Alvarez, Walter et al. (1992): Proximal impact deposits at the Cretaceous-Tertiary boundary in the Gulf of Mexico; a restudy of DSDP Leg 77 sites 536 and 540; with Suppl. Data 92-25
Leg/Site/Hole:
Related Expeditions:
DSDP 77
Identifier:
ID:
1992-035287
Type:
georefid
ID:
10.1130/0091-7613(1992)020<0697:PIDATC>2.3.CO;2
Type:
doi
Creator:
Name:
Alvarez, Walter
Affiliation:
Univ. Calif. at Berkeley, Dep. Geol. and Geophys., Berkeley, CA, United States
Role:
author
Name:
Smit, Jan
Affiliation:
Free Univ. Amsterdam, Netherlands
Role:
author
Name:
Lowrie, William
Affiliation:
ETH Inst. Geophys., Switzerland
Role:
author
Name:
Asaro, Frank
Affiliation:
Geol. Surv. Can., Canada
Role:
author
Name:
Margolis, Stanley V.
Affiliation:
Role:
author
Name:
Claeys, Philippe
Affiliation:
Role:
author
Name:
Kastner, Miriam
Affiliation:
Role:
author
Name:
Hildebrand, Alan R.
Affiliation:
Role:
author
Identification:
Title:
Proximal impact deposits at the Cretaceous-Tertiary boundary in the Gulf of Mexico; a restudy of DSDP Leg 77 sites 536 and 540; with Suppl. Data 92-25
Year:
1992
Source:
Geology (Boulder)
Publisher:
Geological Society of America (GSA), Boulder, CO, United States
Volume:
20
Issue:
8
Pages:
697-700
Abstract:
Restudy of Deep Sea Drilling Project Sites 536 and 540 in the southeast Gulf of Mexico gives evidence for a giant wave at Cretaceous-Tertiary boundary time. Five units are recognized: (1) Cenomanian limestone underlies a hiatus in which the five highest Cretaceous stages are missing, possibly because of catastrophic K-T erosion. (2) Pebbly mudstone, 45 m thick, represents a submarine landslide possibly of K-T age. (3) Current-bedded sandstone, more than 2.5 m thick, contains anomalous iridium, tektite glass, and shocked quartz; it is interpreted as ejecta from a nearby impact crater, reworked on the deep-sea floor by the resulting tsunami. (4) A 50-cm interval of calcareous mudstone containing small Cretaceous planktic foraminifera and the Ir peak is interpreted as the silt-size fraction of the Cretaceous material suspended by the impact-generated wave. (5) Calcareous mudstone with basal Tertiary forams and the uppermost tail of the Ir anomaly overlies the disturbed interval, dating the impact and wave event as K-T boundary age. Like Beloc in Haiti and Mimbral in Mexico, Sites 536 and 540 are consistent with a large K-T age impact at the nearby Chicxulub crater.
Language:
English
Genre:
Serial
Rights:
URL:
Coverage: Geographic coordinates: North:23.5000 West:-85.1300 East:
-84.2200 South:23.2900
Keywords: Stratigraphy; Sedimentary petrology; Atlantic Ocean; biostratigraphy; carbonate rocks; Cenomanian; Cenozoic; Chicxulub; clastic rocks; clastic sediments; Cretaceous; Danian; Deep Sea Drilling Project; distribution; DSDP Site 536; DSDP Site 540; Foraminifera; framework silicates; geochemistry; Gulf of Mexico; impact craters; impact features; impacts; Invertebrata; IPOD; iridium; K-T boundary; Leg 77; limestone; lithostratigraphy; lower Paleocene; lower Tertiary; marine sediments; Mesozoic; metals; metamorphism; meteor craters; microfossils; mudstone; North Atlantic; ooze; Paleocene; Paleogene; paleomagnetism; platinum group; Protista; quartz; sandstone; sedimentary rocks; sediments; shock metamorphism; silica minerals; silicates; stratigraphic boundary; stratigraphy; tektites; Tertiary; Upper Cretaceous; Yucatan Peninsula;
.