Adams (dengiz osti vulqoni)
Adams dengizosti togʻi (shuningdek, Qirq millik rif nomi bilan ham tanilgan) - Tinch okeanining markaziy qismidagi Pitcairn nuqtasi ustidagi suv osti vulqoni, Pitcairn orolining taxminan 100 kilometr (62 mi) janubi-g'arbiy qismida joylashgan.
Geografiya va geomorfologiya[tahrir | manbasini tahrirlash]
Adams 90 kilometr (56 mi) uzunlikdagi 90 ga yaqin dengiz tog'lari maydonining bir qismidir. Pitcairn orolining janubi-sharqida bu tog'lardan eng kattasi joylashgan[1]. Adams boshqa yirik dengiz tog'ining janubi-sharqida, Bounty Seamountda o'rin egallagan[2]. Ushbu dengiz tog'larining aksariyati (Adams va Bountydan tashqari) 0.5 kilometr (0.31 mi) ) balandlikka ega[2]. Ular 1989-yilda RV Sonne tadqiqot kemasi tomonidan kashf etilgan[3].
Bu konussimon[4] dengiz tog'i bo'lib, dengiz tubidan 3,500 metr (11,483 ft) taxminan okean sathidan 39 metr (128 ft) yoki 59–75 metr (194–246 ft) pastda joylashgan. Dengiz tog'ining umumiy hajmi, jumladan, uning poydevori diametri taxminan 30 kilometr (19 mi), yoki 858 cubic kilometre (206 cu mi)ga teng[3]. Adamsning ikkita cho'qqisi bor[4], shuningdek, Adamsda marjon va marjondan olingan qum namunalari topilgan[2]. Uning balandligi hisobga olinsa, oxirgi muzlik davrida Adams vulqoni orol hududdida dengiz tubidan yuqorida bo'lganligini aniqlash mumkin[5].
Uning yon bag'irlari lava oqimlari, vulqon qoldiqlari va gialoklastit bilan qoplangan[4]. Lava oqimlari aa lava xususiyatlari va lava naychalariga ega, tog'ning chuqurroq qismlari esa lapilla va skoriya bilan qoplangan[4]. Parazit teshiklari uning yon tomonlarida konus va tepaliklar hosil qiladi[3].
Geologiya[tahrir | manbasini tahrirlash]
Adams va boshqa dengiz tog'lari Pitcair issiq nuqtasi natijasida vujudga kelgan va bu dengiz tog'larining hozirgi joylashuvi ayni shu qaynoq nuqta hududiga to'g'ri keladir[1]. Bu nuqta Austral qaynoq nuqtasi, Gavayi Avstraliya aynoq nuqtasi va Society qaynoq nuqtasi bilan bir qatorda Tinch okeanidagi bir nechta faol nuqtalardan biri hisoblanadi[3]. Dengiz tog'lari 30 million yillik qobiq sababli ko'tarilgan[6].
Adams dengiz osti tog'ligidan ishqoriy bazalt, traxit[4] va toleyit manbalari topilgan[1].
Portlash tarixi[tahrir | manbasini tahrirlash]
Namunalarning yangi ko'rinishi va cho'kmaning mavjud emasligi Adams vulqonining yaqin kunlarda ham faol bo'lganligini ko'rsatadi[1]. Adams dengizosti tog'idan qazib olingan jinslarning kaliy-argon bilan tahlil qilinishi, tog'ning golosen davriga tegishliligiga, shu jumladan hozirgi vaqtdan 3000 ± 1000 yil avval paydo bo'lganligini tasdiqlaydi[6]. Bounty-dan farqli o'laroq, Adamsvulqoni faol gidrotermal tizim emasligini ko'rsatadi[2].
Biologiya[tahrir | manbasini tahrirlash]
Adams dengiz tog'ida dunyodagi eng chuqur tropik riflardan biri bo'lgan marjon rifi mavjud. U asosan Pocillopora sp va Porites deformis mercanlar natijasida hosil bo'lgan, shuningdek, Pitcairn orol hukumati tomonidan ko'plab rif baliqlari va akulalarini ovlash joyi sifatida qo'llanigan. Adams dengiz tog'i Pitcairn orollariga qarashli dengiz qo'riqxonasining bir qismidir.
Manbalar[tahrir | manbasini tahrirlash]
- ↑ 1,0 1,1 1,2 1,3 Garapić et al. 2015.
- ↑ 2,0 2,1 2,2 2,3 Thießen et al. 2004.
- ↑ 3,0 3,1 3,2 3,3 Hekinian et al. 2003.
- ↑ 4,0 4,1 4,2 4,3 4,4 Binard, Hékinian & Stoffers 1992.
- ↑ Neall, Vincent E.; Trewick, Steven A. (27 October 2008). "The age and origin of the Pacific islands: a geological overview" (en). Philosophical Transactions of the Royal Society of London B: Biological Sciences 363 (1508): 3293–3308. doi:10.1098/rstb.2008.0119. ISSN 0962-8436. PMID 18768382. PMC 2607379. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2607379.
- ↑ 6,0 6,1 Guillou, Garcia & Turpin 1997.
Adabiyotlar[tahrir | manbasini tahrirlash]
- Binard, Nicolas; Hékinian, Roger; Stoffers, Peter (June 1992). "Morphostructural study and type of volcanism of submarine volcanoes over the Pitcairn hot spot in the South Pacific" (en). Tectonophysics 206 (3–4): 245–264. doi:10.1016/0040-1951(92)90379-K. ISSN 0040-1951.
- Garapić, G.; Jackson, M.G.; Hauri, E.H.; Hart, S.R.; Farley, K.A.; Blusztajn, J.S.; Woodhead, J.D. (July 2015). "A radiogenic isotopic (He-Sr-Nd-Pb-Os) study of lavas from the Pitcairn hotspot: Implications for the origin of EM-1 (enriched mantle 1)" (en). Lithos 228-229: 1–11. doi:10.1016/j.lithos.2015.04.010. ISSN 0024-4937.
- Guillou, Hervé; Garcia, Michael O.; Turpin, Laurent (September 1997). "Unspiked K-Ar dating of young volcanic rocks from Loihi and Pitcairn hot spot seamounts" (en). Journal of Volcanology and Geothermal Research 78 (3–4): 239–249. doi:10.1016/S0377-0273(97)00012-7. ISSN 0377-0273.
- Hekinian, R; Cheminée, J.L; Dubois, J; Stoffers, P; Scott, S; Guivel, C; Garbe-Schönberg, D; Devey, C et al. (March 2003). "The Pitcairn hotspot in the South Pacific: distribution and composition of submarine volcanic sequences" (en). Journal of Volcanology and Geothermal Research 121 (3–4): 219–245. doi:10.1016/S0377-0273(02)00427-4. ISSN 0377-0273. https://archimer.ifremer.fr/doc/2003/publication-784.pdf.
- Thießen, O.; Schmidt, M.; Botz, R.; Schmitt, M.; Stoffers, P.. Methane Venting into the Water Column Above the Pitcairn and the Society — Austral Seamounts, South Pacific (en), 2004 — 407–429 bet. DOI:10.1007/978-3-642-18782-7_14. ISBN 978-3-642-62290-8.