±±¾©Ê¯ÓÍ»¯¹¤Ñ§Ôº2026ÄêÑо¿ÉúÕÐÉú½ÓÊÕµ÷¼Á¹«¸æ
²é¿´: 223  |  »Ø¸´: 0

jackspear

гæ (³õÈëÎÄ̳)

[ÇóÖú] ÇóÖúÒ»µÀÌâ

ÌâÄ¿ÈçÏ£º
Rhyolites in the North Shore Volcanic Sequence (MN) yield ¦ÅNd values of -2 to -15, and rhyolites from the Porcupine Mtns(MI) have even lower values at -9 to -21. Basalts of the Portage Lake lavas(Keweenaw Peninsula) have average 87Sr/86Sr intitial ratio of 0.7035. How can you reconcile these values with each other and with your result for the Pigeon River intruions?
Óи½Í¼¡£
´óÉñ½ÌÎÒ£¡

ÇóÖúÒ»µÀÌâ
1.png
»Ø¸´´ËÂ¥

» ²ÂÄãϲ»¶

ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû
Ïà¹Ø°æ¿éÌø×ª ÎÒÒª¶©ÔÄÂ¥Ö÷ jackspear µÄÖ÷Ìâ¸üÐÂ
×î¾ßÈËÆøÈÈÌûÍÆ¼ö [²é¿´È«²¿] ×÷Õß »Ø/¿´ ×îºó·¢±í
[¿¼ÑÐ] 0703 »¯Ñ§ Çóµ÷¼Á£¬Ò»Ö¾Ô¸É½¶«´óѧ 342 ·Ö +4 Shern¡ª- 2026-03-28 4/200 2026-03-29 00:47 by 544594351
[¿¼ÑÐ] 22408 359·Öµ÷¼Á +4 Qshers 2026-03-27 5/250 2026-03-28 21:26 by zhq0425
[¿¼ÑÐ] 071000ÉúÎïѧÇóµ÷¼Á£¬³õÊԳɼ¨343 +7 ССÌðÃæÍÅ 2026-03-25 7/350 2026-03-28 20:25 by ÌÆãå¶ù
[¿¼ÑÐ] ѹ¹ú¼ÒÒ»ÇøÏߣ¬Çóµ¼Ê¦ÊÕÁô£¬Óж÷±ØÐ»£¡ +7 ÃÔÈ˵Ĺþ¹þ 2026-03-28 7/350 2026-03-28 16:47 by ´ß»¯´ó°×
[¿¼ÑÐ] 283Çóµ÷¼Á +3 A child 2026-03-28 3/150 2026-03-28 15:41 by ms629
[¿¼ÑÐ] 0703»¯Ñ§Çóµ÷¼Á +9 ÄÌÓͲÝÝ®. 2026-03-22 10/500 2026-03-28 13:30 by ÌÆãå¶ù
[¿¼ÑÐ] Çóµ÷¼Á +6 «lty 2026-03-25 7/350 2026-03-28 13:13 by ÌÆãå¶ù
[¿¼ÑÐ] 311Çóµ÷¼Á +9 lin0039 2026-03-26 9/450 2026-03-28 13:05 by ÌÆãå¶ù
[¿¼ÑÐ] 081200-314 +3 LILIQQ 2026-03-27 4/200 2026-03-28 09:41 by ±£»¤µØÇòÄãÎÒ×öÆ
[¿¼ÑÐ] 291Çóµ÷¼Á +6 HanBeiNingZC 2026-03-24 6/300 2026-03-28 07:55 by baoball
[¿¼ÑÐ] Çóµ÷¼Á +4 Áã°Ë# 2026-03-27 4/200 2026-03-27 18:07 by yu221
[¿¼ÑÐ] Ò»Ö¾Ô¸Ö£´ó085600£¬310·ÖÇóµ÷¼Á +5 Àîäì¿É 2026-03-26 5/250 2026-03-27 11:14 by ²»³Ôô~µÄ؈
[¿¼ÑÐ] 324Çóµ÷¼Á +8 hanamiko 2026-03-26 10/500 2026-03-27 08:06 by hypershenger
[¿¼ÑÐ] 343Çóµ÷¼Á +4 ÔùÎÒÒ»±¾Êé 2026-03-23 4/200 2026-03-27 00:40 by wxiongid
[¿¼ÑÐ] µ÷¼ÁÇóÊÕÁô +7 ¹ûÈ»ÓÐÎÒ 2026-03-26 7/350 2026-03-27 00:26 by wxiongid
[¿¼ÑÐ] 340Çóµ÷¼Á +3 Amber00 2026-03-26 3/150 2026-03-26 18:57 by ²»³Ôô~µÄ؈
[¿¼ÑÐ] 309Çóµ÷¼Á +4 gajsj 2026-03-25 5/250 2026-03-26 00:27 by Dyhoer
[¿¼ÑÐ] Ò»Ö¾Ô¸ÉϺ£½»´óÉúÎïÓëҽҩר˶324·Ö£¬Çóµ÷¼Á +6 jiajunX 2026-03-22 6/300 2026-03-25 23:05 by licg0208
[¿¼ÑÐ] 086003ʳƷ¹¤³ÌÇóµ÷¼Á +6 íµíµ111 2026-03-24 6/300 2026-03-25 10:29 by 3Strings
[¿¼ÑÐ] ÉϺ£µçÁ¦´óѧ²ÄÁÏ·À»¤ÓëвÄÁÏÖØµãʵÑéÊÒÕÐÊÕµ÷¼ÁÑо¿Éú£¨²ÄÁÏ¡¢»¯Ñ§¡¢µç»¯Ñ§£¬»·¾³£© +4 ÎÒ°®Ñ§µç³Ø 2026-03-23 4/200 2026-03-25 00:59 by 1027_324
ÐÅÏ¢Ìáʾ
ÇëÌî´¦ÀíÒâ¼û