| Abstract: | Two episodes of meltwater influx from glacial Lake Agassiz are recorded as prominent sedimentologic, isotopic, magnetic, and faunal signatures in southern Lake Michigan profundal sediments. As a tributary to the main path of eastward Lake Agassiz flow, southern Lake Michigan recorded only the largest, catastrophic discharges. The distinctive Wilmette Bed, a massive gray mud that interrrupts laminated red glaciolacustrine clays, marks the first episode, which occurred near the beginning of the Younger Dryas cooling events. The associated discharge may have played a role in the inception or severity of the Younger Dryas event. An oxygen isotope excursion in biogenic carbonate and changes in ostracode assemblages mark the second episode, which appears to have had at least two pulses, dated by accelerator mass spectrometer 14C ages on biogenic carbonate at about 8.9 and 8.6 ka. The second episode occurred during the early Holocene peak in global meltwater discharge and apparently had little widespread climatic or oceanographic effect. The contrast between the effects associated with these two episodes of meltwater discharge emphasizes the complexity of the ice sheet-ocean-climate system. -Authors |
| Genre: | Article |
| ProdID: | 70017756 |
| Citation Author: | Colman, S. M.; Keigwin, L. D.; Forester, R. M. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 550 |
| Citation Issue: | 6 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Geology |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 4 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Two episodes of meltwater influx from glacial Lake Agassiz into the Lake Michigan basin and their climatic contrasts; 1994; Article; Journal; Geology; Colman, S. M.; Keigwin, L. D.; Forester, R. M. |
| Citation Start Page: | 547 |
| Citation Volume: | 22 |
| Citation Year: | 1994 |
| Type: | citation/reference |
| Text: | Two episodes of meltwater influx from glacial Lake Agassiz into the Lake Michigan basin and their climatic contrasts; 1994; Article; Journal; Geology; Colman, S. M.; Keigwin, L. D.; Forester, R. M. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sat, 1 Jan 1994 00:00 -0600 |
| Publisher: | |
