|Appears in Collections:||Biological and Environmental Sciences Journal Articles|
|Peer Review Status:||Refereed|
|Title:||Diverse Lithologies and Alteration Events on the Rim of Noachian-Aged Endeavour Crater, Meridiani Planum, Mars: In-Situ Compositional Evidence (Forthcoming)|
Clark, Benton C
Crumpler, Larry S
Grant, John A
Jolliff, Bradley L
Arvidson, Raymond E
Farrand, William H
Herkenhoff, Kenneth E
|Citation:||Mittlefehldt D, Gellert R, VanBommel S, Ming D, Yen A, Clark BC, Morris R, Schröder C, Crumpler LS, Grant JA, Jolliff BL, Arvidson RE, Farrand WH, Herkenhoff KE, Bell J, Cohen B, Klingelhöfer G, Schrader C & Rice J (2018) Diverse Lithologies and Alteration Events on the Rim of Noachian-Aged Endeavour Crater, Meridiani Planum, Mars: In-Situ Compositional Evidence (Forthcoming), Journal of Geophysical Research: Planets.|
|Abstract:||We report the results of geological studies by the Opportunity Mars rover on the Endeavour Crater rim. Four major units occur in the region (oldest to youngest): the Matijevic, Shoemaker, Grasberg and Burns formations. The Matijevic formation, consisting of fine-grained clastic sediments, is the only pre-Endeavour-impact unit and might be part of the Noachian etched units of Meridiani Planum. The Shoemaker formation is a heterogeneous polymict impact breccia; its lowermost member incorporates material eroded from the underlying Matijevic formation. The Shoemaker formation is a close analog to the Bunte Breccia of the Ries Crater, although the average clast sizes are substantially larger in the latter. The Grasberg formation is a 46 thin, fine-grained, homogeneous sediment unconformably overlying the Shoemaker formation, and likely formed as an airfall deposit of unknown areal extent. The Burns formation sandstone overlies the Grasberg, but compositions of the two units are distinct; there is no evidence that the Grasberg formation is a fine-grained subfacies of the Burns formation. The rocks along the Endeavour Crater rim were affected by at least four episodes of alteration in the Noachian and Early Hesperian: (i) vein formation and alteration of pre-impact Matijevic formation rocks; (ii) low-water/rock alteration along the disconformity between the Matijevic and Shoemaker formations; (iii) alteration of the Shoemaker formation along fracture zones; and (iv) differential mobilization of Fe and Mn, and CaSO4-vein formation in the Grasberg and Shoemaker formations. Episodes (ii) and (iii) possibly occurred together, but (i) and (iv) are distinct from either of these.|
|Rights:||This item has been embargoed for a period. During the embargo please use the Request a Copy feature at the foot of the Repository record to request a copy directly from the author. You can only request a copy if you wish to use this work for your own research or private study.|
|820292_2_merged_1518031799.pdf||24.15 MB||Adobe PDF||Under Embargo until 2020-08-09 Request a copy|
|2017JE005474R-SI01.pdf||141.7 kB||Adobe PDF||Under Embargo until 2020-08-09 Request a copy|
Note: If any of the files in this item are currently embargoed, you can request a copy directly from the author by clicking the padlock icon above. However, this facility is dependent on the depositor still being contactable at their original email address.
This item is protected by original copyright
Items in the Repository are protected by copyright, with all rights reserved, unless otherwise indicated.
If you believe that any material held in STORRE infringes copyright, please contact firstname.lastname@example.org providing details and we will remove the Work from public display in STORRE and investigate your claim.