Stable isotope composition of smectite in suevites at the Ries crater, Germany: Implications for hydrous alteration of impactites

The 24-km diameter Ries crater, Germany, exhibits well-preserved crater filling and surficial melt-rich breccia deposits that are believed to have been altered by post-impact hydrothermal fluids. The alteration mineralogy of the crater filling breccias is characterized by clay (smectite, chlorite) and a zeolite assemblage, and secondary clay phases (smectite, minor halloysite) in surficial melt-bearing breccia deposits. Using stable isotope analysis of secondary smectitic clay fractions, evidence of significant hydrous alteration of impactites at large water/rock ratios was found. The estimated fluid temperatures, using data derived by delta(18)O and delta D fractionation, suggest smectite precipitation in surficial breccias in equilibrium with meteoric fluids at temperatures 16 +/- 5 degrees C in agreement with the long-term variation of modern precipitation in the area. The stable isotope composition of smectite in crater-fill breccia, however, suggests a trend of monotonously increasing temperatures from 43 to 112 degrees C. with increasing depth through the breccia sequence. This demonstrates a different origin of alteration and temperature distribution for the surficial and crater filling melt-bearing impact breccias in the Ries crater. Our results suggest that the inverted structure of hydrothermal systems observed in some terrestrial impact craters, including the Ries crater, could indicate the initial configuration of a thermal anomaly in the crater filling sequence, but which is replaced with a normal hydrothermal convection in crater proper, during the course of post-impact cooling. (C) 2010 Elsevier B.V. All rights reserved.

Message from the President of the United States, transmitting copies of a convention concluded at St. Petersburg, the 12th day of July, 1822, under the mediation of the Emperor of all the Russias, between the United States of America and His Britannic Majesty. --

United States. 18th Congress, 1st session, 1823-1824. House. Doc. no. 30.

Message from the President of the United States, transmitting copies of a convention concluded at St. Petersburg, the 12th day of July, 1822

Full Title: Message from the President of the United States, transmitting copies of a convention concluded at St. Petersburg, the 12th day of July, 1822, under the mediation of the Emperor of all the Russias, between the United States of America and His Britannic Majesty. United States. 18th Congress, 1st session, 1823-1824. House. Doc. no. 30. January 25, 1823. Read and referred to the Committee on Ways and Means. Printed by Gales and Seaton

Map - Probable Order of Battle

A map titled "Probable Order of Battle" and dated 28 May 1918. The map is of Montdidier.

Printed Blank Regarding the Insolvent Act of 1864 from James McWhirter to S.D. Woodruff

Printed blank regarding the Insolvent Act of 1864, this was sent to S. D. Woodruff in the matter of William Little, an insolvent. There was to be a meeting on the 10th day of October for public examination of the insolvent. The document was signed by James McWhirter, official assignee, Sept. 20, 1866.

Our Army at Monterey. Being a correct account of the proceedingsandevents which occurred to the Ar from the time of leaving Matamoros to the surrender of Monterrey with a description of the three days battle and the storming of Monterrey: the ceremonies attending the surrender: together with particulars of the capitulation

UANL

Kings of the battle-field: comprising a series of biographical sketches of the most distinguished military leaders...

UANL