Saturday, 4 June 2011
Site area sangiran keep a lot of mysterious that must be uncoverred, turned dry condition and hot keep a life story very amaze. And singkapan from various time that go on up to in this time admit of us meet at several places at area sangiran. Singkapan from 2 million year ago can we enjoy the beauty pass the geology chronology explanation. One of [the] speciality from site sangiran that is existence singkapan stratigrafi that can give description clearly in we to detect old world culture life at ledges sangiran. In face the dumbness sangiran can to give a life story very amaze ever tejadi begin 2 million last year.
Based on watchfulness result bentuknya dome sangiran be geological event that is is preced in 2,4 million year ago happen pengangkatan,gera plate bumi,letusan volcano and time existence glacial so that happen sea water waning final make area sangiran upraised keatas, this matter is proved with sedimet that can we meet alongside river puren singkap blue plate layer from formation kalibeng that is ocean environment region sedimet and until now this is a lot of met sea mollusc fossils.
Formation kalibeng be layer stratigrafi at site sangiran oldest, this geology is sedimet from ocean that present by the end of time pliosen (approximately 2 million year then). This layer is at domination by grey clay kebiruan (napal) and silt clay, with silt sand unit and limestone balanus. Grey clay unit kebiruan that's that be sea sedimet individuality (marine) and many found fossil foraminifera (kind operculina) and sea mollusc (turritela, nassarius, statue, choine, anomia, turricula, ostrea, pleurotama, murex and natica).
Silt sand existence and limestone balanus indicate sedimet from shallow sea and this formation is singkap at area puren and pablengan, and in this time is there is no also vertebrata because environment stills shaped ocean.
Moment sea begins lessened that caused by regional appointment process from volcano activity, and also from process glasial happen silting up. Landing formed (volcano and hilly) be vast by volcano product decay existence, hilly erosion with leavings coast organism. Vegetasi that jut in this time is mangrove forest development existence, vulcanic activity quantity consequence so mangrove forest begins to disappear and landing more vaster (a. M. Semah, 1984).
Then in time 1,8 million year ago happen vulcanic activity enhanced mingkin is dominated by mount activity lawu and mount merapi ancient and lava materials from second mount endapkan fill lagoons exist in area sangiran so that mengendap form layers exist in part under formation pucangan.
Formation pucangan that is formation singkap among others at area cengklik, bapang, and jagan. This layer is dominated by unit breksi laharik that contain sandstone lens silang-siur and river channel sedimet type vulcanic conglomerate. This unit is precipated by system thick current that is known with rain lava term or cold lava. This layer consists of layer napal and black clay that is fresh water lake sedimet and single zone. In this layer is found inserted rust colored clay that contains horizon mollusc marine (anadara, conus, and murex). Horizon this show existence transgresi sea in a word. In formation pucangan under many found animal fossils vertebrata (hind bony) that is among others: elephant (stegodon trigonocephalus), axis lydekkeri, panthera tigris, and hippopotamus (hexaprotodon simplex) and tetralophodon bumiajuensis (widianto, 1995).
In this time is region sangiran before now is where found special sedimet that called mengatomit, contain cangklang mengatomea ocean (alga microscopic silica). Vegetasi existing initially shaped swamp forest then caused by climate change so change in character be opened forest where trees adapt with hard dry season (a. M. Semah, 1984). Reptile animal likes crocodile and turtle quite a few that appear in this time and also pig (suidae) and monkey with first time found male homosexual human fossil existence erectus and meganthropus palaeo-javanicus in layer pucangan part on.
Time glasial that is ice coagulation time at borth pole that cause the happening of sea water waning and landing even also upraised to on and turn into shallow sea. In that time also, volcano activity even also happen so that the lava endapkan at area sangiran and shallow sea environment turns into brackish water environment. Follow a. M. Semah, this matter happens approximately 1,5 million year ago so that precipated black clay layer pucangan and bentuklah brackish forest and mangrove forests (semah, a. M. 1984).
In time next happen erosion at ridges region kendeng from direction north and ridges south from southward that bring materials gravel and sand, this sedimet has klastik so that bentuklah konkresi konglomeratan that consists of konglomeratan limestone and sand then known with the title grenzbank. This happen approximately 900 thousands year ago, erosion happen from southward to north and cover brackish waters and form a landing. In this time is waters absolutely losts from area sangiran.
In this layer is found meganthropus palaeojavanicus and crocodilus sp. Grenzbank that come from period 900.000-800.000 year ago, caused by pleating process in ridges kendeng so relief that etrbentuk experience erosion so that many meterial that carried away by river and precipated to form a coarse conglomerate. Sedimet shaped limestone sedimet calcareous and conglomerate sandstone. This layer is that indicates that waters genuinely has goned from area sangiran.
This layer is many we meet singkapan at brangkal, ngebung, dayu, cape, wonolelo, bubak, glagahombo, and blimbingkulon. Watchfulness that done by missi federation between archaeology watchfulness centre jakarta and museum national d'histoire naturelle french in this layer is success finds ancient human remainder fossil shaped thighbone fragment (femur) that is given code kresna 11 and jaw fragment under (mandibula) with code ardjuna 9. In this formation is quite a few is found mammals fossils and bot rarely finding leavings coral.