XElement("geo:lat", item.Latitude);
 XElement("geo:long", item.Longitude);

<?xml version="1.0"?>
<?xml-stylesheet href="/eqcenter/catalogs/rssxsl.php?feed=eqs7day-M5.xml" type="text/xsl"
              media="screen"?>
<rss version="2.0"
  xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#"
  xmlns:dc="http://purl.org/dc/elements/1.1/">
<channel>
 <title>USGS M5+ Earthquakes</title>
 <description>Real-time, worldwide earthquake list for the past 7 days</description>
 <link>https://earthquake.usgs.gov/eqcenter/</link>
 <dc:publisher>U.S. Geological Survey</dc:publisher>
 <pubDate>Thu, 27 Dec 2007 23:56:15 PST</pubDate>
 <item>
   <pubDate>Fri, 28 Dec 2007 05:24:17 GMT</pubDate>
   <title>M 5.3, northern Sumatra, Indonesia</title>
   <description>December 28, 2007 05:24:17 GMT</description>
 <link>https://example.com</link>
   <geo:lat>5.5319</geo:lat>
   <geo:long>95.8972</geo:long>
 </item>