{
  "title": "How Old are Rocks on Mars?",
  "authors": "HiRISE",
  "metadata": {
	    "thumbnailURL": "https://static.uahirise.org/anews/2020-07-06/ESP_020945_1690.jpg",
    "excerpt": "We have only a vague idea of how old these rocks in Valles Marineris might be."
  },
  "version": "1.5",
	  "identifier": "ESP_020945_1690",
  "language": "en",
  "layout": {
    "columns": 10,
    "width": 1024,
    "margin": 85,
    "gutter": 20
  },
  "documentStyle": {
    "backgroundColor": "#faf7f2"
  },
  "components": [
    {
        "role": "heading1",
        "layout": "heading1Layout",
        "text": "HiPOD: 6 July 2020"
    },
    
    {
        "role": "divider",
        "layout": "bigDividerLayout",
        "stroke": {
            "width": 3,
            "color": "#8c2028"
          }
    },
    {
        "role": "title",
        "layout": "halfMarginBelowLayout",
        "text": "How Old are Rocks on Mars?"
    },

    {
        "role": "photo",
        "layout": "fullBleedLayout",
        "caption": "An enhanced color cutout showing a section of the rock in detail. Less than 1 km across. (NASA/JPL/UArizona)",
        "URL": "https://static.uahirise.org/anews/2020-07-06/ESP_020945_1690.jpg"
    },
        
    {
        "role": "body",
        "format": "html",
        "layout": "hipodMarginLayout",
        "text": "<p><br />We have only a vague idea how old these rocks are. Crater counts can help date landscapes, and clearly this is a young landscape with very few impact craters due to the continual landslides of the steep slopes. The rocks are much older, probably older than the plateaus surrounding Valles Marineris (2 to 3 billion years based on the large craters), unless these are intrusive rocks emplaced later from migrating magma. We need radiometric age dating, either on Mars or from returned samples, to measure the age of igneous (volcanic or plutonic) rock layers within the strata.</p>"
    },

    {
        "role": "body",
        "format": "html",
        "layout": "hipodMarginLayout",
        "text": "<p><br />The age of sedimentary layers such as river or lake deposits can be bracketed by the ages of overlying and underlying igneous layers. Not knowing the absolute ages of bedrock units on Mars is a huge limitation to our understanding of the geologic history. <br /></p>"
    },

    {
        "role": "photo",
        "layout": "fullBleedLayout",
        "caption": "A fuller view of the scene. Less than 5 km across. (NASA/JPL/UArizona)",
        "URL": "https://static.uahirise.org/anews/2020-07-06/ESP_020945_1690-2.jpg"
    },


    {
        "role": "body",
        "format": "html",
        "layout": "hipodMarginLayout",
        "text": "<p><br />ID: <a href='https://uahirise.org/ESP_020945_1690'>ESP_020945_1690</a><br />date: 14 January 2011<br />altitude: 266 km<br /><br />NASA/JPL/UArizona</a></p>"
    },

    {
        "role": "caption",
        "format": "html",
        "layout": "halfMarginBothLayout",
        "text": "Enhanced color image is less than 1 km; black and white is less than 5 km. For full images with scalebars, see the above ID link to our website.<br /><br />"
    }
    

  ],
  "textStyles": {},

  "componentLayouts": {
    "noMarginLayout": {
      "columnStart": 0,
      "columnSpan": 7
    },
    "niceMarginLayout": {
      "columnStart": 0,
      "columnSpan": 10
    },
    "hipodMarginLayout": {
      "columnStart": 0,
      "columnSpan": 9
    },

    "heading1Layout": {
      "columnStart": 0,
      "columnSpan": 7,
      "margin": {
        "top": 24,
        "bottom": 3
      }
    },
    "halfMarginBelowLayout": {
      "columnStart": 0,
      "columnSpan": 10,
      "margin": {
        "bottom": 12
      }
    },
    "fullMarginBelowLayout": {
      "columnStart": 0,
      "columnSpan": 7,
      "margin": {
        "bottom": 24
      }
    },
    "fullMarginAboveHalfBelowLayout": {
      "columnStart": 0,
      "columnSpan": 7,
      "margin": {
        "top": 24,
        "bottom": 12
      }
    },
    "bigDividerLayout": {
      "ignoreDocumentMargin": "right",
      "columnStart": 0,
      "columnSpan": 10,
      "margin": {
        "top": 6,
        "bottom": 6
      }
    },
    "fullBleedLayout": {
      "ignoreDocumentMargin": true
    },
    "halfMarginBothLayout": {
      "columnStart": 0,
      "columnSpan": 8,
      "margin": {
        "top": 12,
        "bottom": 12
      }
    },
"fullMarginAboveLayout": {
      "columnStart": 0,
      "columnSpan": 7,
      "margin": {
        "top": 24
      }
    },
    "halfMarginAboveQuarterBelowLayout": {
      "columnStart": 0,
      "columnSpan": 7,
      "margin": {
        "top": 12,
        "bottom": 6
      }
    }
 },


  "componentStyles": {},

  "componentTextStyles": {
        "default": {
      "fontName": "DINAlternate-Bold",
      "textColor": "#222222",
      "fontSize": 16,
      "lineHeight": 22,
      "linkStyle": {
        "textColor": "#D5B327"
      }
    },
    "default-body": {
      "fontName": "MiloSerifOT-Text",
      "fontSize": 20,
      "lineHeight": 30,
      "paragraphSpacingBefore": 12,
      "paragraphSpacingAfter": 12,
      "linkStyle": {
        "textColor": "#378DBD"
        }
    },

    "default-title": {
      "fontName": "MiloSerifOT-Text",
      "fontSize": 44,
      "tracking": 0,      
      "lineHeight": 48,
      "textColor": "#2e5284"
    },
    "default-intro": {
      "fontName": "DINAlternate-Bold",
      "fontSize": 18,
      "lineHeight": 22,
      "textColor": "#A6AAA9"
    },
    "default-byline": {
      "fontName": "DINAlternate-Bold",
      "fontSize": 15,
      "lineHeight": 18,
      "textColor": "#53585F"
    },
    "default-heading2": {
      "fontName": "DINAlternate-Bold",
      "tracking": 0.05,
      "textColor": "#53585F"
    },
    "default-heading1": {
      "fontName": "MiloOT-Light",
      "tracking": 0.12,
      "textColor": "#53585F"
    },
    "bodyFirstDropCap": {
      "dropCapStyle": {
        "fontName": "DINAlternate-Bold",
        "textColor": "#A6AAA9",
        "numberOfLines": 2
      }
    },
    "default-heading2": {
      "fontName": "IowanOldStyle-Roman",
      "fontSize": 48,
      "lineHeight": 44,
      "textColor": "#53585F"    
    
    },
    "default-caption": {
      "fontName": "MiloSerifOT-Text",
      "fontSize": 14,
      "lineHeight": 18,
      "paragraphSpacingBefore": 12,
      "paragraphSpacingAfter": 12,
      "textColor": "#53585F"
    },
    "default-pullquote": {
      "fontName": "DINAlternate-Bold",
      "fontSize": 30,
      "lineHeight": 36,
      "textColor": "#A6AAA9",
      "hangingPunctuation": true
    },
    "attribution": {
      "fontName": "DINAlternate-Bold",
      "fontSize": 12,
      "lineHeight": 16,
      "tracking": 0.12,
      "textColor": "#53585F",
      "textAlignment": "right"
    }
    }
    
}