajyaruguru yerekana ko kuva ikimenyetso cya Toba crypto-tephra, kwinjiza amakara y’amakara yiyongereye mu gihe ibimenyetso bya kera byakunze kugaragara (Ishusho 2B).
Ibimenyetso byumuriro wakozwe n'abantu birashobora kwerekana gukoresha nkana ku gipimo nyaburanga, abaturage benshi bigatuma abantu benshi cyangwa benshi batwika aho hantu, guhindura iboneka rya peteroli mu gusarura amashyamba yo munsi, cyangwa guhuza ibikorwa.Abahiga-bigezweho bakoresha umuriro kugirango bahindure byimazeyo ibihembo (2).Ibikorwa byabo byongera ubwinshi bwinyamanswa, kubungabunga imiterere ya mozayike, no kongera ubushyuhe bwumuriro nuburinganire bwikurikiranya (13).Umuriro nawo ni ingenzi kubikorwa bikorerwa nko gushyushya, guteka, kwirwanaho, no gusabana (14).Ndetse itandukaniro rito muburyo bwo kohereza umuriro hanze yumurabyo karemano rishobora guhindura uburyo bwo kuzungura amashyamba, kuboneka kwa peteroli, hamwe nigihe cyo kurasa.Kugabanuka kw'ibiti bitwikiriwe n'ibiti byo munsi birashoboka cyane ko byongera isuri, kandi gutakaza amoko atandukanye muri kariya gace bifitanye isano rya bugufi no gutakaza amashyamba yo mu misozi yo muri Afurika (25).
Mu bucukumbuzi bw'ibyataburuwe mu matongo mbere yuko MSA itangira, kugenzura abantu umuriro byashyizweho neza (15), ariko kugeza ubu, imikoreshereze yacyo nk'igikoresho cyo gucunga ibibanza byanditswe gusa mu bice bike bya Paleolithique.Harimo nko muri Ositaraliya.40 ka (36), Gineya Nshya.45 ka (37) amasezerano y'amahoro.50 ka Niah Ubuvumo (38) mukibaya cya Borneo.Muri Amerika, igihe abantu binjiye bwa mbere muri urusobe rw'ibinyabuzima, cyane cyane mu myaka 20 ishize ka (16), gutwika ibihimbano byafatwaga nk’impamvu nyamukuru mu kuvugurura ibimera n’inyamaswa.Iyi myanzuro igomba kuba ishingiye ku bimenyetso bifatika, ariko ku bijyanye no guhuzagurika ku buryo butaziguye amakuru y’ubucukuzi, geologiya, geomorphologique, na paleoen ibidukikije, impanvu yabiteye yashimangiwe.Nubwo amakuru yibanze yo mu nyanja y’amazi yo ku nkombe za Afurika yabanje gutanga ibimenyetso byerekana impinduka z’umuriro mu bihe byashize nka ka (9), hano turatanga ibimenyetso byerekana uruhare rw’abantu biturutse ku bucukumbuzi bw'ibyataburuwe mu matongo, paleoen ibidukikije, na geomorphologie.
Kumenyekanisha umuriro wakozwe n'abantu mubitabo bya paleoen ibidukikije bisaba ibimenyetso byibikorwa byumuriro n’imihindagurikire y’igihe gito cyangwa ahantu h’ibimera, byerekana ko izo mpinduka zidateganijwe n’ibipimo by’ikirere byonyine, no guhuza igihe / umwanya hagati y’imihindagurikire y’imiterere y’umuriro n’imihindagurikire y’abantu inyandiko (29) Hano, ibimenyetso byambere byerekana ko abantu benshi biganjemo MSA hamwe n’abafana ba alluvial mu kibaya cy’ikiyaga cya Malawi byabaye nko mu ntangiriro y’ivugurura rikomeye ry’ibimera byo mu karere.Ikarita 85.Ubwinshi bw'amakara muri MAL05-1B / 1C bugaragaza icyerekezo cyo mukarere k’amakara y’amakara no kuyashyira, hafi ka ka 150 ugereranije n’ibindi bisobanuro 636 ka (Ishusho S5, S9, na S10).Iyi nzibacyuho yerekana uruhare rukomeye rwumuriro muguhindura ibinyabuzima, bidashobora gusobanurwa nikirere cyonyine.Mugihe cyumuriro usanzwe, inkuba ikunze kubaho mugihe cyizuba (39).Ariko, niba lisansi yumye bihagije, umuriro wakozwe numuntu urashobora gutwikwa umwanya uwariwo wose.Ku gipimo cyaho, abantu barashobora gukomeza guhindura umuriro bakusanya inkwi munsi yishyamba.Ingaruka yanyuma yubwoko bwose bwumuriro wakozwe numuntu ni uko ifite ubushobozi bwo gutera ibiti byinshi byibiti, bikamara umwaka wose, no kumunzani.
Muri Afrika yepfo, nko muri 164 ka (12), umuriro wakoreshwaga mu gutunganya ubushyuhe bwamabuye akora ibikoresho.Nko muri 170 ka (40), umuriro wakoreshwaga nkigikoresho cyo guteka ibirayi bya krahisi, ukoresha umuriro wose mubihe bya kera.Ibikoresho bitera imbere-Ahantu heza (41).Inkongi y'umuriro igabanya igifuniko cya arboreal kandi nigikoresho cyingenzi cyo kubungabunga ibyatsi n’ibiti by’amashyamba, aribyo bisobanura ibintu by’ibinyabuzima byahujwe n’abantu (13).Niba intego yo guhindura ibimera cyangwa imyitwarire yinyambo ari ukongera umuriro wakozwe n'abantu, noneho iyi myitwarire yerekana kwiyongera muburyo bugoye bwo kugenzura no gukoresha umuriro nabantu bo hambere ugereranije nabantu bo hambere, kandi byerekana ko umubano wacu numuriro wabayeho a guhinduranya muburyo bwo kwuzuzanya (7).Isesengura ryacu ritanga ubundi buryo bwo gusobanukirwa nimpinduka zikoreshwa ryumuriro wabantu muri Late Pleistocene, ningaruka zizo mpinduka kumiterere yabo nibidukikije.
Kwaguka kwabafana ba Late Quaternary alluvial mukarere ka Karonga birashobora guterwa nimpinduka zigihe cyokongoka kwizuba mugihe cyimvura irenze imvura igereranije, bigatuma isuri yiyongera kumusozi.Uburyo bwibi bintu bushobora kuba igisubizo cy’amazi cyatewe n’imivurungano yatewe n’umuriro, isuri yongerewe kandi ikomeza y’igice cyo hejuru cy’amazi, no kwaguka kwabafana ba alluvial mubidukikije bya piedmont hafi yikiyaga cya Malawi.Izi ngaruka zishobora kuba zirimo guhindura imiterere yubutaka kugirango igabanye ubwikorezi, kugabanya ubukana bw’ubutaka, no kongera amazi kubera guhuza imiterere y’imvura nyinshi no kugabanya igifuniko cya arboreal (42).Kuboneka kwimyanda yabanje kunozwa mugukuraho ibintu bitwikiriye, kandi mugihe, imbaraga zubutaka zirashobora kugabanuka kubera gushyuha no kugabanya imbaraga zumuzi.Exfolisiyasi yubutaka bwo hejuru yongera imyanda yimyanda, ikaba yakirwa no kwirundanya kwabafana kumanuka hepfo kandi byihutisha ishingwa ryubutaka butukura kumiterere yabafana.
Ibintu byinshi birashobora kugenzura uko imiterere yimiterere ihindagurika ryimiterere yumuriro, inyinshi murizo zikora mugihe gito (42-44).Ikimenyetso duhuza hano kiragaragara mugihe cyimyaka igihumbi.Isesengura hamwe n’imiterere y’ubwihindurize byerekana ko hamwe n’imivurungano y’ibimera iterwa n’umuriro ukabije, igipimo cyo guhakana cyahindutse cyane ku myaka igihumbi (45, 46).Kutagira inyandiko z’ibimera byo mu karere bihura n’imihindagurikire yagaragaye mu makara n’ibimera bibangamira iyubakwa ry’ingaruka z’imyitwarire y’abantu n’imihindagurikire y’ibidukikije ku miterere y’imiryango y’ibimera.Nyamara, ibimera binini bituye ahantu nyaburanga bifunguye bigira uruhare mu kubibungabunga no gukumira ibiterwa by’ibiti (47).Ibimenyetso byimpinduka mubice bitandukanye byibidukikije ntibigomba gutegerejweho icyarimwe, ariko bigomba kubonwa nkurukurikirane rwingaruka zishobora kubaho mugihe kirekire (11).Twifashishije uburyo budasanzwe bw’ikirere (29), tubona ibikorwa byabantu nkimpamvu nyamukuru itera imiterere yimiterere yamajyaruguru ya Malawi mugihe cya Late Pleistocene.Nyamara, izi ngaruka zishobora kuba zishingiye kumbere, bitagaragara umurage wibidukikije byabantu.Impinga yamakara yagaragaye mubidukikije bya paleoen ibidukikije mbere yitariki ya kera yubucukuzi bwa kera irashobora kuba irimo ibintu bya antropogeneque bidatera ihinduka ry’ibidukikije nkuko byanditswe nyuma, kandi ntibirimo kubitsa bihagije kugira ngo werekane neza ko abantu bakora.
Imyanda migufi, nkibiva mu kibaya cy’ikiyaga cya Masoko giherereye muri Tanzaniya, cyangwa imyanda migufi y’imisozi mu kiyaga cya Malawi, byerekana ko ubwinshi bw’ibyatsi biva mu byatsi hamwe na tagisi yo mu ishyamba byahindutse, bikaba biterwa n’imyaka 45 ishize.Imihindagurikire y’ibihe ya ka (48-50).Nyamara, gusa kurebera hamwe igihe kirekire cyerekeranye namatongo yikiyaga cya Malawi> 600 ka, hamwe nubutaka bwa kera bwubatswe kera, birashoboka gusobanukirwa nikirere, ibimera, amakara, nibikorwa byabantu.Nubwo abantu bashobora kugaragara mu gice cy’amajyaruguru y’ikibaya cy’ikiyaga cya Malawi mbere ya 85 ka, hafi 85 ka, cyane cyane nyuma ya 70 ka, byerekana ko ako gace gakurura abantu nyuma y’amapfa akomeye arangiye.Muri iki gihe, uburyo bushya cyangwa bwinshi cyane / gukoresha umuriro n’abantu biragaragara ko byahujwe n’imihindagurikire y’ikirere kugira ngo bongere kubaka umubano w’ibidukikije> 550-ka, hanyuma amaherezo akora ibibanza byabanjirije ubuhinzi mbere y’ubuhinzi (Ishusho 4).Bitandukanye n'ibihe byashize, imiterere yimiterere yimiterere irinda urubuga rwa MSA, nigikorwa cyumubano wogusubiramo hagati yibidukikije (gukwirakwiza umutungo), imyitwarire yabantu (uburyo bwibikorwa), hamwe no gukora abafana (kubitsa / gushyingura ikibanza).
(A) Ibyerekeye.400 ka: Nta muntu ushobora kumenyekana.Ibihe by'ubushyuhe bisa n'uyu munsi, kandi ikiyaga ni kinini.Igifuniko gitandukanye, kitarwanya umuriro arboreal igifuniko..Ibihe byumye cyane bibaho mumazi yumye.Uburiri busanzwe buragaragara kandi imyanda yo hejuru irahari.(C) Hafi ya 85 kugeza 60 ka: Urwego rwamazi yikiyaga rwiyongera hamwe niyongera ryimvura.Kubaho kwabantu birashobora kuvumburwa hakoreshejwe archeologiya nyuma ya 92 ka, na nyuma ya 70 ka, gutwika imisozi miremire no kwaguka kwabafana ba alluvial bizakurikiraho.Sisitemu y'ibimera itandukanye cyane, irwanya umuriro byagaragaye.(D) Hafi ya 40 kugeza 20 ka: Ibicuruzwa byangiza amakara mu kibaya cyamajyaruguru byiyongereye.Ishirwaho ryabafana ba alluvial ryarakomeje, ariko ritangira gucika intege nyuma yiki gihe.Ugereranije nubushize bwa 636 ka, urwego rwikiyaga ruguma hejuru kandi ruhamye.
Anthropocène yerekana kwirundanyiriza imyitwarire yubaka niche yateye imbere mumyaka ibihumbi, kandi igipimo cyayo cyihariye kuri Homo sapiens igezweho (1, 51).Mubihe bigezweho, hamwe nogutangiza ubuhinzi, ibibanza byakozwe n'abantu bikomeza kubaho kandi bigenda byiyongera, ariko ni kwagura imiterere yashizweho mugihe cya Pleistocene, aho gutandukana (52).Amakuru aturuka mu majyaruguru ya Malawi yerekana ko igihe cyinzibacyuho y’ibidukikije gishobora kuramba, bigoye kandi bigasubirwamo.Iki gipimo cyo guhinduka kigaragaza ubumenyi bwibidukikije bwibidukikije bwabantu ba none kandi byerekana ihinduka ryabo mubinyabuzima byiganje kwisi muri iki gihe.
Dukurikije protocole yasobanuwe na Thompson n'abandi, iperereza ku rubuga no gufata amajwi y'ibicuruzwa n'ibiranga amabuye y'agaciro ku gace k'ubushakashatsi.(53).Gushyira umwobo wikizamini no gucukura ikibanza kinini, harimo micromorphologie na phytolith sampling, byakurikiranye protocole yasobanuwe na Thompson nabandi.(18) na Wright n'abandi.(19).Ikarita yacu ya sisitemu yamakuru (GIS) ishingiye ku ikarita y’ubushakashatsi bwa geologiya ya Malawi yo muri ako karere yerekana isano iri hagati y’ibitanda bya Chitimwe n’ahantu ha kera (Ishusho S1).Intera iri hagati y’ibizamini bya geologiya na archaeologiya mu gace ka Karonga ni ugufata icyitegererezo cyagutse cyane (Ishusho S2).Ubumenyi bwa Karonga, imyaka ya geologiya nubushakashatsi bwubucukuzi bwubushakashatsi bukubiyemo uburyo bune bwibanze bwubushakashatsi bwakozwe: ubushakashatsi bwabanyamaguru, ibyobo byapimwe kera, ibyobo byapimwe na geologiya hamwe nubucukuzi burambuye.Hamwe na hamwe, ubwo buhanga butuma icyitegererezo cyerekana uburiri bwa Chitimwe mu majyaruguru, hagati, no mu majyepfo ya Karonga (Ishusho S3).
Iperereza ryakorewe hamwe no gufata ibihangano hamwe na cobblestone biranga agace k’ubushakashatsi bw’abanyamaguru byakurikiranye protocole yasobanuwe na Thompson n'abandi.(53).Ubu buryo bufite intego ebyiri zingenzi.Iya mbere ni ukumenya aho ibisigisigi by’umuco byangiritse, hanyuma ugashyira ibyobo by’ibizamini byubucukuzi hejuru y’ahantu hagasubizwa ibisigisigi by’umuco biri ahantu hashyinguwe.Intego ya kabiri ni ukwandika kumugaragaro ikwirakwizwa ryibintu, ibiranga, nubusabane bwabo nisoko ryibikoresho byegeranye (53).Muri uyu murimo, itsinda ryabantu batatu ryagenze intera ya metero 2 kugeza kuri 3 kuri kilometero 147.5 zumurongo, zinyura hafi yigitanda cya Chitimwe cyashushanijwe (Imbonerahamwe S6).
Igikorwa cyabanje kwibanda ku buriri bwa Chitimwe kugirango hongerwemo ibihangano byagaragaye, naho icya kabiri byibanze ku bice birebire bigizwe n'umurongo muremure kuva ku nkombe z'ikiyaga kugera mu misozi miremire uca ibice bitandukanye.Ibi birashimangira ikintu cyingenzi cyerekana ko ibihangano biri hagati yimisozi yuburengerazuba n’ibiyaga bigari bifitanye isano gusa nigitanda cya Chitimwe cyangwa se vuba aha bya Late Pleistocene na Holocene.Ibicuruzwa biboneka mu bindi bibitswe biri hanze y’ahantu, bimurirwa ahandi hantu nyaburanga, nkuko bigaragara ku bwinshi, ingano, n’ubunini bw’ikirere.
Ikizamini cy’ubucukuzi bw'ibyataburuwe mu matongo no gucukura ahantu nyaburanga, harimo micromorphologie na phytolith sampling, byakurikiranye protocole yasobanuwe na Thompson n'abandi.(18, 54) na Wright n'abandi.(19, 55).Intego nyamukuru nugusobanukirwa ikwirakwizwa ryubutaka ryibicuruzwa nubutaka bumeze nkabafana ahantu nyaburanga.Ubusanzwe ibihangano bishyingurwa byimbitse ahantu hose mu buriri bwa Chitimwe, usibye ku nkombe, aho isuri yatangiye gukuraho hejuru yubutaka.Mu iperereza ridasanzwe, abantu babiri banyuze ku buriri bwa Chitimwe, bwerekanwe nk'ikarita ku ikarita ya geologiya ya leta ya Malawi.Igihe abo bantu bahuraga n'ibitugu by'igitanda cya Chitimwe, batangiye kugenda ku nkombe, aho bashoboraga kureba ibihangano byaturutse mu mwobo.Mu kugoreka ubucukuzi hejuru gato (3 kugeza kuri 8 m) uhereye ku bihangano byangirika cyane, ubucukuzi burashobora kwerekana aho buhagaze ugereranije nubutaka burimo, bitabaye ngombwa ko bucukurwa nyuma.Ibyobo byo kwipimisha bishyirwa ku buryo biri hagati ya metero 200 na 300 uvuye mu rwobo rukurikiraho, bityo bigafata impinduka mu buriri bwa Chitimwe n'ibikoresho birimo.Rimwe na rimwe, urwobo rwipimishije rwerekanye urubuga nyuma ruhinduka ikibanza cyuzuye cyo gucukura.
Ibyobo byose byipimisha bitangirana na kare ya 1 × 2 m, bikareba mu majyaruguru-amajyepfo, kandi bigacukurwa mubice bidafite cm 20, keretse ibara, imiterere, cyangwa ibirimo imyanda ihinduka cyane.Andika imitekerereze nubutaka bwimiterere yubutaka bwose bwacukuwe, butambuka neza binyuze mumashanyarazi ya mm 5.Niba ubujyakuzimu bukomeje kurenga 0.8 kugeza kuri m 1, hagarika gucukura muri imwe muri metero kare ebyiri hanyuma ukomeze gucukura muyindi, bityo ukore "intambwe" kugirango ubashe kwinjira mubice byimbitse neza.Noneho komeza ucukure kugeza aho igitanda kigeze, byibuze cm 40 zubutaka bwa archeologique sterile munsi yubukorikori bwibintu, cyangwa ubucukuzi bukaba butagira umutekano (bwimbitse) kuburyo butakomeza.Rimwe na rimwe, ubujyakuzimu bugomba kwagura ikizamini cya metero kare ya gatatu hanyuma ukinjira mu mwobo mu ntambwe ebyiri.
Ibyobo byo gupima geologiya byerekanye mbere ko ibitanda bya Chitimwe bikunze kugaragara ku ikarita ya geologiya kubera ibara ritukura ryihariye.Iyo zirimo imigezi minini nubutaka bwinzuzi, hamwe nubutaka bwa alluvial, ntabwo buri gihe bigaragara umutuku (19).Geologiya Urwobo rwapimwe rwacukuwe nk'urwobo rworoshye rwagenewe gukuraho imvange yo hejuru ivanze kugirango hagaragazwe ibice byo munsi y'ubutaka.Ibi birakenewe kuko uburiri bwa Chitimwe bwajugunywe kumusozi wa parabolike, kandi hari imyanda yaguye kumusozi, ubusanzwe idakora ibice bisanzwe cyangwa gukata.Kubwibyo, ubwo bucukuzi bwaba bwarabaye hejuru yigitanda cya Chitimwe, birashoboka ko hari imikoranire yubutaka hagati yigitanda cya Chitimwe nigitanda cya Pliocene Chiwondo hepfo, cyangwa byabereye aho imyanda y amaterasi yinzuzi yari ikeneye kwandikwa (55).
Ubucukuzi bwuzuye bw'ibyataburuwe mu matongo bukorerwa ahantu hasezeranya umubare munini w'iteraniro ry'ibikoresho biri mu kibanza, ubusanzwe bishingiye ku byobo by'ibizamini cyangwa ahantu hashobora kuboneka umubare munini w’ibisigisigi by’umuco bigenda byangirika.Ibisigisigi nyamukuru byacukuwe byavanywe mu bice by’imyanda yacukuwe ukwayo mu buso bwa metero 1 × 1.Niba ubucucike bwibintu ari byinshi, igice cyo gucukura ni cm 10 cyangwa 5.Ibicuruzwa byose byamabuye, amagufwa y’ibimera na ocher byashushanijwe muri buri bucukuzi bukomeye, kandi nta bunini bugaragara.Ingano ya ecran ni 5mm.Niba ibisigisigi by’umuco byavumbuwe mugihe cyo gucukura, bazahabwa nimero yihariye yo gushushanya nimero yo kuvumbura, kandi nimero zavumbuwe murukurikirane rumwe zizahabwa ibivumbuwe.Ibisigisigi by’umuco birangwa na wino ihoraho, bigashyirwa mu mifuka yanditseho urugero, kandi bigashyirwa hamwe n’ibindi bisigisigi by’umuco bivuye inyuma.Nyuma yo gusesengura, ibisigisigi by’umuco byose bibikwa mu kigo ndangamuco n’ingoro ndangamurage ya Karonga.
Ubucukuzi bwose bukorwa ukurikije ibyiciro bisanzwe.Ibi bigabanijwemo imitoma, kandi ubunini bwamacandwe buterwa nubucucike bwibintu (urugero, niba ubucucike bwibicuruzwa ari buke, uburebure bwamacandwe buzaba buri hejuru).Ibyatanzwe inyuma (kurugero, imiterere yibimera, umubano wimbere, hamwe no kwitegereza kwivanga nubucucike bwibikoresho) byanditswe mububiko bwububiko.Guhuza amakuru yose (kurugero, ibisubizo byashushanijwe mubice, uburebure bwimiterere, impande enye, hamwe nicyitegererezo) bishingiye kumurongo wa Universal Transverse Mercator (UTM) (WGS 1984, Zone 36S).Kurubuga nyamukuru, ingingo zose zanditswemo ukoresheje Nikon Nivo C ya 5 ″ sitasiyo yose, yubatswe kuri gride yaho hafi bishoboka mumajyaruguru ya UTM.Ahantu h'amajyaruguru yuburengerazuba bwa buri kibanza cyacukuwe hamwe na buri kibanza cyacukuwe Ingano yimyanda itangwa mumeza S5.
Igice cya sedimentology hamwe nubumenyi bwubutaka buranga ibice byose byacukuwe byanditswe hakoreshejwe gahunda y’ubuhinzi yo muri Amerika (56).Ibice byimitsi bisobanurwa hashingiwe ku bunini bwingano, inguni, no kuryama.Reba ibintu bidasanzwe hamwe n’imivurungano bijyana nigice cyimitsi.Iterambere ryubutaka rigenwa no kwegeranya sesquioxide cyangwa karubone mu butaka bwo munsi.Ikirere cyo munsi y'ubutaka (urugero, redox, gushiraho ibisigazwa bya manganese bisigaye) nabyo byandikwa kenshi.
Ikusanyirizo ry'icyitegererezo cya OSL rigenwa hashingiwe ku kugereranya ibice bishobora gutanga igereranyo cyizewe cyimyaka yo gushyingura.Ahantu hatangiwe icyitegererezo, hacukuwe imyobo kugirango berekane ubutayu bwa authigenic.Kusanya ingero zose zikoreshwa mugukundana na OSL winjizamo umuyoboro w'icyuma utagaragara (hafi cm 4 z'umurambararo na cm 25 z'uburebure) mumwirondoro wubutaka.
Kurambagiza OSL bipima ubunini bwitsinda rya electron zafashwe muri kristu (nka quartz cyangwa feldspar) kubera guhura nimirasire ya ionizing.Imirasire myinshi ituruka kubora kwa isotopi ya radio ikora mubidukikije, kandi umubare muto wibindi bikoresho byongewe mumiterere yubushyuhe bugaragara muburyo bwimirasire yisi.Electron zafashwe zirekurwa mugihe kristu ihuye numucyo, ibaho mugihe cyo gutwara (ibirori bya zeru) cyangwa muri laboratoire, aho itara ribera kuri sensor ishobora gutahura fotone (urugero, umuyoboro wa Photomultiplier cyangwa kamera yashizwemo igikoresho cyo guhuza) Igice cyo hepfo gisohoka iyo electron isubiye mubutaka.Ibice bya Quartz bifite ubunini buri hagati ya 150 na 250 mm bitandukanijwe no gushungura, kuvura aside no gutandukanya ubucucike, kandi bigakoreshwa nka alikoti nto (
Laboratoire eshatu zigenga zakoze isesengura rya OSL kuri ubu bushakashatsi.Uburyo burambuye kuburyo bwa buri laboratoire bwerekanwe hepfo.Muri rusange, dukoresha uburyo bushya bwo kuvura kugirango dushyireho OSL ijyanye na alikoti nto (ingano icumi) aho gukoresha isesengura rimwe.Ibi ni ukubera ko mugihe cyo kugerageza gukura gushya, igipimo cyo kugarura urugero ruto ruri hasi (<2%), kandi ikimenyetso cya OSL ntabwo cyuzuye kurwego rwibimenyetso bisanzwe.Guhuza laboratoire guhuza imyaka, guhuza ibisubizo imbere no hagati yumwirondoro wapimwe, hamwe no gusobanura geomorphologique yo gusobanura imyaka 14C yibuye rya karubone nibyo shingiro ryiri suzuma.Buri laboratoire yasuzumye cyangwa ishyira mu bikorwa amasezerano amwe, ariko yigenga yemeza ko idakwiriye gukoreshwa muri ubu bushakashatsi.Uburyo burambuye hamwe nisesengura protocole ikurikirwa na buri laboratoire itangwa mubikoresho byinyongera.
Ibuye ryamabuye ryakuwe mubucukuzi bwagenzuwe (BRU-I; CHA-I, CHA-II, na CHA-III; MGD-I, MGD-II, na MGD-III; na SS-I) bishingiye kuri sisitemu ya metero n'ubuziranenge ibiranga.Gupima uburemere nubunini ntarengwa bwa buri gihangano (ukoresheje igipimo cya digitale kugirango upime uburemere ni 0.1 g; ukoresheje Caliper ya digitale ya Mitutoyo gupima ibipimo byose ni 0.01 mm).Ibisigisigi byose by’umuco nabyo bishyirwa mubikorwa ukurikije ibikoresho fatizo (quartz, quartzite, flint, nibindi), ingano yingano (nziza, iringaniye, yuzuye), uburinganire bw ingano, ibara, ubwoko bwa cortex no gukwirakwiza, ikirere / impande zose hamwe nicyiciro cya tekiniki .
Intangiriro yapimwe muburebure bwayo ntarengwa;ubugari ntarengwa;ubugari ni 15%, 50%, na 85% by'uburebure;umubyimba ntarengwa;umubyimba ni 15%, 50%, na 85% by'uburebure.Ibipimo byakozwe kandi kugirango hamenyekane ingano yimiterere yibice byimitsi (radial na Levallois).Byombi bitavunitse kandi byacitse byashyizwe mubikorwa ukurikije uburyo bwo gusubiramo (urubuga rumwe cyangwa urubuga rwinshi, radiyo, Levallois, nibindi), kandi inkovu zoroshye zibarwa kuri mm15 mm na 20% z'uburebure bwibanze.Cores ifite inkovu 5 cyangwa munsi ya mm 15 zashyizwe mubikorwa nka "random".Ubwiyongere bwa cortical yubuso bwibanze bwaranditswe, kandi ugereranije na corticale ya cortical ya buri ruhande yandikwa kumurongo wimitsi yisi.
Urupapuro rupimirwa uburebure bwarwo ntarengwa;ubugari ntarengwa;ubugari ni 15%, 50%, na 85% by'uburebure;umubyimba ntarengwa;umubyimba ni 15%, 50%, na 85% by'uburebure.Sobanura ibice ukurikije ibice bisigaye (byegeranye, hagati, hagati, kure, gucamo iburyo hanyuma ugabanye ibumoso).Kurambura bibarwa mugabanye uburebure ntarengwa n'ubugari ntarengwa.Gupima ubugari bwa platifomu, uburebure, hamwe na platifomu yo hanze yibice by'ibice bitagabanijwe hamwe n'ibice byegeranye, hanyuma ushyire kuri platifomu ukurikije urwego rwo kwitegura.Andika cortical ubwishingizi hamwe nibice kuri bice byose.Impande za kure zashyizwe mu byiciro ukurikije ubwoko bwo kurangiza (amababa, hinge, hamwe n'akabuto ko hejuru).Ku gice cyuzuye, andika umubare nicyerekezo cyinkovu ku gice kibanziriza iki.Mugihe uhuye, andika aho wahinduye no gutera ukurikije protocole yashyizweho na Clarkson (59).Gahunda yo kuvugurura yatangijwe kubenshi mubucukuzi bwo gusuzuma uburyo bwo gusana hamwe nubusugire bwibibanza.
Ibikoresho byamabuye byakuwe mu byobo byipimishije (CS-TP1-21, SS-TP1-16 na NGA-TP1-8) bisobanurwa hakurikijwe gahunda yoroshye kuruta gucukura.Kuri buri gihangano, ibintu bikurikira byanditswe: ibikoresho fatizo, ingano yingirakamaro, ubwuzuzanye bwa cortex, ingano yubunini, ikirere / ibyangiritse, ibice bya tekiniki, no kubika ibice.Ibisobanuro bisobanura kubiranga ibimenyetso byo gusuzuma flake na cores byanditse.
Ibice byuzuye byubutaka byaciwe mubice byagaragaye mubucukuzi no mu myobo ya geologiya.Aya mabuye yashyizwe ahantu hamwe na bombo ya pompe cyangwa impapuro zo mu musarani hamwe na kaseti zapakiye, hanyuma zijyanwa muri Laboratwari ya Jewoloji ya Jewoloji ya kaminuza ya Tubingen mu Budage.Hano, icyitegererezo cyumye kuri 40 ° C byibuze amasaha 24.Noneho bakira munsi yu cyuho, bakoresheje imvange ya polyester idasukuye hamwe na styrene ku kigereranyo cya 7: 3.Methyl Ethyl ketone peroxide ikoreshwa nka catalizator, imvange ya resin-styrene (3 kugeza 5 ml / l).Imvange ya resin imaze gushira, shyushya icyitegererezo kuri 40 ° C byibuze amasaha 24 kugirango ukomere rwose.Koresha ikariso kugirango ukate icyitegererezo cyakomye mo ibice 6 × 9 cm, ubishyire kumurongo wikirahure hanyuma ubisya kugeza mubwimbye bwa 30 mm.Ibice byavuyemo byasuzumwe hifashishijwe icyuma kibisikana, hanyuma bisesengurwa hifashishijwe urumuri rw'indege rufite urumuri, urumuri rwambukiranya imipaka, urumuri rwabaye ruto, hamwe na fluorescence y'ubururu n'amaso yubusa kandi akuza (× 50 kugeza 200).Ijambo no gusobanura ibice bito bikurikiza amabwiriza yatangajwe na Stoops (60) na Courty et al.(61).Ubutaka bugizwe na karubone nodules yakusanyirijwe mu burebure bwa cm 80 yaciwemo kabiri kugira ngo kimwe cya kabiri gishobore guterwa kandi ikorwe mu bice bito (4.5 × 2,6 cm) ukoresheje microscope isanzwe ya stereo na microscope ya petrografi na cathodoluminescence (CL) Ubushakashatsi bwa microscope .Kugenzura ubwoko bwa karubone biritonda cyane, kubera ko imiterere ya karubone ikora ubutaka ifitanye isano nubutaka butajegajega, mugihe imiterere ya karubone yo mumazi yubutaka itigenga kubutaka cyangwa kubutaka.
Ingero zacukuwe hejuru yubutaka bwa karubone yubutaka ikora karubone hanyuma igabanywa kabiri kugirango isesengura ritandukanye.FS yakoresheje stereo na petrographic microscopes ya Groupe Working Geoarchaeology hamwe na microscope ya CL yo mu itsinda rya Experimental Mineralogy Work Group yiga ibice bito, byombi biherereye i Tübingen, mu Budage.Imirasire ya radiocarubone yacukuwe hifashishijwe imyitozo isobanutse kuva ahantu hagenewe imyaka igera ku 100.Igice cya kabiri cya nodules ni mm 3 z'umurambararo kugirango wirinde ahantu hasubiwemo gutinda, imyunyu ngugu ikungahaye, cyangwa impinduka nini mubunini bwa kristu ya calcite.Porotokole imwe ntishobora gukurikizwa kuri MEM-5038, MEM-5035 na MEM-5055 Icyitegererezo.Izi ngero zatoranijwe mu byitegererezo byoroshye kandi ni bito cyane ku buryo bitagabanywa kabiri kugirango bigabanuke.Nyamara, ubushakashatsi buke bwakorewe ku ngero zijyanye na micromorphologique zijyanye n’ibimera byegeranye (harimo na karubone nodules).
Twashyikirije ingero 14C zo gukundana mu kigo gishinzwe ubushakashatsi bwa Isotope (CAIS) muri kaminuza ya Jeworujiya, Atenayi, Amerika.Icyitegererezo cya karubone gifata aside 100% ya fosifori mu cyombo cyimuwe kugirango kibe CO2.Ubushyuhe buke bwo kweza urugero rwa CO2 mubindi bicuruzwa byerekana no guhinduranya catalitike kuri grafite.Ikigereranyo cya grafite 14C / 13C cyapimwe hifashishijwe umuvuduko wa 0.5-MeV yihuta.Gereranya icyitegererezo hamwe nikigereranyo cyapimwe na aside ya oxyde I isanzwe (NBS SRM 4990).Carrara marble (IAEA C1) ikoreshwa nkinyuma, naho travertine (IAEA C2) ikoreshwa nkibisanzwe.Ibisubizo bigaragazwa nkijanisha rya karubone igezweho, kandi itariki yavuzwe itatanzwe itangwa mumyaka ya radiocarubone (BP imyaka) mbere ya 1950, ukoresheje 14C igice cyubuzima bwimyaka 5568.Ikosa ryatanzwe nka 1-σ kandi ryerekana ikosa ryibarurishamibare nubushakashatsi.Hashingiwe ku gaciro ka δ13C gupimwa na isotope ratio mass spectrometrie, C. Wissing ya Laboratoire ya Biogeology i Tubingen, mu Budage, yatangaje itariki yo gucamo isotope, usibye UGAMS-35944r yapimwe kuri CAIS.Icyitegererezo 6887B cyasesenguwe muri kopi.Kugirango ukore ibi, kora sub-sample ya kabiri uhereye kuri nodule (UGAMS-35944r) uvuye ahantu hatoranijwe werekanye hejuru yo gutema.Ihinduramiterere rya INTCAL20 (Imbonerahamwe S4) (62) ryakoreshejwe mu majyepfo y’isi ryakoreshejwe mu gukosora igice cy’ikirere cy’icyitegererezo cyose kuri 14C kugeza 2-σ.