کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5162252 | 1502285 | 2014 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Hopanoid hydrocarbons and perylene in Lake Biwa (Japan) sediments: Environmental control on their abundance and molecular composition
ترجمه فارسی عنوان
هیدروکربن هوپانیدها و پروینن در رسوبات دریاچه بیوا (ژاپن): کنترل زیست محیطی بر فراوانی و ترکیب مولکولی آنها
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
چکیده انگلیسی
Moretene concentration was high above the sections where fall-out events of tephra (tephra AT) occurred ca. 30 kyr before present (BP). This feature suggests that the tephra fall-out events created O2 deficient conditions, resulting in high activity of methane producing bacteria, and of methanotrophic moretene-producing bacteria becoming active above the tephra layer. Five sections at 10-20 kyr, ca. 35 kyr, ca. 70 kyr, ca. 90 kyr and ca.110 kyr BP exhibited peaks in the ratio of 17α, 21β-22R-homohopane to 17β, 21β-22R-homohopane (hopC31αβ/ββ). The n-C23/n-C31 alkane ratio in these sections was 0.6 ± 0.1 (n = 49), very low if compared with typical characteristics of n-alkanes for a Sphagnum peat environment (n-C23/n-C31 ca. 3.6; Bingham et al., 2010). We conclude that Sphagnum peat may not have been an important contributor of n-alkanes over the past 120 kyr. Comparison with previous pollen records for the lake region suggests that high hopC31αβ/ββ values may be caused by production of acidic soil from expansion of temperate conifer (e.g. Cryptomeria) forest under cold and wet climate conditions. The abundance of perylene relative to sediment or total organic carbon (TOC) was high in the sections at ca. 20 kyr, ca. 70 kyr and ca. 90 kyr BP. These sections were approximately in accord with those having a maximum in hopC31αβ/ββ. This concordance indicates that the climatic conditions suitable for the production of perylene quinone in soil surrounding the lake coincided with those for a high hopC31αβ/ββ ratio. Thus, hopC31αβ/ββ and perylene/TOC might be useful as proxies of soil acidity, temperature and humidity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Organic Geochemistry - Volume 76, November 2014, Pages 194-203
Journal: Organic Geochemistry - Volume 76, November 2014, Pages 194-203
نویسندگان
Ryoshi Ishiwatari, Hitoshi Uemura, Shuichi Yamamoto,