Holocene Lake-Effect Precipitation in Northern Michigan

2002 ◽  
Vol 57 (2) ◽  
pp. 225-233 ◽  
Author(s):  
Paul A. Delcourt ◽  
Peter L. Nester ◽  
Hazel R. Delcourt ◽  
Claudia I. Mora ◽  
Kenneth H. Orvis
Keyword(s):  
Late Holocene ◽  
Upper Peninsula ◽  
Winter Storms ◽  
Carbon Isotopic ◽  
Lake Effect ◽  
Southward Shift ◽  
Pine Pollen ◽  
Northern White Cedar ◽  
Stable Oxygen ◽  
Northern Michigan

AbstractHolocene sediments from Nelson Lake, on Michigan's eastern Upper Peninsula, provide isotopic, pollen, and charcoal evidence for a two-step sequence of changes in moisture source and increased lake-effect precipitation during the late Holocene. Between 8000 and 5300 cal yr B.P., a warm, dry climate and zonal atmospheric circulation produced enriched stable oxygen and carbon isotopic values in combination with high percentages of pine pollen and sustained influx of charcoal particles. After 5300 cal yr B.P., decreasing isotopic values in marl and increasing pollen percentages of mesic hardwoods and northern white cedar indicate increased meridional air flow and precipitation from cold winter storms generated in Alberta, Canada. After 3000 cal yr B.P., abrupt declines in values of δ13C and δ18O and increased pollen representation of hemlock, American beech, spruce, and aquatic plants indicate paludification from increased lake-effect snowfall. The moisture was derived from the Great Lakes and transported by Alberta cyclonic storms that were steered across Lakes Superior and Michigan by a southward shift in the modal winter position of the polar jet stream.

Relating jack pine budworm damage to stand inventory variables in northern Michigan

1996 ◽  
Vol 26 (12) ◽  
pp. 2180-2190 ◽  
Author(s):  
Deborah G. McCullough ◽  
Lyle J. Buss ◽  
Larry D. Marshall ◽  
Jari Kouki
Keyword(s):  
Tree Mortality ◽  
Basal Area ◽  
Site Index ◽  
The United States ◽  
Jack Pine ◽  
Inventory Data ◽  
Upper Peninsula ◽  
Jack Pine Budworm ◽  
Lake States ◽  
Northern Michigan

Stand-level mortality and top kill from a 1991–1993 jack pine budworm (Choristoneurapinuspinus Freeman) outbreak were surveyed annually in the Raco Plains area of the Hiawatha National Forest in Michigan's Upper Peninsula from 1992 to 1994. Defoliation was visually estimated and percentage of trees killed or top killed was determined in 104 stands. In 1994, tree mortality attributable to the outbreak averaged 8% and 17% of trees had dead tops. Current stand inventory data, including age, site index, basal area, and size, were acquired from the Hiawatha Forest. Stands were grouped on the basis of inventory variables used for jack pine management in the Lake States region of the United States. Differences in tree mortality and top kill between groups, and associations between tree mortality and inventory variables, were evaluated. Tree mortality was greater in overmature stands and in overstocked stands, but stand size had little effect. Contrary to expectations, mortality was lower on poor sites with low site index values than on better sites with higher site index values. Mortality was not related to abundance of open-grown, full-canopied wolf trees or to abundance of trees infected with pine gall rust (Endocronartiumharknessii (J.P. Moore) Y. Hiratsuka (=Peridermiumharknessii J.P. Moore)). Amount of top kill was related to defoliation severity and was higher in overmature and understocked stands. Top kill was not strongly associated with amount of tree mortality or with inventory variables.

Quartz deformation in the Marquette and Republic troughs, Upper Peninsula of Michigan

1984 ◽  
Vol 21 (7) ◽  
pp. 793-801 ◽  
Author(s):  
Janet Kappmeyer ◽  
David V. Wiltschko
Keyword(s):  
Subgrain Size ◽  
Stress Regime ◽  
Upper Peninsula ◽  
Metamorphic History ◽  
Dislocation Densities ◽  
History Of ◽  
Peak Metamorphism ◽  
Quartz Fabrics ◽  
Upper Peninsula Of Michigan ◽  
Northern Michigan

Quartz fabrics and microstructures in quartzites of the Mesnard and Goodrich formations were examined to better define the deformation and metamorphic history of the Marquette Synclinorium, northern Michigan. Fabric development is very weak in the whole-rock samples and indicates that mica contamination, extensive annealing, and (or) low imposed strains prevented the formation of distinct c-axis fabrics. However, well defined fabrics are preserved in five quartzite pebbles from the Goodrich conglomerate. Double maxima of varying intensities among these pebbles suggest that the northwest section of the district experienced inhomogeneous shear strain. Measured grain sizes yielded differential stresses ranging from 44 to 548 bar (4.4 to 54.8 MPa). Subgrain size data indicate stresses ranging from 151 to 248 bar (15.1 to 24.8 MPa). Dislocation densities determined by observed etch-pit densities using scanning electron microscopy indicate a range of stresses from 330 to 730 bar (33 to 73 MPa). Stress values from dislocation density measurements vary inversely with metamorphic intensity. Cumulatively, these microstructural data indicate that a low-stress regime of deformation preceded a cooler, higher stress pulse. The data also imply that deformation of the Marquette Synclinorium continued after peak metamorphism, contrary to early hypotheses.

Formation processes of cemented features in karstic cave sites revealed using stable oxygen and carbon isotopic analyses: A case study at middle paleolithic Amud Cave, Israel

2008 ◽  
Vol 23 (1) ◽  
pp. 43-62 ◽  
Author(s):  
Ruth Shahack-Gross ◽  
Avner Ayalon ◽  
Paul Goldberg ◽  
Yuval Goren ◽  
Boaz Ofek ◽  
...  
Keyword(s):  
Middle Paleolithic ◽  
Formation Processes ◽  
Carbon Isotopic ◽  
Isotopic Analyses ◽  
Stable Oxygen
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