当前位置: X-MOL 学术Geo-Mar. Lett. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Calcareous nannofossils identify the age and precipitation rates of manganese deposits of the Mozambique Ridge and Mozambique Basin, SW Indian Ocean
Geo-Marine Letters ( IF 2.1 ) Pub Date : 2021-07-17 , DOI: 10.1007/s00367-021-00707-6
M. N. Ovechkina 1, 2 , M. K. Watkeys 2 , W. Kretzinger 2 , M. B. Mostovski 3, 4 , S. M. Perritt 5
Affiliation  

Calcareous nannofossil assemblages identified in manganese deposits dredged at three sites on the Mozambique Ridge and one on the Jaguar seamount in the Mozambique Basin comprise 61 species, including nine reworked ones. The samples represent cores of nodules or encrustations ranging from 4.04 to 0.00 Ma. Dating by nannofossils suggests bi-modal ages for the samples, the late Zanclean–Piacenzian (Pliocene) and the Calabrian (Pleistocene)–Holocene. The calculated rates of manganese precipitation range from 4.7 to 248.3 mm/Ma, which are generally typical for hydrothermal manganese accretion. The bi-modal age distribution points to oceanographic changes during the Pliocene–Holocene. The Pliocene manganese precipitation may reflect the closing of the Panama Isthmus, while the terminal Pleistocene–Holocene accretion may result from oceanic fluctuations caused by glacial and interglacial periods. Fe–Mn oxide precipitation rates at the Makarov Guyot, NW Pacific, re-calculated on the basis of the most recent calcareous nannofossil biostratigraphy, suggest hydrothermal processes of manganese accretion in that part of the West Pacific Seamount Province.



中文翻译:

钙质纳米化石确定了莫桑比克海脊和莫桑比克盆地、西南印度洋锰矿床的年龄和降水率

在莫桑比克海脊的三个地点和莫桑比克盆地美洲虎海山的一个地点挖掘的锰矿床中发现的钙质纳米化石组合包括 61 个物种,其中包括 9 个重新加工的物种。样品代表了范围从 4.04 到 0.00 Ma 的结核或结壳的核心。纳米化石的测年表明样品的双峰年龄,晚期赞克林-皮亚琴基(上新世)和卡拉布里亚(更新世)-全新世。计算出的锰沉淀速率范围为 4.7 至 248.3 mm/Ma,这通常是热液锰增生的典型值。双峰年龄分布表明上新世-全新世期间的海洋学变化。上新世锰降水可能反映了巴拿马地峡的闭合,而更新世-全新世末期的增生可能是由冰期和间冰期引起的海洋波动造成的。根据最新的钙质纳米化石生物地层学重新计算的西北太平洋马卡洛夫古约的 Fe-Mn 氧化物沉淀率表明,在西太平洋海山省的那部分地区存在锰增生的热液过程。

更新日期:2021-07-18
down
wechat
bug