Post-glacial Environmental Change as Recorded by Silver Lake Sediments, Logan County, Ohio PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Post-glacial Environmental Change as Recorded by Silver Lake Sediments, Logan County, Ohio PDF full book. Access full book title Post-glacial Environmental Change as Recorded by Silver Lake Sediments, Logan County, Ohio by Dawit D. Yifru. Download full books in PDF and EPUB format.
Author: Dawit D. Yifru
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 198
Get Book Here
Book Description
Author: Dawit D. Yifru
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 198
Get Book Here
Book Description
Author: Cathy Lee Weiss
Publisher:
ISBN:
Category : Ecology
Languages : en
Pages : 174
Get Book Here
Book Description
Author: Alice Simms Williams
Publisher:
ISBN:
Category : Paleobotany
Languages : en
Pages : 36
Get Book Here
Book Description
Author: Corinne M. Lally
Publisher:
ISBN:
Category : Lake sediments
Languages : en
Pages : 216
Get Book Here
Book Description
To provide greater spatial coverage of late Pleistocene to Holocene environmental change in the Midwestern United States, a 1350 cm long sediment core was collected from Silver Lake in northeast Ohio. Age control was provided by new radiocarbon dates, correlation to a dated lake record from western Ohio, and a prior study of Silver Lake. Lithologic descriptions and sedimentary profiles of dry bulk density (DBD), organic matter (OM), carbonate, C/N, grain size, magnetic properties, and concentrations of terrigenous derived elements (Al, Ti, and K) allow the core to be divided into six periods. The climate interpretations are compared to published regional and hemispheric climate records. The first period is Deglaciation, which spans from 17,560 -- 13,600 cal year BP (1353 - 1188 centimeters below lake floor (cmblf)). Silty sediment with low OM (average 6 %) and high DBD (average 0.832 g/cm3) are interpreted to reflect cold conditions soon after deglaciation. The Latest Pleistocene Period is the second period and spans from 13,600 -- 12,200 cal yr BP (1188 -- 1103 cmblf). Brown to light brown mud with silty layers, a slight increase in % OM (average 9 %) and decrease in DBD (average 0.694 g/cm3) characterize this interval. The Latest Pleistocene Period may have been a time of increased primary productivity in Silver Lake. The third period is the Younger Dryas, which spans from 12,200 -- 11,500 cal yr BP (1103 -- 1070 cmblf). Gray-brown to light-brown silty mud having low % OM (average 6%), high DBD (average 0.703 g/cm3), high concentrations of magnetic minerals, and elevated concentrations of Al, Ti, and K characterize this period. These sediment characteristics are interpreted as cold and dry conditions, increased terrigenous input, and/or decreased primary productivity. The fourth period is the Early Holocene which spans from 11,500 -- 7,450 cal yr BP (1070 -- 824 cmblf), and is divided into two subperiods. During the first subperiod, from 11,500 -- 10,600 cal yr BP (1070 -- 1016 cmblf), there was an increase in % OM (average 28 %) and decrease in DBD (average 0.311 g/cm3) and concentrations of Al, Ti, and K. The first subperiod of the Early Holocene is interpreted to be a period of brief warming. The second subperiod of the Early Holocene spans from 10,600 -- 7,450 cal yr BP (1016-824 cmblf), and is characterized by highly variable % OM and DBD and increased Al, Ti, and K. This subperiod is interpreted as a period of increased aridity. The fifth period is the Mid to Late Holocene which spans from 7,450 -- 200 cal yr BP (824 -- 128 cmblf). Alternating brown and dark brown mud having no visible silty layers, high % OM (average 51%), low DBD (average 0.116 g/cm3), and decreased Al, Ti, and K and magnetic concentration characterize this period. These sediment characteristics are interpreted to reflect warm and moist conditions when primary productivity increased and/or terrigenous influx decreased. However, within the Mid to Late Holocene Period there are six pronounced intervals of decreased % OM and increased Al, Ti, and K suggestive of millennial-scale increases in terrigenous input and/or decreases in lake productivity. These six intervals may be related in part to rapid global climate changes during the Holocene, when temperatures and moisture balance fluctuated. The sixth period is the Anthropogenic Period, which spans from 200 cal yr BP to the present (128 -- 0 cmblf). The Anthropogenic Period is characterized by a pronounced decrease in % OM (average 19%), increase in DBD (average 0.273 g/cm3), and an increase in the mass accumulation rate (MAR) resulting from Euro-American land clearance enhancing watershed erosion.
Author: Roger Yates Anderson
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 28
Get Book Here
Book Description
Lakes in North America that are meromictic or that contain sediments with annual layers are assessed for their potential for reconstruction of ancient climates.
Author: R. M. Cline
Publisher: Geological Society of America
ISBN: 0813711452
Category : Science
Languages : en
Pages : 636
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 634
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Natural history
Languages : en
Pages : 272
Get Book Here
Book Description
Includes book reviews and abstracts.
Author: Paul A. Delcourt
Publisher: Springer Science & Business Media
ISBN: 1461247403
Category : Science
Languages : en
Pages : 451
Get Book Here
Book Description
The synthesis presented in this volume is a direct outgrowth of our ten-year FORMAP Project (Forest Mapping Across Eastern North America from 20,000 yr B.P. to the Present). Many previous research efforts in paleoecology have used plant-fossil evidence as proxy information for primarily geologic or climatic reconstructions or as a bio stratigraphic basis for correlation of regional events. In contrast, in this book, we deal with ecological questions that require a holistic perspective that integrates the interactions of biota with their dynamically changing environments over time scales up to tens of thousands of years. In the FORMAP Project, our major research objective has been to use late-Quaternary plant-ecological data sets to evaluate long-term patterns and processes in forest de velopment. In order to accomplish this objective, we have prepared subcontinent-scale calibrations that quantitatively relate the production and dispersal of arboreal pollen to dominance in the vegetation for the major tree types of eastern North America. Quantification of pollen-vegetation relationships provides a basis for developing quan titative plant-ecological data sets that allow further ecological analysis of both individual taxa and forest communities through time. Application of these calibrations to fossil pollen records for interpreting forest history thus represents a fundamental step beyond traditional summaries based upon pollen percentages.
Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 486
Get Book Here
Book Description
